1、BRITISH STANDARD BS4098:1975 Incorporating Amendment No.1 Method for the Determination of thickness, compression and recovery characteristics of textile floor coverings UDC 677.643:677.017.224+677.017.43BS4098:1975 This British Standard, having been approved by the Textile Divisional Council, was pu
2、blishedunder the authority ofthe Executive Board on 30 September1975 BSI 07-1999 First published January1967 First revision September1975 The following BSI references relate to the work on this standard: Committee reference T/16/5 Draft for comment74/35630 DC ISBN 0 580 08936 3 Co-operating organiza
3、tions The Textile Divisional Council, under whose supervision this British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: British Railways Board* Consumer Standards Advisory Committee of BSI Consumers Associati
4、on Cotton Industry Standards Committee Jute Industry Standards Committee Linen Industry Standards Committee London Transport Executive Man-made Fibres Industry Standards Committee Ministry of Defence* Ropes and Cordage Industry Standards Committee Silk Industry Standards Committee Society of Dyers a
5、nd Colourists Textile Institute* Textile Machinery Industry Standards Committee Textile Research Conference* Trades Union Congress Wool Industry Standards Committee The Government department and scientific and industrial organizations marked with an asterisk in the above list, together with the foll
6、owing, were directly represented on the subcommittee entrusted with the detailed preparation of this British Standard. This subcommittee was set up by the Standing Joint Committee for Textile Test Methods, the members of which were appointed by the Textile Institute and the British Standards Institu
7、tion. Bradford Conditioning House British Carpet Industry Technical Association British Man-made Fibres Federation Cotton Silk and Man-made Fibres Research Association Department of the Environment European-Flooring Institute Federation of British Carpet Manufacturers Fibre Bonded Carpet Manufacture
8、rs Association International Wool Secretariat Retail Trading-Standards Association Inc. Tufted Carpet Manufacturers Association University of Leeds University of Manchester Wira Amendments issued since publication Amd. No. Date of issue Comments 3742 October 1981 Indicated by a sideline in the margi
9、nBS4098:1975 BSI 07-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definitions 1 4 Principle 1 5 Apparatus 1 6 Atmosphere for conditioning and testing 2 7 Test specimens 2 8 Preparation of test specimens 2 9 Test procedure 2 10 Calculation a
10、nd expression of results 2 11 Report 3 Figure 1 Typical thickness-pressure curve for textile floor coverings 4 Publications referred to Inside back coverBS4098:1975 ii BSI 07-1999 Foreword BS4098 was first published in1967 under the title “Method for the determination of thickness, compression and r
11、ecovery of carpets”. In addition to incorporating certain necessary technical changes, in this revision the title has been modified slightly, metric units have replaced imperial units, and the term “textile floor covering” has been used in place of the more restrictive “carpet”. The first edition ha
12、s been withdrawn as of the publication date of this revision. The thickness of a textile floor covering depends upon the pressure applied to it. The ability of a textile floor covering to be compressed and to recover after compression is an important factor in its performance. A background paper on
13、this subject was published in Textile Institute and Industry, 11, no.1 (April)1973. A pressure of2 kPa 1)has been adopted for measuring the initial thickness of textile floor coverings since under the conditions of test this pressure has been found to be just sufficient to flatten any protruding fib
14、res without appreciably compressing textile floor coverings of low density. The highest pressure used in this method is200kPa, which appreciably compresses most textile floor coverings. The method of measuring thickness used in this standard is based on that prescribed in BS4051 “Method for determin
15、ation of thickness of textile floor coverings”. 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 immunity from legal obliga
16、tions. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to4, 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 in
17、side front cover. 1) 1 kpa=1 kN/m 2 =10.2 gf/cm 2 =0.145 lbf/in 2 .BS4098:1975 BSI 07-1999 1 1 Scope This British Standard specifies a method for measuring the thickness, compression and recovery characteristics of all types of textile floor coverings apart from pile carpets with varying thickness a
18、nd/or density of pile, unless these areas can be measured separately. 2 References The titles of the British Standards referred to in this standard are listed on the inside back cover. 3 Definitions For the purposes of this British Standard the following definitions apply: 3.1 initial thickness the
