Plastic parts design

Brookfield, CT 06804-0403 Series of SPE sponsored seminars and workshops are held in various locations throughout the year. Subjects range from Die Design Principles to Plastic Part Design for Economical Injection Molding. A full range of seminars are also conducted in conjunction with SPE s annual technical conference (ANTEC). http //www.4spe.org... 

Malloy, R. A., Plastic Part Design for Injection Molding, Hanser, 1994. 

Chow, W. W. C., Cost Reduction in Product Design, Van Nostrand, New York, 1978. Malloy, R. A., Plastics Part Design for Injection Moulding An Introduction, Hanser, 1998. Morton-Jones, D. H. and Ellis, J. W., Polymer Products Design, Materials and Manufacturing, Chapman Hall, London, 1986. 

Kagan, V. A., Palley, L, Nanjing, J. Plastics part design Low cycle fatigue strength of glass-fiber-reinforced polyethylene terephthalate (PET). J. Reinforced Plastics Compos. 23 (2004) 15, 1607-1614. 

A projection on a plastic part designed to add strength, facilitate aligmnent during assembly, and provide for fastening. 

Creep modulus n. The total deformation measured at constant load over a period of time divided into the applied stress. Creep modulus, if known, simplifies some plastic part designs by allowing the designer to use standard formulas for deformation in which the creep modulus, for the expected service life under load, replaces the conventional, short-time modulus. 

The basic engineering formulas for structural design can be applied to plastic part design, within the limitations of the data available for the material properties, as previously discussed. This information is widely available and is not particular to plastic part design. Therefore, it will not be covered in this chapter. It is, however, found in Machinery s Handbook, 24th Edition, (Industrial Press Inc., New York) as well as in some of the other references listed at the end of this chapter. 

A plastic part is like a chain in that it will fail first at its weakest link. Repair that, and it will fail at its next weakest link and so on. Therefore, the objective in plastic part design is to see to it that no weak point exists such that the part will fail below its design limit. This requires careful attention to a number of critical areas. 

Plastic part design varies considerably according to the process which will be used to manufacture the part. However, similarities exist for many processes which can be categorized according to the manner in which the part is formed and this fact can be used to better understand the nature of the part. The processes can be categorized according to whether the plastic is built up in layers, stretched into shape, or a mold is filled with liquid or melted resin. 

G. Beall, Plastic Part Design for Economical Iiyaction Molding, Seminar Manual, 1982-2000. 

Paulson, D. C. Plastics Part Design for Injection Molding. Videocassette Education Course, Paulson Seminars Program, 1982. 

In this chapter, several production processes are discussed broadly, outlining the basics of each process, the equipment involved, the plastic materials for which the process is feasible, and some typical products made by each particular process. In addition, the chapter describes important aspects of plastic part design and considers the closely related topic of mold design and construction. 

The design of a plastic part and the selection of the plastics manufacturing process are extremely interdependent it is critical to match the plastic part design to the capabihties of the plastics manufacturing process. For example, a plastic part designed for injection molding will not be interchangeable with a... 

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