1、 WORLDWIDE ENGINEERING STANDARDS General Specification GMW15725 Performance Requirements for Engine Compartment Plastic Parts Copyright 2013 General Motors Company All Rights Reserved September 2013 Page 1 of 7 1 Introduction Note: Nothing in this standard supercedes applicable laws and regulations.
2、 Note: In 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 decorative plastic parts used in engine compartment automotive applications as well as applications near the exhaust
3、system. The parts may be functional within themselves or they may be a subassembly of, or attached to, metallic, decorative or functional parts. Note: Additional requirements for coated or painted plastic parts (e.g., emblems, painted engine covers) are given in the relevant performance specificatio
4、ns, not by this specification. Note: All materials used in parts or components in contact with the air of the interior compartment must additionally conform to the interior requirements as specified in GMW14444, Code E. 1.2 Mission/Theme. This standard provides the standard material performance requ
5、irements for decorative plastic parts in the engine compartment or near the exhaust system. Typical applications of the standard are engine cover, water reservoir washer fluid, battery covers, sight shields, etc. 1.3 Classification. The operating characteristics of parts covered by this standard are
6、 operating at continuous temperature of -30 C up to a maximum continuous temperature according to Table 1. Peak temperatures can exceed the maximum continuous temperature by 20 C. These peaks can make up 60 h in the lifetime of the vehicle. Based on the maximum continuous temperature in installation
7、 position within the engine compartment or near the exhaust system, the parts are identified by Class 1 thru Class 4 according to Table 1. Table 1: Operating Temperatures Class Maximum Continuous Temperature in Degrees Celsius (C) Excursion Temperature in Degrees Celsius (C) 1 +110 +130 2 +110 to +1
8、30 +130 to +150 3 +130 to +150 +150 to +170 4 +150 +165 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ISO 7724-1 SAE J1545 2.2 GM Standards/Specifications. GMW3059 GMW14093 GMW14444 GMW16955 GMW3221 GMW14334 Co
9、pyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15725 Copyright 2013 General Motors Company All Rights Reserved September 2013 Page 2 of 7
10、3 Test Preparation and Evaluation 3.1 Resources. 3.1.1 Calibration. The test facilities and equipment 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
11、 in this standard shall be determined correctly with respect to their physical definition. 3.1.3 Facilities. Not applicable. 3.1.4 Equipment. Not applicable. 3.1.5 Test Vehicle/Test Piece. Unless otherwise specified in the relevant test method for the property concerned, either the complete componen
12、t or a section therefrom shall be used for test pieces. Unless otherwise specified in the appropriate test methods at least one test piece shall be tested. 3.1.5.1 Test pieces shall not be tested within 72 h of manufacture. 3.1.5.2 Conditioning. Unless otherwise stated in respective test procedures,
13、 all samples shall be conditioned prior to each requirement test to GMW3221, Code A. 3.1.6 Test Time. Conforming to the relevant test procedures. 3.1.7 Test Required Information. Conforming to the relevant test procedures. 3.1.8 Personnel/Skills. Not applicable. 3.2 Preparation. Conforming to the re
14、levant test procedures. 3.3 Conditions. 3.3.1 Environmental Conditions. Conforming to the relevant test procedures. 3.3.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, rep
15、orts, etc. 3.4 Instructions. Not applicable. 3.5 Data. Not applicable. 3.6 Safety. This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its use. It is the responsibility of the user of this standar
16、d to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 3.7 Documentation. Samples of components or material released to this standard shall be tested for conformity with the requirements of this standard and approved by the resp
17、onsible GM Department prior to the start of delivery of production level components or materials. Any change to the component or material, e.g., design, function, properties, manufacturing process and/or location of manufacture requires a new release of the product. It is the sole responsibility of
18、the supplier to provide the customer, unsolicited, with documentation of any change or modification to the product/process, and to apply for a new release. If not otherwise agreed to, the entire verification test shall be repeated and documented by the supplier prior to start of delivery of the modi
