Reinforced plastics materials properties/processes

Table C.6 Typical properties of copper cold laminate. (Ref Sanyson, R.N., Laminate and Reinforced Plastic Materials and Processes, Handbook of Plastics, Elastomers, and Composites, 3rd ed., C.A. Harper (Ed.), McGraw-Hill, New York, 1996)... 

When a component is manufactured ffom a reinforced plastic, the forming process does more than simply shape the component it also positions the reinforcing particles, and fixes their orientation. This results in an important characteristic of a reinforced polymer its structure usually has directionality, and it shows anisotropy in its physical properties. Moreover, the material is usuaUy inhomogeneous, as the particle orientation and even degree of reinforcement may vary from point to px)int throughout a component. 

This guide provides properties tabulated for unfilled, filled, and reinforced plastic materials that are suitable for all methods of processing into parts. This standard is required to reduce the growing number of material specifications and the paperwork and manhours needed to ensure that parts of known quality are being produced from commercially available materials. The D 4000 standard will eliminate the many certifications required for the same material that a processor might have to obtain from several vendors for one or more customer s. 

Thermosetting unsaturated polyester resins constitute the most common fiber-reinforced composite matrix today. According to the Committee on Resin Statistics of the Society of Plastics Industry (SPl), 454,000 t of unsaturated polyester were used in fiber-reinforced plastics in 1990. These materials are popular because of thek low price, ease of use, and excellent mechanical and chemical resistance properties. Over 227 t of phenoHc resins were used in fiber-reinforced plastics in 1990 (1 3). PhenoHc resins (qv) are used when thek inherent flame retardance, high temperature resistance, or low cost overcome the problems of processing difficulties and lower mechanical properties. 

A wide variety of thermoplastics have been used as the base for reinforced plastics. These include polypropylene, nylon, styrene-based materials, thermoplastic polyesters, acetal, polycarbonate, polysulphone, etc. The choice of a reinforced thermoplastic depends on a wide range of factors which includes the nature of the application, the service environment and costs. In many cases conventional thermoplastic processing techniques can be used to produce moulded articles (see Chapter 4). Some typical properties of fibre reinforced nylon are given in Table 3.2. 

Pultrusion [PHENOLIC RESINS] (Vol 18) [PLASTIC PROCESSING] (Vol 19) [REINFORCED PLASTICS] (Vol 21) [COMPOSITEMATERIALS - SURVEY] (Vol 7) resin properties required for [COMPOSITE MATERIALS - POLYMER-MATRIX - THERMOSETS] (Vol 7)... 

The materials being reviewed in this book, as in the industry, are identified by different terms such as polymer, plastic, resin, elastomer, reinforced plastic (RP), and composite unreinforced or reinforced plastic. They are somewhat synonymous. Polymers, the basic ingredients in plastics, can be defined as high molecular weight organic chemical compounds, synthetic or natural substances consisting of molecules. Practically all of these polymers are compounded with other products (additives, fillers, reinforcements, etc.) to provide many different properties and/or processing capabilities. Thus plastics is the correct technical term to use except in very few applications where only the polymer is used to fabricate products. 

Filament winding (FW) is a fabrication technique for forming reinforced plastic parts of high strength/modulus and lightweight. It is made possible by exploiting the remarkable strength properties of their continuous fibers or filaments encased in a matrix of a resinous material. For this process, the reinforcement consists of filamentous non-metallic or metallic materials processed either in fibrous or tape forms.488 489... 

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