In TS polyester

Table 4.1 Examples of E-glass construction used in TS polyester RPs...

The original development was by Porsche, in 1972, but the mass-production breakthrough was by Ford Europe, molded with fusible core technology by Dunlop Automotive in the UK (subsequently taken over by Siemens). Ford s interest dates back to the 1970s, when it developed a manifold compression molded in TS polyester BMC, but... 

In most GRPs debonding can occur after even a small number of cycles, even at modest levels. If the material is translucent, the buildup of fatigue damage can be observed. The first signs (for example, with glass-fiber TS polyester) are that the material becomes opaque each time the load is applied. Subsequently, the opacity becomes permanent and more pronounced, as can occur in... 

Fig. 2-46 Sequence of push-pull fatigue in unidirectional glass-fiber/TS polyester RPs by mi-crobuckling processes.

Table 3-1 gives typical mechanical property data for four materials, the exact values of which are unimportant for this discussion. Aluminum and mild steel have been used as representative metals and polypropylene (PP) and glass fiber-TS polyester reinforced plastics (GRP) as representative plastics. Higher-performance types could have been selected for both the metals and plastics, but those in this table offer a fair comparison for the explanation being presented. 

These materials, when exposed to continuous high humidity, especially in the presence of an electrical field, hydrolyze into the acid and alcohol precursors from which they are made. The acid plus water present make a conductive material that will cause the material to short the electrical circuit. The process by which the decomposition of the TS polyester takes place is very gradual at first and then accelerates so that extended testing of the material is necessary to be sure that the particular polyester composition used is resistant to hydrolytic degradation. 

The usually reported second largest market for plastics is building and construction consuming about 20 wt%. However, the amount of plastics is only about 5% of all materials consumed in building and construction so that a large growth area exists for plastics when the price is right since then-properties provide durability, performances, insulation, cosmetics, etc. (Fig. 4-5). Different plastics are used that include PVCs, PEs, PMMA, PSs, phenolics, TS polyesters, and many more. Examples of products are listed in Table 4-1. 

In order to simplify the analytical exercise, a particular material was selected for each. The single curved sheet is made of TS polyester fiber glass molded to the shape. The corner supported pan is molded from ABS plastics. The structural foam unit is molded from PP with glass fiber filler. 

The chassis is made from a 1/4 in. sheet of either ABS or TPO vacuum formed into a tub and reinforced with reinforced pultruded glass fiber-TS polyester plastic tubing. The hood and other products are being made from a 20 mm thick sandwich of thermo-formed PPO-alloy skins, glass fabric infused with thermosetting vinyl ester, and a urethane foam core. The bumper and front fascia is thermoformed from a polyolefin elastomer sheet with an UV-resistant cap layer of DuPont s Tediar PVF film. The dash and... 

Test specimens can also be used to simulate some degree of warpage. Figure 5-8 compares unreinforced and reinforced glass fiber-TS polyester flexural-type specimens at different temperatures in a droop test (with a center support), sag test (end supports), and an expansion test (bolted at three points). The study for this particular test is conducted at various temperatures. 

Even though most of the literature on processing specifically identifies or refers to thermoplastics (TPs) as in this book, some thermosets (TSs) are used (TS polyesters, phenolics, epoxy, etc.). The TPs reach maximum heat prior to entering cool mold cavities, whereas the TSs reach their maximum temperature in hot molds (Fig. 6-3). 

The U.S. Navy pioneered in glass-TS polyester RP (hand lay-up) large boat construction with the production of an 8.5 m... 

Figure 8-66 RP (glass fiber-TS polyester plastic) tank trailers are used for hauling corrosive and hazardous materials. In Canada they meet code 312 to operate.

Spray-up Popular system with reinforced plastic production. An air spray gun includes a roller cutter that chops usually glass fiber rovings to a controlled short length before being blown in a random pattern (manually or automatically) onto a surface of the mold simultaneously the gun sprays catalyzed TS polyester plastic. The chopped fibers are plastic coated as they exit the gun s nozzle. The resulting, rather fluffy, RP mass is consolidated with serrated rollers to squeeze out air and reduce or eliminate voids. A closed mold... 

Radome Also called radiation dome. It is a cover for a microwave antenna used to protect the antenna from the environment on the ground, underwater, and in the air (aircraft nose cone, etc.). The dome is basically transparent to electromagnetic radiation and structurally strong. Different materials have been used such as wood, rubber-coated air-supported fabric, etc. The most popular is the use of glass fiber-TS polyester RPs. The shape of the dome, that is usually spherical, is designed not to interfere with the radiation. 

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