1、 WORLDWIDE ENGINEERING STANDARDS General Specification GMW14650 Performance Requirements for Exterior Plastic Parts Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 1 of 10 1 Introduction Note: Nothing in this standard supercedes applicable laws and regulations. Note: In
2、the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Scope. This standard covers the performance requirements of plastic parts used in exterior automotive applications. The parts may be functional assemblies or they may be a subassembly of,
3、 or attached to, metallic, decorative or functional parts. Note: For coated (plated, painted, etc.) parts, not all tests are required. See Table A1 in Appendix A for the specific requirements. Additional requirements for coated or painted plastic parts or parts, which incorporate metals in their con
4、struction, are given in the relevant performance specifications. Note: Some paragraphs reference both GM Worldwide (GMW) test procedures and local test procedures. As soon as the GMW is available, it supercedes the local test procedure. 1.2 Mission/Theme. Not applicable. 1.3 Classification. Not appl
5、icable. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM D523 ISO 4892-1 ISO 7724-1 SAE J1767 ISO 3865 ISO 4892-2 SAE J1545 SAE J2527 2.2 GM Standards/Specifications. 9982223 GMW14093 GMW14688 GMW14914 998222
6、4 GMW14124 GMW14700 L 000 0555 GMW3059 GMW14162 GMW14729 L 000 0556 GMW3221 GMW14334 GMW14864 2.3 Additional References. Component Technical Specification (CTS) Subsystem Technical Specification (SSTS) 3 Test Preparation and Evaluation 3.1 Resources. 3.1.1 Calibration. The test facilities and equipm
7、ent shall be in good working order and shall have a valid calibration label. 3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables as specified in this standard shall be determined correctly with respect to their physical definition. 3.1.3 F
8、acilities. As specified by the relevant test procedure. 3.1.4 Equipment. As specified by the relevant test procedure. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDW
9、IDE ENGINEERING STANDARDS GMW14650 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 2 of 10 3.1.5 Test Vehicle/Test Piece. Unless otherwise specified in the relevant test procedure for the property concerned, either the complete component or a section there from shall be
10、used for test pieces. Unless otherwise specified in the appropriate test procedures, at least three test pieces shall be tested. For test procedures that require a complete component, components shall be randomly selected from a minimum of 50 parts, if not otherwise agreed with responsible Materials
11、 Engineer. 3.1.5.1 Test pieces shall not be tested within 72 h of manufacture. 3.1.6 Test Time. As specified by the relevant test procedure. 3.1.7 Test Required Information. As specified by the relevant test procedure. 3.1.8 Personnel/Skills. As specified by the relevant test procedure. 3.2 Preparat
12、ion. As specified by the relevant test procedure. 3.3 Conditions. 3.3.1 Environmental Conditions. Unless otherwise stated in respective test procedures, all samples shall be conditioned prior to each requirement test to GMW3221, Code A. 3.3.2 Test Conditions. Deviations from the requirements of this
13、 standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 3.4 Instructions. Not applicable. 3.5 Data. As specified by the relevant test procedure. 3.6 Safety. This standard may involve hazardous materials, operations, and equi
14、pment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 3.7 Documentation. Samp
15、les of components or material released to this standard shall be tested for conformity with the requirements of this standard and approved by the responsible GM department prior to the start of delivery of production level components or materials. Any change to the component or material, e.g., desig
