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A Science and Technology Publication
Volume 10, No. 2 Summer, 2001
Wet Process Drainage Effects of White Water Chemistryand Forming
Wire Structures
Effects of Water On Processing and Properties ofThermally Bonded
Cotton/Cellulose Acetate Nonwovens
Microstructural Analysis of Fiber Segments In Nonwoven
FabricsUsing SEM and Image Processing
The Role of Structure On Mechanical Properties of Nonwoven
Fabrics
Studies on the Process of Ultrasonic Bonding of Nonwovens:Part 1
Theoretical Analysis
Pira Abstracts ... Patent Review ... Researchers Notebook ...
Technology Watch ... Directors Corner ... The Association Page
I N T E R N A T I O N A L
NonwovensJ o u r n a l
Sponsored By
About This DocumentThis document has two page of front matter
numbered i and ii
Roman Numeral "Page 1" is located two pages down from here and
is the Table of Contents
Articles on this page as well as the Table of Contents are
linked .Internet and E-mail references are linked
All links are invisible but the "hand" symbol will turn to a
pointer when passed over the link
Roger Chen
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Joint INDA-TAPPI Conference
Please complete and return to INTC or fax to 919-233-1282.
Yes, please send me more information on: Attending
TabletopsName:
__________________________________________________________ Title:
_________________________
Company:
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Address:
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City
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Zip/Postal Code ____________________
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Return To: INDA, P.O. Box 1288, Cary, NC 27512-1288,
919-233-1210, Ext. 0, Fax 919-233-1282, www.inda.org
Major Merger!Big Success!At the request of theindustry, INDA
andTAPPI combined theirtechnical conference toproduce the
largestnonwovens technicalconference in the world.A total of 550
peoplefrom around the worldattended INTC-2000.
Leading EdgeInformation: Polymers & Fibers Properties &
Performance Process Technologies Filtration End-uses Binders &
Additives Wetlaid Absorbents Barriers Melt Extrusions
Hydroentangling Airlaid Mats Biodegradable Polymers Sustainable
Polymers Multi-component Fibers Microfibers Composites &
Laminates State of the Art Information
For Managers withResponsibility for: New Product Development
Research & Development
Technical Marketing & Sales
Testing & Quality Control
Executives fromAround the WorldWill Attend INTC. . . The Placeto
Network: Nonwoven Fabric
Producers
Converters of NonwovenFabrics
Suppliers to NonwovenFabric Producers
http://www.inda.orghttp://www.inda.orghttp://www.inda.org
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INJ Spring 2001 1
A Science and Technology PublicationVol. 10, No. 2 Summer,
2001
PublisherTed WirtzPresidentINDA, Association of theNonwoven
Fabrics Industry
SponsorsWayne GrossExecutive Director/COOTAPPI, Technical
Association ofthe Pulp and Paper IndustryTeruo YoshimuraSecretary
GeneralANIC, Asia Nonwoven FabricsIndustry Conference
EditorsRob [email protected].
[email protected]
Association EditorsCosmo Camelio, INDAD.V. Parikh, TAPPI Teruo
Yoshimura, ANIC
Production EditorMichael JacobsenINDA Director of
[email protected]
Wet Process Drainage Effects of White Water Chemistryand Forming
Wire StructuresOriginal Paper by Daojie Dong, Owens Corning Science
and Technology Center . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . 14Effects of Water On Processing and
Properties of Thermally BondedCotton/Cellulose Acetate
NonwovensOriginal Paper by Xiao Gao, K.E. Duckett, G. Bhat and
Haoming Ron, University of Tennessee . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . 21Microstructural
Analysis of Fiber Segments In Nonwoven FabricsUsing SEM and Image
ProcessingOriginal Paper by E. Ghassemieh, H.K. Versteeg and M.
Acar, Wolfson Schoolof Mechanical and Manufacturing Engineering,
Loughborough University . . 26The Role of Structure on Mechanical
Properties of Nonwoven FabricsOriginal Paper by H.S. Kim and B.
Pourdeyhimi, Nonwovens CooperativeResearch Center, College of
Textiles, North Carolina State University . . . . . 32Studies on
the Process of Ultrasonic Bonding of Nonwovens:Part 1 Theoretical
AnalysisOriginal Paper by Zhentao Mao and Bhuvenesh Goswami, School
of Textiles, Clemson University . . . . . . . . . . . . . . . . . .
. . . . . . . . . . 38
Guest Editorial 3Researchers Toolbox 4Directors Corner
7Technology Watch 10Nonwovens Web 12
Nonwovens Patents 48Worldwide Abstracts 53The Association Page
56Meetings 57
NonwovensI N T E R N A T I O N A L
NonwovensJ o u r n a l
DEPARTMENTS
ORIGINAL PAPERS
The International Nonwovens Journal Mission: To publish the best
peer reviewed research journal with broadappeal to the global
nonwovens community that stimulates and fosters the advancement of
nonwoven technology.
EDITORIAL ADVISORY BOARDCosmo Camelio INDARoy Broughton Auburn
UniversityRobin Dent Albany InternationalEd Engle
FibervisionsTushar Ghosh NCSUBhuvenesh Goswami ClemsonDale Grove
Owens Corning
Frank Harris HDK IndustriesAlbert Hoyle Hoyle AssociatesMarshall
Hutten Hollingsworth & VoseHyun Lim E.I. duPont de NemoursJoe
Malik AQF TechnologiesAlan Meierhoefer Dexter NonwovensMichele
Mlynar Rohm and HaasGraham Moore PIRA
D.V. Parikh U.S.D.A.S.R.R.C.Behnam Pourdeyhimi NCSUArt Sampson
Polymer Group Inc.Robert Shambaugh Univ. of Oklahoma Ed Thomas BBA
NonwovensAlbin Turbak RetiredLarry Wadsworth Univ. of TennesseeJ.
Robert Wagner Consultant
mailto:[email protected]:[email protected]:[email protected]://U.S.D.A.
S.R.R.C.
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The International Nonwovens Journal is brought to you from
Associations from around the world. This critical technical
publi-
cation is provided as a complimentary service to the
membership
of the Associations that provided
the funding and hard work.
PUBLISHER
INDA, ASSOCIATION OF THE NONWOVEN FABRICS INDUSTRYTED
WIRTZPRESIDENT
P.O. BOX 1288, CARY, NC 27511www.inda.org
SPONSOR
TAPPI, TECHNICAL ASSOCIATION OF THE PULP AND PAPER INDUSTRYWAYNE
H GROSS
EXECUTIVE DIRECTOR/COOP.O. BOX 105113
ATLANTA, GA 30348-5113www.tappi.org
http://www.inda.orghttp://www.tappi.orghttp://www.inda.orghttp://www.tappi.orghttp://www.inda.orghttp://www.tappi.org
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Conventional wisdom suggests thatResearch and Development is
essen-tial to the creation and ongoing success ofan industry as
well as individual compa-nies within an industry. The
nonwovenindustry is a prime example of the rolethat R&D has
played in nonwovens brief
history of some60 years.
I have spentalmost 50 yearsassociated withnonwovens andhave had
a ring-side seat in thedynamic growthof the business
from its infancy to a major business seg-ment. It is my intent
to hit some of thehighlights of this growth with a specialemphasis
on the role that R&D played.My use of the term R&D is in
its broad-est sense, which includes process inven-tion,
modification and control; productinvention and modification; and
marketresearch and sales development. Perhapsnonwoven technology
growth is a betterterm than R&D since I look at the wholechain
of events as the end result of tech-nical development.
My introduction to nonwovens came atCallaway Mills, La Grange,
GA, in 1953.I was happily involved in R&D with abroadly
diversified textile firm when theboss called me to his office and
informedme that We are going into nonwovensand you have the
project. I knew nothingof nonwovens beyond the word, but with-in a
year submitted a proposition toinstall a pilot line using Rando
Webbersto produce industrial nonwoven fabrics. I
was then thrown out of R&D and trans-ferred to a production
unit that grew tofour lines. Our plans centered on automo-tive
products (backing for vinyl coat-ings), chaffer fabrics for tires,
shoe find-ings and interlinings.
At this time in history, there were fouror five nonwoven
producers in the coun-try (Pellon, Chicopee, and West
Point-Pepperell being the major players); allwere using proprietary
technologyinvented and modified for specific mar-kets. Total sales
were around $5 million.Great secrecy surrounded the business.As
Technical Director of a small produc-tion unit, I found that I had
to invent theproduct, develop the process and then goout and sell
the product since our indus-trial sales force was unable to handle
thisnew product. In fact, we had to inventthe market and then
invent the customers.
In 1960, I joined Kendall in Boston,which had been a pioneer in
nonwovensfor over 20 years. Their output came fromthree proprietary
lines making specialtyproducts for the electrical, graphic artsand
dairy industries. A NonwovenDivision was formed in 1960 with
totalsales of a little over $3 million! By 1970this new division
was approaching$100 million in sales!
So what happened to make this sleepylittle business explode
during the 1960sand 70s? Major new products wereinvented and
marketed using nonwo-vens. Prime examples include: dispos-able
diapers by P&G, followed by manyimitators; surgical packs and
gowns plusa host of other hospital products fromKimberly-Clark,
J&J, DuPont andKendall; and major new industrial fabric
markets created by DuPont and others.These new markets were a
direct result
of a bewildering array of new technolo-gies introduced by
companies both out-side and inside the textile industry. Itseemed
that everyone was getting into theact! The paper industry
introduced bothwet and dry nonwovens; Kimberly-Clarkbrought forth
Kaycel and Kimlon.DuPont developed flash spun and spun-bond
nonwovens, Monsanto developedchemical spun products, and
Exxoninvented melt blown nonwovens. Itbecame obvious that hundreds
of mil-lions of dollars were being spent bydiverse industries to
get a piece of theburgeoning nonwovens industry. In 1968,we
established a trade association(INDA) to encompass this wide array
ofinterests to promote the business.
