Glass-fiber-reinforced thermoplastic polyesters

Figure 15.1 Glass-fiber-reinforced thermoplastic polyesters applications (numbers represent percentages) [1]...

T. F. Gray, Jr., Properties of a New Glass-Fiber Reinforced Thermoplastic Polyester , 26tA Annual Technical Conference, Reinforced Plastics/Composites Division, Society of the Plastics Industry, Inc., Washington, DC, 1971. 

For TPs, improved chopped strand glass fiber grades for reinforcement of nylon and TP polyester (PET) are from PPG Industries, in response to the increasing use of glass fiber-reinforced thermoplastic RPs, in automotive components especially. They include ... 

The terms reinforced plastics (RP) and composites refer to combinations of plastic materials and reinforcing materials, usually in fiber form (chopped fibers, porous mats, woven fabrics, continuous fibers, etc. see Fig. 7-1). Both thermoset (TS) and thermoplastic (TP) resins are used. When modern RP industry started in 1940, glass-fiber-reinforced unsaturated polyester (TS), low pressure or contact pressure, curing resins were used. Today about 60 percent of the plastics industry uses many different forms of glass fiber-polyester composites. In this chapter the abbreviation RP will be used, and in references to polyester resin it will refer only to TS, as relatively little TP polyester is used in RPs. 

In cavity-compression molding the cold powder or mold material is placed under pressure in a heated mold. The process is also called hot pressing. Glass-fiber-reinforced, unsaturated polyester resins are processed by the heated-cavity-compression molding method. The vulcanization of rubber can also be carried out using this method. High-fidelity records are pressed out of the thermoplasts PVC or poly(ethylene-co-vinyl acetate), while cheaper records are injection molded. 

Thermosets usually provide higher mechanical and thermal properties at a lower material cost than do thermoplastics, more bang for the buck so to speak. However, most of the processes used to fabricate thermoset parts are slower and more limited in design freedom than the thermoplastic processes. Furthermore, the opportunity to utilize 100% of the material which thermoplastics provide is simply not available with thermosets because the regrind cannot be reused. Recycling possibilities are far more limited for thermosets for the same reason. Nonetheless, glass fiber-reinforced thermoset polyester is the material of choice for many outdoor applications in a severe environment such as boats and truck housings. 

Glass-fiber-reinforced thermoplastic Thermoplastic polyester 20 to 35 1.3... 

Some of the common types of plastics that ate used ate thermoplastics, such as poly(phenylene sulfide) (PPS) (see Polymers containing sulfur), nylons, Hquid crystal polymer (LCP), the polyesters (qv) such as polyesters that ate 30% glass-fiber reinforced, and poly(ethylene terephthalate) (PET), and polyetherimide (PEI) and thermosets such as diaHyl phthalate and phenoHc resins (qv). Because of the wide variety of manufacturing processes and usage requirements, these materials ate available in several variations which have a range of physical properties. 

Table 15.2 Selected properties of 30% glass-fiber-reinforced (GFR) thermoplastic polyester composites [15-17]...

POLYCYCLO-ITEXYLENE-Dl METHYLENE TEREPHTHALATE. PCT is 1,4-cyclohexvlene-dimethylene terephthalate and is a high-temperature. semicrystalline thermoplastic polyester. PCT possesses excellent thermal properties. Injection molding is the predominant method of processing glass fiber-reinforced grades of PCT. It is widely used for... 

The matrix in reinforced plastics may be either a thermosetting or thermoplastic resin. The major thermosetting resins used in conjunction with glass-fiber reinforcement are unsaturated polyester resins and, to a lesser extent, epoxy resins. These resins have the advantage that they can be cured (cross-linked) at room temperature, and no volatiles are liberated during curing. 

Thermoplastic saturated polyesters are widely used in synthetic fibers and also in films and molding applications. The production of polyester fibers accounts for nearly 30% of the total amount of synthetic fibers. Unsaturated polyesters are mainly used in glass-fiber reinforced plastic products. 

Chem. Descrip. Decabromodiphenyl oxide CAS 1163-19-5 EINECS/ELINCS 214-604-9 Uses Flame retardant tor thermoplastics and fibers, ind. HIPS, glass-reinforced thermoplastic polyester molding resins, LDPE extrusion coatings, PP (homo and copolymers), ABS, nylon, PBT, PET, PU, SBR latex, textiles, rubber... 

Plastics, particularly polymer-based composites (both thermoplastic and thermoset composites), have been exploited in transportation appUcations for decades. The use of common composites such as glass or carbon fiber reinforced unsaturated polyesters, epoxy, and poly(vinyl ester) matrices is well known. The unique advantage of composites is their strength (tensile strength 4-6 times that of steel) and stiffness, despite their lightweight. 

Phosphinates denoted by the general formula [R -R -P0(=0)] M (M = metal or N H, / ), are efficient fire retardants for engineering thermoplastics such as glass fiber-reinforced polyamides and polyesters. Synergistic effects with nitrogen-containing materials such as melamine have been reported [50, 51]. 

In thermoplastics, carbon fiber compounds have been developed with nylon, polysulfone, thermoplastic, polyester, polyphenylene sulfide, polycarbonate, polypropylene, polyamide-imide, and ethylene/tetrafluoroethylene copolymer. Carbon fiber-reinforced molding compounds are available with carbon fiber contents of various levels such as 20, 30, and 40 weight percent. Nylon 66 molding compounds have also been developed with hybrid combinations of carbon and glass fiber reinforcements. 

The glass-reinforced thermoplastic polyester resins are nnusual in that they are the first thermoplastic that can compare with, or are better than, thermosets in electrical, mechanical, dimensional, and aeep properties at elevated temperatures (approximately 150°C), while having superior impact properties. The glass fiber concentration usually ranges from 10 to 30 percent in commercially available grades. In molded parts, the glass fibers remain slightly below the surface so that finished items have a very smooth surface finish as well as an excellent appearance. 

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