1、BRITISH STANDARDBS ISO 24335:2006Laminate floor coverings Determination of impact resistanceICS 97.150g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g
2、58BS ISO 24335:2006This British Standard was published under the authority of the Standards Policy and Strategy Committeeon 17 March 2006 BSI 17 March 2006ISBN 0 580 47977 3National forewordThis British Standard reproduces verbatim ISO 24335:2006 and implements it as the UK national standard. The UK
3、 participation in its preparation was entrusted to Technical Committee PRI/60, Resilient floor coverings, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, a
4、nd keep UK interests informed; monitor related international and European developments and promulgate them in the UK.A list of organizations represented on this committee can be obtained on request to its secretary.Cross-referencesThe British Standards which implement international publications refe
5、rred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online.This publication does not purport to include all the necessary provis
6、ions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to iv, pages 1 to 11 and a ba
7、ck cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsReference numberISO 24335:2006(E)INTERNATIONAL STANDARD ISO24335First edition2006-03-01Laminate floor coverings Determination of impact re
8、sistance Revtements de sol stratifis Dtermination de la rsistance aux chocs BS ISO 24335:2006ii BS ISO 24335:2006iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Apparatus 1 4 Test specimens . 6 4.1 General. 6 4.2 Specimens for the small-diameter ball test 6 4.3 Specimens for th
9、e large-diameter ball test 6 4.4 Conditioning 6 5 Procedure 6 5.1 Impact by small-diameter ball . 6 5.2 Impact by large-diameter ball 8 6 Expression of results . 9 6.1 Small-diameter ball . 9 6.2 Large-diameter ball. 9 7 Test Report 10 Bibliography . 11 BS ISO 24335:2006iv Foreword ISO (the Internat
10、ional Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has bee
11、n established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical stand
12、ardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for
13、 voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all
14、 such patent rights. ISO 24335 was prepared by Technical Committee ISO/TC 219, Floor coverings. 1Laminate floor coverings Determination of impact resistance 1 Scope This International Standard specifies how to determine the impact resistance of laminate floor covering elements. The test described me
15、asures the ability of the surface layer to withstand impact from both small and large objects dropped on the floor covering. The testing is destructive by means of the impact on the surface layer from one small and one larger steel ball simulating different scenarios. The force of the small steel ba
16、ll and the drop height of the larger steel ball are used to define the ability for a laminate floor covering element to withstand impact. The precision of the method is not known. When interlaboratory data becomes available, a precision statement will be added in subsequent revisions. 2 Normative re
17、ferences The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 291, Plastics Standard atmospheres f
18、or conditioning and testing 3 Apparatus 3.1 Conditioning chamber, in accordance with ISO 291, with a standard atmosphere of (23 r 2) C and relative humidity (50 r 5) %. 3.2 Polyethylene foam, thickness (2 r 0,5) mm, density (35 r 5) kg/m3. 3.3 Small-diameter ball apparatus 3.3.1 Impact tester, consi
19、sting of an impact bolt with a 5 mm steel ball mounted at one end, which is projected once against the surface under test by the release of a compression spring. The spring compression force before release can be adjusted continuously from 0 N to 90 N by means of a force-setting barrel (see Figure 1
20、). The newton-metre (Nm) scale also provided on the tester is only to be used for orientation, as the introduction of a non-linear scale involves relatively great inaccuracies. The compression spring is 100 mm long when released and has a constant of (1 962 r 50) N/m. It is compressed by drawing bac
21、k the impact bolt and is held in the loaded position by a retainer which engages in the bolt. It is released to deliver the impact blow by a release unit that withdraws the retainer. 3.3.2 Force-producing arrangement, (for example, a scale-pan and weights) capable of being suspended from the impact
22、bolt to exert a compressive force on the spring. BS ISO 24335:20062 3.3.3 Support fixture, which clamps to the shaft of the impact tester and provides a convenient mounting of sufficient mass for the tester to be held at right angles to the surface of the specimen and to avoid recoil following the r
23、elease of the impact bolt (see Figure 2). 3.3.4 Steel plate, having dimensions of approximately 300 mm u 300 mm u 50 mm. 3.3.5 Contrast medium, e.g. graphite, talcum, or solution of dye in alcohol, to contrast with the colour of the surface layer of the element under test. Dimensions in millimetres
24、Key 1 retainer 2 release lever 3 impact bolt 4 knob 5 steel ball 6 compression spring 7 force-setting barrel (housing) Figure 1 Impact tester (shown with spring compressed) BS ISO 24335:20063Dimensions in millimetres Key 1 observation slot 2 clamp screw 3 pressure bolt 4 shaft of impact tester 5 3 0
