Glass flexural modulus, comparison

Figure 6-57. A flexural modulus comparison of three glass-fiber-reinforced compounds. 

As a further comparison, the flexural modulus of glass-filled polyphenylene sulfide at 450° F is about 10 times that of unfilled polytetra-fiuoroethylene at room temperature. These data illustrate the outstanding retention of stiffness of this material at elevated temperatures. The heat-deflection temperature of polyphenylene sulfide containing 40% glass fibers is greater than 425°F, accounting for the excellent retention of mechanical properties at elevated temperatures. 

Figure 7.6 Comparison of flexural modulus of glass fiber reinforced engineering thermoplastics. Data on the unfilled resins are included for comparison. (To convert from psi to Pa multiply by 6895.)...

Inspection of the data in Table 6.7 reveals that in absolute terms the flexural moduli of the common structural metals aluminium and steel are respectively 7 and 20 times greater than their present glass-reinforced polymer competitors. When a comparison is made of the specific flexural modulus property, then the difference between the metals and structural plastic reduces to about 3 5 times. For example, steel is about three times stifler than polycarbonate. Exceptionally, however, glass-filled EPDM and RIM urethane still have specific modulus properties of approximately 20-65 times less than the reinforced hard plastic resins and metals. Therefore, as a simple material replacement comparison, for a RRIM urethane or glass-filled EPDM, to replace a metal component and maintain the same stiffness inevitably means using a much greater volume of polymer... 

A comparison of the properties of surface-treated phlogopite mica with talc, calcium carbonate, glass, and the unfilled resin is given in a technical bulletin produced by Marietta Resources International, Ltd. (10). Table 14.7 shows that 40 wt% mica-filled polypropylene (Profax 6523) had a higher flexural modulus than 30 wt% glass fiber-filled polypropylene (1.04 X 10 psi versus 0.93 X 10 psi). The compound filled with 40 wt% surface-modified mica also had higher Izod impact than the 40 wt% talc-filled compound (0.65 versus 0.45 ft-lb/in). 

Tensile and flexural moduli of thermoplastics are dramatically increased with glass reinforcement as shown in Table 3-1. Three- to five-fold increases in flexural modulus can be readily obtained in thermoplastic resins with the addition of glass fibers. Flexural modulus values to 1,300,000 psi can be realized with the addition of 30% glass fibers to 6/6 nylon. The flexural modulus data comparison is presented to demonstrate the ability of glass fibers to increase dramatically the rigidity of a series of thermo-... 

In Table 3, a comparison is made between two levels of chemical coupling for flexural strength, modulus and fatigue data at 20 and 40wt% fiber glass levels. The mega coupled SGFR polypropylene (FT)... 

From comparison of mechanical properties of the roving and fabric composites it is clear that, fabric composites were more brittle and less anisotropic than roving composites, with almost 3-times lower flexural strength and 5-times higher shear modulus. Note that fabric composites contained lower amounts of fiber. It is also seen that. E-glass fabric composites were more brittle than basalt ones. 

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