1、 ENGINEERING STANDARDS Test Procedure LIMITED USE EDS-T-7420 Determination of Tension Set Under Constant Elongation Do Not Use on New Program; No Replacement. ,h 75 48#88 ?U9I- Note: 8 E:48t G8 =97 FF7 957%L+ , FG P-P Program 72P# 957%L: 6#$ . Copyright 2011 General Motors Company All Rights Reserve
2、d August 2011 Originating Department: GM Korea Engineering Standards Page 1 of 8 Version : 5 1 Scope Note: Nothing in this standard supersedes applicable laws and regulations. Note: In the event of conflict between the Korean and English language, the Korean language shall take precedence. 1.1 Purpo
3、se. The purpose of this standard is to determine the tension set characteristics of elastomeric test pieces or products, after these have been stretched to a specified strain. 1.2 Applicability. This standard is intended to measure the ability of elastomers of hardness within the range 30 to 94 (Sho
4、re A or IRHD) to retain their visco-elastic properties after extension to a specified strain. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. BS 2648 DIN 50011 2.2 GM Standards/Specifications. EDS-T-7408 2.3 Addi
5、tional References. None 3 Resources 3.1 Equipment. 3.1.1 Measuring Device. 3.1.1.1 Gauge for Test Piece Thickness Measurement. The thickness is measured by means of a dial gauge. The circular contact foot should be flat, with a diameter between 3.5 and 10 mm. The pressure of (202) KPa shall be capab
6、le of being exerted over the entire contact area. For elastomers of hardness below 35 (Shore A), the contact pressure should be reduced to (102) KPa. 1 P7 :0 : ., E:48 6&F !7$ :4-8! 9I8x $4=F 3L 6$ . :0 : F67t 7568 18 88x 7 , F6* 72T8p) F$ . 1.1 +95 . ., E:48t 9I 488p) #)X: ,h 4G D D# 9PE8 75 48#82e
7、8x ?U9IF#$ , +958 8$ . 1.2 957 -88 . ., E:48t $ 30 ) 94 (Shore A D# IRHD)8 -887 8# ,h .E7 $4F7 89I(8p) 48F 1B72P8 9DA2e8x 8T:Fd 88F C2e8x ?U9IF#$ 957F$ . 2 4) E:4 / :0 : C-H +d%P 9I8 6# F 48 07 38%P E:48x 957F$ . 2.1 17 E:4 / . BS 2648 DIN 50011 2.2 GM E:4 / . EDS-T-7408 2.3 dA E:4 / . None 3 4G 88
8、3.1 4G 8/x . 3.1.1 ?U9I 8/x . 3.1.1.1 % ?U9Id . 4G D8 % # $86 8: (Dial Gauge)* 87F7 ?U9IF$ . $86 8:8 %0 9E=+8t DAF6 F+ 3.5 ) 10 mm8 :*8x 49l6 F$ . DF 98 9E=+7 (202) KPa8 6)Y8x 4F 3L 866 F$ . $ 35 (Shore A)8F8 ,h# 9E=6)Y8 (102) KPa8$ . GM KOREA ENGINEERING STANDARDS EDS-T-7420 Copyright 2011 General
9、Motors Company All Rights Reserved August 2011 Page 2 of 8 Version : 5 3.1.1.2 Gauge for Length Measurement. 3.1.1.2.1 The length of the test piece shall be measured by means of a suitable measuring device to the nearest 0.1 mm. 3.1.1.2.2 For ring test pieces, the reference length shall be the inner
10、 diameter of the ring. To determine the reference length, either a graduated cone, allowing measurement to be made to the nearest 0.5mm, shall be used or the reference length shall be measured by an optical method, free of tension, with an accuracy of 0.5 mm. 3.1.2 Oven. Heating oven with forced cir
11、culation capable of maintaining the required temperature (clause 4.1) within the specified tolerance. (Ovens complying with DIN 50011 Part1, clause 2.2 or BS 2648 are suitable). 3.1.3 Straining Device. 3.1.3.1 Strip Test Pieces. 3.1.3.1.1 Consisting of a metal rod or other suitable guide fitted with
12、 pairs of holders, one fixed and one mobile for the ends of the test piece. The holders shall be in the form of self-tightening clamps for strip test pieces, or in the form of jaws to securely hold the tab ends of strip test pieces with enlarged ends. 3.1.3.1.2 The operation by means of the mobile h
13、older is desirable. (e.g. a screwed rod which can meet the tolerance of extension speed specified in clause 4.3) 3.1.3.1.3 Suitable stops or graduations may also be provided, to avoid over-extension in the initial straining of the test piece. 3.1.3.2 Ring Test Pieces. 3.1.1.2 l8 ?U9Id . 3.1.1.2.1 (G
14、I 4G D8 l8# 95$-F $ * 87F7 0.1 mm: ?U9IF$ . 3.1.1.2.2 * 4G D8 E:4*# !8$ . E:4* ?U9IFd 88F2P# #-F D# $+7 $4F l8-F8p) 9 9PE8t )=-O8t $4) 4G F$ . 3.2.1.4.2 8GI $4? 9PE (7 G$+8 8F$) :08F2P 9 8F $+8x J$) :08F2P 9=8t :4/x 09I :E7 FpF6 F$ . :4/x8 782e8x 88F2P 4G D7 75F8x :0: 6# ,p &%8 6=* 17F$ %P$ . 3.2.3
15、E4 . 3.2.3.1 E:4* (Lo)# ( 4G D 887 -? * (Bench Marker) D# 8*7 75F8x :0: 6 4G 7$72P &P 3L 8# 8A * 87F7 E4F$ . 8-L958p) E:4*# 25 ) 50 mm 866 F+ ( 4G D8 7# 50 mm4 9$ . 3.2.3.2 * 4G D , * GI18x 8* 9PE ,* 8GI$4? 9PE &%8t !8x E:4*) F$ . 3.2.4 4G D8 3L( . 4G D8t 2F 3P 81 4G F$ . GM KOREA ENGINEERING STANDA
16、RDS EDS-T-7420 Copyright 2011 General Motors Company All Rights Reserved August 2011 Page 5 of 8 Version : 5 3.2.5 Conditioning of Test Pieces. For initial sample approval and arbitration purposes, the minimum time between vulcanization and testing shall be 7 days. For routine quality control test,
17、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 this period. 4 Procedures 4.1 Preparation. For test conditions of the permanent set, see the following table. Reg
18、ulations on test conditions for each item shall be separately specified in the drawing and material spec. 3.2.5 4G D 9 . 2F 848 81 7)Y8x -O: 68t 1B) -?F6 F$ . 4 4G 9F$ . 75 48 #88 = L 6 F L 4L5 F L 4 100(%) Where, L0 = 2F 3P81 4G F7 5 0:E :E8F8x 9 0) 9IF$ . (:E8F8( 0* 7*=3P8p) -d7(F7 :E87 88?F F8x +
19、F$ . 72F 4 G 818 4G 8x 4) :FF$ . 8)$ 7# 7P8 0 :E :E8 F8x 2TBF# 8$ . 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 728 957 7 .* 9IF# 8t ., E:4 1788 =y8 1F8$ . 7 768 9I8 7.1 98,l 76 . 75 48 #88 : ) 9P9I / -PF%L6$ . Issue / P9I8)Y Publication Date / 38 88 Description (Organization) / 9PP9I76 (:04.2P ) 5 AUG 2011 Apply new Engineering Standard Template. Limited use with no replacement (Polymer / Organic Material Lab Team) / 4 d3TE:4 64 957 . F9I957 ($4=E:4 68 ) =* (G)8*4G D4 )
