1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW16847 Test Locations of Natural Weathering of Exterior Plastics Copyright 2012 General Motors Company All Rights Reserved September 2012 Originating Department: North American Engineering Standards Page 1 of 3 1 Scope Note: Nothing in this standard
2、supercedes applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. In many instances, GM has required natural weathering to take place in the Miami, Florida area and/or the Phoenix, Arizona ar
3、ea. This specification describes the process for approval of new test locations for natural weathering of exterior plastic materials. Natural weathering shall be conducted in regions that offer extreme solar environments. 1.2 Foreword. Not applicable. 1.3 Applicability. This specification applies to
4、 natural weathering tests that are conducted on plastic materials intended for use on the exterior of vehicles. Natural weathering requirements can be found in the appropriate material specifications for the plastic material. 2 References Note: Only the latest approved standards are applicable unles
5、s otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. None 3 Resources 3.1 Facilities. Not applicable. 3.2 Equipment. Not applicable. 3.3 Test Vehicle/Test Piece. Not applicable. 3.4 Test Time. Not applicable. 3.5 Test Required Information. Not applicabl
6、e. 3.6 Personnel/Skills. Not applicable. 4 Procedure 4.1 Preparation. Obtain a minimum of 5 years weathering information from the new natural weathering test site. This must include Total Solar Radiation for 5 degrees direct exposure, and relative humidity. 4.2 Conditions. 4.2.1 Environmental Condit
7、ions. 4.2.1.1 Miami, Florida. As an alternate to the Miami, Florida area, relative humidity shall be in the range of 50% to 100%. Additionally, depending on the length of exposure required in the applicable material specification for the plastic, the Total Solar Radiation must be equivalent as shown
8、 in Table 1. 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 GMW16847 Copyright 2012 General Motors Company All Rights Reserved September 20
9、12 Page 2 of 3 Table 1: Solar Radiation Equivalents to Years in Miami, Florida Years in Miami, Florida Approximate Total Solar Radiation (MJ/m2) Approximate Total Solar Radiation (Langleys) 1 6300 150 500 2 12 600 301 000 3 18 900 451 500 4 25 200 602 000 5 31 500 752 500 For example, if the applica
10、ble plastic material specification requires 2 years natural weathering exposure in the Miami, Florida area, then an alternate test site can be used, provided the relative humidity is 50% to 100%, and the testing is carried out until a total solar radiation of 12 600 MJ/m2 (301 000 Langleys) has been
11、 reached. 4.2.1.2 Approved Test Locations Include: Miami, Florida 4.2.1.3 Phoenix, Arizona. As an alternate to the Phoenix, Arizona area, relative humidity shall be 50%. Additionally, depending on the length of exposure required in the applicable material specification for the plastic, the Total Sol
12、ar Radiation must be equivalent as shown in Table 2. Table 2: Solar Radiation Equivalents to Years in Phoenix, Arizona Years in Phoenix, Arizona Approximate Total Solar Radiation (MJ/m2) Approximate Total Solar Radiation (Langleys) 1 7600 181 200 2 15 200 362 400 3 22 800 543 600 4 30 400 724 800 5
13、38 000 906 000 For example, if the applicable plastic material specification requires 5 years natural weathering exposure in the Phoenix, Arizona area, then an alternate test site can be used, provided the relative humidity is 50%, and the testing is carried out until a total solar radiation of 38 0
14、00 MJ/m2 (906 000 Langleys) has been reached. 4.2.1.4 Approved Test Locations Include: Phoenix, Arizona 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4
15、.3 Instructions. Upon review of the new alternate weathering test site, if it can be shown that samples tested at that site can meet the relative humidity and solar radiation requirements, then the responsible GM Engineer shall review with the GM Global Plastics Team and revise this specification to
16、 add the new weathering site. 5 Data 5.1 Calculations. Not applicable. 5.2 Interpretation of Results. Not applicable. 5.3 Test Documentation. Not applicable. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitte
17、d without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW16847 Copyright 2012 General Motors Company All Rights Reserved September 2012 Page 3 of 3 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety
18、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. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. Not app
19、licable. 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: Test to GMW16847 9 Release and Revisions This standard was originated in August 2012. It was first approved by the Plastics Global Subsystem Leadership Team in September 2012. It was first published in September 2012. Issue Publication Date Description (Organization) 1 SEP 2012 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-,-,-
