Short glass fibers commercial composites

For over 35 years, commercial glass fiber manufacture has exhibited continuous growth in volvune to meet increasing demands in the market place for short glass fiber reinforced (SGFR) composites in many... 

A traditional chemical extraction process that uses an alkaline sodium hydroxide solution has also been applied to the same wooden material. Fibers extracted by the two methods have been used as reinforcement for the two commercial polypropylenes the conventional isotactic polypropylene, and maleic anhydride functionalized isotactic polypropylene (iPPMA). The composites have also been subjected to a water absorption treatment. To assess the reinforcement effect of fibers, composite characterization techniques and determination of mechanical properties have been performed with particular attention to the fiber-matrix interfacial characteristic. The results have been compared with those of short glass reinforced polypropylene composites. 

Comparing the Mori-Tanaka s average strain model with experimental data on commercial short glass fiber filled polypropylene composites. 

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). 

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. 

At this point, it should be mentioned that for these two MFC systems, PP/PET and PE/PET, static mechanical test data were obtained only for the compositions 1 1 (by wt), but were compared to those of commercial PP and PE composites containing 30% (by wt) glass fibers. An independent study [50] on the effect of blend composition (30/70, 50/50, 70/30 by wt) of PP/PET and PE/PET blends showed that the respective values of the mechanical parameters (cr, E, and s) differ only slightly (around 20%) between blends containing 50 or 30% (by wt) reinforcing component (PET). In other words, the observed differences in the mechanical behavior of the short GF-reinforced composites (30% by wt) and the MFC systems (with 50 wt% reinforcing component) cannot be explained by the various contents of reinforcement, but are due to the specific characteristics of the MFCs. 

Even though reinforcement efficiency is lower for discontinuous than for continuous fibers, discontinuous and aligned-fiber composites (Figure 16.8ii) are becoming increasingly more important in the commercial market. Chopped-glass fibers are used most extensively however, carbon and aramid discontinuous fibers are also used. These short-fiber composites can be produced with moduli of elasticity and tensile strengths that approach 90% and 50%, respectively, of their continuous-fiber counterparts. 

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