19、fied 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. 3.7.1.1 Test Report. The test report shall have the same outline and numbering as this test specification. 4 Requirements and Procedure 4.1 Raw Material
20、 Specification Conformance. The components of the assembly must be made from materials which meet the individual material specifications shown on the engineering drawing in addition to meeting the requirements of this performance specification. Engineering qualification of an approved source is requ
21、ired for the material specification called out on the part drawing/math data. Only sources listed in the GM Materials File (MATSPC database) under the material specification number per drawing callout/math data have been qualified by engineering as meeting the requirements of this material specifica
22、tion. 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 ENGINEERING STANDARDS GMW15725 Copyright 2013 General Motors Company All Rights Reserved September 2013 Page
23、 3 of 7 4.2 Regrind. The percent regrind allowed per part shall not exceed the numeric value following the suffix RE symbol. If Home Scrap regrind (scrap that is reused back into the same part) is the only type to be specified for use, the letters HS should follow the numeric regrind value. The use
24、of regrind must not preclude the part from meeting the other specified characteristics of part performance. Furthermore, in any case, The maximum regrind content shall be limited to the percent (%) that was validated and submitted for Production Part Approval Process (PPAP). The type of regrind must
25、 be of the same material that was validated and submitted for PPAP. The regrind must be clean, dry, and free of contamination. Examples: RE50 = 50% maximum regrind RE20HS = 20% maximum Home Scrap regrind Note: If regrind is to be used, all test parts must be manufactured with the maximum amount of r
26、egrind the supplier intends to use. 4.2.1 When this specification and RE suffix does not appear on the part print, no regrind is approved for use. 4.2.2 No painted, laminated or plated regrind may be used without the written approval of the GM Materials Engineering Department. 4.3 Resistance to Temp
27、erature Humidity Cycle. Test pieces shall be assembled to jigs or formers so as to simulate as closely as possible actual service conditions. The complete test assembly shall then be subjected to the following test cycle: 4.3.1 This cycle shall be performed one time using the temperatures from Table
28、 2. 24 h 1 h at Temperature A. 4 h 0.5 h at Temperature C. 72 h 1 h at Temperature B. 24 h 1 h at +40 C 3 C and 93% 5% relative humidity (RH). 4 h 0.5 h at Temperature Celsius. 24 h 1 h at +22 C 3 C. Humidity paragraph required for moisture containing materials only (e.g., polyamide and polyester).
29、If there are any questions concerning the material, contact the responsible GM Materials Engineer. Table 2: Test Temperatures Temperature in Degrees Celsius (C) A B C Class 1 +130 +110 -30 Class 2 +150 +130 -30 Class 3 +170 +150 -30 Class 4 Specially defined -30 Note: Class 4, Temperature A and B sh
30、all be defined on the part drawing/math data. 4.3.2 Requirement. Test pieces shall show no cracking, crazing, appreciable color changes, discoloration, cloudiness, blistering, objectionable shrinkage, deformation, loss of adhesion to the substrate between layers of the composite, or other changes de
31、trimental to serviceability. Test pieces shall comply with the dimensions specified on the drawing after completion of the test. 4.4 Resistance of Material to Heat Ageing/Oxidation Stability. Note: Only for parts made of polypropylene. Copyright General Motors Company Provided by IHS under license w
32、ith General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15725 Copyright 2013 General Motors Company All Rights Reserved September 2013 Page 4 of 7 4.4.1 Parts located in the engine compartment or near the exha
33、ust system require additional, particularly effective stabilization to avoid the degradation by oxidation of the material in hot air. Test pieces shall be exposed for 336 h 2 h (14 days) in an air circulating oven operating at +150 C 3 C. 4.4.2 Requirement: No visible indication of local discolorati
