Fiberglass

Fiberglass

a.k.a.Glass-reinforced plastic (GRP)

Glass-fiber reinforced plastic (GFRP)

HistoryAncient Egyptians and Phoenicians are among the many civilizations who produced small amounts of coarse glass fibers for decoration

1870 - John Player developed a method for mass-producing glass fibers with a steam jet process. It was used for insulation.

1880 – Hermann Hammesfahr was awarded a patent for a fiberglass cloth interwoven with silk

Source: http://chemsrv1.uwsp.edu/fire/FireCD/macrog/mpm/composit/fiber/fibeglas/history.htm

History

Present

1942 – Owens-Corning were already producing fiberglas and polyester airplane parts

1937 – Ray Greene, working with Owens-Corning produced a sailboat w/ polyester resin/fiberglass composite

Source: http://chemsrv1.uwsp.edu/fire/FireCD/macrog/mpm/composit/fiber/fibeglas/history.htm

Dale Kleist, working for Corning Glass, accidentally discovered an easy method to create fiberglass: when a jet of compressed air hit molten glass. In 1936, the companies Corning Glass and Owens-Illinois patented the product “Fiberglas”

Carlton Ellis of Du Pont was awarded a patent for polyester resin.

Present Age Application

Pool

Window

Tanks

Present Age ApplicationCar door

Cow

Insulators

Roofing

Acoustic wall

Submarine Hull

Present Age Application

• Fiber sheets

Fiberglass

• Composite material using resin as matrix and glass fiber as reinforcement

GLASS FIBERReinforcement

Glass Fiber

• Properties– Mechanical Properties• similar to glass but different strength value

– Chemical Stability• Susceptible to alkaline solutions and hot water

– Thermal Properties• High heat resistance

– Electrical Properties• insulator

Source: http://www.umaine.edu/adhesion/gardner/5502002/glass%20fibers.pdf

Return to Contents Next: Processing

Glass Fiber Processing

Batching

Melting

Fiberization

Source: http://www.madehow.com/Volume-2/Fiberglass.html#b

Coating

Drying

Raw Materials

PackagingNext: Raw MaterialsReturn to Contents

Glass Fiber ProcessingRaw Materials

• Major– Silica – Glass former– Limestone – Soda Ash – Lowers mt.

pt. w/ limestone– Waste glass – a.k.a.

cullet

• Others– Calcined Alumina– Borax– Feldspar– Magnesite– Etc.

Source: http://www.madehow.com/Volume-2/Fiberglass.html#b

Next: BatchingReturn to Contents

Glass Fiber ProcessingBatching

• Batching - exact quantities of raw materials are mixed together before being melted.

• Materials are added to lower the working temperature and add additional properties.

• Some properties of other components:– Al2O3, CaO, MgO – alkali-resistant

– B2O3 – increase Tmelting - Tcrystalline

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

Glass Fiber ProcessingBatching

• E-glass (Electrical resistance)– Contains Al2O3, CaO, MgO, and B2O3

• S-glass (Strength)– Contains Al2O3, MgO, and B2O3 and significantly more

SiO2

• C-glass (Chemical resistant)– Large content of B2O3

• A-glass (Alkali resistant)– No content of B2O3

Next: Melting

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

Return to Contents

Glass Fiber ProcessingMelting

• Common furnaces has three sections:– “Receiver”• The batch is melted and uniformly. Bubbles are also

removed• High temperature (1400oC or 2552oF)

– Refiner• High temperature (1370oC or 2500oF)

– Forehearth – beneath this is are bushings

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

Glass Fiber ProcessingMelting

• Three approaches to melting– Indirect melt – a.k.a. marble remelt• Molten glass is sheared and rolled into marbles w/

diameter of 0.62 inch (15-16 mm), then cooled and packaged to a fiberization process.• Useful for outsourcing

– Large-scale direct melt• 8000-100000 tons per year

– Small-scale direct melt – a.k.a. paramelters• 150 to 200 metric tons per year

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

Next: FiberizationReturn to Contents

Glass Fiber ProcessingFiberization

• Extrusion – Extruded through 200-

8000 bushings made of Pt-Rh alloy

– Bushings are heated electronically to maintain T (1204oC/2200oF) and consequently, glass viscosity and thickness

