Glass Fiber Polymers

Glass Fiber Polymers & Plastics

Prepared By:Sartaj SinghM.E. – MechanicalUID: 13MME1006

CONTENTS

1) Introduction

3) Glass and fiber structure

4) Information of Glass polymer

5) Information of Fiber Reinforced composite

6) Properties and application of GFRP

7) Literature Review

Introduction Glass Fiber-reinforced polymer (GFRP) (also fiber-reinforced

polymer) is a composite material made of a polymer reinforced with fibers.

The fibers are usually glass, carbon, aramid although other fibers such as paper or wood have been sometimes used.

GFRPs are commonly used in the aerospace, automotive, marine, and construction industries.

FRP also referred to as a fiber-reinforced polymer is a composite material made of a polymer matrix and some reinforcing materials

In FRP, material made up of polymer matrix which is discussed in the next slide:

Plastics : Plastics are synthetic materials, which means that they are artificial, or manufactured. Synthesis means that "something is put together," and synthetic materials are made of building blocks that are put together in factories.

The building blocks for making plastics are small organic molecules - molecules that contain carbon along with other substances. They generally come from oil (petroleum) or natural gas, but they can also come from other organic materials such as wood fibers, corn, or banana peels! Each of these small molecules is known as a monomers because it's capable of joining with other monomers to form very long molecule chains called polymers. The process to do so is called polymerization.

  Crude oil, the unprocessed oil that comes out of the ground, contains

hundreds of different hydrocarbons, as well as small amounts of other materials. The job of an oil refinery is to separate these materials and also to break down (or "crack) large hydrocarbons into smaller ones.

A petrochemical plant receives refined oil containing the small monomers they need and creates polymers through chemical reactions.

A plastics factory buys the end products of a petrochemical plant - polymers in the form of resins - introduces additives to modify or obtain desirable properties, then molds or otherwise forms the final plastic products.

Polymers are everywhere: Plastics are polymers, but polymers don't have to be plastics. The way plastics are made is actually a way of imitating nature, which has created a huge number of polymers. Cellulose, the basic component of plant cell walls is a polymer, and so are all the proteins produced in your body and the proteins you eat. Another famous example of a polymer is DNA - the long molecule in the nuclei of your cells that carries all the genetic information about you.

People have been using natural polymers, including silk, wool, cotton, wood, and leather for centuries. These products inspired chemists to try to create synthetic counterparts, which they have done with amazing success.

Thermoplastics : Plastics are classified into two categories according to what

happens to them when they're heated to high temperatures. Thermoplastics keep their plastic properties: They melt when heated, then harden again when cooled. Thermo sets, on the other hand, are permanently "set" once they're initially formed and can't be melted. If they're exposed to enough heat, they'll crack or become charred.

80% of the plastics produced are thermoplastics and of these Polyethylene, Polypropylene, Polystyrene and Polyvinylchloride (PVC) are the most commonly used (70%).

Thermoplastics Plastics that can be reshaped When ice is heated, it melts. When a thermoplastic object is heated,

it melts as well.

The melted ice can be formed into a new shape, and it will keep that shape when it's cooled. Similarly, a melted thermoplastic object can be formed into a different shape, and it will keep that new shape when it's cooled.

THERMOSETS Just as a raw egg has the potential to become a boiled egg, a fried

egg, and so on, thermosetting polymers have the potential to become all sorts of different objects.

Once an egg has been boiled, however, you can't make it into a fried egg. In the same way, once a thermosetting plastic object has been formed, it can't be remade into a different object.

GLASS[3]

•Insulating material•to form a very strong and light FRP composite material called glass-reinforced plastic (GRP), popularly known as "fiberglass“•not as strong or as rigid as carbon fiber, it is much cheaper and significantly less brittle.

[5]We talk about glass from time to time when we're discussing polymers, especially when we're talking about composite materials. Glass fibers are often used to reinforce polymers. But what is this stuff called glass? We use it with polymers a lot, obviously, but is glass itself a polymer? Before we tackle that question, let's take a look at what glass is. The highest quality glass has the chemical formula SiO2. But this is misleading. That formula conjures up ideas of little silicon dioxide molecules, analogous to carbon dioxide molecules. But little silicon dioxide molecules don't exist.