16、n, function, properties, manufacturing process and/or location of manufacture requires a new release of the product. It is the sole responsibility of the supplier to provide the customer, unsolicited, with documentation of any change or modification to the product/process, and to apply for a new rel
17、ease. If not otherwise agreed to, the entire verification test shall be repeated and documented by the supplier prior to start of delivery of the modified or changed product. In some cases, a shorter test can be agreed to between the responsible GM department and the supplier. 3.7.1 Test Results. Th
18、e test report shall have the same outline and numbering as this test specification. 4 Requirements and Procedure 4.1 Weather-Ometer Resistance (SAE J2527/ISO 4892-1, ISO 4892-2). Reference Table 1 for exposure limits; a class shall be called out based upon the part application (typical examples are
19、provided). Note: Only for unpainted parts with exposure to direct or indirect sunlight. If the entire part cannot be exposed, the GM Materials Engineer shall determine the location of the test samples. 4.1.1 ISO Procedure. Test as per the conditions of ISO 4892-1 and ISO 4892-2. Inner and outer filt
20、er: Borosilicate. Radiant exposure: 0.50 W/m at 340 nm. Test Program Cam Number seven (7). 102 0.5 minutes light only. 18 0.5 minutes light and spray. Black-standard temperature: +80 C 3 C. 4.1.1.1 Visual Evaluation. Wash weathered specimens prior to making measurements and observations. Wash with s
21、crubbing action, using a sponge that is saturated with a solution consisting of soap and deionized water at +23 C 3 C. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLD
22、WIDE ENGINEERING STANDARDS GMW14650 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 3 of 10 4.1.1.2 Examination with microscope (enlargement: 50x). Test pieces shall show no cracks, no pores or other damages of surface. 4.1.2 SAE International (SAE) Procedure. Test as pe
23、r the conditions of SAE J2527, Method A with extended filters. 4.1.2.1 Inspect per 4.1.1.1 and, if needed, per 4.1.1.2. Table 1: Exposure Limit Guidelines Application Class Note 1 Test Method Radiant Energy Parts exposed to direct sunlight above belt line with large horizontal surfaces (e.g., tonnea
24、u covers, cargo box trim, fascia uppers; step pad or top cap, vinyl roof/simulated convertible, rear end spoilers/horizontal appliqus, decorative decals, emblems, nameplates, ornamentation, anti-chip film). 1 SAE J2527 4500 kJ/m ISO 4892-1 ISO 4892-2 5400 kJ/m Parts exposed to direct sunlight above
25、belt line with midsize horizontal surfaces and parts that have both vertical and horizontal surfaces (e.g., cowl vents, body mounted pillar and license plate appliqus, grilles, wheel opening moldings, ditch moldings, sunroof assembly, roof/luggage racks). 2 SAE J2527 3500 kJ/m ISO 4892-1 ISO 4892-2
26、4200 kJ/m Other parts exposed to direct sunlight above belt line and all parts exposed to direct sunlight below belt line (e.g., body side moldings, lower body claddings, rocker moldings, mud guards, assist steps, glass trim, bumper systems, antenna housing, mirror housing). 3 SAE J2527 2500 kJ/m IS
27、O 4892-1 ISO 4892-2 3000 kJ/m Hidden parts not exposed to direct sunlight. 4 SAE J2527 1250 kJ/m ISO 4892-1 ISO 4892-2 1500 kJ/m Parts with no exposure to direct sunlight. 5 SAE J2527 0 kJ/m ISO 4892-1 ISO 4892-2 Note 1: In case no class is assigned, Class 3 applies as the default standard for the r
28、adiant energy. To ensure timely Production Part Approval Process (PPAP), at the discretion of the responsible GM Material Engineer, surrogate parts or plaques may be weathered instead of actual production parts (Regional Validation timing constraints will dictate this. GMNA requires weathering resul
29、ts at Validation Documentation Complete (VDC), while GM Europe (GME) does not require results until Post Validation Audit (PVA). If allowed, surrogate parts or plaques must have been processed similarly to the production parts (e.g., injection molded, vacuum formed, regrind, etc.) 4.1.3 Requirement.