19、thickness of a textile floor covering measured under a pressure of2kPa 3.2 compression the change in thickness of the textile floor covering when the pressure is increased from2kPa to200kPa 3.3 work of compression the work done on the textile floor covering when the pressure is increased from2kPa to
20、200kPa, i.e.the area under the load-compression curve NOTECompression takes no account of the shape of the load-compression curve. Work of compression will distinguish between textile floor coverings which, although they have the same value of compression, have differently shaped load-compression cu
21、rves. 3.4 percentage thickness recovery the thickness to which the textile floor covering recovers when the pressure is diminished from200kPa to2kPa, expressed as a percentage ofthe initial thickness 3.5 percentage compression recovery the change in thickness when the pressure is diminished from200k
22、Pa to2kPa, expressed as a percentage of the compression 3.6 percentage work recovery the work done by the textile floor covering when the pressure is diminished from200kPa to2kPa, expressed as a percentage of the work of compression from2kPa to200kPa pressure, i.e.(the area under the load-recovery c
23、urve divided by the area under the load-compression curve) 100 NOTEPercentage thickness recovery is based upon the total thickness of the textile floor covering. Percentage compression recovery would normally be expected to rank textile floor coverings in the same order as the percentage work recove
24、ry. Percentage work recovery is mainly influenced by the work done by movement of the pile in carpets and is thus more sensitive to change in the pile than percentage thickness recovery and has a much lower value. 4 Principle The thickness of a textile floor covering specimen is measured as the dist
25、ance between the reference plate on which the textile floor covering rests and a parallel circular presser-foot exerting a known pressure to an area between300mm 2and1000mm 2inclusive within a larger area of textile floor covering. By applying a series of increasing, and subsequently of decreasing,
26、loads to the specimen, the thickness at various pressures and the load-compression and load-recovery curves are determined. 5 Apparatus 5.1 The instrument used for measuring the thickness shall have a circular plane presser-foot of area between300mm 2and1000mm 2 . It shall be capable of exerting pre
27、ssures normal to the surface of the textile floor covering from2kPa to200kPa with intermediate values of5kPa,10kPa,20kPa,50kPa,100kPa and150kPa, with an accuracy of0.2kPa. The instrument shall have a means of measuring thickness with an accuracy of0.1mm over a range of25mm. The movement of the press
28、er-foot shall be normal to the plane of the textile floor covering. The reference plate on which the specimen rests shall be plane, at least125mm125mm in size, and parallel to the presserfoot to within one part in500. The reference plate and the presser-foot shall be flat to an accuracy of0.0125mm.
29、If a dial gauge is used for the thickness measurement, it shall conform to the requirements of BS907. The rigidity of the instrument frame should be such that no measurable deflection occurs under the loads to be used. 5.2 The circular guard ring shall have a mass of1000g, an external diameter not g
30、reater than125mm and an internal diameter of d+40mm (d being the diameter of the presser-foot in mm), such that a pressure of at least1 kPa is exerted. A throat of40mm width may be cut from the guard ring. 5.3 A straightedge, e.g.a ruler, for brushing the surface of the specimen.BS4098:1975 2 BSI 07
31、-1999 6 Atmosphere for conditioning and testing 6.1 The atmosphere required for conditioning and testing is the standard atmosphere for testing textiles specified in BS1051, i.e.an atmosphere of relative humidity652% and temperature20 2 C. 7 Test specimens 7.1 Textile floor coverings with yarn pile
32、or flocked pile. Prepare sufficient specimens to allow at least five tests to be made. Test specimens shall be at least75mm 75mm, but they may be of any larger dimensions as required by other tests, or several measurements may be made on one larger sample provided that the centres of the areas in co
33、ntact with the presser-foot are not less than75mm apart and the whole area of the specimen is supported in the same horizontal plane. Select these specimens well away from distorted parts of the sample. Test areas shall not contain the same warp and weft threads. 7.2 Textile floor coverings other th
34、an those covered by7.1. Prepare sufficient specimens to allow ten tests to be made. Test specimens shall be at least125mm 125mm, but they may be of any larger dimensions as required by other tests, or several measurements may be made on one larger sample provided that the centres of the areas in con