The slow, simple, inexpensive textileequipment that started the
nonwovenbusiness underwent massive technicalinnovation to stay in
the game in face ofthe assault from outside. In 1962, Kendallhelped
P&G invent the disposable diapertopsheet. We used a 40-inch
card linerunning 20 yards/minute. By 1964, wewere stretching a
40-inch card web to60 inches and running at 60 yards/min.By 1966,
we stretched a 40-inch cardweb to 90 inches and ran at 90
yards/min.This stretched web was an innovationthat forecast the
high-speed randomizingcards specifically designed for nonwo-vens.
Today, reportedly, there are five-meter wide card lines capable of
operat-ing speeds up to 1000 meters per minute!
Since I entered the industry, the non-wovens business in North
America hasgrown from approximately $5 million tothe current $3.8
billion and 25.6 billionyards (INDA 2000 Estimates). Vast
tech-nology changes have occurred.
So, is it all over? Of course not! Fiftyyears from now, the
industry will be asdifferent and advanced from today astoday is
from when I started in 1953.Leading the charge to make this
happenwill be the hundreds of R&D people cur-rently working on
nonwovens and thehundreds that will follow to keep the rev-olution
going.
Have a nice journey! Wayne Hays
CONTINUE THEJOURNEYBy Wayne HaysFormer INDA Chairman and
Recipient of theIDEA 01 Lifetime Achievement Award
GUEST EDITORIAL
INJ Summer 2001 3
Roger ChenReturn To Table of Contents
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Useful Microwave TechnologyIn a few short years, the handy
microwave oven has become very ubiq-uitous (ubiquitous: adj,
seeming to bepresent everywhere). In view of itsspeed, economy,
efficiency and conve-nience, it is not too surprising that thistool
has made its way out the kitcheninto a wide variety of other
applica-tions.
The adaptation of microwave tech-nology to applications within
the textileand nonwovens industries has beensomewhat slow and still
rather limited.Through the efforts of several groups,however, this
situation is changing, andthe microwave system is finding its
wayinto numerous uses in the productionplant and also in the
laboratory.
The first commercial use ofmicrowave heating for a textile
dryingunit operation was probably the appli-cation to drying rayon
filament yarnbobbins. In this application, the wet,freshly spun and
washed filament bob-bin was placed on a conveyor that slow-ly
passed through a zone of microwaveradiation. Each individual bobbin
wasrotated on its axis as it slowly traversedits path through the
drying zone.Bobbins of dry filament were removedfrom the unit.
The first use of a microwave systemin the laboratory was
undoubtedly thedrying of small textile fabric samples asa part of
the determination of moisturecontent. For this application, the
speedand convenience were unparalleled byother methods. However,
this methodand other similar trial efforts highlight-ed a major
problem with the microwave
systems available uniformity of thetreatment. In the kitchen
microwaveoven, the target is often on a turntable toprovide
multiple passes in front of thesource to hopefully even out
randomlyoccurring hotspots. Unless the treat-ment is done
uniformly, hotspots candevelop, resulting in over-heating insome
areas and under-heating in others.
To correct this problem, recent workhas focused on the use of
waveguidesto serpentine the microwave energyback and forth across
whatever materialis being treated. With proper design ofthe
waveguides and supporting equip-ment, a specific environment for
theparticular wavelengths can be created toprovide a controlled
distribution of themicrowave energy, making it possible toachieve
uniform exposure to any mater-ial moved though a channel or space.
Insome designs, the waveguide itself actsas the treatment space and
the position-ing (top, bottom, middle) of the materi-al as it
travels through the space canprovide additional control over
theenergy picked up by the material.
With this improved uniformity in dis-tribution, some amazing
results can beachieved. Two different fabrics can bepassed through
a carefully designedchannel or oven plenum, the one fabricentering
wet and the other being dry. Onemerging, both of the fabrics are at
anequal level of dryness, with no over-heating of the dry fabric.
This is thetype of result that technologists havehoped for from
microwave technology,and now it appears to be available.
One company that has been a leaderin this work is Industrial
Microwave
Systems (IMS) of Morrisville, NC(IMS, 3000 Perimeter Park
Drive,Morrisville, NC; 919-462-9200;www.industrialmicrowave.com).
Theirpatented design concept is called thePlanar Drying System and
it usesmicrowave energy focused at specificangles to achieve
various treatment pos-sibilities. Some of their applicationshave
involved treating tubular knits,sheets of individual yarns in yarn
sizingapplications, and others. In a systemdesigned for terry towel
drying, fasterproduction speeds were possible withthe uniform
treatment. An additionalbenefit in this case was that the fabrichad
good softness, even though a chem-ical fabric softener was not
employed.
This method has also ben applied tothe drying of carpet tile. In
this applica-tion, uniform drying can be achievedwithout damaging
the backing or sub-strates, and there was no heat degrada-tion of
the carpet material.Significantly, substantially increaseddrying
speeds can also be achieved.Installations have been made up to
30-feet wide and material can be treated ina thickness up to two
inches.
This company has recently becomeinvolved in several nonwoven
applica-tions, one of which has been assisted bya grant from the
federal Department ofEnergy, which is interested in the ener-gy
saving possibilities with this type ofsystem. This has involved
direct drying,drying of printed webs and coatedwebs, as well as
treatment and drying ofcomposite and laminated structures.
The system has also been applied tothermosol dyeing; in this
case the excel-lent uniformity has virtually eliminatedthe usual
liquor migration in the treatedfabric, resulting in more uniform
dyedistribution. With a suitable design,microwave drying in a dye
beck or jetdyeing unit can be achieved with a tem-perature
variation within the fabric ropeof only 0.10C.
The beauty of the microwave systemis the fact that the energy
absorption canbe controlled to a rather fine degree.The oscillating
microwave energy is notabsorbed to any degree by nonpolarmaterials.
This includes most polymeric
RESEARCHERSTOOLBOX
INJ DEPARTMENTS
4 INJ Summer 2001
http://www.industrialmicrowave.com).http://www.industrialmicrowave.com).Roger
ChenReturn to Table of Contents
http://www.industrialmicrowave.com).
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INJ Summer 2001 5
materials and most fibers of interest tothe textile and nonwoven
industries.The polar water molecules held within anonpolar matrix
do absorb the energyvery efficiently, as they attempt to oscil-late
in a synchronous manner to themicrowave oscillations. Because of
thevelocity of the oscillations, the watermolecules become heated,
putting themin an ideal condition to be evaporatedfrom the
substrate.
As soon as the substrate has lost itswater content, no further
absorption ofthe microwave energy occurs, and sothe substrate does
not heat up, but canactually begin to cool. As a conse-quence, the
energy absorption can bevery specific to water if the proper
sys-tem is employed.
Other molecules in addition to waterwill absorb microwave
radiation, soapplications beyond drying are alsopossible. Metals
absorb energy from amicrowave source. This feature resultsin some
limitations, but also in someunique applications. For example,
finemetal powder can be suspended in aninactive medium, which is
printed ontoa substrate. Only the printed pattern isheated as the
substrate traverses a treat-ing system. Many other variations
havebeen conceived for exploitation of thesystem.
Numerous laboratory uses formicrowave treatment are evolving
andfinding utility in a variety of applica-tions. These will be
discussed further ina subsequent issue of the
InternationalNonwovens Journal.
Nonwoven Processing Equipment atTexas Tech
A frequently encountered problem innonwoven development work: A
goodconcept needs further work and somepilot trials, but the
necessary equipmentis not available!
One of the most effective solutions tothis dilemma is to seek
the necessaryequipment elsewhere and to makearrangements to use the
equipment on atemporary basis. In these circum-stances, the
facilities at various univer-sities is often the answer. Such
facilities
can generally be leased or otherwise bemade available on a fee
basis. This canfrequently be accomplished, with theadded bonus that
skilled operating per-
sonnel can also be obtained. When theright location is
identified, this can bean elegant solution to the problem.
A few years ago, INDA organized a
RESEARCHERS TOOLBOX
PORTABLE SPECTROSCOPY OFFERS A SOLUTION TO AN AGE-OLD RESEARCH
PROBLEM
Every now and then laboratory scientists are given a problem
where theywished they could take their laboratory into the plant,
the customers opera-tion, or some other remote location to study a
particular situation. The scientisthas often been convinced that if
only they could get the infrared unit or someother equipment into a
particular location, the answer could be easily obtained.
A sizeable step forward in making that wish come true is the
advent andadvances associated with portable spectroscopy units.
Feature articles in thisDepartment in previous issues of the
International Nonwovens Journal havedwelt with the advances being
made in equipment to assist in identifying plasticmaterials slated
for recycling efforts. Now, further powerful equipment and
capa-bilities have advanced beyond, with the development of
portable spectrometerswith broad capabilities and even portable
FTIR equipment.
The Tristan line of spectroments typifies some of these
advances. This partic-ular product line is the development of an
alliance of three German companiesthat brought their specific
talents together to develop this sophisticated system.The company
m-u-t GmbH brings their engineering and development experienceon
R&D operations to the alliance. Photon Technology International
Inc (PTI)has broad experience in spectroscopy, as does PhotoMed
GmbH, with specialskills in applications.
Together, the group has developed the portable and versatile
Tristan unit, whichcan measure absorption, reflection, transmission
and fluorescence by measuringthe wavelengths and intensities of
light emission. It can rapidly and simultane-ously detect the
entire spectral output of light from ultraviolet to the near
infrared,along with an extended-red sensitive version. The unit
includes the light sources,probes, sample handling accessories,
optics system, computer for control andrecording of spectra.