Fiber-Reinforced Composites [8] Fiber-reinforced composites are composed of axial

particulates embedded in a matrix material. The objective of fiber-reinforced composites it to obtain a material with high specific strength and high specific modulus.  (i.e. high strength and high elastic modulus for its weight.) The strength is obtained by having the applied load transmitted from the matrix to the fibers. Hence, interfacial bonding is important.  

Classic examples of fiber-reinforced composites include fiberglass and wood.

Fiber GeometrySome common geometries for fiber-reinforced composites are discussed in the next slide:

AlignedThe properties of aligned fiber-reinforced composite materials are highly anisotropic. The longitudinal tensile strength will be high whereas the transverse tensile strength can be much less

than even the matrix tensile strength.  It will depend on the properties of the fibers and the matrix, the interfacial bond

between them, and the presence of voids.

RandomThis is also called discrete, (or chopped) fibers. The strength

will not be as high as with aligned fibers, however, the advantage is that the material will be isotropic and cheaper.

WovenThe fibers are woven into a fabric which is layered with the

matrix material to make a laminated structure.

Polymers in Automobiles

Plastics vs. Metals Polymer Applications in Automobiles

- Instrument Panels- Engine- Windows- Tires- Body Panels

Overview

Compete with other materials based on:◦ Weight savings◦ Design flexibility◦ Parts consolidation◦ Ease of fabrication

Why use plastics?

Polymers used

Car Part Polymer

Trim Panels (3) Polypropylene (PP)

Impact Absorber Thermoplastic Olefin (TPO)

Radio Housing ABS/Polycarbonate(PC)

Door Outer Panel ABS/Polycarbonate(PC)

Handle Polypropylene (PP)

Fog Light Cover Thermoplastic ElastomericOlefin (TEO)

Tire Elastomers

Plastic Body Panels - Chevy Corvette since 1953

Body Panels

Sheet Steel - still most commonly used for vehicle body structureAluminum - weighs less but costs morePlastics - increasingly used for metals parts replacement

1. Cost2. Flexural Modulus3. Coefficient of Thermal Expansion4. Chemical Resistance5. Impact Resistance6. Heat Deflection Temperature (HDT)

Choosing a material:

• Better color match• Incorporate in existing facilities• Assembly line temperatures exceed 200oC

Alloys:Polyphenylene ether/polyamide ABS/PolyestersABS/Polycarbonates

• Larger choice in materials• Additional steps take time• More plastics will enter the market as assembly lines are redesigned

Advantage of plastics

PROPERTIES •Low coefficient of expansion•High dimensional stability•High tensile strength•High heat stability•Better abrasion and wear resistance•Better toughness and impact strength

APPLICATIONS•Aerospace•Missile tech•Automotives•High speed machinery•Equipment parts•Coolers•Office cabins•Room insulations

In aerospace industries many of the parts are of glass fiber [9]

car bodies and some parts [10]

In missile work [11] Room insulation [12] In high speed machinery like Quilting machines [13]

LITERATURE REVIEW

Daiane Romanzini VOL . 15 (2012) [L1]

This study aims to verify changes in chemical composition and thermal stability of the ramie fibers after washing with distilled water. One additional goal is to study glass fiber and washed ramie fiber composites focusing on the effect of varying both the fiber length (25, 35, 45 and 55 mm) and the fiber composition. The overall fiber loading was maintained constant (21 vol.%). Based on the results obtained, the washed ramie fiber may be considered as an alternative for the production of these composites. The higher flexural strength presented being observed for 45 mm fiber length composite, although this difference is not significant for lower glass fiber volume fractions: (0:100) and (25:75). Also, by increasing the relative volume fraction of glass fiber until an upper limit of 75%, higher flexural and impact properties were obtained.

Preparation and characterization of ramie-glass fiber reinforced polymer matrix hybrid composites

Christopher Wonderlya, VOL . 36 (2005)

Comparison of mechanical properties of glass fiber and carbon fiber

Glass and carbon fiber composite laminates were made by vacuum infusion of vinyl ester resin into bi axially knitted glass and carbon fiber fabrics. The strengths of the glass and carbon fiber specimens in tension, compression, open hole tension, open hole compression, transverse tension, indentation and ballistic impact were compared. The carbon fiber laminates proved mechanically superior under loading conditions where the strength is mainly fiber dominated, i.e. under tensile loading and indentation. The ratio of the carbon fiber laminate strength to the glass fiber laminate strength, for laminates of equal thickness, was similar to the ratio of the fiber tensile strengths. The glass fiber laminates were equally strong or stronger under loading conditions where the strength is mainly resin dominated, i.e. compressive loading and ballistic impact. In the carbon fiber specimens, the failure was in general more localized and the strengths had more scatter than in the glass fiber specimens.

