1、BRITISH STANDARD BS 2752:2003 Chloroprene rubber compounds Specification ICS 83.060 BS 2752:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 18 June 2003 BSI 18 June 2003 The following BSI references relate to the work on this British Sta
2、ndard: Committee reference PRI/54 Draft for comment 02/122016 DC ISBN 0 580 41852 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted to PRI/54, Rubber compounds, upon which the following bodies were represented: British Rubber Manufacturers Asso
3、ciation Ltd. Chemical Industries Association Ministry of Defence RAPRA Technology Ltd. Tun Abdul Razak Research Centre Amendments issued since publication Amd. No. Date CommentBS 2752:2003 BSI 18 June 2003 i Contents Page Committees responsible Inside front cover Foreword ii 1S c o p e 1 2 Normative
4、 references 1 3 Classification 1 4C o m p o s i t i o n 2 5 Preparation of test sheet 2 6 Physical properties of the vulcanized test sheet 2 7M a r k i n g 2 Annex A (informative) Guidance for the preparation and testing of rubber products 4 Bibliography 5 Table 1 Compound classification 1 Table 2 P
5、hysical properties of two-thickness test sheets 3BS 2752:2003 ii BSI 18 June 2003 Foreword This British Standard has been prepared under the direction of PRI/54, Rubber compounds. It supersedes BS 2752:1990 which is withdrawn. One technical change has been made, namely the inclusion of the larger ty
6、pe 1 dumbbell of BS 903-A2 as an alternative to the type 2 dumbbell for the measurement of tensile strength and elongation at break (Table 2). This edition otherwise comprises an editorial revision of the 1990 standard, in which the presentation has been changed to align the text with other British
7、Standards in the group. It is emphasized that this British Standard covers chloroprene rubber compounds for general purpose applications and does not require the special compounding which is necessary to achieve improvement in any one specific property. Other British Standards in this group for rubb
8、er compounds are as follows: BS 1154, Specification for natural rubber compounds. BS 1155, Specification for natural rubber compounds for extrusion. BS 2751, Specification for general purpose acrylonitrile-butadiene rubber compounds. BS 3227, Specification for butyl rubber compounds (including halob
9、utyl compounds). BS 6014, Specification for ethylene propylene rubber compounds. BS 6996, Specification for mineral oil resistant acrylonitrile-butadiene rubber compounds. The following British Standards are also relevant to this standard. BS 3558, Glossary of rubber terms. BS 3734-1, Rubber Toleran
10、ces for products Part 1: Dimensional tolerances. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages
11、This document comprises a front cover, an inside front cover, pages i to ii, pages 1 to 5 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.BS 2752:2003 BSI 18 June 2003 1 1 Scope This British Standard specifies compositional and physic
12、al property requirements for five chloroprene rubber compounds of hardness range 40 IRHD to 80 IRHD, designated C40, C50, C60, C70 and C80. These compounds are intended for the manufacture of items in the form of extrusions, mouldings, moulded or calendered sheet and for items cut or punched from sh
13、eet. NOTE 1 The compounds do not necessarily have good electrical insulating properties. NOTE 2 The chloroprene rubber compounds specified in this standard are not required to be compounded to be resistant to ozone attack and their resistance to ozone is not tested. Potential users should seek techn
14、ical advice if they are unsure as to whether ozone resistance is required for their application. The inherent level of resistance in chloroprene rubber may not be sufficient. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated r
15、eferences, only the reference cited applies. For undated references, the latest edition of the referenced document (including any amendments). BS 903-A1:1996, Physical testing of rubber Part A1: Determination of density. BS 903-A2:1995, Physical testing of rubber Part A2: Method for determination of
16、 tensile stressstrain properties. BS 903-A6:1992, Physical testing of rubber Part A6: Method for determination of compression set at ambient, elevated or low temperatures. BS 903-A13:1990, Physical testing of rubber Part A13: Determination of stiffness at low temperature (Gehman test). BS 903-A19:19
17、98, Physical testing of rubber Part A19: Rubber, vulcanized or thermoplastic Accelerated ageing and heat resistance tests. BS 903-A26:1995, Physical testing of rubber Part A26: Method for Determination of hardness (hardness between 10 IRHD and 100 IRHD). BS 903-A37:1997, Physical testing of rubber P
18、art A37: Determination of adhesion to and corrosion of metals. BS ISO 1817:1999, Rubber, vulcanized Determination of the effect of liquids. 3 Classification Compounds shall be classified according to their vulcanized hardness, in international rubber hardness degrees (IRHD), and designated by grade
19、as shown in Table 1. Table 1 Compound classification Grade designation Hardness after vulcanization (IRHD) C40 a C50 C60 C70 C80 a Compound C40 is not necessarily suitable for extrusion. 40 4 +5 50 4 +5 60 4 +5 70 4 +5 80 4 +5BS 2752:2003 2 BSI 18 June 2003 4 Composition The compounds shall be based
20、 solely on slow crystallization rate chloroprene polymer(s) reinforced only with carbon black, vulcanized with metallic oxides and containing at least 2 parts per hundred of rubber by mass (p.h.r.) of a suitable antioxidant. All ingredients of the mix shall be free from grit and extraneous material.