Developed applications include analysis of ingredients andraw
materials, textile color control, identification of plastics, glass
and other recy-clates. A power source allows eight hours of remote
operation. (PhotonTechnology International, 1009 Lenox Drive, Suite
104, Lawrenceville, NJ08648; 609-896-0310; Fax: 609-896-0365;
www.tristan-home.com)
Portable FTIR technology has been used for a wide variety of
analyses, includ-ing organic chemicals, inorganic materials, clays,
soils, paints and other coatingmaterials, petrochemicals, petroleum
products, adhesives, plastics and others. Aninteresting application
that has quite fully exploited the potential of this
portableequipment is in connection with the examination of
paintings, sculpture andother art objects.
In this case, the on-site capabilities, as well as the
non-destructive characterand the adaptability to extremely small
sample size have been significant advan-tages. This has allowed art
conservators and experts to authenticate art objectsand also to
eliminate fraud and counterfeit items. Further, this technique
hasbeen very useful in examining deterioration and guiding
restoration efforts. Oneadditional interesting use for portable
FTIR has been in examining petroglyphson stone walls and in caves
at some remote archeological sites.
Maybe that difficult problem out in the plant can be studied and
solved withFTIR analysis after all.
http://www.tristan-home.com http://www.tristan-home.com
http://www.tristan-home.com
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survey of the nonwoven process andtesting equipment available at
the majoruniversities in the US; a report of thefacilities
available at that time was pre-pared. Material from this report is
cur-rently available at www.inda.org.
With an announcement coming out ofTexas Tech, a new location and
theirnew process equipment now needs to beadded to this roster.
Texas TechUniversity in Lubbock, TX has recentlyadded some advanced
needling equip-ment, which puts them in a potent posi-tion to
become deeply involved in non-woven technology. This equipment
isbeing added to the International TextileCenter at Texas Tech,
under the direc-
tion of Dr. Seshadri Ramkumar, AdjunctProfessor at Texas
Tech.
The Nonwoven Laboratory at theInternational Textile Center will
be thefirst facility in the U.S. to have thisneedling capability.
It is based on thestate-of-the-art Fehrer H1 Technologyneedlepunch
loom. The principle of theH1 Technology and of this equipment isthe
special properties that can beobtained by oblique angled needle
pen-etration. This unique capability isachieved by means of an
asymmetrical-ly curved needling zone, accompaniedby a straight
needle movement. Becauseof this design, some fibers are punchedor
inserted at an angle rather than in a
vertical direction. According to thedesign developer, the
advantages of thisnew technology include the following:
1. The longer needle path results inbetter fiber orientation and
fiber entan-glement than the conventional needlemachine.
2. Superior web properties can beobtained with fewer needle
penetra-tions.
3. It greatly enhances the constructionof composite and hybrid
products.
4. It delivers increased productivityversus conventional
needlepunchlooms.
The processing line includes units forcomplete processing, from
bale to fin-ished fabric. A Tatham Card fitted witha
three-roller/seven-roller design is fedby a Tatham Single Automatic
Feeder,Model 503; this latter unit is equippedwith a volumetric
delivery system. AMicrofeed 2000 unit is included in theline to
monitor the fiber delivery fromthe chute section of the volumetric
hop-per and to speed of the card feed rollers;this compensates for
any discrepancybetween the pre-programmed targetweight and the
continuously monitoredactual weight. Thus, the Microfeedunit
ensures extremely accurate fiberdelivery into the card unit. The
webfrom the card is delivered from the sin-gle doffer section of
the card to aTatham conventional design crosslap-per. The line is
equipped with an ACInverter-controlled drive system.
A research program focusing on thisnew line has been supported
by aresearch contract from the Soldier andBiological Chemical
Command of theU.S. Department of Defense. The majorobjective of
this research program is todevelop special protective fabrics
thatcan be used by the Command to provideadvanced textile materials
to all branchesof the military.
Additional information can be obtainedfrom Dr. Seshadri S.
Ramkumar,Texas TechUniversity, International Textile Center,
Box45019, Lubbock, TX 79409; 806-747-3790,ext. 518; Fax:
806-747-3796; [email protected]; www.itc.ttu.edu/ram.htm.
INJ
6 INJ Summer 2001
RESEARCHERS TOOLBOX
INTC 2001: A GREAT TOOL FOR BOTH THE INDA AND TAPPI TECHNICAL
COMMUNITY
The 2nd Annual International Nonwovens Technical
Conference(INTC) 2001, co-sponsored by TAPPI & INDA, will be
heldSeptember 5-7, 2001 at the Renaissance Harborplace Hotel in
Baltimore,Maryland. Over 80 technical papers will be presented in
14 sessions,making INTC 2001 one of the largest technical
conferences ever in thenonwovens industry.
Combining the TAPPI Nonwovens and INDA technical conferenceshas
worked out for the better of the technical nonwovens community.
Oneexample is found in the Properties and Performance session.
NormLifshutz will present results on the development of a fiber
length testmethod conducted in a TAPPI Fiber Length task force,
while MikeThomason will present INDA test methods on behalf of the
INDA TestMethods Committee.
Other sessions of focus are: Absorbents, Barrier, Binders &
Additives,Filtration, Finishes & Surfaces, Mats &
Insulation, On-Line Measurements,Polymers & Fibers, Properties
& Performances, Sustainability, and four ses-sions have been
devoted to new process technologies.
INTC 2001 will once again offer attendees the nonwoven
tutorialtaught by industry veterans, Roy Broughton, of Auburn
University, TerryYoung, Procter & Gamble, and Alan Meierhoefer,
Ahlstrom Fibers. Otherreturning favorites include the Student Paper
session, the NewTechnologies Showcase and the evening tabletop
event and reception.
The six technical committees of the TAPPI Nonwovens Division
Properties and Performance, Process Technology, Building and
IndustrialMat, Binders and Additives, Polymers and Fibers, and
Filtration willmeet during the lunch sessions on September 5th and
6th.
Written papers are due to INDA by June 26 and presentations in
elec-tronic form are due to TAPPI by August 1.
For conference or registration information regarding INTC 2001,
visitINDAs website at www.inda.org or call 919-233-1210.
http://www.inda.org.mailto:s.ramku-mar@http://www.itc.ttu.edu/ram.htm.http://www.inda.orghttp://www.inda.org.mailto:[email protected]://www.itc.ttu.edu/ram.htm.http://www.inda.orgmailto:[email protected]
ChenReturn to Table of Contents
http://www.inda.org.mailto:s.ramku-mar@http://www.itc.ttu.edu/ram.htm.http://www.inda.org
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Success In Innovation ProjectsA research center within the
Wharton
School of Business at the University ofPennsylvania focuses on
innovation andentrepreneurship. The Sol C. SniderEntrepreneurial
Research Center isstaffed with world-renown scholars andresearchers
and has done some far-reaching research in the correlation
ofinnovation with other business and eco-nomic factors.
A recent study was directed towardthe effects on innovation team
perfor-mance of three underlying elements ofmanagement organization
and opera-tion. The three elements studied indetail were as
follows:
Task Structure: The physical organi-zation of the innovation
team.
Project Framing: Delineation of theproject goals and
methodology.
Team Deftness: Team effectivenessas assessed by past performance
andother factors.
The study used a total of 138 innova-tion projects for analysis,
projects inwhich the ultimate success and effec-tiveness could be
quantified.
The results of this study suggestedthat the absence of Project
Framing interms of clearly specified goals andresponsibilities had
a negative correla-tion with team performance. Clearlydefined goals
and clean-cut responsibil-ities are critically vital to the
innovativesuccess of the team. Any uncertainly inthese two factors
were manifestly oper-ative in detracting from the perfor-mance of
the innovation team.
The factor of Team Deftness corre-lated with performance of the
team, andalso had an impact on Project Framing.The researchers
suggested that this fac-tor had a moderating effect on the
totalperformance, and could help to modify
some of the problems associated withProject Framing. This
suggested thatexperienced and capable innovatorscould overcome, to
a certain extent, theshortcomings of management in notclearly
defining the goals and teamassignments. In essence, the
experi-enced innovators sensed the need andfilled this missing
factor themselves.
The researchers concluded that theoften-assumed positive
relationsbetween organization of the team andits success is valid,
but only for relative-ly high levels of organization and oncomplex
projects.
The message: Organize your teamwell; provide very clear-cut
objectivesand responsibilities; and use capableand experienced
people on your innova-tion team.
Attracting Laboratory TechniciansSome concerted thinking and
action
is being devoted to the position of labo-ratory technician. In
the past, many ofthe individuals who are lab technicianshave come
into the laboratory withoutexperience; it often has been the
respon-sibility of the employer to train suchindividuals and to
equip them for theresponsibilities they will eventually
begiven.
Such home-grown talent may havesufficed in the past. Certainly,
someoutstanding people have come upthrough the ranks in this
fashion. Morethan a few patents covering nonwoventechnologies have
the name of an out-standing lab technician as a co-inventor.
However, training of laboratory tech-nicians is being done more
and more bytrade schools, community colleges andeven universities.
A capable lab techni-cian can be a real asset to a R&D
estab-lishment. Consequently, more thought
is being given to the proper training anddevelopment of such
talent. ThePartnership for the Advancement ofChemical Technology
recently conduct-ed a Research Profile Study to assessthe
personality traits, attitudes, learningstyles and values of quality
lab techni-cians. The study, sponsored by theNational Science
Foundation, coverednot only such individuals, but also stu-dents
studying for such a career, as wellas instructors involved in their
training.
The study found these individuals tobe highly collaborative and
only moder-ately independent or competitive. Thestudents also tend
to be more introvert-ed than the general class of students,and they
are nontraditional, with manyolder than 30.
In focusing on the ideal instructionfor these individuals, the
study revealedthat curriculum designers should con-sider including
group problem-solvingactivities and roundtable discussions intheir
courses for lab technicians. Theseare the skills and environmental
fea-tures involved in this type of work, andso appropriate training
should be pro-vided.
Also, the study showed that almosthalf of the technician
students have afriend who works in a laboratory orsimilar job,
suggesting that current labworkers are a good conduit for
gettingthe word out to prospective students.Further, greater
efforts should be madeto assure these students that the
careersavailable put them in a good position totruly become
professional researchers.
