Plastics Handbook

The plastics industry typically categorizes plastic materials by their chemical family and assigns material acronyms with respect to this family. While this is common practice, it does not reflect reality in the plastics industry, because the materials are sold under their trade names, each with a very specific property spectrum. In fact, the trade name is the only criterion for identification (similar to an order number). Standards defining the properties of specific material classes, such as are common practice for metals, have been introduced for thermosetting materials only. The materials within one family typically exhibit a wide range of properties.

Plastics in general have gained significant technological and economic importance alongside metals and ceramics. Globally, plastics represent a larger production volume today than steel or aluminum, thanks to the considerable growth of this material class (Fig. 2.1).

In this chapter we will introduce the characteristic properties of plastics and the testing methods required to determine them. It is our goal to develop and improve a general understanding of this group of materials. Our descriptions will be general and qualitative and the diagrams displaying material characteristics are meant to help gain insight into the behavior of this group of materials. Some tables and figures provide a comparison of selected plastics; however, these comparisons are also only means to foster a general understanding.

The manufacturing of plastic parts includes all forming processes. In general, manufacturing engineering distinguishes between:

Comparisons between different plastic materials will be based on characteristics provided in Table 3.1 in Section 3.1 (see also CAMPUS database or ISO 10350). For example, in general, no values for impact strength will be provided, because these values typically do not contribute significant information to either part design or a part’s load bearing capacity, see also Section 3.3.3. As a general rule of thumb it can be assumed that parts made from resin types with a lower modulus of elasticity and a higher elongation at yield (elongation at break) will be more ductile (tougher) under excessive loads.

Polymers are rarely processed as pure raw materials. More often, a polymer contains several additives to aid during processing, add color, or influence structure, properties, or chemical/aging resistance. These include lubricants, anti-blocking agents, release agents, stabilizers, antistatic agents, electrically conductive additives, flame retardants, colorants, impact modifiers, plasticizers, bonding agents, fillers, and reinforcing and blowing agents. Residuals of these additives as well as of synthesis additives, such as catalysts, emulsifiers, precipitants, curing agents, and accelerators, may remain in the molded component (intentionally or not) and affect its serviceability.

This chapter provides comparisons of the most important properties of plastic materials in table format. When possible, tables and charts referring to specific classes of plastic materials were placed in the respective chapter.