21、 NOTE 1 Brown factice, up to 10 parts per hundred of rubber by mass, may be used. No reclaimed rubber or ground vulcanized rubber shall be used. NOTE 2 Chemical analysis may be carried out on either two-thickness sample sheets or sample items, as practicable, to verify that the composition of the mi
22、x conforms to this clause. The methods described in BS 4181-1, BS 5923-2, BS 7164-2.2, BS 7164-3, BS 7164-5, BS 7164-7.1, BS 7164-13, BS 7164-14, BS 7164-21 and BS 7164-22.1 should be used where relevant. 5 Preparation of test sheet From each batch of rubber mix, a two-thickness test sheet of the fo
23、llowing dimensions shall be prepared for testing. The sheet shall be approximately 250 mm square with a thicker section along one side 35 mm to 50 mm wide and (6.30 0.15) mm thick. The remainder of the sheet shall be (2.00 0.15) mm thick. The thicker sections of the sheet shall not be additionally v
24、ulcanized. If part of the 6.3 mm section is moulded in the form of cylindrical buttons, complying with the type B test piece defined in BS 903-A6 for the purpose of compression set tests, the mould cavities shall be individually charged with pellets and not by the flow of the excess rubber from the
25、remainder of the mould. The minimum number of buttons moulded shall be nine and they shall be in a group at one end of the 6.3 mm section. 6 Physical properties of the vulcanized test sheet Test pieces cut from the test sheet (see Clause 5) shall comply with the relevant requirements given in Table
26、2 when tested by the methods specified in Table 2. NOTE Guidance for the preparation and testing of rubber products is given in Annex A. 7 Marking The compound, as sheet or items, shall be accompanied by the following information (see also BS ISO 2230): a) number and date of this British Standard, i
27、.e. BS 2752:2003 1) , and grade designation; b) quarter and year of cure; c) manufacturers identity or trade mark; d) manufacturers batch number or similar means of production identity. 1) Marking BS 2752:2003 on or in relation to a product represents a manufacturers declaration of conformity, i.e.
