Thermoplastics product design

Ethylene—Propylene Rubber. Ethylene and propjiene copolymerize to produce a wide range of elastomeric and thermoplastic products. Often a third monomer such dicyclopentadiene, hexadiene, or ethylene norbomene is incorporated at 2—12% into the polymer backbone and leads to the designation ethylene—propylene—diene monomer (EPDM) mbber (see Elastomers, synthetic-ethylene-propylene-diene rubber). The third monomer introduces sites of unsaturation that allow vulcanization by conventional sulfur cures. At high levels of third monomer it is possible to achieve cure rates that are equivalent to conventional mbbers such as SBR and PBD. Ethylene—propylene mbber (EPR) requires peroxide vulcanization. 

MARGOLis, J. M. (Ed.), Engineering Thermoplastics, Marcel Dekker, New York and Basel (1985) Morton-jones, d. h. and Ellis, j. w.. Polymer Products—Design, Materials and Processing, Chapman and Hall, London (1986)... 

Several anthraquinone dyes are used in dyeing thermoplastics such as polymethacrylate, (modified) polystyrene, and polycarbonate. The dyes also are used in combination with titanium dioxide or other materials to provide body colors for the thermoplastics. Initially compounds with relatively simple structures were used, many of them drawn from stocks of existing intermediates. Since then new products designed to satisfy the specific requirements have become available. 

In summary, the final properties of thermoplastic articles depend both on the molecular structure of the polymer and on the details of the fabrication operations. This is a disadvantage, in one sense, since it makes product design more complicated than with other materials that are less history-dependent. On the other hand, this feature confers an important advantage on plastics because fabrication particulars are additional parameters that can be exploited to vary the costs or balance of properties of the products. 

BECK, R. D., Plastic Product Design, Van Nostrand-Reinhold, New York (1970) coLLYER, A. A., A Practical Guide to the Selection of High Temperature Engineering Thermoplastics, Elsevier Advanced Technology, London (1990)... 

Morphology is the study of the physical form or structure of a material (thermoplastics crystallinity or amorphous) the physical molecular structures of a polymer or in turn a plastic. As a result of these structures in production of plastics, processing the plastics into products, and product designs, great differences are found in mechanical and other properties as well as processing plastics. 

In the process of production of rubber articles a lot of trade products designated to spray the working surfaces of the molds is used - ranging from soap solutions to silicone oils. However, these separating substances are not suitable for the production of elastomeric pharmaceutical closures and toys from a soft thermoplastic elastomer [73],... 

When not being used in conjunction with another process, like thermoforming or blow molding, profile extrusions are the variety most often used by product designers. They can be either solid or hollow and, for the most part, are made of thermoplastic materials (although thermoset materials can be extruded with special equipment). Therefore, the effect of nonuniform cooling is precisely the same for extrusion as it is for the molding processes sink and distortion. 

In 2001, PPE/PP alloys were commercialized under the Noryl PPX designation. This new alloy creates a market niche between engineering thermoplastics and high-performance polyolefins. PPE/PP alloys offer product designers materials that fill the gap between the basic properties of high-end polyolefins and the stronger performance characteristics and attributes of engineering thermoplastics. 

Other household environmental problems are presented by the piano keyboard (Fig. 12-2) and the furnace humidifier (Fig. 12-3). Piano keys must be resistant to household chemicals, cleaners, foods, and perspiration. Organs played in night clubs often have melamine keys for improved cigarette resistance. Piano sharps require a scratch resistant material since the player may strike the keys with his fingernails organ sharps can be thermoplastic because the player rolls over the keys. Styrene acrylonitrile (SAN) is commonly used for natural keys and for telephone handsets that encounter the same problems. Bottle caps often crack (Fig. 12-4) when fastened extra tight and craze from exposure to environmental products, conditions, and lost liners. Products designed for laboratory or other use must be tested for their resistance to environmental chemicals as illustrated in Fig. 12-5. 

While virtually every thermoplastic material can be foamed, the specific characteristics that can be attained with microcellular processing (extrusion or injection molding) are very much dependent on the type of material, type of SCF, and the product design. 

Ogorkiewicz, R.M. (ed.). Thermoplastics Properties and Design, John Wiley, New York (1974). Ehrenstein, G.W. and Erhard. G., Designing with Plastics, Hanser [John Wiley] (1984). Morton-Jones, D.H. and Ellis, J.W., Polymer Products Design, Materials Processing, Chapman and Hall, New York (1986). 

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