GMW14108Oct2005

Test Method for the Resistance of Materials to Cracking from

Bending at Cold Temperature

© Copyright 2005 General Motors Corporation All Rights Reserved

October 2005 Originating Department: North American Engineering Standards

Page 1 of 2

1 Scope

This procedure documents the testing to determine if a material will withstand bending at cold temperature without cracking.

Note: Nothing in the specification supersedes applicable laws and regulations unless specific exemption has been obtained.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

2 References

Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. GMW3221

3 Test Equipment

Mandrel (approximately 175 mm length X 75 mm diameter) The mandrel may be hollow. Aluminum is recommended for corrosion resistance.

Cold Chamber capable of maintaining -30 ± 2°C

Mechanical Convection Oven capable of maintaining 93 ± 2°C

4 Test Material

Carpet or similar flexible materials.

5 Test Method

5.1 Summary of Test Method. The specimens cut from the sample shall be tested in the “as received” condition. Additional specimens cut from the same sample shall be tested after having been oven aged. All of the specimens shall be tested for resistance to cracking when bent at cold temperature. The bending occurs as the specimens are slowly wrapped around a mandrel. The purpose of the test is to detect brittleness or

cracking when the specimens are bent at cold temperature.

5.2 Test Sample Preparation.

5.2.1 Cut four specimens from the sample approximately 150 X 150 mm. Condition two “as received” specimens for a minimum of 24 hours to the requirements of GMW3221 Code A prior to testing.

5.3 Test Procedure.

5.3.1 Oven age two of the four specimens for 168 ± 0.5 h at 93 ± 2°C in a mechanical convection oven.

5.3.2 Condition oven aged specimens for a minimum of 24 h to the requirements of GMW3221 Code A.

5.3.3 Place all four specimens plus the mandrel in a cold chamber for a minimum of 4 h at -30 ± 2°C. Note: Gloves shall be worn while handling specimens and the mandrel in the cold chamber to prevent heat transfer to the specimens or the mandrel.

Note: One (1) “as received” specimen shall be wrapped so that the face side of the specimen is in contact with the mandrel. One (1) “as received” specimen shall be wrapped with the backside of the specimen in contact with the mandrel. Follow the same procedure using both oven aged specimens.

5.3.4 Slowly wrap each of the specimens individually around the mandrel as described in the note above.

6 Evaluation and Rating

6.1 Examine each of the specimens for cracking crazing, etc.

7 Report

7.1 Report any cracking, crazing, etc. according to the evaluation criteria in the material specification. Report if the cracking occurred when the specimen was tested face side or backside to mandrel.

GMW14108 GM WORLDWIDE ENGINEERING STANDARDS

© Copyright 2005 General Motors Corporation All Rights Reserved

Page 2 of 2 October 2005

8 Safety

This method may involve hazardous materials, operations, and equipment. This method does not propose to address all the safety problems associated with its use. It is the responsibility of the user of the method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

9 Coding System

This material specification shall be referenced in other documents, drawings, VTS, CTS, etc. as follows:

Test to GMW14108 10 Release and Revisions

10.1 Release. This test method originated in March 2005 and was approved by Global Textile Development Group in May 2005. It was first published in October 2005.