1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW17081 Plastic Part Properties Copyright 2014 General Motors Company All Rights Reserved January 2014 Page 1 of 5 1 Scope 1.1 Material Description. 1.1.1 Material Identification. 1.1.1.1 Marking of Parts. All plastic parts shall be marked usi
2、ng the latest version of ISO 11469. For example, polycarbonate would be indicated as follows: “ PC ” 1.1.1.1.1 All Parts. Marking is required on all plastic parts except in cases where fit, function, or appearance is compromised. Extruded parts are also excluded from this requirement. 1.1.1.1.2 Comp
3、osite Parts. A molded part that is manufactured using more than one polymer type shall have the plastic symbols for each polymer type identified on the part. Examples of manufacturing using more than one polymer type are co-injection molding and two-shot molding. 1.1.1.1.3 Small Parts. In cases wher
4、e the letter height must be smaller than 1.5 mm in order to fit on the part, marking is not required. For ease of locating for recycling, make the marking as large as possible without hindering appearance or function. 1.1.1.1.4 Relationship to Other Markings. Where possible, the International Organi
5、zation for Standardization (ISO) marking shall be located near the part number, cavity number, molding date, or other markings on the part. If there is not room near the other markings, or there are no other markings on the part, then the ISO marking shall be in an area that can be easily found when
6、 the part is disassembled from the vehicle. 1.1.1.2 Standard Drawing Notes. Mark all plastic parts per ISO 11469. 1.2 Symbols. A symbol for the general type of plastic resin is to be used and a letter-number symbol for each quality level of each property or characteristic. For example, an automotive
7、 interior part might be specified as follows: GMW17081 ABS (DSB83, RE20). Refer to 3.2.1. Note: While this format provides the means for characterization and specification of each property and combination of properties for a broad range of materials, it is subject to possible misapplications since i
8、mpossible property combinations can be coded if the user is not familiar with available commercial materials. 1.3 Typical Applications. Plastic parts that have additional requirements beyond the material properties. 1.4 Remarks. Plastics should be described in terms of specific performance character
9、istics desired in the molded part. An infinite number of such descriptions can be formulated by the use of one or more standard statements (based on standard tests) each designating a quality level of a property or characteristic. Users of plastic parts can, by selecting different combinations of pe
10、rformance characteristics, specify different combinations of properties desired in various parts. This standard provides a system for specifying significant properties of commonly used plastics, including un-pigmented and pigmented, unfilled and filled products. It is intended to apply to parts (not
11、 resins) used in the automotive and related industries. It is also intended to be used either as the sole descriptor of a material or within the body of a specification covering the common standard characteristics required where additional specialized requirements are detailed. 2 References Note: On
12、ly the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM D3763 ISO 62 ISO 176 ISO 11469 Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted witho
13、ut license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW17081 Copyright 2014 General Motors Company All Rights Reserved January 2014 Page 2 of 5 2.2 GM Standards/Specifications. GMW3013 GMW3116 GMW14093 GMW14672 GMW3059 GMW3221 GMW14124 GMW15424 2.3 Additional References. TMC003 Material Safet
14、y Data Sheet guidance documents (available at ). 3 Requirements 3.1 Requirements on Test Specimens. Reference GMW3221. 3.2 Physical Requirements. 3.2.1 Suffix Requirements. See Table 1 for a summary of the suffix symbols. Table 1: Suffix Symbol Characteristics Suffix Symbol Characteristic DS Dimensi
15、onal Stability PL Parting Lines PR Impact Resistance PS Multi-Axial Instrumented Impact RE Regrind TC Thermal Cycle Resistance VL Volatile Loss WA Water Absorption Z Other Characteristics 3.2.1.1 Suffix DS Dimensional Stability. 3.2.1.1.1 Unrestrained 4 h Exposure. After 4 h exposure in an oven, par
16、ts shall conform to the dimensions and tolerances shown on engineering drawings. The oven shall be set at the temperature, in degrees Celsius, indicated by the numerals following the suffix DS-symbol. Where appropriate, parts shall be held during measuring and heating in a manner similar to that enc