R&D Return On InvestmentA sizeable portion of the
industries
throughout the world would considerthemselves to be a part of a
vastresearch-driven enterprise. Certainlythose in the nonwovens
industry wouldconsider their activities to fit into
thisclassification. (Note the message in theeditorial in this
issue.)
Such research-driven companiesalmost invariably believe or at
least paylip service to the concept that moneyinvested in R&D
activities provide apayback. Proof of such a return, howev-er, is
always difficult to establish, espe-
DIRECTORSCORNER
INJ DEPARTMENTS
INJ Summer 2001 7
-
8 INJ Summer 2001
cially if inadequate accounting practicesare employed. Too
frequently the evi-dence is ephemeral, a gut feeling, oranecdotal
in nature. Many businessleaders want a more precise and defend-able
basis for the annual agonizing deci-sions involved in approving the
R&Dbudget.
Surely the $419 billion chemicalsindustry in the U.S. is a
research-drivenaffair. And yet, even this business seg-ment
struggles with the Return OnInvestment for the R&D
budget.Noteworthy is the fact that the chemicalindustry portion of
the total U.S. R&Dinvestment has been declining for years,from
11% in 1956 to about 8% in thepast decade.
The exact reason for this decline isuncertain; perhaps the
percentages areskewed by the fact that the computerand related
research-oriented industrieshave grown so much in the past
decadeand chemicals are just a smaller piece ofthe whole.
Undoubtedly another factoris that no one has exactly quantifiedwhat
kind of bang these companies getfor their research buck.
A new report from the Council forChemical Research (CCR)
addressesthis problem by analyzing data frommore than 80 publicly
traded chemicalcompanies. From this study the conclu-sion was drawn
that, on the average,every dollar invested in chemical R&Dtoday
yields $2 in operating incomeover six years. This has apparently
con-firmed many of those gut feelings.
In the next phase being pursued bythis program, CCR will
evaluate resultsfrom specific types of R&D. It is hopedthis
study will lead to techniques, topicsand evidence that will further
validatethese concepts. This should materiallyhelp to further
sharpen the businesscommunities view of R&D expenses inthe
chemical industry. It is sincerelyhoped that similar forces are
actingwithin the nonwovens industry.
Getting the Message OutOne of the most difficult
responsibili-
ties for a Research Director is to get outthe numerous messages
associated with
DIRECTORS CORNER
MEETING STAFFING NEEDS WITH SENIORS
Although conditions change quite rapidly, there does seem to be
continuingproblems with research organizations filling all of their
staff needs. TheResearch Administrator feels this is especially
true when it comes to filling theempty slots with good people.
One potential source that may be overlooked in this search is
the labor pool ofolder workers and even senior citizens. Of course,
most of these slots requirespecial skills. However, such special
skills are not unknown amongst the reser-voir of such older
people.
Some universities have done an excellent job with this approach,
enlisting theservices of experienced and seasoned professionals.
Sometimes the position iscreated with a specific individual in
mind, perhaps to teach a special course orassist with a special
project. The position of Adjunct Professor, AdjunctResearch
Scientist or similar is often used to designate and exploit such
talent.There are several notable examples of this approach within
academe at the pre-sent time, in both the practical as well as the
theoretical domain.
However, virtually all levels of technical, scientific and
business activities canbe considered for this approach. A second
career, even at a lower level and asomewhat different arena, may be
attractive to individuals with talent, skills andexperience. The
old wisecrack about the person who retired and then went seek-ing a
job after six weeks likely has a solid basis in fact.
This is borne out by data from the recent U.S. Census. The
number ofAmericans 65 and older working or seeking work increased
10% between March1999 and March 2000 to 4.5 million, the Census
Bureau said in a recent report.These data indicated that there was
a 22% increase in seniors in administrativesupport positions,
including clerical jobs, and an 18% increase in sales job.
The Alliance for Retired Americans, in pointing to these
increases, indicatesthere are 32.6 million in the age group over
65, 1% more than in the previousyear. Not all of these people want
to work, obviously, but an increasing portionapparently do want to
continue to work.
It is interesting that a recent Wall Street Journal article (May
23, 2001)described an effort by the American Association of Retired
People. This organi-zation wanted to select the Best employers for
workers over 50. They mailedinvitations to 10,000 companies to
provide information to assist in the selection.Only 14 companies
responded!
Many companies indicated they had not given that aspect of their
HumanResources efforts any consideration. It seemed to be an area
where the averageemployer was largely out of step with the aging of
the work force.
There are some companies that are exceptions, of course; they
obviously areexceptional. At CVS drugstore chain, for example, 15%
of the employees areover 55; CVS actively recruits older workers.
It says they stay with the compa-ny longer and show more
commitment.
There are obstacles to some of these practices, including
phased-retirement,where an employee goes from a full-time status to
employment that is less thanfull-time. Some of the obstacles are
related to retirement, taxation, pension bene-fits, etc. These
obstacles may require federal legislation to correct. Working
con-ditions, flexibility and a desire for autonomy may be other
factors to consider.
Overall, however, this is an employee pool that will receive
more considera-tion by managers in the future. After all, during
the year of 2001, the number ofworkers who are 40 and above will
surpass those under 40 for the first time.Good Hunting!!
-
safety, accident prevention, pollutioncontrol and the like. It
is a task that isnever finished; it has so many aspects,and yet can
be critically important,especially in retrospect following
anevent.
Pity the plight of the poor SafetyManager/Industrial
Hygienist/Environ-mental Manager who must deal withsuch
motivational things all the time.
The problem is to continuously getthe messages out to all
personnel, getthem to read or study the materials atregular
intervals, and then repeat andreinforce the messages
unceasingly.Thats quite a challenge.
One enterprising Safety and Hygieneofficer within the Procter
& Gambleorganization chose a rather unusualapproach that has
proved to be quiteeffective. He acknowledges that he didnot get
prior management approval forthe technique, undoubtedly because
hewas rather confident that such approvalwould not be forthcoming.
Neverthe-less, he moved ahead with determina-tion by regularly
posting his safety mes-sages in the bathroom stalls at the
P&GHealth Care Research Center in Mason,Ohio. To ensure
sufficient time for theentire message to be read and studied,the
postings were made adjacent to thetoilet commode, where they would
beeasily available to every occupant.
The safety-related items were soonreferred to as potty postings,
alsocalled toilet tabloids. The managerconfessed that there was a
certainamount of resistance to the approach atfirst, but the
message was getting out!One associate complained that Our lastbit
of privacy is being invaded by safetymessages! Another asked the
question,Is no place sacred?
Undaunted, Allan Bayless, the SafetyManager, persevered in the
program andwas rewarded within a few weeks whenthe grousing
subsided and some positivecomments began to emerge. He reportedthat
some colleagues even began tooffer suggestions and to request
newpostings if the current ones stayed uptoo long.
He now has management approval,
and reports that the approach is beingtried at other P&G
locations. His expe-rience has shown that popular topicsinclude a
range of rather violent events.Apparently everyone loves an
accident,a flood, a fire or a reaction gone crazy.He always tries
to exploit the describedevent by discussing what went wrongand what
should be done to correct thesituation. Bayless found this
approachto be much more effective than simplee-mailing individuals.
After all, an e-mail can be discarded with a key stroke!
If this approach sounds useful andfurther information in
desired, Baylesscan be contacted via e-mail
[email protected].
An Environmental PolicyThe peoples of this earth have come a
long way in developing an environmen-tal conscience and doing
the rightthing. The past 40 years have seen alarge portion of the
population growfrom disinterest into a strong concern forthe worlds
environment and the legacythat will pass to future generations.
The effort has had its distracters ofcourse. On the one side
there have beenthe adamant resisters and the obscenepolluters. On
the other side have beenthe eco-extremists and eco-thugs.Despite
this situation, progress has beenachieved.
An interesting policy statement on theenvironment and their
relationship to ithas recently come from one of the non-woven
industrys major members J.W. Suominen Oy, Nakkila, Finland.
While Suominens EnvironmentalPolicy statement is simple and
straight-forward, it clearly provides a basis fordecisions both
large and small. It can bereadily understood by top
management,board members, middle managers andemployees at all
levels, as well as bycustomers, competitors and the generalpublic.
It would seem that all sectors ofthe industry would benefit from a
simi-lar, simple statement or credo thatwould guide all phases of a
companysoperations.
An example of SuominensEnvironmental Policy statement
appears
in the box on this page. To decrease environmental loading,
JWS uses BATNEEC (Best AvailableTechnology Not Entailing
ExcessiveCosts), minimizes the waste and recy-cles where feasible.
JWS commits tofulfill relevant environmental legisla-tion,
regulations and other obligations.
Top management establishes the envi-ronmental objectives and
appropriateresources for their implementation andmonitors their
performance.Supervisors are responsible for imple-mentation of
environmental targetsrelated to their area of responsibility
andcontinually aim to consider theimprovement of environmental
perfor-mance while developing activities andworking practices.
Personnels commitment, as well asthe recognition of their own
responsibil-ity, is ensured by systematic training,communication
and encouragement.
While it may not be perfect, it is con-cise and understandable!
INJ
INJ Summer 2001 9
DIRECTORS CORNER
ENVIRONMENTAL POLICYJ.W. Suominen develops, produces
and supplies nonwovens profitablyaccording to customers needs,
such
that the activitys adverse environmen-tal impacts are as slight
as possible.
JWSs key environmental aspects are:
Prevention of pollution.
Continual improvement so thatenvironmental loading, in relation
to
production volume, decreases annually.
Environmental loading is moni-tored and measured
comprehensively
and the results are public.
mailto:[email protected]:[email protected]
ChenReturn to Table of Contents
mailto:[email protected].
-
Tracing Water Pollution SourcesIn the past, water polluters have
benefit-
ted from the fact that water pollution can beclearly identified,
but the source of pollu-tion is much more difficult. That
situationmay be changing somewhat, with theadvent of a DNA
fingerprinting test totrace the source of water pollution.