30、 Exposed parts shall not exhibit any indications of surface tackiness or embrittlement, change in hardness, blooming, blistering or other factors that might affect the function or appearance of the part. 4.1.3.1 Color Change. The color change shall not exceed a Delta E* of 3.0 units (E* 3.0 is allow
31、ed). The color change shall be measured per ISO 7724-1, or SAE J1545 and SAE J1767 (CIELAB color space, 10 degree observer, metering orifice 25 mm, Illuminant D65, SPI (Specular Component Included) or, CIEL*a*b*, D65 illuminant, SPI (Specular Component Included). Visual color change that is consider
32、ed objectionable shall override the Delta E measurement. Part must not exhibit objectionable color change. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEE
33、RING STANDARDS GMW14650 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 4 of 10 4.1.3.2 Gloss Change. On each part, measure gloss per ASTM D523, using 60 degrees geometry. If the 60 degrees gloss of the original, unweathered sample is higher than 70 units, 20 degrees geo
34、metry should also be used to measure the gloss in this area, both before and after exposures. The Gloss retention shall be 80% or greater for Class 1, 75% or greater for Class 2, 60% or greater for Class 3 and 50% or greater for Class 4. Note: This test is only required for smooth high gloss mold-in
35、-color parts. 4.2 Resistance of Material to Heat Ageing. Test pieces shall be exposed for 168 2 h (7 days) in an air circulating oven operating at: Above belt line parts (Class 1, 2, or 3):+ 85 C 3 C. Below belt line parts (Class 4 or 5): + 75 C 3 C. Note: This test is required for all parts, Molded
36、-In-Color, Painted, Hard Coated or Plated. 4.2.1 Requirement. Test pieces shall show no significant surface changes, particularly changes in color or gloss, no embrittlement, increase in hardness, no objectionable shrinkage or other changes detrimental to serviceability. 4.3 Resistance to Temperatur
37、e - Humidity Cycle (Dimensional Stability). Test pieces shall be assembled to jigs or formers so as to simulate as closely as possible actual service conditions. The test setup shall be reviewed by at least one of the following: Design Release Engineer, Validation Engineer or Materials Engineer. The
38、 complete test assembly shall then be subjected to the following test cycle: 4.3.1 The test cycle may be commenced at any of the individual stages provided the full cycle is sequentially completed. This cycle shall be carried out two times without interruption: 17 h 0.5 h at -30 C 3 C. 72 1 h at +85
39、 C 3 C (Classes 1, 2, and 3). +75 C 3 C (Class 4 or 5). 24 h 1 h Humidity (GMW14729). 7 h 0.5 h at -30 C 3 C. 24 h 1 h Humidity (GMW14729). 24 h 1 h at +22 C 3 C. Note: This test is required for all parts; Molded-In-Color, Painted, Hard Coated or Plated. 4.3.2 Requirement. Test pieces shall show no
40、cracking, crazing, appreciable color changes, discoloration, cloudiness, blistering, objectionable shrinkage, and deformation, loss of adhesion to the substrate between layers of the composite or other changes detrimental to serviceability. Test pieces shall comply with the dimensions specified on t
41、he drawing after completion of the test. Recommendation: Checks should be made after each stage of the two (2) cycles. 4.4 Resistance to Humidity. Test pieces shall be exposed for 168 h 2 h humidity (GMW14729). The parts shall be evaluated after conditioning to GMW3221, Code A. Note: This test is re
42、quired for all parts that are produced in a hygroscopic material like Nylon. 4.4.1 Requirement. Test pieces shall show no significant surface changes, particularly changes in color or gloss, or other changes detrimental to serviceability. Test pieces shall comply with the dimensions specified on the
43、 drawing after completion of the test. 4.5 Stone Impact Testing (GMW14700 Method A or B). Note: Only for unpainted parts in direct stone impact area, e.g., grilles, fascias, etc. If part is too small or geometry does not permit a flat surface, plaques can be used. The plaques must have the same or s
44、imilar surface as the original part. Tests shall be conducted on test pieces. In the as-received condition. After resistance of material to heat ageing (see 4.2) and conditioning to GMW3221, Code A. After resistance to temperature cycling (see 4.3) and conditioning to GMW3221, Code A. 4.5.1 Requirem
45、ent. Slight indentation marks caused by impact permissible. No whitening, cracks, or objectionable defects allowed. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWID
46、E ENGINEERING STANDARDS GMW14650 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 5 of 10 4.6 Scratch and Mar (GMW14688, Method A). Note: Only for rigid unpainted parts (stiffness greater than Shore D40) that are visible and the customer can touch. Body trim including, bu
47、t not limited to, fascias, body side moldings, claddings, wheel flares, step pads and pillar appliqus shall be subjected to the Erichson Scratch Test per GMW14688. The test is to be performed on three samples cut from production parts. If part is too small or geometry does not permit a flat surface,
48、 plaques can be used. The plaques must have the same or similar surface as the original part and be molded using the same process. 4.6.1 Requirement. The 10 N loads shall have a Delta L (L) rating of 1.5 or lower. 4.7 Resistance to Sulfur Dioxide Staining and Hydrogen Sulfide Staining (GMW14864). No
49、te: Only for parts near the exhaust system. 4.7.1 Requirement. There shall be no visible change of the surface which was in contact with the reagents. Test pieces shall be examined with the naked eye and the exposed area compared with the surrounding area of the test piece. 4.8 Fuel Resistance. Note: Only for parts near the tank filler i