Sang-Su Ha et al VOL . 34 (2012)

Bond fiber-reinforced polymer bars in unconfined concrete strength of glass

In this study, 35 flexural tests of beams and slabs were carried out to experimentally determine the bond strength of spliced GFRP bars with no transverse reinforcement. The test variables included splice length, cover thickness, and bar spacing. The splice lengths were relatively large to test realistic splice lengths used in the field (longer than 30db in most tests). In addition, four beams with conventional steel rebar splices were also tested to compare theirbond strengths with those of the GFRP bars. Test results showed that the bond strengths of the specimenswith GFRP bars were lower than those of the steel rebars. Although the average bond strength of the GFRPbars decreased with increasing splice length and decreasing cover thickness/bar spacing, the bondstrength of the long splice increased when c/dbP2.5, in which c denotes the smaller of the minimumconcrete cover and 1/2 of the bar clear spacing. Two equations for predicting the average bond strengthof GFRP bars in unconfined concrete are proposed based on the regression analysis of the 33 test results from the beams and slabs that failed by concrete splitting.

Lin Ye et all VOL . 55 (2013)

Effect of Fiber particles on interfacial properties of carbon fiber–epoxy composite

This study assessed the effect of rigid nanoparticles on fiber–matrix adhesion in fiber-reinforced polymer composites by means of a transverse fiber bundle (TFB) test method with the fiber bundle transversely embedded in the middle of the TFB specimens. Fracture surfaces of the TFB specimens were examined by scanning electron microscopy and transmitting electron microscopy to identify dispersion and morphologies of nanoparticles on and near the fiber–matrix interfaces. A finite element analysis was conducted to identify the distribution and magnitude of the thermal residual stresses within the TFB specimen to correlate the TFB tensile strength with the fiber/matrix interfacial strength. The coefficient of thermal expansion and cure volume shrinkage of matrices with different amounts of particles were experimentally evaluated and were included in the FE simulation. Results showed that the addition of nanosilica particles in the epoxy matrix did not noticeably affect the interfacial bonding behavior between fibers and matrix.

A. Kalali, M.Z. Kabir VOL . (19) 2 (2012)

Cyclic behavior of perforated masonry walls strengthened with glass

fiber reinforced polymers

In this experimental study, the cyclic behavior of six, one-half scale, perforated unreinforced brick walls, before and after retrofitting, using Glass Fiber Reinforced Polymers (GFRPs), is investigated. The walls were built using one-half scale solid clay bricks and cement mortar to simulate the traditional walls built in Iran during the last 40 years of the 20th century. These walls had a window opening at their center. One brick wall was unreinforced and considered a reference specimen. Three walls were directly upgraded after construction using GFRPs. The fifth wall was first strengthened and tested. Then, the seismically damaged specimen was retrofitted, using GFRPs, and tested again. Each specimen was retrofitted on the surface of two sides. All specimens were tested under constant gravity load and incrementally increasing in-plane loading cycles. During the test, each wall was allowed to displace in its own plane. The key parameter was the strengthening configuration including the cross layout, grid layout, and combined layout. Strengthening by means of GFRPs significantly improved the strength, deformation capacity, and energy absorption of the brick wall. The increase in performance parameters was dependent upon GFRP layout.

References http://www.nature.com/nmat/journal/v10/n4/fig_tab/nmat2978_F1.html http://www.pslc.ws/macrog/glass.htm http://www.nobelprize.org/educational/chemistry/plastics/readmore.html http

://fog.ccsf.cc.ca.us/~wkaufmyn/ENGN45/Course%20Handouts/14_CompositeMaterials/03_Fiber-reinforcedComposites.html

http://www.iqnet-certification.com/userfiles/Airbus%20.jpg http://web-cars.com/images/vette_img/early_corvette-grp_a.jpg http

://images.defensetech.org/wp-content/uploads/2013/11/anti-ship-missile-490x326.jpg

http://static.guim.co.uk/sys-images/Guardian/Pix/commercial/2009/11/4/1257352337770/R38-Fiberglass-Insulation-001.jpg

http://www.abminternational.com/images/galleries/xl-6000r-single-needle-quilting-machine/xl-6000r-photos/xl-6000r-single-needle-quilting-machine-04.jpg

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