This test, which was developed at theUniversity of
Missouri-Columbia, is basedon tracing the water pollution back to
itssources by using the DNA from bacteria.The presence of fecal E.
coli bacteria microbes that live in the intestines of theirhost
until they are excreted commonlyis employed to establish if the
pollution isdue to human or animal wastes. Whilethese organisms of
themselves are non-pathogenic, their presence in a water givesa
warning of the potential presence of otherdisease-producing strains
of E. coli, salmo-nella or hepatitis virus that can also befound in
human and animal waste.
The method utilizes a technique knownas DNA pattern recognition,
or ribotyping.This novel approach takes advantage of thefact that
each host species harbors specifictypes of E. coli in the
intestinal tract thathave specific DNA patterns, or finger-prints.
The DNA results are then com-pared to known DNA patterns from
knownhost species. This then gives an indicationof possible sources
of the contamination.
At the present time, the method can beused to clearly identify
contaminationcoming from eight common hosts:humans, cows, pigs,
horses, dogs, chick-ens, turkeys and migratory geese. Furtherwork
is being carried out to expand theDNA database of hosts and to
furtherrefine the technique to identifying charac-teristics of
pollution sources. Currentchemical analysis, of course, can
providevery precise information on the presence oforganic and
inorganic pollutants; thesedates, coupled with water flow and
move-ment patterns, can generally pinpoint thesources with
convincing results.
Active AntibacterialsThe use of antibacterial agents in a
host
of consumer, medical and industrial prod-ucts has exploded in
the past few years.Seven times as many antibacterial prod-ucts were
produced in 1998 than in 1992.Antibacterial finish has become the
stan-dard finish in some textile product cate-gories. Nonwoven
products have partici-pated in this action is a significant
way,especially in nonwoven wipes.
The practice has become sufficientlywidespread that
consideration has beengiven to legislation to stiffen controls
onthe use of such materials. Some warningshave been put forth by
the medical pro-fession, arising from the concern that
suchmaterials can kill beneficial germs as wellas deleterious ones.
Also, there is concernthat resistance to such agents can developand
could lead to a range of super-germs.
Despite such concerns, the use of theseagents is
proliferating.
Most such agents act by leaching fromthe material to which they
are originallyapplied, and then contact the microorgan-isms and
kill them by such contact. Theseare the leaching type agents.
Their effectiveness diminishes as theleaching continues, of
course, and theleaching can lead to excessive skin con-tact or even
to the crossing of the skin bar-rier; such behavior can lead to a
variety ofproblems.
Another class of antibacterial agents isactually bound to the
substrate by molec-ular or other forces. Such bound mate-rials
usually have hydrophilic or othergroups in the molecule which can
pene-trate the microorganism, allowing quater-nary ammonium groups
or other groupsto rupture the organisms cell wall, lead-ing to
expiration. This bound type ofmaterial can kill when the
organismresides on the substrate; hence, it is morelimited in
scope.
An interesting class of durable agentswas recently described
with the added
feature of being capable of regenerationof the active chemical
moiety. In thisagent, one functional group is used toattach the
molecule permanently to cellu-lose fiber via a molecular bond. The
func-tional group also contains a cyclic hydan-toin group, which
can be easily chlorinat-ed to form the reactive cyclic
chloro-hydantoin group. This latter group is aneffective
disinfecting agent that is widelyused in swimming pools and other
simi-lar applications. As the disinfectingaction continues, the
chloro-group is con-verted back into the unsubstituted hydan-toin
group. This latter group can be easi-ly converted back into the
active chloro-hydantoin form; such chlorination can bedone simply
by treating the fabric with achlorine bleach. Hence, the
regenerablefeature.
Very recently a special polymer hasbeen developed at
MassachusettsInstitute of Technology that is claimedto have special
germicidal properties.When the polymer is coated onto a
hardsurface, the developers claim that it isthere permanently and
can guard againstinfections commonly spread by sneezesand dirty
hands. The materials isdescribed as hexyl-PVP
(PVP-polyvinylpyridine).
The PVP portion has been known to beactive in solution, but
attempts to immo-bilize the material on a surface seemed torender
the polymers totally inactive. Theresearchers found that the
addition of thealkyl chain (3-6 carbon atoms) eliminatedthe
inactivation. It is claimed that thismaterial in a coating form is
able to kill upto 99% of Staphylococcus, Pseudomonas,and E. coli,
all common disease-causingorganisms. The killing action is stated
tobe via a powerful chemical-electricalaction. The researchers have
hypothesizedthat the addition of the polymer side chainof the right
length provides flexibility forthe coating material to penetrate
the bac-terial cell wall envelope on contact and doits job. These
are the first engineered sur-faces that have been shown to kill
air-borne microbes in the absence of any liq-uid medium. This work
suggests a newpossible approach to engineer a solid sur-face to
provide bacteria-killing action.
The major markets for most types of
TECHNOLOGYWATCH
INJ DEPARTMENTS
10 INJ Summer 2001
-
INJ Summer 2001 11
biocides is for water treatment, paint pro-tection, wood
preservation and similarapplications. Use in textile and fiber
mate-rials is significant, however, and is contin-uing at a fast
pace.
Another somewhat related develop-ment in chemical/biological
activity oftextile fibers concerns cotton wipes thatcan be used to
decontaminate nerveagents on contact. This work involvescovalently
linking an enzyme to cottonfiber. The enzyme,
organophosphorushydroxylase from Pseudomonas diminu-ta, is the only
enzyme known to detoxifya wide range of nerve agents. The modi-fied
fabric rapidly hydrolyzes the agentParaoxan (a nitrophenyl ester),
indicatingthe immobilized enzyme retains it activi-ties. The fabric
can also convert the infa-mous nerve gas, Sarin, along with
others,as well as the toxic insecticides parathionand
methylparathion, to harmless by-products. The fabric doesnt
irritatehuman skin and retains 70% of its originalenzyme activity
after two months, eitherrefrigerated or stored at room
tempera-ture.
Modified fibers and fabrics can obvi-ously be made to do
wondrous feats.
More Chemical ScaresA recent action by a government-spon-
sored panel of scientists and environmen-talists has the
potential of creating a super-abundance of chemical scares in the
future.If the course outlined by this panel is fol-lowing, research
administrators are in for arough ride ahead.
The problem centers around a report bya National Toxicology
Program panel,which concluded in May, 2001, that somechemicals can
affect laboratory animals atvery low levels, well below the no
effectlevels.
This rather shocking, self-contradictoryconclusion violates a
fundamental princi-ple of toxicology namely that the dosemakes the
poison. This principle assertsthat all substances can act as
poisons in suf-ficiently high amounts, even such benignsubstances
as water, sugar and salt; youname it. However, below their
toxicdoses, such substances are considered notto be poisons.
The government panel concluded thatthere is credible evidence of
the effect ofsome chemicals on laboratory animals atsuch very low
levels. The evidence seemsto flow from concern with so-called
endocrine disruptors, also referred to asenvironmental
estrogens. These materialsare described as hormone-like chemicals
inthe environment that can disrupt normalhormonal processes and
cause everythingfrom cancer to reproductive problems
toattention-deficit disorder.
The public concern with these possi-bilities began with claims
based onresearch work by the University ofMissouri researcher
Frederick vom Saaland a book he published, entitled OurStolen
Future. He carried out experi-ments on laboratory mice that
purported-ly showed that very low doses of somechemicals increased
prostrate weight inmale mice and advanced puberty infemale mice.
The doses employed werethousands of times lower than currentsafe
standards.
Reportedly, no other laboratory has beenable to reproduce vom
Saals work; repro-ducibility of experiments is necessary, ofcourse,
before a conclusion can be accept-ed. However, vom Saal all but
guaranteedthat his work will never be reproduced. Hisexperiments
involved a unique strain ofmice that he inbred in his laboratory
forabout 20 years. When the mice stoppedproducing the results he
wanted, he killedthem.
However, the results he promoted wereembraced by others who felt
they matchedtheir environmental and political agenda.The panel
given the assignment to assessthis situation was apparently loaded
withsuch individuals.
In any event, the panel recommendedthat the EPA consider
changing its guide-lines for assessing risk of reproductive
anddevelopmental effects from chemicals.According to some experts
this recom-mendation is likely to spread to othernational and
international regulatory agen-cies.
The low-dose theory could put virtuallyevery industrial chemical
and many con-sumer products at risk of being stringentlyregulated
or banned without a scientificbasis. This development bears
watching byanyone concerned with chemicals andproducts. Further
information can beobtained at several websites,
includingwww.junkscience.com. INJ
TECHNOLOGY WATCH
SYNTHETIC PAPER SHOWING EXCEPTIONAL GROWTH
Originally introduced into Japan several years ago, synthetic
paper is startingto show exceptional growth in a variety of markets
and applications. This product consists of thin plastic sheet
material containing a filler or a spe-
cial coating to give it the printing characteristics of
conventional paper. The basefor a synthetic paper may be
polyethylene, polypropylene, polystyrene or poly-ethylene
terephthalate; suitable fillers are titanium dioxide, calcium
carbonate orvarious silicas. typical paper coatings based on clay,
calcium carbonate or othermaterials can be employed to provide a
good printing surface.
The growth of this type of material is expected to be in excess
of 8% per year,from a current base of about $200 million; this will
result in a 166 million poundmarket by the year 2005, according to
one recent study.
The use in specialty label applications is the largest current
market for thesematerials. However, it is anticipated that growth
in other related markets willexceed the growth in labels; these
other market applications include commercialprinted products, such
as greeting cards, menus, maps, books and covers, signageand
point-of-purchase displays. In the label market segment,
significant applica-tions include pressure sensitive labels,
in-mold labels, and unsupported tags.
