Glass-aramid

Because people everywhere tend to take their fun seriously, they spend freely on sports and recreational activities. The broad range of properties available from plastics has made them part of all types of sports and recreational equipment for land, water, and airborne activities. Roller-skate wheels are now abrasion- and wear-resistant polyurethane, tennis rackets are molded from specially reinforced plastics (using glass, aramid, graphite, or other fibers), skis are laminated with plastics, and so on. 

Short fibre reinforced polyamide E-glass Aramid Carbon... 

Figure 6.10. Glass, aramid and carbon fibre reinforced composites tensile modulus versus tensile strength examples...

SUPreM, Plytron, Quadrax (Gurit Suprem) consolidated tapes or fabrics are made from continuous fibres impregnated with thermoplastic powder. The fibres can be glass, aramid, carbon, steel and the matrices are polyethylene, polypropylene, polyamide, PPS, polyetherimide, PEEK, thermoplastic polyimide, or fluorothermo-plastic. High levels of fibres can be obtained, 65% in volume, for example. 

EMS hybrid yarns or Schappe s preimpregnated yarns are a combination of reinforcing fibres (glass, aramid or carbon) and polyamide 12. 

Pi-Pregs (Porcher Industries), balanced or UD composites, are made of glass, aramid or carbon fibre reinforced thermoplastics (PPS, PEI,TPU, PA 12). 

The reinforcements amenable to RTM are similar to those used for pultrusion, except that they need not be continuous in nature. Thus, E-glass, S-glass, aramid, and carbon fibers are commonly used, as are discontinuous filaments such as wood fiber and polyesters. Even metal and ceramic fibers can be used in this technique. In one method, the preform is fabricated by spraying 12- to 75-mm-long chopped fiber rovings onto a preshaped screen. A binder sprayed with the fibers keeps them in place and holds the preform shape, which is then placed in the mold. 

The standard ASTM D2585 filament wound pressurized bottle test method utilizes a 0.15-m (5.75-in.)intemal diameter filament wound bottle as the test article. This standard test method (with variation in bottle sizes) has been used extensively by the rocket motor industry [47-50] to evaluate glass, aramid, and graphite fiber composite vessel performance. This test method has generally shown good results, but is a relatively expensive test method. Testing of one 0.5-m (20-in.) diameter bottle can cost up to 20K. Other disadvantages are ... 

Also, fibers are controversial. In one currently used handbook, natural, inorganic fibers such as wollastonite or asbestos have been included among fillers whereas other fibers were included in a separate group with only three materials glass, aramid, and graphite. But, mixtures of fibrous and particulate materials are found in many composites today and various natural materials having fibrous structures are considered fillers in technical papers. Again our definition includes these examples. 

If concrete removal is not required or supplementary reinforcing bars cannot be used, external reinforcement can be applied. For instance, steel bars may be encased in a shotcrete layer or steel plates may be bonded onto the concrete surface. Recently, the use of steel plates has been substituted by fibre-reinforced plastics (F. R.P.), that are composite materials with glass, aramide or carbon fibres embedded in a polymeric matrix (usually an epoxy system). F. R.P. are available in the form of laminates or sheets that are bonded to the concrete surface using an epoxy adhesive [11]. They are typically used to improve the flexural and shear strength or to provide confinement to concrete subjected to compression. The... 

Thermoset plastic, Thermoplastic Glass, aramid, carbon, graphite, whisker, metal, etc. Mechanical strength, wear resistance, elevated temperature resistance, energy absorption, thermal stability... 

The generally low-specific gravity and high strength of reinforcement fibers such as glass, aramid, carbon, and graphite can provide other benefits. For example, the toughness of these fibers allows them to be molded into very thin constructions. Each have special characteristics,... 

Roving, spun A heavy low-cost glass, aramid, etc. fiber strand consisting of filaments that are continuous but doubled back on themselves. 

Unit Single Single skin Sandwich Sandwich skin aramid/ aramid/ carbon/ CSM/WR glass glass aramid polyester epoxy epoxy epoxy Strip Framed wood/ aluminum Framed epoxy alloy steel ... 

CSM/WR glass glass aramid wood aluminum Framed ... 

AramidP E-glas Aramid E-glass Aramid E-glass... 

Although this author claims no special expertise in the toxicology of materials, it seems fair to say that the weight of opinion at present is reassuring about fibres in existing use. Glass, aramid and polyethylene fibres are all much safer than asbestos. In common with traditional materials such as wood and cotton, they must always be handled with care, especially if they are finely divided and therefore in respirable forms, i.e. small (<3 pm) diameter short fibres or fine dust. 

The word reinforcement will refer in this book exclusively to strong, stiff fibres. They can be made of glass, aramid (e.g. KevlaT (DuPont)) or high molecular weight polyethylene (e.g. Dyneema (DSM)), carbon/graphite, polyamide (nylon), jute, and so on. The fibres can be long, virtually continuous or short (e.g. 1mm). 

Attention also needs to be paid to the correct selection of the reinforcing fibre if the maximum longevity of the vessel is to be achieved. When reinforcing fibres are mentioned in the chemical process industry, three kinds are concerned glass, aramid and carbon or graphite. For the manufacture of cost competitive corrosion-resistant vessels for use in industry then the selection may be reduced to just one, glass. 

Glass, aramid and carbon fibres are the most commonly applied fibres in polymer-matrix composites. Further fibres composed of boron or basalt... 

Composite reinforcement Polyester, glass, natural cellulosics (e.g. hemp, flax) Glass Glass Glass, aramid, carbon... 

Fibre reinforced polymers (FRPs) are composed of a reinforcement material (glass, aramid or carbon fibres) surrounded and retained by a (thermoplastic or thermosetting) polymer matrix (unsaturated polyester, epoxy, vinyl ester, or polyurethane). FRPs were first used in the rehahiUtation of reinforced or pre-stressed concrete, but they have also been widely used in the reinforcement of timber structures. 

Properties E-Glass S-Glass Aramid Kevlar 49 Graphite Boron... 

Strength fibers can be reduced by hybridization, i.e., by designing composites reinforced with mixed HS-glass/carbon, HS-glass/aramid, or HS-glass/boron fibers. 

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