Fiber reinforcement compounding

Epoxy resins continue to be essential preliminary products for the manufacturing of fiber-reinforced compound materials with glass, carbon or plastic fibers imbedded. As far as their mechanical properties are concerned, they can compete with metal materials, for example, in car manufacturing, boat building and aircraft construction. 

IMMs with the proper screw designs process short or long fiber reinforced compounds. As an example with a suitable machine and... 

Various processes are reported to provide a means to pulsate the melt to improve performance of the extruded product. An example is the Scorim process reviewed in the Injection Molding section in this chapter. A variation in the IM process has been applied to production of reinforced extruded TP pipe. This has been a center of interest, on the argument that a predictable orientation of fiber would considerably increase the pressure resistance of the pipe, without the need to increase wall-thickness (on the analogy of winding a TS resin pipe with continuous filament). The Scorim process combines the extrusion of a fiber-reinforced compound with pressure pulsing around the periphery of the die, which appears to have the effect of orientating the reinforcement. 

The increasing use of plastics with abrasive fillers and reinforcements created a demand for an even more abrasion resistant barrel than the standard iron/boron type. The use of glass fiber reinforced compounds for injection molding has been the single most important factor since a fabricator would be lucky if they could reach 6 months of continuous operation. This need has been successfully answered by the development of liner materials containing metallic carbides such as tungsten carbide and titanium carbide extending their life. 

Long fiber reinforced compounds polyamides. Basic/mechanical/thermal properties ... 

Bos FI, Mussig J, van den Oever M (2006) Mechanical properties of short flax fiber reinforced compounds. Compos A Appl Sci 37(10) 1591-1604 Bose R (1952) A comparative study of the microbiological decomposition of some cellulosic fibers. Sci Cult India 17(10) 435 36... 

For the manufacturing of injection-moldable natural fiber/PP-compounds, the band of the fiber is impregnated by the PP-melt in a continuously running extruder line. The natural fiber reinforced compound is granulated at the extruder exit. Melt compoimding of short-cut fibers has not proved viable because of metering problems with the natural fibers. 

These are only typical values to account for many different grades, molding conditions, product shapes, wall thicknesses, and other variants. The plastics presented are basically unfilled or reinforced. GR refers to glass-fiber-reinforced compounds that usually have 10 to 40 percent, by weight, reinforcement. Other reinforcements, particularly graphite, and different fillers can result in significant different C3.TEs. 

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

For the MI and HI compounds, fibers are added to increase the impact strength. Cotton fibers and paper pulp fibers increase the impact strength of the MI PF by five times. Rayon yard, nylon filament, or glass fibers are used to increase the impact resistance of the HI PF up to a factor of 20. However, the fiber-reinforced compounds suffer from poorer surface finish and they require higher molding pressures. The composition of a typical PF mixture is listed in Table 7.1. ... 

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