1、BRITISH STANDARD BS 4840-1: 1985 Rigid polyurethane (PUR) foam in slab form Part 1: Specification for PUR foam for use in transport containers and insulated vehicle bodies UDC 678.664-405.8-412:678.06:62-758:621.869.888.8BS4840-1:1985 This British Standard, having been prepared under the directionof
2、 the Plastics StandardsCommittee, was published under the authority ofthe Board of BSI and comes intoeffect on 28 June 1985 BSI 07-1999 First published as BS 4840 June1973 First revision as BS 4840-1 June1985 The following BSI references relate to the work on this standard: Committee reference PLM/4
3、6 Draft for comment 83/38545 DC ISBN 0 580 14377 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Plastics Standards Committee (PLM/-) to Technical Committee PLM/46, upon which the following bodies were represented: Association of Build
4、ing Component Manufacturers Ltd. Brick Development Association British Board of Agrment British Plastics Federation British Rigid Urethane Foam Manufacturers Association British Urethane Foam Contractors Association (BUFCA) Chief and Assistant Chief Fire Officers Association Department of the Enviro
5、nment (Building Research Establishment) Department of the Environment (Building Research Establishment Fire Research Station) Department of the Environment for Northern Ireland Department of the Environment (Housing and Construction Industries) Department of the Environment (Property Services Agency
6、) Engineering Equipment and Materials Users Association Felt Roofing Contractors Advisory Board Fire Offices Committee Greater London Council Institute of Refrigeration Ministry of Defence National Cavity Insulation Association National Coal Board National Federation of Roofing Contractors National
7、House-building Council Phenolic Foam Manufacturers Association Royal Institute of British Architects Shipowners Refrigerated Cargo Research Association Structural Insulation Association The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Bitu
8、minous Roofing Council Rubber and Plastics Research Association of Great Britain Amendments issued since publication Amd. No. Date of issue CommentsBS4840-1:1985 BSI 07-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Designation 1 3 Composition and form 1 4 Sam
9、pling 1 5 Physical properties 1 6 Dimensional tolerances 3 Appendix A Guidance for designers 4 Appendix B Burning properties of PUR foam and recommendations regardingitsuse 4 Appendix C Guidance intended to minimize fire hazards 4 Appendix D Method for the determination of apparent water absorption
10、5 Table 1 Physical property requirements 2 Table 2 Dimensional tolerances for lengths, widths and diagonals 3 Publications referred to Inside back coverBS4840-1:1985 ii BSI 07-1999 Foreword This Part of BS4840 has been prepared under the direction of the Plastics Standards Committee and, together wi
11、th Part 2, it supersedes BS4840:1973 which is withdrawn. The separation of the standard into two Parts more accurately reflects the current technology and use of rigid polyurethane (PUR) foam in slab form. Materials covered in this Part are designated type1(LD) and type1(HD). Type1(LD) covers those
12、materials previously designated type1in BS4840:1973 and in addition includes materials for use in insulated vehicle bodies. Type1(HD) covers materials of high density for high compressive load-bearing applications, such as load-bearing beams in transport containers. Other principal changes from BS48
13、40:1973 are as follows. a) For type1(LD) material, the requirement for shear strength parallel to the major plane of the slab is150kPa whereas previously it was175kPa. b) For both type1(LD) and type1(HD) materials, requirements are now included for water vapour permeability and apparent water absorp
14、tion. Requirements for rigid (PUR) foam in slab form for refrigerator cabinets, cold rooms and stores, which is designated type2, are specified in BS4840-2. Although this Part is intended primarily for quality assurance uses, guidance has been included for those involved in design work (Appendix A).
