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The onset of thermal degradation dictates the maximum temperature at which a polymer can be used. It is an important limitation in how the polymer is manufactured and processed. For instance, polymers become less viscous at higher temperatures which makes injection moulding easier and faster, but thermal degradation places a ceiling temperature ...
Polybenzimidazole (PBI, short for poly[2,2’-(m-phenylen)-5,5’-bisbenzimidazole]) fiber is a synthetic fiber with a very high decomposition temperature. It does not exhibit a melting point, it has exceptional thermal and chemical stability, and it does not readily ignite. [1]
PTFE is a thermoplastic polymer, which is a white solid at room temperature, with a density of about 2200 kg/m 3 and a melting point of 600 K (327 °C; 620 °F). [26] It maintains high strength, toughness and self-lubrication at low temperatures down to 5 K (−268.2 °C; −450.7 °F), and good flexibility at temperatures above 194 K (−79.15 ...
Injection moulding is widely used for manufacturing a variety of parts, from the smallest components to entire body panels of cars. Advances in 3D printing technology, using photopolymers that do not melt during the injection moulding of some lower-temperature thermoplastics, can be used for some simple injection moulds. An injection moulding ...
Atactic polypropylene has lower density, melting point and softening temperature than the crystalline types and is tacky and rubber-like at room temperature. It is a colorless, cloudy material and can be used between −15 and +120 °C.
Thermoplastic composites (TPCs) are a class of composite materials that consist of a thermoplastic polymer matrix reinforced with fibers such as carbon, glass, or aramid. Unlike thermoset composites, which undergo irreversible curing, thermoplastics can be melted and reshaped multiple times, making them more recyclable and repairable.
Melting zone (also called the transition or compression zone): most of the polymer is melted in this section, and the channel depth gets progressively smaller. Metering zone (also called the melt conveying zone): this zone melts the last particles and mixes to a uniform temperature and composition.
Polymer degradation is the reduction in the physical properties of a polymer, such as strength, caused by changes in its chemical composition.Polymers and particularly plastics are subject to degradation at all stages of their product life cycle, including during their initial processing, use, disposal into the environment and recycling. [1]