1、BRITISH STANDARD BS 5241-2: 1991 Rigid polyurethane (PUR) and polyisocyanurate (PIR) foam when dispensed or sprayed on a construction site Part 2: Specification for dispensed foam for thermal insulation or buoyancy applicationsBS5241-2:1991 This British Standard, having been prepared under the direc
2、tionof the Plastics and Rubber Standards Policy Committee, was published underthe authority of the Standards Board and comes into effect on 31May 1991 BSI 08-1999 First published as BS 5241 July1975 Second edition May 1991 The following BSI references relate to the work on this standard: Committee r
3、eference PRM/72 Draft for comment 90/36146 DC ISBN 0 580 19568 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Plastics and Rubber Standards Policy Committee (PRM/-) to Technical Committee PRM/72, upon which the following bodies were r
4、epresented: Association of Building Component Manufacturers Brick Development Association British Board of Agrement British Plastics Federation British Rigid Urethane Foam Manufacturers Association Calcium Silicate Brick Association Limited Cavity Foam Bureau Chief and Assistant Chief Fire Officers
5、Association Department of the Environment (Building Research Establishment) Department of the Environment (Construction Industries Directorate) Engineering Equipment and Materials Users Association Flat Roofing Contractors Advisory Board Loss Prevention Council Ministry of Defence National Cavity In
6、sulation Association National Federation of Roofing Contractors National House-building Council Phenolic Foam Manufacturers Association Polyethylene Foam Insulation Association Royal Institute of British Architects The following bodies were also represented in the drafting of the standard, through s
7、ubcommittees and panels: British Ceramic Research Ltd. British Urethane Foam Contractors Association (BUFCA) Department of the Environment Department of the Environment (Property Services Agency) RAPRA Technology Ltd. Amendments issued since publication Amd. No. Date CommentsBS5241-2:1991 BSI 08-199
8、9 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Designation 1 3 Composition 1 4 Sampling 1 5 Physical properties 1 6 Marking 1 Appendix A Notes for designers 4 Appendix B Guidance on thermal conductivity design and 3 day values 4 Appendix C Burning characteristics
9、 of polyurethane and polyisocyanurate rigidfoams and recommendations regarding their use 4 Table 1 Physical properties 2 Table 2 Designation codes for thermal conductivity 3 Publication(s) referred to Inside back coverBS5241-2:1991 ii BSI 08-1999 Foreword This Part of BS 5241 has been prepared under
10、 the direction of the Plastics and Rubber Standards Policy Committee, and is the final Part of the revision of BS5241:1975, which is withdrawn. The standard has now been divided into two Parts to bring the standard in line with the current technology. In Part 1 the specific requirements of sprayed p
11、olyurethane and polyisocyanurate foams applied externally have been detailed, whereas Part 2now covers the requirements for applications where foam is dispensed and introduces requirements for the thermal conductivity to be designated by the manufacturer. The attention of contractors and purchasers
12、is drawn to the fact that this specification covers the foam only. It may be necessary to apply primers or vapour retarders to the substrate to enhance the adhesion, prevent corrosion or reduce vapour transmission. WARNING. Adequate fire precautions should be taken when repairing any structure conta
13、ining polyurethane or polyisocyanurate foams. Do not use welding or flame cutting equipment. 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 no
14、t of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1to4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will
