GMW3013 |
This specification includes Standard Requirements for GM
Worldwide Material Specifications (numbered GMWXXXXX) that apply to
plastics as well as some comments on requirements for plastic part
performance. It also describes the Plastics Certification Statement
which contains certified property data and other information needed
to write GMW specifications and/or approve molding compounds to GMW
specifications.
Note that only the minimum requirements for the approval of
plastic materials are described herein. The part manufacturer or
material processor reserves the right to specify more requirements
to satisfy their processing needs and quality systems.
The main purpose of this structure of the Standard Requirements
for Engineering Material Specifications is to provide designers,
purchasers and suppliers with a selection of possible alternative
materials for certain applications. The GMW specifications for
plastics shall be preferred in drawings to local specifications
(e.g., QK XXXXXX, GMP.XXX.XXX).
Material Description.
Material Identification. Additional
characteristics, imparted by additives or special chemistry are
indicated by code letters in this specification. While it is
preferred to include these characteristics in the title of GMW
Plastic Specifications, the code letters may be used as part of a
specification call-out, if necessary. Such uses of code letter
suffixes are to appear in alphabetical order (e.g., GMW19P-POM-H
1DZ).
Symbols. For the marking and identification of
vehicle components and materials, the following standards shall
apply:
• ISO 1043-1 Plastics – Symbols - Part 1: Basic polymers
• ISO 1043-2 Plastics – Symbols - Part 2: Fillers and
Reinforcing Materials
• ISO 11469 Plastics - Generic Identification and Marking of
Plastic Products.
For vehicle components and materials having a weight of more
than 100 g, see also GMW3116.
Typical Applications. All plastic material
supplied to GM and included in parts supplied to GM.
Remarks. In GMW plastics specifications,
materials are described by the chemical, mechanical, physical and
other properties of the granules or test specimens manufactured
therefrom.
Particular material types are combined in groups according to
their chemical structure. These groups differ from each other by
their main application, essential additives and characteristic
properties as well as type and content of filler (if
applicable).
|