17、ountered during actual use of the part. For example, DS85 = 4 h at 85 C. 3.2.1.1.2 Restrained 4 h Exposure. When the letter F follows the numerals, parts shall be held/fixtured during measuring and heating in a manner to replicate the vehicle installation. For example, DS85F = 4 h at 85 C held/fixtu
18、red to replicate vehicle installation. 3.2.1.1.3 Other Exposure Periods. Where 4 h exposure is not appropriate, other exposure periods may be specified by amending the suffix DS-symbol as follows: DSA = 1 h DSB = 2 h DSC = 8 h DSD = 16 h DSE = 24 h For example, DSC85 = 8 h at 85 C Copyright General
19、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 GMW17081 Copyright 2014 General Motors Company All Rights Reserved January 2014 Page 3 of 5 3.2.1.2 Suffix PL
20、Parting Line. For parting lines that are visible when the part is in the vehicle installed position or will be handled during vehicle operation, the finished molded part shall have an acceptable offset when evaluated as described in GMW15424. 3.2.1.3 Suffix PR Impact Resistance. Parts shall show no
21、evidence of cracking when impact tested at point or points indicated on the engineering drawing. If no points are indicated on the drawing, this test shall be omitted. Tests shall be conducted according to GMW14093 immediately following exposure of the part to one of the conditions listed in Table 2
22、 (as specified by the first numeral of the suffix PR-symbol), while the part is at test temperature and utilizing a minimum energy (as indicated by the second, or second and third numeral of this symbol) times the factor 0.1 J. For example, PR120 = Subject part to 23 C for 4 h, impact at 2 J. 3.2.1.
23、4 Suffix PS Multi-Axial instrumented Impact Test. The impact resistance shall be defined as the Total Energy under the Curve when tested using a multi-axial instrumented impact tester per ASTM D3763. Test panels shall be 2.5 mm 0.2 mm thick by a minimum of 100 mm diameter or 100 mm square. Parts wit
24、h thicknesses other than 2.5 mm shall be indicated using a Z suffix. The impact speed shall be 6.7 m/s or 2.2 m/s (indicated by the first letter following the PS-symbol). The impact probe shall have a 12.7 mm diameter; and the clamping rings shall have a 76.2 mm inner diameter. The test shall immedi
25、ately follow exposure of the part to one of the conditions listed in Table 2 (as specified by the first numeral of the suffix PS-symbol), while the part is at test temperature, and utilizing a minimum energy (as indicated by the second, or second and third numeral of this symbol) times the factor 0.
26、1 J. A = 2.2 m/s for exterior parts B = 6.7 m/s for interior parts For example: PSB120 = Subject part to 23 C for 4 h, impact at 2 J at 6.7 m/s per ASTM D3763. 3.2.1.5 Suffix TC Thermal Cycle Resistance. Parts shall be subjected to the test cycle indicated by the numeral following the suffix TC-symb
27、ol. See Table 2. At the conclusion of the test, the parts shall show no objectionable material degradation, shrinkage, blistering, distortion or other effects which would detract from appearance or affect performance. Table 2: Thermal Cycle Resistance Suffix Symbol Environmental Cycle TC1 Normally u
28、sed for interior parts above the beltline, GMW14124, Cycle D. TC2 Normally used for interior parts below the beltline, GMW14124, Cycle E. TC3 Normally used for exterior parts above the beltline, GMW14124, Cycle C. TC4 Normally used for exterior parts below the beltline, GMW14124, Cycle F. TC5 Platin
29、g cycle for completely enveloped parts, GMW14672. TC6 Plating cycle for parts not completely enveloped, GMW14672. TC7 Moisture cold cycles tested per GMW14124, Cycle A. 3.2.1.6 Suffix VL Volatile Loss per ISO 176 Method E. As determined by the test method described in ISO 176 (Method E), the volatil
30、e loss shall not exceed the value indicated by the numeral or numerals following the suffix VL-symbol expressed as mass percent. Where the test temperature is not appropriate, other temperatures may be specified by amending the suffix symbol as follows: VLA = 70 C VLB = 80 C VLC = 100 C VLD = 105 C
31、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 GMW17081 Copyright 2014 General Motors Company All Rights Reserved January 2014 Page 4 of 5
32、VLE = 120 C VLF = 150 C For example, VLD15 = 15% maximum volatile loss at 105 C 3.2.1.7 Suffix WA Water Absorption. The water absorption as determined by ISO 62 shall not exceed the value following the suffix WA-symbol in Percent (%) times the factor of 0.10. For example, WA35 = 3.5% maximum 3.2.1.8
33、 Suffix Z Other Characteristics. Other characteristics shall be specified by the purchaser. Note: The symbol Z appended to the specification number indicates the existence of requirements other than those designated by symbols explained above. These are normally shown in the body of engineering draw