• Attenuation– Drawing extruded

molten glass into filaments using high-speed winder (tangential speed of ~2miles/~3km per minute)

– High-speed winding applies tension

– Diameter 4m to 34m

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

*Varying cooling process change the form of the fiber

Glass Fiber ProcessingFiberization

Next: Coating

Molten glass flowing through bushings

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

Back to Glass Fiber Processing

Glass Fiber ProcessingCoating

• A.k.a. Sizing• 0.5-2% (w/w)• 3 common types:– Lubricants – Protect filaments from abrading and

breaking– Binders – binds resin to glass fiber– Coupling agents – increase affinity for specific

resins

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

Back to Glass Fiber Processing Next: Drying

Glass Fiber ProcessingDrying

Sized filaments are collected

The strand is wound onto a drum

Dried in an oven

Source: http://www.compositesworld.com/articles/the-making-of-glass-fiber

Glass Fiber ProcessingDrying

• Collection of sized filaments– Strands• produce twine-like strands

– Winders• produce balls or “doffs”• Used in attenuation

– Creel• produce multi-end products

Back to Glass Fiber Processing Next: Packaging

Source: http://www.umaine.edu/adhesion/gardner/5502002/glass%20fibers.pdf

Glass Fiber ProcessingPackaging

• Continuous-filament– Rolled in drums and formed into yarns

• Staple-fiber– while cooling, jets of air break filaments into

lengths of 8-15 inches

Source: http://www.madehow.com/Volume-2/Fiberglass.html#b

Glass Fiber ProcessingPackaging

• Chopped fiber– Yarns are chopped into short, uniform lengths

• Glass wool– Cooling involves a downward jet of (hot) air,

making the fibers fall randomly onto a conveyor belt, forming a fleecy mass

Back to Glass Fiber Processing

Source: http://www.madehow.com/Volume-2/Fiberglass.html#b

Next: Resins

RESINSMatrix

Resins

• Three major types of resin: Polyester, Epoxy, and Vinyl, all of which are thermosets.

Return to Contents Next: Properties

Resin Properties

• Polyester– Permeable to moisture– Stable– For light-weight objects– Cure time ~20-30 min.– Lower cost than epoxy

Source: http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Student%20Presentations/Glass-reinforced%20Plastic.pptx

Resin Properties

• Epoxy– Moisture resistant– Superior reliability, properties, and lifespan– Withstands more extreme conditions (acid, heat)– Can bond dissimilar materials– High tensile strength– More flexible– Variable cure time

Source: http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Student%20Presentations/Glass-reinforced%20Plastic.pptx

Resin Properties

• Vinyl– Combined properties of Unsaturated Polyester

and Epoxy– Easy to handle at room T– Better chemical resistance– Greater corrosion resistance– Greater cure rate control– Cheaper than epoxy, but more costly than

polyestersNext: Processing

Source: http://scholar.lib.vt.edu/theses/available/etd-42198-113329/unrestricted/ch1.pdf

Return to Contents

Resin Processing

• Essentially polymerization in a large scale

Next: Raw Materials

Raw Materials

Polymerization

Processing

PurificationReturn to Contents

Resin ProcessingRaw Materials

Polyester• Glycols

– Propylene glycol – low cost, balanced properties

– Bisphenol A/PG – good chemical resistance, high heat deflection T

• Acids/anhydrides– Unsaturated acids/anhydrides– Saturated acids/anhydrides

Epoxy• Alkaline catalyst(amine or

NaOH)• Bisphenol A• Epichlorohydrin• Solvent• Water

Source: http://processflowsheets.blogspot.com/2011/05/epoxy-resin-manufacturing-process.html

Source: http://www.umaine.edu/adhesion/gardner/5502002/polyester%20resins.pdf

Resin ProcessingRaw Materials

• Vinyl esters– There are various ways to produce vinyl esters,

usually of resins and unsaturated acids• Addition products of epoxide resin and ethylenically

unsaturated monocarboxylic acids• Glycidyl methacrylate + multifunctional phenol (e.g.

