Processing reinforcement type

A hard-and-fast rule to be followed by all intending to use plastics is to design for plastics. As an example, for the same-size cross-section the strength of conventional plastics (not the high-performance reinforced types) is considerably less than that of most metals. The designer will thus find it necessary to increase thickness, introduce stiffening webs, and/or possibly use design inserts of various types of threads to secure the proposed product. The process will in some instances also require modification to the shape of the equipment used to produce the product. 

The reinforcement type and form chosen (woven, braided, chopped, etc.) will depend on the performance requirements and the method of processing the RP (Fig. 6-15). Fibers can be oriented in many different patterns to provide the directional properties desired. Depending on their packing arrangement, different reinforcement-to-plastic ratios are obtained (Appendix A. PLASTICS TOOLBOX). 

Patents published in the year 2004 have been analysed by polymer type, reinforcement type, and material structure and process type see Figure 7.4 (a) and (b). 

Fiber reinforced plastic FRP is a term that is usually used as a generic term for all fiber RPs, regardless of process and type of fiber. 

The process of IM is used for reinforced TPs (RTPs) however, it is principally used for (URTPs) and some TSs. IM machines (IMMs) represent over half of all the primary plastic fabricating machines in the world processing all types of plastics and plastic compounds representing just a USA multibillion-dollar business. Figure 5.29 is a simplified version of IM machine (IMM) where plastic flows from hopper, through plasticator (screw-barrel), to mold cavity. 

A processor can produce products whose mechanical properties in any direction are both predictable and controllable. This is done by carefully selecting the resin and the reinforcement in terms of both composition and orientation, followed by the appropriate process. All types of shapes can be produced flat and complex shapes, solid and tubular rods/pipes, molded shapes/housings/complex configurations, structural shapes (angles, channels, box and I-beams, etc.), and so on. RPs can basically produce the strongest materials in the world, as summarized in Fig. 7-2 (1-3, 24, 30-33, 52, 54, 102, 188, 230-266). 

Chen and Lein [26] have described a proprietary process for the manufacture of pultruded hybrid fiber (glass/carbon)-reinforced unsaturated polyester composites. To investigate the effect of reinforcement type and content on the properties, composites with various fiber contents were fabricated. Flexural strength, flexural... 

When a system of interconnected pores in a hardened concrete matrix is filled with a polymer during the impregnation process, another type of reinforcement is created. 

The various types of base materials can be classified by the reinforcement type, the resin system used, the glass transition temperature (Tg) of the resin system, as well as many other properties of the material. With the advent of lead-free assembly processes, properties other than Tg are becoming as important, if not more important when selecting a base material. The decomposition temperature (Ta) is one of these properties and will be defined shortly. 

The concept of hybrid reinforcement consisting of primary and processing fibres was developed in conjunction with asbestos replacement [97,98]. In this case it was difficult to develop synthetic fibres that would simultaneously provide the reinforcing effect and the filtering and solid retention characteristics which are needed in the Hatscheck process. These types of combination were discussed in Section 9.6, dealing with asbestos replacement. 

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