1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW17025 Polybutylene Terephthalate General Purpose, High Flow, Injection Moldable Exterior Lighting Applications Only Copyright 2013 General Motors Company All Rights Reserved August 2013 Page 1 of 3 1 Scope This specification covers the prope
2、rties of a general purpose high flow, injection moldable polybutylene terephthalate (PBT). 1.1 Material Description. Approved paint systems that can be used on this material are listed in the GM Approved Paint on Parts Systems (GM APOPS) database. 1.2 Symbols. The material abbreviation according to
3、ISO 11469 is PBT. 1.3 Typical Applications. Typical applications include the following: Headlamp bezels. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM D6869 ISO 188 ISO 1133 ISO 7792-2 ISO 75-1/2 ISO 294-1
4、 ISO 1183 ISO 11469 ISO 179/1eA ISO 527-1/2 ISO 1874-2 ISO 15512 2.2 GM Standards/Specifications. GMW3013 GMW3221 GMW3232 GMW14335 GMW3059 2.3 Additional References. TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements Materials approved to this specification shall me
5、et the requirements of GMW3013. 3.1 Requirements on Test Specimens. Unless otherwise specified, injection molding of test specimens shall be accomplished per ISO 294-1 with the conditions for injection molding from ISO 7792-2. All values indicated herein are based on material considered to be in the
6、 dry-as-molded state with moisture content of 0.02% maximum (ASTM D6869; ISO 15512, Method A or B; or GMW14335). Immediately after molding, specimens shall be sealed in moisture-proof containers and stored at 23 C 2 C for at least 24 h prior to test as specified in ISO 1874-2. All tests shall be per
7、formed on unannealed specimens immediately after their removal from the containers in a controlled atmosphere per GMW3221, Code A, unless otherwise specified. In addition, tests specified at temperatures below or above 23 C 2 C shall be conducted at the specified temperature using specimens conditio
8、ned at the specified temperature for 4 h minimum. The minimum values specified in the property tables must be met by test specimens in natural, black, or in a standard sampled color if natural or black are not available. 3.2 Requirements on Delivery. Important physical, mechanical and thermal proper
9、ties that characterize the material are summarized in Table 1. The color shall be specified on drawings, in material specifications and otherwise. 3.3 Compound Properties. See Table 1. The following are also required for full standard approval. The minimum number of lots per test required is one in
10、natural: Poissons Ratio, Coefficient of Linear Thermal Expansion (CLTE), mold shrinkage, stress strain curve at multiple temperatures (-30 C, +23 C, +85 C). See GMW3013 for the test procedures. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo
11、 reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW17025 Copyright 2013 General Motors Company All Rights Reserved August 2013 Page 2 of 3 3.4 Performance Requirements. Performance requirements shall be specified on part drawings or in component
12、specifications. All parts manufactured from molding compounds shall be resistant to the media they contact at their places of use. Table 1: Compound Properties (Natural and Black) Property Value Standard Density 1.23 g/cm to 1.33 g/cm ISO 1183, Method A Melt Flow Rate 22 g/10 minutes minimum ISO 113
13、3 (250 C, 2.16 kg) Tensile Strength at Yield 52 MPa minimum ISO 527-1/2, specimen A, test speed 50 mm/minute Tensile Strength Retention after Heat Aging 75% retention minimum ISO 188, 1000 h at 120 C Tensile Modulus 2000 MPa minimum ISO 527-1/2 Notched Charpy at +23 C 2 C 2.7 kJ/m minimum ISO 179/1e
14、A, edgewise impact Notched Charpy Impact at -40 C 2 C 2.0 kJ/m minimum ISO 179/1eA, edgewise impact Notched Charpy Impact after Heat Aging, +23 C 75% retention minimum ISO 188, 1000 h at 120 C Deflection Temperature Under Load, 1820 kPa 46 C minimum ISO 75-1/2, flatwise, unannealed Flammability 100
15、mm/minute GMW3232, Sample 355 mm 2 mm x 100 mm 2 mm x 2 mm 0.2 mm thick 4 Manufacturing Process Not applicable. 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event
16、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 requirements of this material specification and approved
17、 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 testing and documentation normally required for initial
18、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. If not otherwise agreed, all release tests shall be rep
19、eated 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 Sheets/Safety Data Sheets (MSDS/SDS). For new product
20、 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 Labeling of Chemicals (GHS) requirements or other
21、country-specific MSDS/SDS 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 GMW17025 Copyright 2013 General Motors Company All Rights Reserved
22、 August 2013 Page 3 of 3 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 supplied to this standard must comply with the require
23、ments of GMW3059, Restricted and Reportable Substances for Parts. 6 Approved Sources Materials supplied to this specification must be approved by General Motors. A list of approved materials can be found in MATSPC. This GM Material File is provided to third parties to reduce redundant testing of mat
24、erials. If approved material already listed is used, the part supplier can use GM Material File reference for Production Part Approval Process (PPAP) material approval. If the decision is made to use a not yet approved material, contact Materials Engineering for details on the approval process. The
25、material approval process must be completed prior to PPAP start date of the part supplied to General Motors. 7 Notes 7.1 Glossary. MATSPC: Global repository of GM approved materials for corresponding GM Engineering Standards. 7.2 Acronyms, Abbreviations, and Symbols. CLTE Coefficient of Linear Therm
26、al Expansion GHS Globally Harmonized System of Classification and Labeling of Chemicals GM APOPS General Motors Approved Paint on Parts Systems MSDS Material Safety Data Sheet PBT Polybutylene Terephthalate PPAP Production Part Approval Process SDS Safety Data Sheet 8 Coding System This standard sha
27、ll be referenced in other documents, drawings, etc., as follows: Material per GMW17025P-PBT 9 Release and Revisions This standard was originated in July 2013. It was first approved by the Plastics Global Subsystem Leadership Team in August 2013. It was first published in August 2013. Issue Publication Date Description (Organization) 1 AUG 2013 Initial publication. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