28、a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also
29、be desirable.BS 2752:2003 BSI 18 June 2003 3 Table 2 Physical properties of two-thickness test sheets Physical property Grade designation Test method in BS 903 parts or BS ISO series and type of test piece where appropriate C40 C50 C60 C70 C80 Hardness after vulcanization (IRHD) Part A26, method N,
30、two plies, 6.30 mm and 2.00 mm, with the thicker ply on top Density (Mg/m 3 ) Agreed value 0.02 a Part A1, method A Minimum tensile strength (MPa) 9 12 13 13 13 Part A2, type 1 or type 2 dumbbells Minimum elongation at break (%) 450 400 250 200 100 Maximum compression set (%) 30 30 25 25 25 Part A6,
31、 type B test piece Lubricated, h at (70 1) C Resistance to liquids BS ISO 1817, h at (40 1) C Volume change (%) after immersion in 0 0 0 0 0 liquid B +100 +80 +70 +70 +60 Resistance to low temperature Temperature in C at which the stiffness shall not exceed 70 MPa 40 40 30 30 30 Part A13, using ethy
32、l alcohol/CO 2cooling medium Adhesion to and corrosion of metals There shall be no corrosion or pitting of the metals, and the vulcanizates shall not adhere to the metal surfaces or show any sign of liquid exudation. Discoloration of the metal surfaces shall not be considered cause for rejection. Pa
33、rt A37, using carbon steel and copper. (168 2) h, (70 1) C Resistance to accelerated ageing 0 0 0 0 0 Part A19, air-oven method A, (168 2) h, (70 1) C Change in hardness degrees (IRHD) +7 +7 +7 +7 +7 Part A26, method N, measurement before and after ageing on the same 2 plies each 2.00 mm thick Maxim
34、um change in tensile strength 12 12 12 12 12 Part A2, type 1 or type 2 dumbbells (% of original value) Maximum change in elongation at break 20 20 20 20 20 (% of original value) a No values are specified for density, but it is recommended that a value be established for each composition. This may pr
35、ovide a useful check when a series of batches of the same composition has to be tested for compliance with this British Standard. 40 4 +5 50 4 +5 60 4 +5 70 4 +5 80 4 +5 24 2 0 24 2 0 BS 2752:2003 4 BSI 18 June 2003 Annex A (informative) Guidance for the preparation and testing of rubber products Th
36、is British Standard specifies requirements for the rubber compounds when tested using a press-cured sample sheet. Where manufactured articles are to be tested, the shape and size can prevent the preparation of some or all test pieces. In this case, agreement between manufacturer and purchaser should
37、 be sought on the procedure to verify compliance of the manufactured article. Where standard test pieces can be prepared from the articles they may be used for quality control tests. Finished rubber items should be free from surface imperfections, voids, inclusions, flow marks, moulding faults and d
38、efects which would impair satisfactory performance and should show minimal accelerator bloom. Finished rubber items should be stored in accordance with BS ISO 2230.BS 2752:2003 BSI 18 June 2003 5 Bibliography BS 1154:2003, Specification for natural rubber compounds. 2) BS 1155:2003, Specification fo
39、r natural rubber compounds for extrusion. 2) BS 2751:2001, Specification for general purpose acrylonitrile-butadiene rubber compounds. 2) BS 3227:2003, Specification for butyl rubber compounds (including halobutyl compounds). 2) BS 3558-1:1997, Glossary of rubber terms Part 1: International terms. 2
40、) BS 3558-2:2001, Glossary of rubber terms Part 2: Additional British terms. 2) BS 3734-1:1997, Rubber Tolerances for products Part 1: Dimensional tolerances. 2) BS 4181-1:1985, Identification of rubbers by infra-red spectrometry Part 1: Method for identification of hydrocarbon, chloroprene, nitrile
41、 and chlorosulphonated polyethylene rubbers. BS 5923-2:1980, Methods for chemical analysis of rubber Part 2: EDTA titrimetric method for determination of zinc content of rubber products. BS 6014:2003, Specification for ethylene propylene rubber compounds. 2) BS 6996:2003, Specification for mineral o
42、il resistant acrylonitrile-butadiene rubber compounds. 2) BS 7164-2.2:1990, Chemical tests for raw and vulcanized rubber Part 2.2: Sample preparation Vulcanized rubber. BS 7164-3:1992, Chemical tests for raw and vulcanized rubber Part 3: Methods for determination of solvent extract. BS 7164-5:1991,
43、Chemical tests for raw and vulcanized rubber Part 5: Methods for determination of ash content. BS 7164-7.1:1990, Chemical tests for raw and vulcanized rubber Part 7.1: Methods for determination of polymer content Polyisoprene content. BS 7164-13:1994, Chemical tests for raw and vulcanized rubber Par
44、t 13: Method for determination of total hydrocarbon content. BS 7164-14:1996, Chemical tests for raw and vulcanized rubber Part 14: Methods for determination of carbon black content. BS 7164-21:1996, Chemical tests for raw and vulcanized rubber Part 21: Determination of nitrogen content. BS 7164-22.
45、1:1994, Chemical tests for raw and vulcanized rubber Part 22.1: Determination of chlorine content Parr bomb method. BS ISO 2230:2002, Rubber products Guidelines for storage. 2) Referred to in the foreword only.BS 2752:2003 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BS
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