15、 This Part also contains guidelines (Appendix B and Appendix C) on burning properties and fire hazards. These guidelines are in accordance with the principles recommended in BS6336. Attention is drawn to BS6586-1 which specifies requirements for rigid polyurethane foam produced by the press injectio
16、n method for use in transport containers and insulated vehicle bodies. 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 confer imm
17、unity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 6, 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
18、 amendment table on the inside front cover.BS4840-1:1985 BSI 07-1999 1 1 Scope This Part of BS4840 specifies requirements for the composition, physical properties and dimensional tolerances of rigid polyurethane (PUR) foam in slabs (blocks, boards and sheets) for the thermal insulation of transport
19、containers and insulated vehicle bodies. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Designation The materials specified in this Part of BS4840 are designated type1(LD) and type1(HD). These materials differ principally in their compressive s
20、trength. Type1(LD) is for thermal insulation of transport containers and insulated vehicle bodies and type1(HD) is for high density compressive load-bearing members in these constructions. NOTEType1(HD) is generally used as an insulated support between the cargo floor and the base structure. As such
21、, the stress experienced by the PUR foam is mainly compressive. 3 Composition and form The slabs shall consist of rigid polyurethane (PUR) foam, shall be flat and shall have a uniform cellular structure. NOTENo requirement for odour is included as its assessment is largely subjective. However, it is
22、 recommended that the material should be supplied free from objectionable odour. The slabs should also be supplied free from irregular surface skin. 4 Sampling One slab shall be selected at random for test from each five hundred slabs of any consignment, or from the total if this is less than five h
23、undred. In the event of non-compliance of any slab with the requirements of this standard, two more slabs shall be tested from the same group of five hundred. If either of these slabs does not comply, the whole consignment shall be considered not to comply with the requirements of this standard. 5 P
24、hysical properties The physical properties shall comply with the requirements given in Table 1.BS4840-1:1985 2 BSI 07-1999 Table 1 Physical property requirements Physical property Test requirements Test method Type 1 (LD) Type 1 (HD) Max. thermal conductivity at10 C, W/(mK) 0.021 0.040 Method 7 as d
25、escribed in clause 2 of BS 4370-2:1973 Carry out the test, at a mean temperature of10 C,30 2 days after manufacture and after conditioning throughout this period at23 2 C and50 5% r.h. NOTESeeAppendix A for thermal conductivity measured 3 days after manufacture. Min. compressive strength normal to t
26、he major plane of the slab, kPa 210 2100 Method 3 of BS 4370-1:1968 Apply force normal to the major plane of the slab Min. shear strength parallel to the major plane of the slab, kPa 150 No requirement Method 6 as described in clause 1 of BS 4370-2:1973 Min. tensile strength, parallel to the major p
27、lane of the slab, kPa 210 No requirement Method 9 as described in clause 4 of BS 4370-2:1973 Apply force parallel to the major plane of the slab Min. tensile strength, perpendicular to the major plane of the slab, kPa 240 No requirement Method 9 as described in clause 4 of BS 4370-2:1973 Apply force
28、 normal to the major plane of the slab Dimensional stability max. mean linear change, % Test conditions: Method 5A as described in 5.2 of BS 4370-1:1968 Cut the length and width of the test specimen parallel to the major plane of the slab 24 h at 15 2 C 24 h at 100 2 C 24 h at 70 2 C and 95 5 % r.h.
29、 1 2 3 1 2 2 Max. water vapour permeability normal to the major plane of the slab, ng/(Pasm) 5.5 5.5 Method 8 as described in clause 3 of BS 4370-2:1973 Carry out the test at38 0.5 C,88 2% r.h. on one face of the test specimen and0% r.h. on the other. Cut the cylindrical test specimens255mm thick su
30、ch that their plane faces are parallel to the major plane of the slabBS4840-1:1985 BSI 07-1999 3Table 1 Physical property requirements Table 2 Dimensional tolerances for lengths, widths and diagonals 6 Dimensional tolerances The permissible deviation of thickness shall be 1.5mm. Other dimensional to
31、lerances shall comply with the requirements given in Table 2. Physical property Test requirements Test method Type 1 (LD) Type 1 (HD) Max. apparent water absorption by volume, % 6.5 6.5 Appendix D Min. closed cell content apparent volume, % 85 No requirements Method 10 as described in clause 5 of BS
32、 4370-2:1973 Burning characteristics a extent of burning not to exceed125mm extent of burning not to exceed125mm BS 4735 a CAUTION. The small-scale laboratory test described in BS4735 is solely for assistance in monitoring consistency of production and is not for use as a means of assessing the pote
33、ntial fire hazard of a material in use. (SeeAppendix B and Appendix C.) Lengths or widths Permissible deviations of lengths or widths Maximum differences between the longest diagonals of rectangular slabs mm mm mm Up to and including 100 1 3 Over 100 up to and including 1 000 1.5 5 Over 1 000 up to
