1、BRITISH STANDARD BS3757:1978 Incorporating Amendment No. 1 Specification for Rigid PVC sheet UDC 678.743.22415BS3757:1978 This British Standard, havingbeen prepared under thedirection of the Plastics Standards Committee, was published under the authority ofthe Executive Board on 29 December1978 BSI
2、07-1999 Part 1 first published June 1964 Part 2 first published March 1965 First revision (Parts 1 and 2 combined) December 1978 The following BSI references relate to the work on this standard: Committee reference PLM/40 Draft for approval 78/52110 ISBN 0 580 10342 0 Cooperating organizations The P
3、lastics Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: British Plastics Federation* British Resin Manufacturers Association Chemical Industries Associati
4、on Department of Industry, Chemicals and Textiles Department of Industry, National Physical Laboratory Department of the Environment, Building Research Station Electrical and Electronic and Insulation Association (BEAMA)* Electrical Installation Equipment Manufacturers Association (BEAMA) Electrical
5、 Research Association* Engineering Equipment Users Association Institution of Production Engineers Ministry of Defence* Plastics and Rubber Institute Post Office Royal Institute of British Architects Rubber and Plastics Research Association of Great Britain Society of Chemical Industries The Society
6、 of Motor Manufacturers and Traders Limited The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: British Refrigeration and Air Conditioning Association Department
7、of the Environment (PSA) Furniture Industry Research Association Packaging and industrial Films Association Pira (The Research Association for the Paper and Board, Printing and Packaging Industries) Amendments issued since publication Amd. No. Date of issue Comments 6291 July 1990 Indicated by a sid
8、eline in the marginBS3757:1978 BSI 07-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definition 1 4 General requirements 1 5 Performance requirements 3 Appendix A Determination of resistance to delamination 4 Appendix B Determination of reten
9、tion of embossed surface after heating 4 Appendix C Determination of retention of embossed surface after heating of sheet to be used for vacuum forming 5 Appendix D Determination of impact strength 5 Appendix E Determination of tensile strength 6 Appendix F Determination of dimensional change at120
10、C 6 Figure 1 Test wedge 4 Table 1 Type descriptions 1 Table 2 Sheet thickness (in millimetres) 1 Table 3 Performance requirements 2 Table 4 Period of immersion in relation to thickness 5 Table 5 Period of heating in relation to thickness 6 Publication referred to Inside back coverBS3757:1978 ii BSI
11、07-1999 Foreword This British Standard has been prepared under the direction of the Plastics Standards Committee. Part1 of BS3757 was first published in1964 and Part2 in1965. In this revision the previous Parts1 and2 of the standard have been combined. Preferred thicknesses of sheet are given and SI
12、 units have been used. In this revision two of the types of sheet, types A2 and C2, previously included, have been deleted. This is because it is considered that it is not possible to lay down a single requirement relevant to all chemical contact application. For applications involving contact with
13、chemicals refer to the note to Table 1. This standard includes tests that provide the basic data for the control of quality of rigid PVC sheet. Such data are not, however, necessarily suitable for design purposes. The methods of test used in this standard are, as far as possible, those described in
14、BS2782. The method of manufacture has an effect on certain properties, the most important being dimensional stability of the material at high temperatures (see Table 3, note3). During 1973-4 several discussions took place in the Executive Board of BSI as a result of concern about potential fire haza
15、rds involved in the rapidly increasing use of many polymeric materials, especially for furnishing and construction purposes. Issues of great public importance were involved, relating in particular to the use of laboratory fire tests to define quality requirements, in view of the general lack of corr
16、elation between the results obtained in such small scale tests and the fire performance of materials and products in actual conditions of use. The Executive Board decided that a detailed review of all the issues involved should be carried out as a matter of urgency, and that this should be comprehen
17、sive in scope rather than limited to polymeric materials. For this purpose an authoritative co-ordinating committee on fire tests was established. In the meantime certain general principles were laid down regarding the terminology and approach to be adopted in immediate revisions and amendments of t
