GMNA-9984835-1991.pdf

m =JOOb379 000491,4 382 GENERAL MOTORS ENGINEERING STANDARDS I Materials and Processes - Paint PRIMER, POWDER, CONDUCTIVE POROSITY SEALING FOR SMC 9984835 1 SCOPE. This specikation covers the requirements for a conductive powder porosity sealing primer for use on SMC plastics. This primer may be applied over in-mold coating or bare SMC. The powder primer shall provide a smooth, adhesion promoting surface which will promote electrostatic application of subsequent coatings. The primer must have the ability to fill minor surface imperfections in the substrate and act as a barrier to prevent popping of topcoats during subsequent bakes. 1.1 This primer is part of a total painted product system and must meet requirements set forth in the specifications for other materials with which it is used This specification shall be used in conjunction with the Approved Paint on Plastics Systems (APOPS), a section of the on-line Materials Specifi- cation file (MATSPC), which lists approved substrate, clean- ing, priming and topcoat combinations. 2 REFERENCED STANDARDS. GM4353M GM4365M GM9523P GM9524P 9984801 ASTM D1921 ASTM D345 1 3 REQUIREMENTS. 3.1 Surface Preparation. Powerwash per 9984801. Any deviation must be approved by the involved GM Paint Engineering Department. 3.2 Application. Apply at dry film thickness as specified per supplier recommendations. 3.3 Bake. Preheat temperatures or bake conditions shall not exceed those identified in Figure 1 of GM4365M. Surface of the part must be within the range of time and temperature specified by the primer supplier for cure. Tie in oven and ambient temperature must be regulated to meet this rquire- ment without exceeding over/under bake specifications. 3.4 Appearance. Must meet the rquirements of GM4353M with the following exceptions: 3.4.1 This primer may be sanded 100% provided that adequate film thickness is retained to ensure porosity sealing characteristics. 3.4.2 Since film build rquirements may differ for powder coatings, the 101 Itm (4.0 mil) limitation is an inappropriate identification of excessive recoats for this technology. 3.5 Performance. This material must meet the requirements of GM4365M with the following modifications: 3.5.1 Supplier shall identify particle sixe and distribution per ASTM D1921. 3.5.2 Mass percent solids and VOC content shall be deter- mined using ASTM D345 1. 3.5.3 For tests 1 through 4 identified in Table 1 and tests 1 through 4.7, and 8 in Table 2 test conditions shall include the following: Normal film / Normal bake (N/N) Lowfilm/Highbake(L/H) High film / Low bake (H/L) Normal film / ELPO bake (N/E) 3.5.4 Solvent Penetration test per GM9524P shall be per- formed at primer thickness specified by the supplier. 3.5.5 The following requirements in GM4365M are not applicable to this specification: 3.1.5 (Viscosity), 3.1.6 (Resi- SiStiVity) 3.6 Conductivity. Conductivity of dried film shall achieve 140 minimum per GM9523P. 3.7 Approval. When testing is satisfactorily completed per the above requirements, approval to this specification will be given. For full specific system approval refer to the QuaMica- tion Procedures Section in the APOPS. 3.8 Sanding. Primed parts may be sanded to remove dirt or minor imperfections. However, all sanding dust must be removed from the parts before shipping. If parts are wet sanded, deionized water must be used for final rinse. 4 SOURCE SHIPMENT RESPONSIBILITY. It will be the responsibility of the supplier to insure that the material is not exposed to temperatures during shipment which would cause the material to fail to meet any of the rerements of this specification. 5 INITIAL SOURCE APPROVAL No shipment shall be made by any supplier until representative initial production samples have been approved by engineering as meeting the requirements of this specification. 5.1 Completed copies of the GM Material Safety Data Sheet and Critical Material Register (available from the engineering department or laboratory), or equivalent, must be submitted with any new submissions or where a composition change has occurred. 6 INSPECTION AND REJECTION. All shipments of material or parts under contract or purchase order manufac- tured to this specification shall be quivalent in every respect to the initial samples approved by engineering. There shall be no changes in either formulation or manufacturing pm permitted without prior notification and approval by engi- neering. Lack of notification by the supplier constitutes grounds for rejection of any shipment. While samples may be taken from incoming shipments and checked for conformance to this specification, the supplier shall accept the responaibii- MARCH 1991 PAGE 1 9984835 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 21:30:07 MDTNo reproduction or networking permitted without license from IHS -,-,- - 900b379 0004915 ,?I,9 1 GENERAL MOTORS ENGINEERING STANDARDS 1 Materials and Processes - Paint 1 PRIMER, POWDER, CONDUCTIVE POROSITY SEALING FOR SMC 9984835 ty for incoming shipments meeting this specification without meeting the requirements of this specification. Sources are dependence upon purchaser s kpection. available through the on-line MATSPC System. 7 APPROVED SOURCES. Engineuing qualification of an approved source .is required for this spui!ication. only 8 GENERAL INFORMATION. This is a newly issued sources listed in the GM Corporate Materials File under this specification approved by the Paint Materials Specitkation specification number have been qualified by engineering as committee in October 1990. 9964835 PAGE 2 MARCH 1991 Copyright General Motors North America Provided by IHS under license with GM Licensee=IHS Employees/1111111001, User=Japan, IHS Not for Resale, 06/23/2008 21:30:07 MDTNo reproduction or networking permitted without license from IHS -,-,-