Painted Plastic Parts Performance Requirements
|Publication Date:||1 May 2019|
Note: Nothing in this standard supercedes applicable laws and regulations.
Note: In the event of conflict between the English and domestic language, the English language shall take precedence.
Purpose. This standard covers organic surface coatings on plastic parts and components used for automotive exterior and interior applications on motor vehicles, for painted components within the engine compartment, and for exterior lighting hardcoat and anticondensation coating.
Applicability. This specification details the performance requirements for applied paints on plastic parts used for either exterior, interior, exterior lighting, or engine compartment applications on motor vehicles. This includes the laboratory test requirements for GM Approved Paint on Parts (APOPS), Validation Testing Complete (VTC), Production Part Approval Process (PPAP) approval, processing conditions, and routine quality control for exterior and interior plastic painted automobile components.
APOPS Approval vs. PPAP Approval. Refer to Figure 1. Prior to producing parts in the production setting, a GM approved substrate and a GM approved paint is specified by GM on part drawings or otherwise to use in making the part. APOPS is intended as detailed review of a new combination of GM approved substrate, GM approved paint, and production paint process for a specific molder/painter. This is accomplished by the GM Materials Engineer with the supplier. An APOPS approval is documented with either:
1. Entry into the GM Materials Approved Source List, reference Section 7.
2. Approval document from GM to supplier.
Typically, the molder/painter may re-use the APOPS approval for an additional new part that has the same substrate/paint/pain
For new combinations of substrate/paint/pain
Raw Material Approvals. This specification applies only to substrate and paint related materials that have been qualified and approved to the appropriate GM specifications.
Substrates. The substrate must be approved to the appropriate GM material specification. For previously unpainted substrates, substrate paintability may be demonstrated per GMW16172 (plaques or parts), or via APOPS testing to the appropriate table:
• Appendix A, Table A1 for exterior applications (including weathering of parts per Appendix A, Table A1).
• Appendix A, Table A2 for engine compartment applications.
• Appendix A, Table A3 for interior trim applications (including paint over chrome).
This plaque testing applies only to the demonstration of the ability of the substrate resin to be painted not the qualification of production parts for paint performance requirements.
Paints. Paints shall be approved to the appropriate GM specification. For exterior topcoat applications, GMW3005 requirements must be met for approval to the appropriate, e.g., 998XXXX paint specification. GMW17434 must be met for all new paint colors when applicable, as specified. For interior paints, the requirements of the applicable GMWXXXXX paint specification must be met.
Paints Without GM Approval. In situations or regions where the paint approval process is new, GMW14797 requirements can be followed for APOPS testing on the part, and then the approval for the paint must be completed. The GM engineer shall work with the paint supplier to fulfill the requirements of GMW3005 for exterior topcoats, GMW17105 for primers for plastics, and the applicable GMWXXXXX for interior paints. The paint would then be approved by GM Engineering and listed in the GM Materials Approved Source List under the appropriate GM 998XXXX or GMWXXXXX specification. Additionally, in the APOPS approval for the part, it must be noted that the GM paint approval is in progress, and estimated date of completion must be included.