Bisphenol-A)

Source: http://scholar.lib.vt.edu/theses/available/etd-42198-113329/unrestricted/ch1.pdf

Next: PolymerizationReturn to Contents

Resin ProcessingPolymerization

Polyester EpoxySource: http://chem.chem.rochester.edu/~chem424/epoxy.htm

Source: http://www.umaine.edu/adhesion/gardner/5502002/polyester%20resins.pdf

Resin ProcessingPolymerization

• Vinyl

Source: http://scholar.lib.vt.edu/theses/available/etd-42198-113329/unrestricted/ch1.pdf

Next: PurificationReturn to Contents

Resin ProcessingPurification

• Evaporators and phase separators in the processes separate the final resin from unreacted reactants and unwanted brine.

Next: ApplicationReturn to Contents

ResinsApplication to Glass Fibers

Polyester• Hardening catalyst (methyl

ethyl ketone peroxide, or MEKP) with a very low ratio (few drops per ounce of resin)

• Mixed with some wax - wax rises as resin cures

• Open surface must be facing up

• Wax is removed afterwards

• Exothermic

Epoxy• Varying hardening catalyst

type and ratio, depending on type of epoxy (common ratios are 1:1, 3:1, 4:1)

Source: http://centralfloridafieros.com/forum/index.php?topic=149.0;wap2

Source: http://centralfloridafieros.com/forum/index.php?topic=149.0;wap2

ResinsApplication to Glass Fibers

• Vinyl Esters– Ideally catalyzed by triphenylphosphine, but can

cure by itself– Requires diluents (e.g. styrene)• Usually composed of 40-50 wt. % styrene

Next: FiberglassReturn to Contents

FIBERGLASSCombining the resin and glass fiber

Source: http://www.youtube.com/watch?v=dEhSaFfaSKg

Fiberglass – the ComboStrength: High Tensile and Compressive strengthWeakness: Shear

Strength: ElasticWeakness: Low stiffness

Fiberglass

• Common types of fiberglass products– Roving• long and narrow bundle

Source: http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Student%20Presentations/Glass-reinforced%20Plastic.pptx

Fiberglass

• Common types of fiberglass products– Chopped Strand Mat• Short strands piled randomly isotropic strength• Least expensive• Versatile• Soaks up the most resin waterproof

Source: http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Student%20Presentations/Glass-reinforced%20Plastic.pptx

Fiberglass

• Common types of fiberglass products– Cloth • cross-hatch pattern bidirectional strength• Requires least amount of resin• Not waterproof• More expensive than mats• Great strength but low stiffness

Source: http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Student%20Presentations/Glass-reinforced%20Plastic.pptx

Fiberglass

• Common types of fiberglass products– Woven Roving• bidirectional interweaving of rovings, thicker than cloth• For large applications• Uses large strands

Source: http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Student%20Presentations/Glass-reinforced%20Plastic.pptx

Fiberglass

• Common types of fiberglass products

– Pultruted• Pultrusion process: Roving is pulled through a resin to

saturate glass. A die shapes the fibers while heat is applied to set the fibers and resin. Finished pieces are cut to desired size.

Source: http://www.ce.sc.edu/deptinfo/members/faculty/ray/web1/Ugrad/ECIV%20303/Student%20Presentations/Glass-reinforced%20Plastic.pptx

Return to Contents

Fiberglass ProcessingMolding

Plug

Mold release agent

Gelcoat

Lay-up

Cure

Removal from mold

Finish

Source: http://www.clubkitclearcote.com/instructions/Hand%20Layup.pdf

Fiberglass ProcessingMolding

• Plug– Object with desired shape– Can be formed with foams, wood, plaster, etc.

• Mold– Supports glass fibers during resin curing

• Mold release agent– E.g. Polyvinyl alcohol

• Gelcoat – Pigmented resin, harder, more durable finish– Followed by a coating of a fiberglass

Source http://centralfloridafieros.com/forum/index.php?topic=149.0;wap2

Fiberglass ProcessingMolding

• Lay-up– Hand lay-up• Hand pressure/vacuum/rollers used to ensure even

resin application

– Spray lay-up• Resin and reinforcements are sprayed onto the vertical

mold

– Vacuum bag• Fiber and resin are sucked to conform to the mold using

a vacuum

Source: http://www.clubkitclearcote.com/instructions/Hand%20Layup.pdf

Fiberglass ProcessingMolding

• Cure– Longer curing time = greater shrinkage

• Removal from mold• Finish

Source: http://www.clubkitclearcote.com/instructions/Hand%20Layup.pdf

Return to Contents

Fiberglass

End