34、on and/or brittleness by material degradation. 4.5 Resistance to Heat with Visual Evaluation. Note: Only applicable to parts which have an appearance requirement. 4.5.1 Test pieces shall be exposed dependent upon their class to 168 h 1 h at Temperature B per Table 2. An air circulating oven with a t
35、emperature tolerance 3 C shall be used. 4.5.2 Wash weathered specimens prior to making measurements and observations. Wash with scrubbing action using a sponge that is saturated with a solution consisting of soap and deionized water at +22 C 3 C. Exposed parts shall not exhibit any indications of su
36、rface tackiness or embrittlement, change in hardness, blooming, blistering or other factors that might affect the function or appearance of the part. The color change shall not exceed E 3.0 units. The color change shall be measured according to ISO 7724-1 or SAE J1545 (CIELAB color space, 10 degrees
37、 observer, metering orifice 10 mm, Illuminant D65, specular component included). Visual evaluation by the Design Responsible Engineer and GM Materials Engineer shall override the measured value in cases of disagreement. Component level natural weathering can and should substitute for component level
38、 accelerated weathering whenever possible. 4.6 Impact Resistance (GMW14093). Note: For parts with large plain areas, e.g., engine cover, test shall be conducted on components. If no specific area of the part is assigned on the drawing to meet the impact requirements, the part shall be tested in the
39、thinnest section and meet these requirements. Impact resistance to GMW14093 - 3/2.5 J minimum. In the as-received condition. After resistance to paragraph 4.3 Temperature Humidity Cycle. 4.7 Resistance to Fluids. All materials shall be resistant to the media they contact, such as aliphatic and aroma
40、tic hydrocarbons, fuels, lubricants, oils, greases and alcohols at their places of use. Tables 3, 4, and 5 per GMW16955 define typical requirements for such resistance to fluids, which apply or do not apply based on installation position. The part drawing/math data shall call out the applicable item
41、s. Additional fluids, if applicable, shall be noted on the part drawing/math data. 4.7.1 Standard Engine Compartment Resistance. If (Standard) is specified for resistance to fluids, the following fluids in Table 3, as defined in GMW16955, will be tested. Copyright General Motors Company Provided by
42、IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15725 Copyright 2013 General Motors Company All Rights Reserved September 2013 Page 5 of 7 Table 3: Fluid Reference Table for Standard
43、 Engine Compartment Resistance According to GMW16955 Fluid Description A1/A2 Brake Fluid C Commercial Washer Fluid according to GMW14334 D Diesel Fuel E Engine Coolant F Engine Oil G Gasoline Fuel L Transmission Fluid/Power Steering Fluid Note: Other regional Original Equipment Manufacturer (OEM) in
44、itial fill equivalent liquids may be used per the discretion of the approving GM Engineer. Part shall be resistant to the liquids of the region the part is delivered to. 4.7.2 Fluids in Table 4 as Defined in GMW16955. Test per GMW14334 - X - Rating 4, 24 h immersion time. Table 4: Fluid Reference Ta
45、ble According to GMW16955 Fluid Description A1/A2 Brake Fluid B Battery Acid C Transit Coating/ Protective Wax according to GMW14334 D Diesel Fuel E Engine Coolant F Engine Oil G Gasoline Fuel H Ethanol Fuel E85 I Ethanol Fuel E100 K Sodium Chloride Solution L Transmission Fluid/Power Steering Fluid
46、 M Diesel Exhaust Fluid 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 ENGINEERING STANDARDS GMW15725 Copyright 2013 General Motors Company All Rights Reserved S
47、eptember 2013 Page 6 of 7 4.7.3 Fluids in Table 5 as Defined in GMW16955. Test per GMW14334 B - Rating 4. Table 5: Fluid Reference Table According to GMW16955 Fluid Description C Commercial Cleaning Agents according to GMW14334 C Commercial Washer Fluid according to GMW14334 4.7.4 Alternative test m
48、ethod for parts having an extra protection coating on the side facing the engine compartment: 5 mL of the respective liquid shall be put on the side facing the engine compartment over 25 cm2. Test temperature, test time and evaluation as defined in paragraphs 4.7.2 and 4.7.3 respectively. 4.7.5 Requ
49、irement. There shall be no color change, loss of bond, material degradation, or tackiness following the test. Note: Other regional OEM initial fill equivalent liquids may be used per the discretion of the approving engineer. 5 Provisions for Shipping Not applicable. 6 Notes 6.1 Glossary. MATSPC: Global repository of GM approved materials for corresponding GM E
