1、 ENGINEERING STANDARDS Test Procedure SUPERCEDED EDS-T-7424 Determination of Compression Set This standard may be applied only for current projects. It is Superceded for all future projects and replaced by ISO815. 4G ,h8 75 6 :888 ?U9I- Note: 8 E:48t G8 =97 FF7 957%L+ , FG P-P Program .Bd# ISO815 )
2、$4=F7 957F$ . Copyright 2011 General Motors Company All Rights Reserved September 2011 Originating Department: GM Korea Engineering Standards Page 1 of 5 Version : 5 1 Scope Note: Nothing in this standard supersedes applicable laws and regulations. Note: In the event of conflict between the Korean a
3、nd English language, the Korean language shall take precedence. 1.1 Purpose and Applicability. The purpose of this standard is to determinate the residual deformation of elastomers which have been subjected to a constant deformation for a periods at a room temperature or more. 2 References Note: Onl
4、y the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. None 2.3 Additional References. None 3 Resources 3.1 Equipment. 3.1.1 Thickness Gauge. The thickness gauge must be capable of indicating the test pi
5、ece thickness to an accuracy of 0.01 mm. The two contact members consist of domed surfaces of diameter 25 mm, formed on rods 10mm diameter, between which the test pieces are placed. The contact pressure between the contact members shall be (0.850.03) N. The thickness gauge shall normally consist of
6、one fixed contact member, with the other moving vertically above it, and linked to a dial gauge. 1 P7 :0 : ., E:48 68t 9I%L6 8 $* F;8t 3L:8p) 8% F 3L 88p+ $86 8:7 7$%L6 8$ . GM KOREA ENGINEERING STANDARDS EDS-T-7424 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 2 of 5
7、 Version : 5 3.1.2 Testing Apparatus. The testing apparatus consists of polished, flat, and corrosion-resistant pressure plates. The pressure plates are adjusted to a predetermined distance h1 by means of spacers. This distance should be 75 % of the initial height. 3.1.2 4G 8? . E+ 7$* , DA , !.42e8
8、 C2e8x 4: 6DD8 8$4 (Spacer)7 8F 6“8 h1+A 9I)%T 3L 8# 9) %L6 8$ . 8 h18t -F8p) 4G 8x :FF$ . 3.2.2.3 9EF%P 4G D8t 9E=84 6# 1B) 4G F$ . 3.2.3 4G D 3L( . 3P 818 4G D8x 4G F$ . GM KOREA ENGINEERING STANDARDS EDS-T-7424 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 3 of 5 V
9、ersion : 5 4 Procedures 4.1 Conditions. 4.1.1 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. 4.1.2 Conditioning. For initial sample approval and arbitration p
10、urposes, the minimum period between vulcanization and testing shall be 7 days. For routine quality control tests, the minimum period shall be 3 days. The test pieces shall be maintained at a temperature of +23 E 5K for at least 8 hours, immediately prior to test, and shall be free from strain during
11、 this period. 4.1.3 Period and Temperature of Test. The test should be carried out one of the following conditions. Code Period ( ? hour) Temperature ( E K) A 72 +235 B 24 +702.5 C 24 +1002.5 D 24 +1252.5 E 24 +1502.5 F 24 +1752.5 G 24 +2002.5 H 24 +2502.5 Z Specially defined / -$ 9I Specially defin
12、ed / -$ 9I 4.2 Instructions. 4.2.1 The initial thickness (h0) of the test piece is accurately measured to within 0.05 mm at a temperature of 23 E 5K (measured at center of cylindrical test pieces). Components or portions of components of irregular shape are measured at their thickest point. 4.2.2 Af