At the present time major producers include: PPG, Oji Paper
(Japan) throughtheir subsidiary Yupo, Nan Ya Plastics, ExxonMobil,
and Arjobex (a three-wayjoint venture of BP, Arjo Wiggins (London),
and Appleton Papers). Some ofthese properties and markets suggest
possible usage of nonwoven materials.
http://www.junkscience.com.http://www.junkscience.com.Roger
ChenReturn to Table of Contents
http://www.junkscience.com.
-
Distance LearningIt used to be that a remote location pre-
cluded a number of activities for a per-son who was so
unfortunate. An oppor-tunity to study and continue ones educa-tion
was certainly one of those factorsthat had to be sacrificed. No
More!!!
If the men and women serving in theU.S. Navy aboard a ship at
sea anywherein the world can continue their graduateeducation,
location is no longer an insur-mountable barrier. The solution is
whatis referred to as Distance Learning.That is not learning about
how far faris, but rather it signifies learning that canbe done at
virtually any distance fromthe source of the teaching.
A growing number of universities andcolleges are beginning to
offer anexpanding selection of courses that arepresented via the
Internet. This arrange-ment is not the same as a
correspondencecourse, as the student can virtually bepresent in the
usual class setting andhave direct and instantaneous contactwith
the instructor and fellow students,all by means of a computer
terminal anda communications link.
Many universities are working to con-vert their classroom
materials into a formmost suitable for this medium.Professors and
teachers are learning howthe usual teaching methods can be
mosteffectively converted into the cyberspaceclassroom. Some
adaptation of methodsand materials must be made, of course,but the
transition is being mastered.
At the government level, the SmallBusiness Administration (SBA)
hasintroduced the new SBA Small BusinessClassroom, which brings
electronic busi-ness courses to anyone with a standardInternet
connection. This virtual class-room provides interactive, easily
accessi-ble courses on the topics most in demandby small-business
owners. Typical class-
es include: The Business Plan (inEnglish and Spanish) or How to
RaiseCapital For a Small Business. At the endof each lesson,
students can participate ina scheduled chat room, or call a
toll-freenumber to talk with a counselor(www.sba.gov and then
select SBAClassroom).
Not a part of Distance Learning, therewere recent press reports
on several cam-puses involving enterprising studentsputting todays
lecture notes on the webfor the benefit of friends who missed
theclass. Some professors objected strenu-ously to this practice,
even claiming thatnotes from their lectures were akin tocopyrighted
material. In direct contrastto that attitude is the recent
announce-ment by Massachusetts Institute ofTechnology (MIT) that
over the next 10years, the university will post materialsfor almost
all of its courses on the WorldWide Web, accessible to one and all
at nocharge. Materials posted will include
course outlines, reading lists, lecturenotes and
assignments.
As ambitious as this approach is (esti-mated cost is $10 million
per year), it isprobably not the same as getting an MITeducation
for free. Unlike DistanceLearning programs, which involve regu-lar
exchanges between faculty and stu-dents, there will be no course
credit ordegrees offered to people who accessOpen-CourseWare, as it
is being called.
Nevertheless, the early response to theMIT move has been very
positive. Notonly in developing countries, but inadvanced nations
as well the benefits ofDistance Learning are being appreciatedand
used. This activity will undoubtedlyfurther increase concern with
theDigital Divide, which separates thosewho do not have access to
the Internetfrom those who do.
Some professional societies arebecoming involved in the process.
TheSociety of Dyers and Colourists in theUK has presented a
Distance Learningmodule on Principles of Engineeringand Coloration
Theory. Future planscall for additional modules on ColorPhysics,
Colorant and PolymerChemistry, Coloration Technology,
andOrganization and Management.
Within the nonwoven technology sec-tor some steps in this
direction have been
THE NONWOVENWEB
INJ DEPARTMENTS
12 INJ Summer 2001
SPAM VS. spam
Even a novice on the Internet is familiar with the junk E-mail
that virtuallyabounds on the net and goes under the name of spam.
Such unsolicitedmail is a fact of life on the Internet and it is a
rare netizen who hasnt experiencedit.
On the other hand, there is a well-known spiced lunch meat made
of porkshoulders and ham that is known worldwide, and considered a
choice delicacy inmany parts of the world. This product of Hormel
Foods Corporation goes by abrand name that is considered a very
valuable piece of intellectual property SPAM registered trade mark
for the meat product.
For several years Hormel fought against the use of the word spam
to desig-nate the wrong kind of e-mail. They worked diligently to
protect their name andto police the mounting misuses. After this
valiant effort, the company has final-ly acquiesced to a
compromise, as outlined on their official SPAM
website(www.spam.com/ci/ci-in.html). Hormel says it no longer
objects to that otherdesignation, as long as it is spelled in small
letters spam, that is. However, forthis concession, they expect
their trademarked product to be spelled in capitalletters SPAM
brand of meat product.
Seems like a reasonable compromise.
http://www.sba.govhttp://www.spam.com/ci/ci-in.html).http://www.sba.govhttp://www.spam.com/ci/ci-in.html).http://www.sba.govhttp://www.spam.com/ci/ci-in.html).
-
INJ Summer 2001 13
made and more are being taken. Accessto specific nonwoven
technology trainingis becoming available from some univer-sities.
Problems still exist, such as thematter of oversight and quality
control,as expressed by some committees withinvarious universities.
Also, there is thequestion of the more subtle interactionsbetween
student and teacher which natu-rally arise from questions and
answers,and by other means.
However, as more experience isgained, the processes will
undoubtedlyimprove. After all, a telephone call to acolleague can
be a form of DistanceLearning.
Electronic SignaturesThe electronic signature law went into
effect in June of 2000. This law givesdigitally signed documents
the samelegal weight as those with physical sig-natures. In
essence, this allows a personto simply click a box and accomplish
thesame results as signing a document withpen and ink.
It may come as no surprise, however,to learn that individuals
and companieshave been slow to stamp their signatureon business
transactions via electronicmeans. Even with companies that coulduse
this method to a great extent, such asfinancial services and legal
firms, therehas been a reluctance to use the method.
One roadblock to the acceptance ofelectronic signatures is
obviously theproblem with the ability to verify thesigners identity
in court. It is rather dif-ficult for an individual to deny a
signa-ture when it is there in ink on a docu-ment; it is
considerably easier to deny itwhen done by an electronic
keystroke,especially if there was no one around atthe time.
There have been attempts to useadvanced technology to eliminate
thisfactor, and companies are offering secu-rity means to eliminate
this uncertainty.Unfortunately, these means are ratherexpensive,
especially for a single or onlya few signatures.
Where there are repetitive transactionsbetween two companies
that have a con-tinuing relationship, or transactions with-
in a small, closed trading community, theconcept may be very
viable.
Some of these problems are very simi-lar to those encountered on
the Internet,where a great deal of effort has beenexpended to
establish secure boundariesaround business transactions.
Anonymityis an inherent feature of the net and elec-tronic space.
This characteristic isacceptable for some interactions, but
cer-tainly not for others. For now, most com-panies are taking a
wait-and-see atti-tude toward the electronic signature.
Sci/Tech Web Awards 2001One of the very interesting websites
on
the Internet is that of the science journal,Scientific American
(www.scientifi-camerican.com). The site provides aTable of Contents
of current and pastissues, and even posts the full text ofsome of
the articles.
The publication also conducts an annu-al search of scientific
sites and selectsfive sites from 10 different categories toreceive
their Sci/Tech Web Award2001. The sites are selected for a
varietyof reasons, as the selections are aneclectic mix from the
practical to theacademic to the downright silly.
The categories covered by their searchinclude Archaeology and
Paleontology;Earth and Environment; Astronomy andAstrophysics;
Engineering andTechnology; Biology; Mathematics;Chemistry;
Medicine; ComputerScience; and Physics
Some very interesting websites arisefrom the list of their
selections. There isa site that gives a listing of a vast numberof
acronyms, listed alphabetically or bytopic, along with definitions
for thou-sands of the most current IT-relatedwords
(www.whatis.com). The medicalcategory has an online version of
theclassic reference book, Grays Anatomy,with 1,247 engravings from
the original1918 publication (www.bartleby.com).The Engineering and
Technology catego-ry offers an interesting web page thathighlights
bad product designs resultingin items that are hard to use because
theydo not follow human factors principles(www.baddesigns.com
).
The variety in the sites selected for theaward gives an
appreciation of the diver-sity of material that is posted on the
web.
Computer VirusesA new version of the computer virus
has struck the Internet. This recent virus,called sulfnbk,
doesnt do much harmto your system, but it sends you on a wildgoose
chase to find and eradicate anobscure and innocuous utility file
(sulfn-bk.exe) in Windows 98/Me before a sup-posed
expiration/explosion date.
When dealing with such matters, it isvery helpful to be able to
call on someexpert advice and help. Again, theInternet comes up
with the answer. Onesource of such assistance is a
computerinformation resource (www.geek.com).This site has a variety
of useful informa-tion, including a consumer warning areathat can
be of real help in a situation ofthis type.
Also, another site can be a usefulresource when it comes to
computervirus myths, hoaxes, urban legends, hys-teria and such.
This site(www.vmyths.com) is dedicated to pro-viding the truth
about computer virusmyths and hoaxes. This site includesinformation
on new viruses as well as oldones, as it points out that Old
hoaxesnever die, they just get a new life cycle.
Relatively New StuffThis phrase is the byword for a website
that is an online marketplace for used anddiscounted scientific
equipment. The site(www.einsteinsgarage.com) offers usedand
still-in-the-box, brand-name instru-ments, equipment, supplies,
chemicals,safety apparatus, protective clothing,teaching aids and
more. Their motto isThe theory of relatively new stuff, atake-off
from the original Einstein.
