1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW17083Substrate Surface Stress Test for molded ABS and ABS/PC Copyright 2013 General Motors Company All Rights ReservedDecember 2013 Page 1 of 31 ScopeNote: Nothing in this standard supercedes applicable laws and regulations.Note: In the event of conflic
2、t between the English and domestic language, the English language shall takeprecedence.1.1 Purpose. This standard describes the evaluation of ABS and ABS/PC molded parts for surface stress,molding defects (hardening) and internal stress.This test is only for qualitative judgment and gives indication
3、s of faults in the molded substrate prior to plating.A quantitative measurement using this method is not possible.1.2 Foreword. Not applicable.1.3 Applicability. Molded ABS and ABS/PC parts for chrome plating according GMW14668.2 ReferencesNote: Only the latest approved standards are applicable unle
4、ss otherwise specified.2.1 External Standards/Specifications.None2.2 GM Standards/Specifications.GMW146683 Resources3.1 Facilities.3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a validcalibration label.3.1.2 Alternatives. Alternative test faciliti
5、es and equipment may also be used. However, all measuringvariables as specified in this standard shall be determined correctly with respect to their physical definition.3.2 Equipment.3.2.2 Glass or plastic container large enough to dip the complete part (for ABS and ABS/PC parts).3.2.3 Thermostat to
6、 maintain the test temperature (for ABS and ABS/PC parts).3.2.4 Glacial acetic acid (water free, chemically pure, CAS 64-19-7) (for ABS parts only).3.2.5 Isopropanol (CAS 67-63-0) (for ABS/PC parts only).3.2.6 Acetone (CAS 67-64-1) (for ABS/PC parts only).3.2.7 Organic red dye, e.g. Sanodal Red B3LW
7、 (for ABS/PC parts only).3.3 Test Vehicle/Test Piece. Complete samples as molded.3.4 Test Time. Not applicable.3.5 Test Required Information. Not applicable.3.6 Personnel/Skills. Not applicable.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo
8、 reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW17083 Copyright 2013 General Motors Company All Rights ReservedDecember 2013 Page 2 of 34 Procedure4.1 Preparation. As specified for the relevant test in paragraph 4.3.4.2 Conditions.4.2.1 Enviro
9、nmental Conditions. As specified for the relevant test in paragraph 4.3.4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Suchrequirements shall be specified on component drawings, test certificates, reports, etc.4.3 Instructions.4.3.1 ABS (Glacial
10、 Acetic Acid).4.3.1.1 Test Instructions.a Ensure that the part is completely dry prior to submerging in acid.b The part shall be dipped 30 s at (+24 3) C in acetic acid.c After dipping, the part shall be rinsed and dried at (+24 3) C (room temperature).d The part shall be evaluated for surface stres
11、s (see paragraph 4.3.1.2, item a) and hardening (seeparagraph 4.3.1.2 item b).e The dried part shall be dipped 2 minutes at (+24 3) C in the acetic acid again.f Afterwards, the part shall be rinsed and dried at room temperature again.g The part shall again be evaluated for internal stress (see parag
12、raph 4.3.1.2, item c).4.3.1.2 Evaluation.a Whitening of the surface (dense patterns) can be an indication of surface stress. The more dense thepattern, the higher the stress (see Note 1).b Hardening of the surface is indicated by discoloration. Proper molding surfaces show a uniform whitesurface. Po
13、or molding surfaces show white areas and dark, shiny areas on the same part, indicatingnonuniform distribution of the butadiene over the molding surface (see Note 2).c Cracks in the plastic material are an indication of very high stress levels in the part. The severity of thecracking indicates the s
14、everity of the stress.Note 1: The use of slightly colored grey resins often provides a greater degree of contrast in examination.Note 2: Weld lines, areas new gates and surfaces at the end of flow are typically more prone to stress.4.3.2 Test Procedure for ABS/PC (Organic Dye).4.3.2.1 Test Solution.
15、 The test solution is made up consisting of Isopropanol 750 ml/l, Acetone 250 ml/l andan organic compatible red dye 0.08 g/l.4.3.2.2 Test Instructions.a Immerse the part in the red dye solution for the appropriate amount of time (typically (5 to 10) minutes,dependent on material).b Immediately rinse
16、 part in running water to remove excess dye, and blow part dry using cool air.c Evaluate the part for surface stress (see paragraph 4.3.2.3).4.2.3 Evaluation.a Pink or reddish coloration variations are an indication of surface stress.b If the color change is minimal, the part may not be etched or th
17、e test material may require changing.c If the variation in color change across the surface of the component is extensive, the degree of etchingmay also mirror this change. The subsequent adhesion of the electrodeposit may be compromised due tothe variation in stress of the base material and its abil
18、ity to be evenly etched.d Dyes tend to penetrate faster in areas of lower stress. This test may also indicate that stress levels are sohigh that stratification of the resin has occurred. And, poor adhesion and potential delamination may result.5 Data5.1 Calculations. Not applicable.5.2 Interpretatio
19、n of Results. If any stress is detected by stress test for ABS or ABS/PC tooling and moldingparameter changes should be made to eliminate as best possible any surface or internal stresses in the partprior to plating.Copyright General Motors Company Provided by IHS under license with General Motors C
20、ompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW17083 Copyright 2013 General Motors Company All Rights ReservedDecember 2013 Page 3 of 3The results of testing should be compared during tool changes and periodically during
21、 molding operations to aknown reference part that assured stress free plating with required adhesion.5.3 Test Documentation. The results shall be represented in a test report with reference to this TestProcedure.6 SafetyThis standard may involve hazardous materials, operations, and equipment. This s
22、tandard does not propose toaddress all the safety problems associated with its use. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.7 Notes7.1 Glossary. Not applicable.7.2
23、Acronyms, Abbreviations, and Symbols.CAS Chemical Abstracts Service8 Coding SystemThis standard shall be referenced in other documents, drawings, etc., as follows:Test to GMW170839 Release and RevisionsThis standard was originated in November 2013. It was first approved by Global Finishes and Coatin
24、gs Teamin December 2013. It was first published in December 2013.Issue Publication Date Description (Organization)1 DEC 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-,-,-
