1、BRITISH STANDARD BS 6057-1.2: 1990 ISO 2027:1990 Rubber latices Part 1: Specification and coding Section 1.2 Specification for evaporated, preserved natural rubber latices NOTEAttention is drawn to BS 6057-0 “General introduction” issued separately.BS6057-1.2:1990 This British Standard, having been
2、prepared under the directionof the Rubber StandardsPolicy Committee, waspublished under the authorityof the Board of BSI and comes into effect on 31August1990 BSI 11-1999 First published February1981 Second edition August1990 The following BSI references relate to the work on this standard: Committe
3、e reference RUM/38 Draft announced in BSINews July1990 ISBN 0 580 18862 0 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Rubber Standards Policy Committee (RUM/-) to Technical Committee RUM/38, upon which the following bodies were repre
4、sented: British Rubber Manufacturers Association Malaysian Rubber Producers Research Association Medical Sterile Products Association Tropical Growers Association Amendments issued since publication Amd. No. Date CommentsBS6057-1.2:1990 BSI 11-1999 i Contents Page Committees responsible Inside front
5、 cover National foreword ii 1 Scope 1 2 Normative references 1 3 Requirements 1 4 Sampling 1 Table 1 Requirements 2 Publication(s) referred to Inside back coverBS6057-1.2:1990 ii BSI 11-1999 National foreword This Section of BS6057 has been prepared under the direction of the Rubber Standards Policy
6、 Committee and is identical with ISO2027:1990 “Natural rubber latex concentrate, evaporated, preserved Specification”, published by the International Organization for Standardization (ISO). It supersedes BS6057-1.2:1981, which is withdrawn. The Technical Committee has reviewed the provisions of ISO7
7、780 and ISO8053, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applica
8、tion. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding British Standard ISO 35:1989 BS 6057 Rubber latices Section 3.1:1990 Determination of mechanical stability of natural rubber latex concentrate (Id
9、entical) ISO 123:1985 Part 2:1987 Sampling (Identical) ISO 124:1985 Section 3.2:1987 Determination of total solids content (Identical) ISO 125:1990 Section 3.3:1990 Determination of alkalinity of natural rubber latex concentrate (Identical) ISO 126:1989 Section 3.4:1990 Determination of dry rubber c
10、ontent of natural rubber latices (Identical) ISO 506:1985 Section 3.6:1987 Determination of volatile fatty acid number (Identical) ISO 706:1985 Section 3.8:1987 Determination of coagulum content (sieve residue) (Identical) ISO 2005:1985 Section 3.13:1987 Determination of sludge content (Identical) S
11、ummary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1and2, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside f
12、ront cover.BS6057-1.2:1990 BSI 11-1999 1 1 Scope This International Standard gives specifications for natural rubber latex concentrate which has been concentrated by evaporation. It does not apply to natural rubber latex concentrates which have been concentrated by centrifuging or creaming, or to la
13、tices from natural sources other than Hevea brasiliensis, or to compounded latex or vulcanized latex. This International Standard covers requirements for evaporated natural rubber latex concentrates of the following types: NR latex, type HA evaporated: Evaporated latex concentrate preserved with amm
14、onia only or with ammonia together with other preservative(s), with an alkalinity of at least0,60% (m/m) with respect to the latex. NR latex, type KHS evaporated: Evaporated latex concentrate preserved with potassium hydroxide and having a nominal total solids content of73% (m/m). NR latex, type KLS
15、 evaporated: Evaporated latex concentrate preserved with potassium hydroxide and having a nominal total solids content of68% (m/m). 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the ti
16、me of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO main
17、tain registers of currently valid International Standards. ISO 35:1989, Natural rubber latex concentrate Determination of mechanical stability. ISO 123:1985, Rubber latex Sampling. ISO 124:1985, Rubber latices Determination of total solids content. ISO 125:1990, Natural rubber latex concentrate Dete
18、rmination of alkalinity. ISO 126:1989, Natural rubber latex concentrate Determination of dry rubber content. ISO 506:1985, Natural rubber latex concentrate Determination of volatile fatty acid number. ISO 706:1985, Rubber latex Determination of coagulum content (sieve residue). ISO 2005:1985, Natura
19、l rubber latex concentrate Determination of sludge content. ISO 7780:1987, Rubbers and rubber latices Determination of manganese content Sodium periodate photometric methods. ISO 8053:1986, Rubber and latex Determination of copper content Photometric method. 3 Requirements The latex concentrate shal
20、l conform to the requirements given inTable 1. In the case of NR latex concentrate, type HA evaporated, the chemical nature and approximate quantity of any preservative(s) other than ammonia shall be stated. NR latex concentrate, type HA evaporated, shall not contain fixed alkali added at any stage
21、in its production. 4 Sampling The latex concentrate shall be sampled by one of the methods specified in ISO123.BS6057-1.2:1990 2 BSI 11-1999 Table 1 Requirements Characteristic Limits Document specifying method of test type HA evaporated type KHS evaporated type KLS evaporated Total solids content,
22、% (m/m), min. 61,5 72,0 67,0 ISO 124 Non-rubber solids a , % (m/m), max. 5,5 8,0 7,5 Alkalinity (as NH 3 ), % (m/m) with respect to the latex, min. 0,60 ISO 125 Alkalinity (as KOH), % (m/m) with respect to the latex, min. 0,75 0,80 ISO 125 Mechanical stability, seconds, min. 540 ISO 35 Coagulum cont
23、ent, % (m/m), max. 0,05 0,05 0,05 ISO 706 Copper content, mg/kg of total solids, max. 8 8 8 ISO 8053 Manganese content, mg/kg of total solids, max. 8 8 8 ISO 7780 Sludge content, % (m/m), max. 0,40 0,40 0,40 ISO 2005 Volatile fatty acid (VFA) number As agreed by the interested parties but not to exc
24、eed 0,20 ISO 506 Colour on visual inspection No pronounced blue or grey Odour after neutralization of ammonia with boric acid No pronounced odour of putrefaction a The difference between total solids content and dry rubber content. Dry rubber content shall be determined in accordance with ISO 126.BS
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