18、he British Standards involving small scale fire tests. This British Standard has been drawn up to comply with these principles. Changes may be made at a later date as a result of the general review undertaken by the co-ordinating committee mentioned above. Certification. Attention is drawn to the ce
19、rtification facilities described on the inside back cover of 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 application. Compliance with a British Standard does not of itself confe
20、r immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesiandii, pages1to6, 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
21、 amendment table on the inside front cover.BS3757:1978 BSI 07-1999 1 1 Scope This British Standard specifies requirements for rigid PVC sheet of nominal thickness0.25mm and above. Rigid PVC sheet is classified into six types as shown in Table 1, and is available in a wide range of colours. Types A a
22、nd B are manufactured by press lamination or press surfacing and types C and D by calendering or extrusion. Table 1 Type descriptions 2 References The title of the publication referred to in this standard is given on the inside back cover. 3 Definition 3.1 for the purposes of this British Standard t
23、he following definition applies rigid PVC sheet Rigid thermoplastic sheet consisting of polyvinyl chloride and/or copolymers of vinyl chloride of which the major constituent is vinyl chloride, suitably compounded with other ingredients 4 General requirements 4.1 Appearance. Unless otherwise agreed,
24、the sheet shall be uniform in colour, transparency or opacity and finish, and shall be reasonably free from detrimental scratches, dents, pimples and inclusions. Embossed sheet shall have the pattern uniformly applied. 4.2 Thickness. The preferred nominal thicknesses of sheet are given in Table 2. T
25、he thickness of a sheet at any point shall not differ from the nominal thickness by more than the tolerance given in Table 2. The thickness of plain sheet shall be determined by micrometer as described in method512B of BS2782:1970 and the thickness of embossed sheet shall be measured gravimetrically
26、 generally in accordance with method512A of BS2782:1970. For a particular embossed surface and where the relationship between gravimetric and micrometer thickness is known, the thickness may be measured non-destructively by micrometer but method512A of BS2782:1970 shall be used in case of dispute. T
27、able 2 Sheet thickness (in millimetres) Type Description (see note) A1 C1 General purpose sheet suitable for most applications and fabricating techniques. A3 C3 Sheet similar to types A1 and C1 but with specific impact strength. The chemical resistance of these types may be inferior to that of types
28、 A1 and C1. B D Sheet particularly suitable for deep vacuum forming. These types are generally characterized by a lower softening point and the maximum service temperature of articles made from them may consequently be reduced. NOTEThe descriptions of the various types in Table 1 are given for gener
29、al guidance, but the suitability of the material for a particular application depends on several factors and the suppliers advice should always be sought before a final choice is made, particularly where the application involves contact with chemicals. The suitability of the product for any chemical
30、 application should be assessed on background knowledge and service conditions required, and, if necessary, tests relevant to the specific applications should be carried out. Where the sheet is to be used in contact with foodstuffs or potable water, discussion with the supplier is essential since se
31、lected formulations are normally required in such cases. Intending users of rigid PVC sheet for foodstuffs contact applications are advised to consult the “Code of practice for plastics in foodstuffs contact applications” published by the British Plastics Federation, 5 Belgrave Square, London SW1X8P
32、H, with the cooperation of the British Industrial Biological Research Association. Nominal thickness Thickness tolerance for any point on the sheet Types A and B (pressed) Types C and D (calendered or extruded) 0.25 0.5 0.75 20% 1.0 1.5 18% 2.0 2.5 3.0 3.5 4.0 4.5 15% 10% 5.0 6.0 8.0 9.0 10.2 12.0 1
33、8.0 24.0 10% BS3757:1978 2 BSI 07-1999 4.3 Length and width. For sheets up to3m long, the length and width of a sheet when measured at23 2 C shall be within the tolerance0mm+6mm of the nominal size, and the lengths of the diagonals shall not differ by more than1mm per500mm length of sheet. For speci
34、al shapes, the tolerances on linear dimensions shall be as agreed between the supplier and the purchaser. 4.4 Delamination. When a sheet of not less than1.5mm nominal thickness is tested in accordance with the requirements of Appendix A, it shall show no signs of delamination. 4.5 Horizontal burning
