Unreinforced thermoplastics, propertie

Best property balance Stiffest unreinforced thermoplastic Low friction Nylon... 

Table 9.25 Properties of thermoset and thermoplastic/glass fiber RPs (SMCs. BMCs, etc.) and unreinforced thermoplastics...

The primary advantages of LFTs are their superior mechanical properties and reduced tendency to creep (Bartus et al., 2006), compared to unreinforced thermoplastics, and ability to fill complex geometries, corrosion resistance and low weight, compared to metals. 

TABLE 12-4 Comparison of Unreinforced and Reinforced Thermoplastics Properties... 

Fig, 3-21 shows the variation of 100-s 0.5% tensile secant modulus with temperature. The results indicate the significant improvement in properties by reinforcing the polymer matrices with glass fibers. The stiffness between reinforced and unreinforced thermoplastics remains fairly constant over the temperature range fi om 20 to 100 C. The most outstanding thermoplastic material in terms of stiffness is the 30% glass-filled Noryl (J). 

Injection moulding has been briefly described in Chapter 8. The use of filled materials does not significantly effect the moulding process although higher barrel temperatures and greater injection pressures may be required. Table 7 compares the properties of some reinforced and unreinforced thermoplastics and illustrates how the presence of reinforcing fibre improves most of the mechanical and physical characteristics of polymers. 

Polyester polyols, 25 464 468 Polyester resin(s), 11 302 coating resins, 7 104-106 cyclopentadiene and dicyclopentadiene applications, 8 230 flammability of, 20 115-116 properties in powder coating, 7 43t standard test methods for, 20 11 It unreinforced, 10 187t weathering of, 20 116 Polyester resin-based powder coatings, organic titanium compounds in, 25 125 Polyester resin composites, 26 762-763 Polyester resin formulations ingredients of, 20 96t unsaturated, 15 511-512 Polyesters, 10 185-189, 497 12 655-656. See also Thermoplastic polyesters Unsaturated polyesters acid resistance of, 20 7-8 antioxidant applications, 3 121 aromatic ionic, 23 722 based on 1,4-cyclohexanedimethanol, 12 674-675... 

The characteristics of the three most common thermoset resin systems used in pultrusion are compiled in Table 11.2 [3]. It is noteworthy that unreinforced polyesters and vinylesters shrink 7-9% upon crosslinking, whereas epoxies shrink much less and tend to adhere to the die. These epoxy characteristics translate into processing difficulties, reduced processing speed, and inferior component surface finish. It is normal practice to use resin additives to improve processability, mechanical properties, electrical properties, shrinkage, environmental resistance, temperature tolerance, fire tolerance, color, cost, and volatile evaporation. It is normally the resin, or rather its reactivity, that determines the pulling speed. Typical pulling speeds for polyesters tend to be on the order of 10-20 mm/s, whereas speeds may exceed lOOmm/s under certain circumstances. Apart from the resins characterized in Table 11.2, several other thermosets, such as phenolics, acrylics, and polyurethanes, have been tried, as have several thermoplastics (as will be discussed in Sec. 11.2.6). 

Table 9.24 Property guide for unreinforced and reinforced thermoplastics and thermosets vs. metals...

Chapter 11 contains mechanical and electrical data on hundreds of plastics in tabular form. These data are described in the standard ISO 10350-1 1998, which is titled Plastics—Acquisition and Presentation of Comparable Single-point Data— Part 1 Moulding Materials. This standard ISO 10350 identifies specific test procedures for the acquisition and presentation of comparable data for many basic properties of plastics. The properties included are often in manufacturers technical data sheets. All the data are defined by ISO standards rather than ASTM standards. Part 1 applies to unreinforced and reinforced thermoplastic and thermosetting materials. While similar ASTM standard-... 

TABLE 28.2. Physical properties of most used unreinforced thermosets and thermoplastics. 

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