1、 ENGINEERING STANDARDS Test Procedure SUPERCEDED EDS-T-7759 Cross Hatch Test Method of Organic Coatings This standard may be applied only for current projects. It is Superceded for all future projects and replaced by GMW14829. 8TdD98 9E=2e 4G - Note: 8 E:48t G8 =97 FF7 957%L+ , FG P-P Program .Bd# G
2、MW14829 ) $4=F7 957F$ . Copyright 2011 General Motors Company All Rights Reserved June 2011 Originating Department: GM Korea Engineering Standards Page 1 of 6 Version : 4 1 Scope Note: Nothing in this standard supersedes applicable laws and regulations. Note: In the event of conflict between the Kor
3、ean and English language, the Korean language shall take precedence. 1.1 Purpose. The purpose of this standard is to determine the efficiency of adhesion of organic coatings to metallic or polymeric substrates; and the adhesion of the organic coating one on another. 1.2 Applicability. The adhesion o
4、f organic coatings as determined by this standard shall be defined by the separation of near scribed lines in the shape of a lattice pattern cut through the coating, before and after exposure to defined environmental conditions. 2 References Note: Only the latest approved standards are applicable un
5、less otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. EDS-T-7005 EDS-T-7143 EDS-T-7507 2.3 Additional References. None 3 Resources 3.1 Equipment. 3.1.1 Apparatus as required by the appropriate standard. 3.1.2 Cutting tools. 3.1.2.1 A sharp, pointed sc
6、riber. 3.1.2.2 Suitable tools are as follows: 3.1.2.2.1 A single cutting tool: When the cutting edge has worn to 0.1 mm it is necessary to regrind. 1 P7 :0 : ., E:48 6 . 4 Procedures 4.1 Conditions. 4.1.1 Conditioning. Test pieces shall be tested immediately after conditioning to EDS-T-7507-B. 4.1.1
7、.1 For oven dried organic coatings: after coating and baking, R.T (23 E r 5K) exposure 20 30 hours. 4.1.1.2 For air dried organic coatings: after coating and drying, R.T (23 E r 5K) exposure 72 96 hours. 4.1.1.3 Components from the supplier: to be tested without conditioning in the condition as rece
8、ived. 4.1.2 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. 4.2 Instructions. 4.2.1 Unless otherwise specified the test shall be performed at +23 E 5K. Teat pi
9、eces shall be kept high temperature. 4.2.2 The coating thickness shall be determined to within 2 . 4.2.3 For coating thickness of up to 60 , a cutting tool of 1mm spacing shall be used. For coating thickness of above 60 , a cutting tool of 2mm spacing shall be used. 4.2.4 The cutting tool face shall
10、 be held in a plane normal to the test piece surface. With uniform pressure on the cutting tool six parallel cuts into the organic coating shall be made using a non-interrupted stroken at a rate of 20mm/s to 50mm/s. All cuts shall penetrate through to the substrate but shall not cut too deeply into
11、the latter. If it is impossible to penetrate through to the substrate due to the hardness or excessive thickness of the coating, the test becomes invalid and shall be so stated in the report. The operation shall be repeated at an angle of 90to the original cuts, thus forming a lattice pattern. 4 4G 9) 9P9I / -PF%L6$ . Issue / P9I8)Y Publication Date / 38 88 Description (Organization) / 9PP9I76 (:04.2P ) 4 JUN 2011 Apply new Engineering Standard Template. Superceded (Polymer / Organic Material Lab Team) / 4 d3TE:4 64 957 . F9I957 =* (G)8*4G D4 )