The items offered cover a range ofproducts from well-known
equipmentmanufacturers. They are offered on anauction basis,
although users can sell,auction and advertise surplus equip-ment as
well. Einsteinsgarage is amember of Alchematrix, a whollyowned
e-commerce subsidiary ofFisher Scientific. INJ
THE NONWOVEN WEB
http://www.whatis.com).http://www.bartleby.com).http://www.baddesigns.comhttp://www.geek.com).http://www.vmyths.com
http://www.einsteinsgarage.com
http://www.whatis.com).http://www.bartleby.com).http://www.baddesigns.comhttp://www.geek.com).http://www.vmyths.com
http://www.einsteinsgarage.com Roger ChenReturn to Table of
Contents
http://www.whatis.com).http://www.bartleby.com).http://www.baddesigns.comhttp://www.geek.com).http://www.vmyths.com
http://www.einsteinsgarage.com
-
AbstractThis paper reports the effects of white water
characteristics
and forming wire parameters on wet process drainage. Byemploying
a recently developed lab tester, the present investi-gation
conducted drainage experiments of long (32 mm)fiberglass in
polyacrylamide (PAM)-based white water with areal (commercial)
forming fabric in position. The formingwires under investigation
cover air permeability from 465 to715 CFM and drainage index from
9.5 to 22.
Drainage experiments show that both PAM concentrationand
shearing (mixing) effect can strongly affect wet processdrainage.
So, white water of fixed composition, but with a dif-ferent mixing
history may behave very differently, and anincrease in input mixing
energy usually results in a substantialincrease in drainage.
Mat basis weight also strongly influences wet processdrainage.
Although an increase in basis weight always reducesthe rate of
drainage regardless of wire structure, its impact ismuch stronger
on the wires with a high air permeability and alow drainage index
than the ones with a low air permeabilityand a high drainage
index.
Another important finding of this study was that drainageindex
did not predict the performance of a forming wire, andthe main
causes were believed to be the fundamental differ-ences between the
wet-formed glass mat (WFGM) andpapermaking processes. Also,
correlation between air per-meability and wet process drainage was
found very complex:while air permeability may be used as an
empirical parame-ter to predict drainage for light weight mats at
low PAM con-centrations, however, the higher the web basis weight
and thehigher the PAM concentration, the more likely it would
fail.
Key Words
Wet process, drainage, forming wire, drainage index,
airpermeability, polyacrylamide, basis weight, shearing effect
IntroductionDrainage is one of the critical process variables in
a wet
process (the wet-formed glass mat process or the WFGMprocess).
Wet process uses higher viscosity white water andoperates at low
slurry consistencies. Its drainage operation isusually more
challenging than in a typical papermakingprocess, which is the
primary reason that an inclined delta for-mer, instead of a
Fourdrinier machine, is normally used in awet process to dewater
fiberglass slurries.
Wet process drainage is a complex process depending onboth the
physical characteristics of a fiber slurry and thedetailed
structure of a forming fabric. The slurry characteris-tics
encompass fiber content, fiber length and diameter, andwhite water
chemistry, etc. The wire parameters may includeat least air
permeability and drainage index, etc. Sincedrainage has great
influence on both the sheet properties [1-4]and the mill
performance, the paper industry has consistentlydevoted a great
deal of resources to gain fundamental under-standings in this area
[5-12]. Several experimental methods [6,13, 14] have been developed
to measure the drainage, or free-ness, of papermaking furnishes,
among which the CanadianStandard Freeness (CSF) test [14] is the
most common one.
Though various lab drainage testers have been successfullyused
to characterize the drainage characteristics of papermak-ing
furnishes, they are generally not applicable to the fiber-glass
slurries used in a wet process [15]. It is also worth not-ing that
these lab drainage testers are limited to estimate onlythe drainage
characteristics of furnishes and are not capable ofevaluating the
effects of forming wire parameters [15]. In real-ity, a drainage
process is controlled by the combination ofwhite water
characteristics and the parameters of a formingfabric. Therefore,
it would be very important to measure thedrainage rate under the
combined conditions of all these para-
Wet Process Drainage Effects ofWhite Water Chemistry andForming
Wire StructuresBy Daojie Dong*, Senior Scientist, Owens Corning
Science & Technology Center,Granville, OH 43023
ORIGINAL PAPER/PEER-REVIEWED
14 INJ Summer 2001
* The author is currently a Senior Engineer with Decillion,LLC,
Granville, Ohio
-
INJ Summer 2001 15
meters.Recently, a wet process mimic device (WPMD) has been
developed at the Owens Corning Science and TechnologyCenter that
is capable of measuring the drainage rate of wetprocess slurries
with real (commercial) forming fabrics inposition. The detailed
information about the WPMD structureand developmental work can be
found elsewhere [15].
In the present investigation, the WPMD was used as a toolto
study the effects of both fiberglass slurry characteristics
andforming wire parameters on wet process drainage. The rate
ofdrainage was measured under a simulated line speed and
cor-related to various parameters, such as, PAM concentration
ofwhite water, mixing effect, web basis weight, fabric air
per-meability and wire drainage index. The approaches used werevery
practical, and the reported results are expected to haveclose
correlation to real wet process operations. Theoreticalmodeling of
the drainage process is out of the scope of thispaper, but might be
addressed in the future.
ExperimentalApparatus
Drainage experiments were carried out using a wet processmimic
device (WPMD) as shown in Figure 1. The detailedstructure and
operation procedures of the WPMD were report-ed elsewhere [15].
Briefly, the WPMD consists of three stain-less steel chambers and
two functional blocks, the drainagefunctional block (DFB) and the
fiber bleed-through functionalblock (FBTFB). As shown in Figure 1,
the three chambers arevertically arranged to create a gravitational
flow field. TheDFB block is positioned in between the top and
middle cham-bers, while the FBTFB block connects the middle and
bottomchambers together.
The DFB, the heart of this tester, is primarily composed of(1) a
gate (or shut-ter), (2) a piece of20 X 20 inch (51X 51 cm)
formingfabric mounted ona holder, (3) amovable formingbed (MFB)
con-sisting of a seriesof supporting bars,(4) a driving andcontrol
system thatcontrols the move-ment and speed ofthe MFB, and (5)
aflow control sys-tem that providesinitial settings fordrainage
experi-ments.With forming wireA (as defined inTable 1) in
posi-tion, the reported
WPMD has a maximum pure water drainage rate of about 145gallons
per minute per square foot of forming area (gpm/ft2) ina
gravitational field. In the present work, drainage experimentswere
not carried out at its maximum capability. Instead, a setof
parameters on the WPMD were chosen so that wire A pro-vided a pure
water drainage rate of ~85 gpm/ft2. The rest ofexperiments were all
conducted under these fixed conditions.
Forming WiresAs reported earlier [15], one of the special
features of this
WPMD lies in its capabilities of measuring drainage rate
usingreal (commercial) forming fabrics. In the present study,
threecommercial forming wires were selected (from three
differentsuppliers) and some of the wire parameters were
summarizedin Table 1. These wires have similar structures and all
fall inthe double layer category. But, their meshes, strand
diametersand weaving patterns are very different from each
other.
In Table 1, the fiber support index (FSI) and caliper data
wereobtained from respective wire manufacturers. The AP(s) andthe
DI(s) are the specified air permeability in cubic feet perminute
per square foot (CFM) and the specified drainage
index,respectively. The wire samples were measured for air
perme-ability at the Owens Corning Science and Technology
Centerbefore testing and the results were 715, 630 and 465CFM
forwires A, B and C, respectively. Due to the changes in air
per-meability value, the corresponding drainage indexes
wererecalculated as 9.5, 17.8 and 21.1, respectively. In the
section ofResults and Discussion, the measured air permeability
(AP)and the recalculated drainage index (DI), the data in the last
tworows of Table 1, were used to correlate to drainage.
To study the effect of wire parameters on drainage rate, 20X 20
inch wire samples were installed into the DFB block fordrainage
testing, and all the comparisons were made underidentical
experimental conditions.
MaterialsDrainage experiments were conducted with Owens
Corning
786M 1.25 inch fiber, Cytec Superfloc A1885, and Rhone-Poulenc
Rhodameen VP-532 SPB. The 786M is a chemicallysized fiberglass with
a mean diameter of 16 microns. TheSuperfloc A1885 is an anionic,
high molecular weight poly-acrylamide (PAM) and functions as a
viscosity modifier. The
Figure 1WET PROCESS MIMIC DEVICE
Table 1FORMING WIRE SPECIFICATIONS
Wire ID A B CMesh (top) 56 X 26 65 X 52 107 X 54Mesh (bottom) 65
X 38 107 X 28Layers 2 2.5 2.5Caliper (inches) 0.080 0.075 0.0435FSI
36.0 48.4 86.0AP(s) (CFM) 750 660 490DI(s) 10.0 18.6 22.2AP (CFM)
715 630 465DI 9.5 17.8 21.1
-
Rhodameen VP-532 SPB is an ethoxylated fatty amine, a sur-face
active molecule, and functions as a dispersant. In addi-tion, a
small amount of defoamer was also used to controlfoam and assist
the experiments.
DrainageIt is known that the PAM viscosity modifier is sensitive
to a
shearing effect. The received PAM was first diluted to 0.5wt.%
and agitated for 30 minutes. The same batch of dilutedPAM was used
for the entire experimental work to avoid pos-sible variations in
raw material and in dilution procedure.
The drainage volume was fixed as 20 gallons (of pure water,or
white water, or fiber slurry). For white water (withoutfibers)
testing, 20 gallons of water was fed into the top cham-ber,
followed by a predetermined amount of PAM and 5 dropsof defoamer.
The formulated white water was then agitatedunder specified
experimental conditions before drainage.
A two step procedure, similar to a thick-thin stock proce-dure,
was used in the preparation of fiberglass slurries. First,10
gallons of water were charged into the top chamber, fol-lowed by 10
drops of dispersant and 5 drops of defoamer.Then, the mixer
(agitator) was turned on and a pre-weighedamount of fiberglass was
added immediately. In the mean-time, a timer was started to record
mixing time. After oneminute of mixing, a predetermined amount of
PAM wasadded, and additional water was fed to make up a total
volumeof 20 gallons.