35、 characteristics of a150mm 13mm 1.5mm test specimen when exposed to a small flame. When tested in accordance with method508A (as amended in1974 1) ) of BS2782:1970 three consecutive specimens shall not burn to the first mark and shall show no flame or afterglow5s after the burner has been removed. N
36、OTEThe test method described in method508A is used primarily for the purpose of monitoring the consistency of production of the PVC sheet. Its use gives an indication of a suitable formulation which influences the performance of a test specimen as measured by this method. In no circumstances shall t
37、he test results thus obtained be considered as an overall indication of the potential fire hazards presented by PVC sheet under the actual conditions of use. 4.6 Retention of embossed surface after heating. When embossed sheet of typesC1 andC3 is tested in accordance with the method described in App
38、endix B, the general pattern of the embossed surface shall remain without substantial loss of depth. When agreed between the supplier and the purchaser, embossed sheet that is to be used for vacuum forming shall be tested in accordance with the method described in Appendix C and the depth of the emb
39、ossed pattern shall remain substantially unchanged. A test temperature other than160 C may be used by agreement between the supplier and the purchaser. Table 3 Performance requirements 1) Amendment No. 3 published 1974 to BS 2782:1970. Property Expressed as Test method Min. or max. Minimum nominal t
40、hickness to which test applies Types A1 C1 A3 C3 B D Softening point C BS2782-1: Method120A min 70 70 60 60 50 50 Impact strength Number of failures Appendix D max. 1.0mm a a No failures No failures a a Tensile strength MPa Appendix E min. 45 45 38 38 38 38 Elastic modulus in bend MPa Method335A of
41、BS2782:1978 min. 0.5mm 2500 2500 2000 2000 2000 2000 Dimensional change at120 C % Appendix F (see note 3) max. 5 15 5 15 15 b NOTEThe dimensional change test (Appendix F) is included to indicate the maximum dimensional change that may be encountered during fabrication processing at high temperatures
42、. These changes in dimensions at120 C are not reflected in the behaviour of the material at normal temperatures when little change may be expected. a TypesA1, B,C1,and D may be tested for impact strength by the method described in Appendix D and the permitted number of failures shall be subject to a
43、greement between the supplier and the purchaser. b Type D may be tested in accordance with the requirements of Appendix F but the test temperature and the limits shall be as agreed between the supplier and the purchaser.BS3757:1978 BSI 07-1999 3 5 Performance requirements When the material is tested
44、 in accordance with the methods listed in Table 3 the results for each type shall comply with the appropriate requirements given in Table 3. For certain specialized applications, additional test requirements may be appropriate. In such cases the test methods and limits shall be agreed between the su
45、pplier and the purchaser. Wherever possible, the test methods in BS2782 should be used. Additional requirements of this type may, for example, include the following: electrical properties, mechanical properties at temperatures other than23 C, mechanical properties after ageing, notch sensitivity (im
46、pact strength), colour fastness to light, resistance to specific chemicals.BS3757:1978 4 BSI 07-1999 Appendix A Determination of resistance to delamination A.1 Thickness limitation. This method is intended for sheet not less than1.5mm thick. A.2 Form of test specimen. A rectangular specimen150mm lon
47、g,25mm wide and of the thickness of the sheet under test shall be used. It shall be cut from the edge of the sheet with its length parallel to the edge of the sheet. A.3 Number of test specimens. One specimen shall be used. A.4 Apparatus. The following apparatus shall be used. A.4.1 Vice, mounted on
48、 a rigid base, for holding the specimen. A.4.2 Light hammer or mallet A.4.3 Wedge, having the dimensions shown in Figure 1 and made from tempered steel, e.g.a machined hacksaw blade. A.5 Procedure. Clamp the specimen in the vice with its width vertical, and so that one150mm edge is horizontal and15m
49、m above the jaws of the vice. Place the sharp point of the wedge on the horizontal edge of the specimen, the width of the wedge being parallel to the plane of lamination of the specimen. Strike the wedge a sharp blow with the hammer or mallet and repeat this at five approximately equidistant points across the thickness of the specimen, these points being approximately equidistant along the length of the specimen. If, at
