Thermoplastics and Short Glass Fibers

Lightweight reinforced thermoplastics materials with great strength and stiffness are needed in a number of so-called technical applications. Therefore short glass fibers are used to stiffen thermoplastics, for instance polypropylene, polyamides and also more technical polymers such as polybutylene terephthalate. Thermoplastic processors do not compound themselves their materials and consequently there is quite a large choice of ready-to-be-processed SGF reinforced thermoplastic composites. Table 7.6 gives the average properties of typical commercial PP-SGF composites, as compiled from manufacturers data sheets (when available). 

As can be seen, the hardness, the tensile and flexure properties and the thermal resistance (HDT, Vicat) generally increase with higher fiber loading, with however a large scatter that likely reflects the various grades of polypropylene used, as well as (unknown) differences in compounding processes. E-glass fibers are the most common type but the actual fiber dimensions are 

Mechanical properties of commercial polypropylene-short glass fibers composites squares are averaged suppliers data the vertical bars indicate the standard deviations shaded diamonds are data from one single manufacturer the curves were calculated with the modified Guth and Gold equation, using an anisometry factor equal to 4.5. 

Impact resistance of commercial short glass fibers-filled polyamides. 

Flexural and tensile moduli of commercial SGF-filled polyamide 6 composites compared with the predictions of the Ffalpai-Tsai model. 

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