15、 be indicated in the amendment table on the inside front cover.BS5241-2:1991 BSI 08-1999 1 1 Scope This Part of BS5241specifies the physical property and compositional requirements for dispensed polyurethane (PUR) and polyisocyanurate (PIR) foams used for thermal insulation of external surfaces and
16、for positive buoyancy, e.g. small boats, buoys or pontoons, for surface applications. NOTEThe titles of publications referred to in this standard are listed on the inside back cover. 2 Designation The materials shall be designated according to their compression strength and ignitability characterisi
17、tcs into five types (see Table 1). Each type shall be further divided into subtypes by the addition of a code to indicate the thermal conductivity (see5.2). NOTEThe higher strength materials are clearly of benefit in robust applications, e.g. in very cold applications. Type3is preferred for buoyancy
18、 applications because of its greater resistance to water penetration (see Appendix A). The designation shall consist of a three component code comprising the following items, in the order presented. a) The number and date of this British Standard, i.e. BS5241-2:1991. b) A number indicating the foam
19、type, as given in Table 1. c) A double digit number to indicate the thermal conductivity selected in accordance with Table 2. An example of the designation required for a type4foam with a thermal conductivity of0.020W/(mK) (see5.2) is as follows: BS 5241-2:1991/4/20. 3 Composition The material shall
20、 be of rigid polyurethane (PUR) or polyisocyanurate (PIR) foam. A material indicated by (PUR) shall be substantially composed or urethane linkages and one indicated by (PIR) shall be substantially composed of isocyanurate linkages. NOTENo requirements for odour is included as its assessment is large
21、ly subjective. However, it is recommended that the material should be free from objectionable odour. 4 Sampling Samples shall be prepared in a suitably designed jig of similar thickness to the application, and constructed from the same material as the facing materials being treated. 5 Physical prope
22、rties 5.1 General The materials shall comply with Table 1when tested in accordance with the methods listed therein. 5.2 Thermal conductivity Thermal conductivity shall be determined by either method7A or7B of BS4370-2:1991at a mean temperature of10 C, 302days after manufacture. Materials shall be co
23、nditioned throughout this period at23 2 C and50 5 % r.h. NOTESee additional guidance in Appendix B on information concerning the thermal conductivity design values and on the values to be obtained3days after manufacture. 6 Marking The material, packaging, or invoice shall be clearly marked with at l
24、east the following information: a) the manufacturers name or trademark; b) the designation 1)as given in clause2. 1) Marking BS5241-2:1991on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufacturer that the product meets the r
25、equirements of the standard. The accuracy of the claim is therefore solely the responsiblility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BS 5241-2:1991 2 BSI 08-1999 Table 1 Physical properties P
26、hysical property Test requirement Test method Foam type Foam type Foam type Foam type Foam type 1 2 3 4 5 Density core minimum (in kg/m 3 ) 30 40 50 35 35 Method 2of BS 4370-1 Minimum compressive strength (inkPa) (see Appendix A) 100 150 200 150 150 Method 3 of BS 4370-1 applying the force in a dire
27、ction normal to the major plane of the foam Dimensional stability: maximumchange (in %) Method 5A or 5B of BS 4370-1 24 h at 15 2 C 1 1 1 1 1 24 h at 100 2 C 2 2 2 2 2 24 h at 125 2 C 2 2 24 h at 70 2 C and 95 5 % r.h. 3 3 3 3 3 Closed cell content: minimumapparent volume (in %) 85 85 90 90 90 Metho
28、d 10 of BS 4370-2 Burning characteristics: extentofburning (in mm) 125 125 125 125 25 Method 8 of BS 4735 (see cautionary note) Maximum water vapour permeability in ng/(Pasm) 5.5 5.5 3.5 5.5 8.5 Method 8 of BS 4370-2 at 38 C and 88 % r.h. Maximum apparent water absorption by volume (in %) 6.5 6.5 2.