13、ter determine the compression set at 25 %, the test piece are placed on the lower pressure plate. 4.2.3 The spacers shall be interposed on each side and the upper plate shall be placed on the test piece with the direction of compression. 4.2.4 The upper plate shall be brought down so as to compress
14、the test piece, until it contacts the spacers at h1. 4.2.5 The apparatus above will be maintained under the conditions about temperature and the period as specified on clause 4.1.3. 4 4G 9 “8* 9IF 4D8x F. 6DD 887 7)X “#$ . 4.2.3 8$4* 6;7 “ 1. 6DD8x 4G D8 6%L# -F8p) 7)X “#$ . 4.2.4 6“8 h1+A 6%L$) 1DD
15、8x 98$ . 4.2.5 1d8 4G 9*E8x 4.1.3 94A$ . GM KOREA ENGINEERING STANDARDS EDS-T-7424 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 4 of 5 Version : 5 4.2.6 After an appropriate period, the test pieces shall be relieved from strain, and placed upon a surface of low therm
16、al conductivity(e.g. wooden bench top), for a period of 30 minutes, at a temperature of 23 E 5K. 4.2.7 The thickness h2 will be measured. 4.2.8 After measurement, cut the test piece. If any internal defects, such as porosity, are discovered, the test result should be rejected. 5 Data 5.1 Evaluations
17、. The compression set, expressed as a percentage of the initial deflection is calculated as follows. Compression Set = h 4 F h 6h4 F h 5 100(%) Where, h0: the initial height of the test piece. h1: the height of the test piece in the deflected state. h2: the height of the test piece after recovery. 5
18、.2 Expression of Results. The compression set is reported with reference to this test method as individual values or as the arithmetic mean of the values obtained. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the saf
19、ety 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. Compression Set: To be the proportionate residual contraction
20、 remaining after the removal of strain from the test piece to which a constant deflection of 25% is applied. 7.2 Acronyms, Abbreviations, and Symbols. Not applicable. 4.2.6 1d 9 “ G 4G 9*E8x F=F7 !8t 7(98$ ,p= (79 4G D % h2 * ?U9IF$ . 4.2.8 % ?U9I G 4G D8x 9:8888t $847 8F (7 $4F %) EdF$ . 75 6 :888
21、= h 4 F h 6h4 F h 5 100(%) 7 d2P , h0: 4G D8 %P 1B8 4G D % . h2: G.)%P 4G D8 % . 5.2 0 E4 . 75 6 :8888t 558 0F8! 0F&8 13TD8p) d)F$ . 6 6|987 $4F 7 9 ., E:48t 88G ,p: , 86 , 8/x &%8x E FF 3L 8$ . ., E:48t 87 $4F 170 4)%P +& 6|98 ,l9P8 F8x 9P4F:# 6#$ . &d(2P 17 987 95FF 6|980 I 1B* 9DF , -18 9PF 728 9
22、57 7 .* 9IF# 8t ., E:4 1788 =y8 1F8$ . 7 768 9I8 7.1 98,l 76 . 75 6 :888 : 25 %8 89I 6(8x 957F 9PE7 $4F 68x F9PF G8 -, G.)%P 87 6( (/x8 )8x 8-,F$ . 7.2 66 -C dGl . F$-1F 68 . GM KOREA ENGINEERING STANDARDS EDS-T-7424 Copyright 2011 General Motors Company All Rights Reserved September 2011 Page 5 of
23、5 Version : 5 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: 8 Ed - $* ,l2P! $+ &%72P ., E:48 87%T &# $80 M8 EdF$ . English Compression Set to EDS-T-7424 - C - 40 % min Specified Requirements Test Condition in clause 4.1.3 Test Method Designation ,l 75 6:888 - EDS-T-7424 - C 40 % 81 7 F 4.1.39) 9P9I / -PF%L6$ . Issue / P9I8)Y Publication Date / 38 88 Description (Organization) / 9PP9I76 (:04.2P ) 5 SEP 2011 Apply new Engineering Standard Template. Superceded (Polymer / Organic Material Lab Team) / 4 d3TE:4 64 957 . F9I957 =* (G)8*4G D4 )