While the slurry (or white water) being prepared, the
movableforming bed (MFB) was set in motion at a desired speed,
andother drainage parameters were also set at desired values.
Whenthe slurry was ready for testing, the gate (or shutter) was
openedinstantly and the drainage process began. The time duration
ofdrainage was recorded and the average drainage rate was
calcu-lated based on the known parameters of the WPMD. In thiswork,
a unit of gallons per minute per square foot forming area(gpm/ft2)
was selected for the rate of drainage.
A dual-propeller mixer driven by an air motor wasemployed for
agitation. The mixer was positioned at the cen-ter of the chamber
with its lower and higher propellers 2 3/8(6 cm) and 11 5/8 (29.5
cm) above the top surface of theforming fabric. The mixing
(shearing) effect was controlled bythe inlet pressure of compressed
air to the air motor.
ViscosityWhite water viscosity was measured with a
Brookfield
Model DV-II+ viscometer.
Results and DiscussionPAM Effect
Figure 2 shows the influence of polyacrylamide concentra-tion on
the drainage of white water (without fibers). All thewhite waters
used in Figure 2 were mixed for 5 minutes witha compressed air
setting of 28 psig. So, PAM concentrationwas the only variable,
which ranged from 0 to 165 ppm with0 representing pure water.
As indicated in Figure 2, the presence of PAM
significantlyreduced the rate of drainage. For wires A and B, the
drainage
rate of pure water was ~83 gpm/ft2, and the presence of 66
and165 ppm PAM has reduced the drainage rate by ~35% and55%,
respectively. For wire C, the presence of 66 and 165 ppmPAM has
reduced the drainage rate of pure water by ~50% and74%,
respectively.
The presence of PAM also significantly reduced thedrainage rate
of fiberglass slurries as shown in Figure 3. Thenine data points
used in the figure had a same consistency of0.012%, and each slurry
was agitated for 5 minutes with apressure setting of 28 psig on the
driving air motor.
Interestingly, the three wires responded similarly to the
changesin PAM concentration. The drainage rate dropped sharply
whenthe PAM concentration was increased from 10 to 65 ppm. As
thePAM concentration was further raised to 165 ppm, the
drainagerate continued decreasing, but with a much lower slope.
Basis Weight
16 INJ Summer 2001
Figure 2EFFECT OF PAM CONCENTRATION ON
WHITE WATER DRAINAGE
Figure 3EFFECT OF PAM CONCENTRATION ON
FIBERGLASS SLURRY DRAINAGE
-
INJ Summer 2001 17
Gravity drainage, in essence, is a filtration process with
thepressure defined by the gravity head of suspension over aformed
web [9] supported on the forming wire. It is obviousthat the web
thickness and its degree of compression willaffect the rate of
drainage. Since the primary focus of thispaper is to deal with the
practical aspects of drainage in wetprocess, the web effect on
drainage rate was treated withrespect to mat basis weight in pounds
per hundred square feet(pounds/CSF).
Three consistency values of 0.008%, 0.012% and 0.018%were
purposely designed to study the web effect on drainagerate. These
values, based on the particular parameters of theWPMD, correspond
to the formed webs with fiber basisweight of 0.81, 1.30 and 1.86
pounds per hundred square feet(pounds/CSF), respectively. If a 19%
of loss on ignition (LOI),a typical number for fiberglass roofing
mats, is also accountedfor, the three consistency values would
correspond to the fin-ished wet process mats with basis weight of
1.00, 1.60 and2.30 pounds/CSF. In Figures 4 and 5, drainage rate
was plot-ted with respect to mat basis weight for the convenience
ofreaders in the nonwovens industry. The fiberglass slurries usedin
Figure 4 were all prepared at a fixed PAM concentration of165 ppm,
and in Figure 5 at a fixed PAM concentration of 66ppm.
As indicated in Figures 4 and. 5, the rate of drainage
wasreduced as the basis weight was increased from 1.0 to 1.60
and2.30 pounds/CSF. However, the degrees of change were dif-ferent
among the three wires. For example, at a fixed PAMconcentration of
165 ppm (Figure 4), the drainage line forwire A has the highest
slope, the line for wire B is less steep,and the line for wire C
has the lowest slope. As a result, wireB has reached comparable
drainage rates to wire A at basisweights above 1.60 pounds/CSF,
though its rate of drainagewas ~20% lower than wire A at a basis
weight of 1.0pounds/CSF. Figure 4 also indicated that the
difference indrainage rate between wire C and the others was
gradually
reduced as the increase in mat basis weight.At a fixed PAM
concentration of 66 ppm (Figure 5), the
same trend seemed to hold. Wires A and B had similardrainage
rates at all three basis weights. Wire C, again, neverreached
comparable drainage rates to wires A and B, thoughthe difference
was gradually reduced as the basis weight wasincreased.
Shearing (Mixing) EffectFigures 6 and 7 show that the PAM-based
white water was
very sensitive to shearing (mixing) effect. All the slurries
usedin the two figures had exactly the same composition: 165 ppmof
PAM, ~2 ppm dispersant, ~1 ppm defoamer and a fiberglassconsistency
of 0.012%. The variations in drainage rate werecaused solely by
different shearing (mixing) history. In Figure6, all the slurries
were prepared with a fixed mixing time of 5minutes, but, mixing
pressure on the air motor was variedfrom 14 to 60 psig. In Figure
7, all the slurries were preparedwith a fixed mixing pressure of 40
psig, but mixing time wasvaried from 5 to 200 minutes.
Figure 6 indicates that, as mixing pressure was increasedfrom 14
to 60 psig, the viscosity of white water was reducedslightly (from
2.5 to 2.24 cps, ~10% reduction), however, therate of drainage was
increased by ~70%. Both wires A and Bresponded to the shearing
effect similarly.
At a fixed mixing pressure of 40 psig, as illustrated inFigure
7, the prolonged mixing dramatically increased the rateof drainage.
As the mixing time was extended from 5 to 30,67, and 200 minutes,
the rate of drainage was increased by~90%, 130% and 220%,
respectively. In the meantime, thewhite water viscosity was reduced
from 2.29 to 2.20, 2.05 and1.78 cps, respectively.
In Figure 8, all the data points in Figures 6 and 7 were
com-bined and replotted against the viscosity of white water.
Itclearly indicates that the two sets of data (from Figures 6 and7)
followed a similar trend with respect to the white water vis-
Figure 4EFFECT OF BASIS WEIGHT ON DRAINAGE RATE
(PAM = 165 PPM, DISPERSANT = 2 PPM,AND DEFOAMER = 1 PPM)
Figure 5EFFECT OF BASIS WEIGHT ON DRAINAGE RATE
(PAM = 66 PPM, DISPERSANT = 2 PPM,AND DEFOAMER = 1 PPM)
-
cosity. The two wires A and B, again, responded similarly tothe
mixing effect. The results in Figure 8 indicated that thestrong
mixing (shearing) effect has broken the PAM molecu-lar structures,
resulting in a reduction in flow resistance.
Forming Wire and DrainageAs mentioned earlier, wet process
drainage is a filtration
process and depends on both the characteristics of white
waterchemistry and the structures of a forming fabric. In the
paperindustry, air permeability (AP) and drainage index (DI) are
thetwo parameters that are believed closely related to thedrainage
performance of a forming fabric. Air permeability isan
experimentally determined value that measures the air flowrate in
cubic feet per minute (CFM) per square foot of fabric.
Drainage index, as defined in Eqn. 1, is a calculated value
[16,17] that takes into account for both the structural
parametersand air permeability of a forming fabric.
Where, AP is the air permeability in cubic feet per
minute (CFM) per square foot, Nc is the CD (cross or trans-verse
direction) mesh count, and b, as defined in Eqn. 2, is theCD
support factor on the sheet side.
Although drainage index is usually believed to be a more
accurate prediction for the drainage capability of a
formingfabric on a paper mill, there have been only a few reports
[16,17] that correlated the rate of drainage to drainage index.
Onthe other hand, there have been no known reports thataddressed
how drainage index and air permeability of a form-ing fabric affect
the rate of drainage in a WFGM process. Thefollowing discussion
would provide some interesting results.
Air PermeabilityFigure 9 is a plot of drainage rate versus the
wire air per-
meability under various experimental conditions. The
resultsshown in Figure 9 included pure water, white waters with
dif-ferent PAM concentrations, and fiberglass slurries at
variousconsistencies. The legend water stands for pure water; theWW
for white water with the last three digits representingthe PAM
concentration in parts per million; and the X-Y fora fiberglass
slurry in white water, in which the first number, X,represents the
mat basis weight and the second number, Y, thePAM concentration in
parts per million. For instance, the leg-end WW033 represents a
white water with a PAM concen-tration of 33 ppm, and the legend
1.60-165 stands for a
18 INJ Summer 2001
Figure 6EFFECT OF MIXING PRESSURE ON DRAINAGE.
(CONSISTENCY 0.012%, PAM 165 PPM,DISPERSANT 2 PPM, DEFOAMER 1
PPM,
MIXING TIME 5 MIN.)
Figure 8DRAINAGE RATE VERSUS WHITE WATER VISCOSITY
(CONSISTENCY 0.012%, PAM 165 PPM,DISPERSANT 2 PPM, DEFOAMER 1
PPM)
Figure 7EFFECT OF MIXING TIME ON DRAINAGE.
(CONSISTENCY 0.012%, PAM 165 PPM,DISPERSANT 2PPM, DEFOAMER 1
PPM,
MIXING PRESSURE 40PSI)
(1)
(2)
-
INJ Summer 2001 19
fiberglass slurry that has a PAM concentration of 165 ppm
andwould form a mat of 1.60 pounds/CSF after being dewatered.
Figure 9 indicates that for pure water and the white watersat
various PAM concentrations, air permeability was a goodprediction
for the rate of drainage. The drainage line for purewater and the
four lines for white waters (WW