29、0 6.5 6.5 As described in Appendix B of BS 5241-1:1989 CAUTION. The small scale laboratory test described in BS 4735 is solely for assistance in monitoring consistency of production and is not for use as a means of assessing potential fire hazard of a material in use (see Appendix C).BS5241-2:1991 B
30、SI 08-1999 3 Table 2 Designation codes for thermal conductivity Thermal conductivity a(see5.2) Code W/(mK) 0.015 15 0.016 16 0.017 17 0.018 18 0.019 19 0.020 20 0.021 21 0.022 22 0.023 23 0.024 24 0.025 25 0.026 26 0.027 27 0.028 28 0.029 29 0.030 30 0.031 31 0.032 32 a CAUTION. These values are30da
31、y values for quality control purposes. For corresponding long term design values the manufacturers advice should be sought.BS5241-2:1991 4 BSI 08-1999 Appendix A Notes for designers Attention is drawn to the following points of specific relevance to rigid PUR and PIR foams. a) Type 1are normally fou
32、nd to be suitable for most general purpose insulation between0 C and85 C, and for positive buoyancy in surface applications less than1m in depth. Higher compression strength materials, type2, are used in thermal insulation applications where temperatures fall into the range 30 C to85 C and for buoya
33、ncy in water depths up to3m. Type3are used for temperatures 100 C to85 C and in water depths from3m to10m. Thermal insulation for temperatures lower than 100 C and buoyancy in depths of water greater than10m need special formulations not covered by this specification. Types4or5 are to be used for th
34、ermal temperatures exceeding85 C but less than150 C. Type3foams are also more stable for applications where a greater degree of robustness is required, such as applications in floats or tank roofs which may be subject to foot traffic. b) When specifying materials for the insulation of district heati
35、ng pipes designers should also consult BS4508. Appendix B Guidance on thermal conductivity design and 3day values In addition to the30day maximum thermal conductivity value which forms the specification value for the purposes of this standard, two related maximum thermal conductivity values have pra
36、ctical importance, and will be necessarily provided for the product by the manufacturer as follows. a) Design value of thermal conductivity. This figure takes into account the limited diffusion of gases which can take place in the foam with time. The design value should be used as a basis for user c
37、alculations. Generally this will be higher than or equal to the30day value. b) The 3 day value of thermal conductivity. This value is often used in manufacturing control operations, to ensure the quality of product is regularly maintained. Generally it will be lower than or equal to the 30day value.
38、 Appendix C Burning characteristics of polyurethane and polyisocyanurate rigid foams and recommendations regarding their use Consideration of the fire performance of the finished structure incorporating rigid polyurethane (PUR) foam is relevant to the possible hazard associated with PUR foam. This s
39、hould be assessed using BS6336 which gives recommendations on how fire hazard should be considered, taking into account the design of the end product and any possible risk to which it might be exposed in use. PUR foam is an organic, and hence combustible material. Care should be taken to avoid ignit
40、ion, particularly since the burning rate of the foams, if exposed, can be significantly greater than that of wood. The contribution to fire growth of PUR is controlled by the type of finish or facing used in conjunction with the foam. It is generally accepted that insulation contained behind facings
41、 of high heat capacity does not have a significant effect on the initial rate of fire growth which is primarily affected by the fire performance of the exposed surface lining. Recent research 2)has indicated that generally, provided the insulation is contained within a cavity wall with limited venti
42、lation so that circulation of air and hot gas is prevented in the cavity, an effective restriction to fire spread can be achieved. Care should be taken during installation or repair of any structure or article which contains PUR to avoid any possible ignition sources. 2) Fire performance of combusti
43、ble insulation in masonry cavity walls. B.F.W. Rogowski, Fire Safety Journal, 1984/85, 8, 119134.BS5241-2:1991 BSI 08-1999 Publication(s) referred to BS 4370, Methods of test for rigid cellular materials. BS 4370-1, Methods 1 to 5. BS 4370-2, Methods 6 to 10. BS 4508, Thermally insulated underground
44、 pipelines. BS 4735, Laboratory method of test for assessment of the horizontal burning characteristics of specimens no larger than 150 mm 50 mm 13 mm (nominal) of cellular plastics and cellular rubber materials when subjected to a small flame. BS 5241, Rigid polyurethane (PUR) and polyisocyanurate
45、(PIR) foam when dispensed or sprayed on a construction site. BS 5241-1, Specification for sprayed foam thermal insulation applied externally. BS 6336, Guide to development and presentation of fire tests and their use in hazard assessment. BS 5241-2: 1991 BSI 389 Chiswick High Road London W4 4AL BSIB
46、ritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of Br
47、itishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the
48、 technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orde
49、rs for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Variou