35、tact with the presser-foot are not less than75mm apart and the whole area of the specimen is supported in the same horizontal plane. Select these specimens well away from distorted parts of the sample, and ensure that the area tested has not been previously compressed by a guard ring. Test areas sha
36、ll not contain the same warp and weft threads. 8 Preparation of test specimens For specimens with a pile, brush lightly the use-surface, firstly against, then with the direction of pile lean, using a straightedge, e.g.a ruler. Lay out the specimens flat, singly and with the use-surface uppermost, in
37、 the standard atmosphere for testing textiles for a period of at least24h before testing. 9 Test procedure Ensure that the apparatus is placed on a vibration-free surface, and check that the presser-foot shaft moves freely with negligible friction. With the presser-foot and base plate in contact, se
38、t the gauge to read zero or, alternatively, obtain the zero reading for the base plate. Place the specimen, use-surface uppermost, on the base plate so that no part of the presser-foot will be within20mm of the edge of the specimen or within75mm of any previous measurement. (Whena textile floor cove
39、ring of more than one thickness level or pile construction is being tested, no part of the presser-foot shall be within20mm of a change of construction.) Lower the presser-foot gently onto the specimen to apply a pressure of2kPa, and after30s note the gauge reading to the nearest0.1mm. Use the guard
40、 ring when testing textile floor coverings without pile. NOTEThe guard ring may be used when testing other constructions. Without raising the presser-foot, add extra mass carefully 2)to increase the pressure to5kPa and record the gauge reading after30s. Then immediately increase the pressure to10kPa
41、 and after30s record the gauge reading. Continue this procedure, raising the pressure in turn to20kPa,50kPa,100kPa,150kPa and200kPa, recording the gauge reading in each case when the pressure has been applied for 30s. Immediately after taking the gauge reading at the highest pressure, reduce the pre
42、ssure to150kPa. After30s record the gauge reading and reduce the pressure to100kPa. Continue removing the mass at30s intervals, recording the gauge reading before the removal of each incremental mass, down to the original pressure of2kPa. Do not at any time decrease the pressure during the loading s
43、equence or increase it during the unloading sequence. Repeat the procedure for each specimen. 10 Calculation and expression of results 10.1 The thickness for each specimen shall be tabulated to the nearest0.1mm at each pressure. When a textile floor covering of more than one thickness level or pile
44、construction has been tested, the results for each level shall be tabulated separately and each level treated separately in the calculations and graphs that ensue. 2) Take care to add extra mass gently so that the required pressure is not exceeded.BS4098:1975 BSI 07-1999 3 The mean for each pressure
45、 shall be calculated and plotted on a graph as in Figure 1 with lines joining the mean values. The individual values of thickness at each pressure shall also be plotted on the same graph so as to display the variation. 10.2 One or more of the following estimates of compression and recovery may then
46、be calculated from the mean results: a) the compression (t 2 t 200 ) to the nearest0.1mm; b) the work of compression, in joules per square metre, estimated as the area under the loading curve 3) , e.g.area ABD in Figure 1; c) the percentage thickness recovery,100t r /t 2 ; d) the percentage compress
47、ion recovery, (t r t 200 )/(t 2 t 200 ) 100; e) the percentage work recovery, as estimated by the ratio of the work of recovery to the work of compression 3) , e.g.100 area BCE/area ABD in Figure 1. 11 Report 11.1 The report shall state that the tests were performed in accordance with this standard
48、and shall indicate which of any optional or alternative requirements have been met. 11.2 The mean thickness of the sample at2kPa, to the nearest0.1mm, and the number of specimens tested shall be reported. A graph of the individual observations with lines joining the mean values shall be given. If re
49、quired, the calculated values of compression, work of compression, percentage thickness recovery, percentage compression recovery or percentage work recovery shall be stated. In Figure 1, t 2 is the initial thickness at2kPa pressure (point A), t 200 is the compressed thickness at200kPa pressure (point B), t r is the recovered thickness at2kPa pressure after loading to200kPa pressure (point C). 3) Calculate the area under the curve as (1.5t 2 +4t 5 +7.5t 10 +20t 20 +40t 50 +50t 100 +50t 150 173t 200 ) J/m 2 where t 2is the thickness at2 kPa (mm), t 5is the t
