Plastic Molding Compounds
|Publication Date:||1 September 2013|
This standard provides a system for specifying significant properties of commonly used plastics, including unpigmented and pigmented, unfilled and filled products. It is intended to apply to resins (not parts) primarily as used in the automotive and related industries. It is also intended to be used either as the sole descriptor of a material or within the body of a specification covering the common standard characteristics required, whereas additional specialized requirements are detailed.
Note: The resin supplier must provide a certification statement meeting the resin requirements per the callout of this standard. This certification must be loaded into the GM Material Specification File (MATSPC).
The material description is based on the principle that plastics should be described, insofar as is possible, in terms of specific performance characteristics desired in the resin, and that an infinite number of such descriptions can be formulated by the use of one or more standard statements (based on standard tests), each designating a quality level of a property or characteristic.
Users of plastic resin can, by selecting different combinations of performance characteristics, specify different combinations of properties desired in various resins.
Possible standard statements are defined in 8.1.
To permit line callout (e.g., designation on a part drawing, in the math data or in a component specification) of the material descriptions mentioned, the system includes a symbol for the general type of plastic resin to be used and a letter-number symbol for each quality level of each property or characteristic.
Example: The complete GMW15702 for an automotive resin might be specified as follows: GMW15702- 120014 >ABS< (A2, A64, BJ730, D113, EM230/216/20, RT3.4, SS52). The callout that is referenced on a part drawing in math data or in a component specification would be GMW15702-120014 or GMW15702-120014 >ABS<
Note: While this cell type format provides the means for close characterization and specification of each property and combination of properties for a broad range of materials, it is subject to possible misapplications since impossible property combinations can be coded if the user is not familiar with available commercial materials.
To prevent this kind of misapplication for plastic resin, it is required that the actual certification data relevant to the specified call out be uploaded to GM MATSPC.
Symbols. The symbol of the plastic resin shall be indicated per ISO 11469, ISO 1043, ISO 18064 and SAE J1344 on the part drawing and/or in the math data file.
Typical Applications. Plastic resins used in the automotive and related industries.