34、ings under the heading Supplementary Material Requirement. 3.2.2 Requirements on other Stages during Life Cycle. 3.2.2.1. Suffix RE Regrind. The percent regrind allowed per part shall not exceed the numeric value following the suffix RE-symbol. If Home Scrap regrind as defined in GMW3116 (scrap that
35、 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 of regrind must not preclude the part from meeting the other specified characteristics of part performance. In any case: The maximum regrind content shall be
36、limited to the percent that was validated and submitted for Production Part Approval Process (PPAP). The type of regrind must be of the same material that was validated and submitted for PPAP. The regrind must be clean and dry, free of contamination. The regrind must be blended proportionately with
37、the virgin. When this specification and RE suffix does not appear on the part print, no regrind is approved for use. No painted, laminated or plated regrind may be used without the written approval of the GM Materials Engineering Department. Note: To specify a regrind material, consult the following
38、 specifications: GMW3116, Recyclability/Recoverability (see the definition of regrind in the Glossary). GMW3013, General Requirements for Handling of Technical Terms of Delivery for Plastics (see Additional Requirements in Section 3). Use this RE call-out to specify a regrind material if a line call
39、-out is the chosen method of specification. For example, RE50 = 50% maximum regrind, RE20HS = 20% maximum Home Scrap only. 4 Manufacturing Process Not applicable. 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid i
40、n the country of usage. 5.2 Language. In the event of conflict between the English and domestic language, the English language shall take precedence. 5.3 Inspection and Rejection. Samples of components or materials released to a GM material specification shall be tested for conformity with the requi
41、rements of this material specification and approved by the responsible Engineering department prior to commencement of delivery of bulk supplies. A new approval must be received for any changes, e.g., properties, manufacturing process, location of manufacture, etc. If not otherwise agreed, all testi
42、ng and documentation normally required for initial release must be completed. It is the responsibility of the supplier to inform the customer in a timely manner, without solicitation, and to include documentation of all modifications of materials and/or processes and to apply for a new release. Copy
43、right 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 GMW17081 Copyright 2014 General Motors Company All Rights Reserved January 2014 Page 5 of 5 If n
44、ot otherwise agreed, all release tests shall be repeated and documented by the supplier prior to commencement of delivery of non-conforming bulk supplies. In individual cases, a shorter test can be agreed to between the responsible Engineering department and the supplier. 5.4 Material Safety Data Sh
45、eets/Safety Data Sheets (MSDS/SDS). For new product submissions, or when a change in chemical composition of an existing product has occurred, a complete copy of the Material Safety Data Sheet/Safety Data Sheet must be submitted in compliance with the Globally Harmonized System of Classification and
46、 Labeling of Chemicals (GHS) requirements or other country-specific MSDS/SDS requirements. In addition, product MSDS/SDS submissions must be in compliance with specific country General Motors TMC003 Material Safety Data Sheet/Safety Data Sheet guidance documents where available. 5.5 All materials su
47、pplied to this standard must comply with the requirements of GMW3059, Restricted and Reportable Substances for Parts. 6 Approved Sources Materials supplied to this specification must be approved by General Motors. The appropriate GM Materials Engineering department(s) must confirm material as meetin
48、g the requirements of this specification. Any test data sheets of material submitted to General Motors for such confirmation (e.g., during PPAP) under this material specification must list all properties and must apply corresponding test methods of this material specification. 7 Notes 7.1 Glossary.
49、MATSPC: Global repository of GM approved materials for corresponding GM Engineering Standards. 7.2 Acronyms, Abbreviations, and Symbols. % Percent GHS Globally Harmonized System of Classification and Labeling of Chemicals ISO International Organization for Standardization MSDS Material Safety Data Sheet PPAP Production Part Approval Process SDS Safety Data Sheet 8 Coding S