34、and including 2 000 2.5 7 Over 2 000 up to and including 4 000 5 13 Over 4 000 10 25BS4840-1:1985 4 BSI 07-1999 Appendix A Guidance for designers PUR slabstock foams of apparent densities30 kg/m 3to37kg/m 3are normally suitable for type1(LD) and140kg/m 3to200kg/m 3for type1(HD). The attention of des
35、igners is drawn specifically to the following points: a) the possible increase in the value of the thermal conductivity of type1(LD), which can increase to0.025W/(mK) measured at a mean temperature of10 C over a period of time depending upon environmental conditions; b) the maximum thermal conductiv
36、ity at30days of0.021W/(mK) for type1(LD) corresponds to a maximum of0.019W/(mK) measured3days after manufacture and at a mean temperature of10 C; c) the need for water and moisture vapour barriers on the surfaces of the PUR foam; d) the possibility of corrosion at the interface of PUR foam and metal
37、 surfaces in the presence of water vapour; e) the possible deleterious effects, including odour, of some adhesives; f) the fire performance of the complete structure, which is largely determined by the facings applied to the foam and the design of the component or structure (seeAppendix B); where Fi
38、re Regulations apply, these usually specify given ratings for Standard Fire Tests on specimens of the completed structure and should be considered at an early stage. Appendix B Burning properties of PUR foam and recommendations regarding its use The fire performance of the finished structure or arti
39、cle which contains PUR foam is most relevant when considering the possible fire hazard associated with PUR foam. PUR foam is an organic material and hence is combustible. Care should be taken to avoid its ignition, particularly since the burning rate of the PUR foam, if exposed, can be significantly
40、 greater than that of wood. The risk of ignition and fire growth associated with PUR foam in building construction, industry, transport, etc., should be assessed in accordance with the recommendations of BS6336, i.e.consideration should be given to the design of the end product formed from, or incor
41、porating the PUR foam and the risks to which it might be exposed. Recommendations on the provision of suitable protective measures, together with references to appropriate regulatory requirements are given in the British Standards for the end products. In general, the performance of the latter is pr
42、imarily controlled by the type of finish or facing used in conjunction with the foam and the way in which the composite is used. This standard is concerned only with the specification of PUR foam as a basic material, formulated so that under certain well-defined conditions, its tendency to ignite is
43、 reduced to a given level, when tested as described in BS4735. Whilst treatment to this level can prevent sustained ignition of PUR foam by small energy sources such as a match or small burner flame, this is no longer true if the severity of the source is increased. Once ignition has occurred, compl
44、iance with the requirement for ignitability given in Table 1 ceases to be relevant; in fact, any modification in formulation introduced to satisfy the requirement may adversely affect the levels of smoke generated in a “fully-developed” fire. Care should be taken during the construction or repair of
45、 any structure or article which contains PUR foam. The use of heat sources such as welding torches in the vicinity of the foam should be avoided unless precise instructions are available on safety measures appropriate to the individual construction. Appendix C Guidance intended to minimize fire haza
46、rds The following practices are recommended wherever PUR foam is manufactured, stored or fabricated. a) Maintain good housekeeping standards. b) Observe stringent fire precautions, especially in respect of welding operations. Prohibition of smoking, except in designated areas, is advised. c) Ensure
47、that employees are fully aware of the potential fire hazards presented by these materials. d) Consult HM Factory Inspectorate for advice in respect of fire precautions during manufacture, storage and handling. e) Maintain fire drill procedures in consultation with the Fire Authority.BS4840-1:1985 BS
48、I 07-1999 5 f) Inform the Fire Authority of materials being used. g) Install suitable fire protective systems as required by the situation, e.g.fire-segregated storage, automatic sprinkler system, fire detection system. Appendix D Method for the determination of apparent water absorption D.1 Princip
49、le This method describes a procedure for determining the apparent water absorption of rigid cellular materials resulting from immersion in water under specified conditions of depth and time. The principle of the method is that the buoyant force of an object less dense than water when submerged is equal to the weight of water it displaces less the dry weight of the object. Water absorbed by the object reduces the buoyant force by reducing the volume of water displaced. The water absorption absorption may be deter
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