25、00 g 6 foot 7 steel ball Figure 2 Support fixture for impact tester BS ISO 24335:20064 3.4 Large-diameter ball apparatus 3.4.1 Free-fall test apparatus, of the type shown in Figure 3, or the equivalent. Dimensions in millimetres Key 1 power supply 2 transformer and rectifier 3 junction box with dupl
26、ex receptacle 4 angle iron brackets (Attach firmly to wall or column. Shall be plumb and perpendicular to the base plate.) 5 junction box with indicator light 6 19-mm mounting board for test apparatus medium or high density board 7 coiled wire lead 8 6,5-mm wide slot 9 machinists steel sliding scale
27、, 1 800 mm long 10 electromagnet on sliding mount 11 wing nut 12 foot switch 13 460 mm u 460 mm u 19 mm steel plate base levelled and set firmly to the floorFigure 3 Free-fall test apparatus BS ISO 24335:200653.4.2 Polished stainless steel ball, with a mass of (224 r 3) g, a diameter of 38,1 mm and
28、no damaged or flattened surfaces. 3.4.3 Clamping jig, capable of holding the test specimen flat or the equivalent. See Figure 4. Dimensions in millimetres Key 1 base 2 clamps 3 test specimen Figure 4 Example of clamping jig BS ISO 24335:20066 3.4.4 Marking pen, black, water-washable marking pen (sui
29、table for overhead transparencies). 3.4.5 Cloth, clean, damp, soft, white cloth. 3.4.6 Fluorescent light, overhead white fluorescent lights with bulb(s) positioned parallel to the line of sight and providing an intensity of 800 lx to 1 100 lx (75 foot-candles to 100 foot-candles) on the specimen sur
30、face. 4 Test specimens 4.1 General Take, from five laminate floor covering elements, the materials to be tested. If the laminate floor covering element is equipped with a factory-applied underlay, all tests shall be carried out with this material kept on, i.e. no pre-attached underlay material must
31、be taken off prior to testing. The material shall be tested in accordance with the manufacturers intention for installation in order to simulate as real in situ situations as possible. 4.2 Specimens for the small-diameter ball test Take, from each of the five elements, one test specimen having dimen
32、sions of approximately 180 mm u 180 mm. In the case of width smaller than 180 mm, the dimensions shall be w (in millimetres) by 180 mm. 4.3 Specimens for the large-diameter ball test Take, from each of the five elements, one test specimen having dimensions of approximately 300 mm u 300 mm, with a jo
33、int if needed. 4.4 Conditioning Test specimens are normally measured in the received state. For type approval or verification purposes, the test specimens shall be stabilized to a constant mass in an atmosphere of (23 r 3) C and (50 r 5) % relative humidity. Constant mass is considered to be reached
34、 when the results of two successive weighing operations, carried out at an interval of 24 h, do not differ by more than 0,1 % of the mass of the test specimens. If there is any deviation from this conditioning, it shall be stated in the test report. 5 Procedure 5.1 Impact by small-diameter ball 5.1.
35、1 Principle The specimens from the laminate floor covering are subjected to the impact from a 5-mm steel ball mounted at one end of a spring-loaded bolt. The minimum spring force needed to cause visible damage is used as a measure of resistance to impact by small-diameter ball. 5.1.2 Calibration of
36、the impact tester a) Suspend the impact tester (3.3.1) with the impact bolt pointing upwards so that its longitudinal axis is free to hang vertically under gravity. b) Set the force-setting barrel, which serves to vary the impact force, to zero on the scale. Compress the spring by a force Fe(calibra
37、tion force) using a suitable arrangement (for example, weights in a scale-pan) BS ISO 24335:20067suspended from the knob used to draw back the impact bolt, ensuring that the bolt is clear of the retainer of the release unit. c) Turn the force-setting barrel until the retainer of the release unit is
38、just in contact with the impact bolt. This position can be determined by increasing or decreasing the compressing force very slightly to observe whether the retainer is just in contact. Record the indicated force, Fx, on the scale of the instrument corresponding to the calibration force, Fe. d) Repe
39、at this calibration procedure for various values of Fxin the range required, and draw a graph relating values of the scale reading Fxto values of the calibration force, Fe(see Figure 5 for an example). e) The graph will be an approximately straight line which will not pass through the origin, becaus
40、e a constant but undetermined force is exerted during the calibration procedure by the mass of the impact bolt and any suspension arrangement (for example, a scale-pan). Draw a second line passing through the origin and parallel to the first line. This second line is the calibration graph of the ins
41、trument and shall be used to correct every indicated force, Fx, employed in testing. f) Prepare a new calibration graph after every 500 tests. Key X calibration force, Fe, in newtons Y scale reading on instruments, in newtons Figure 5 Example of calibration graph relating actual force to scale value
42、 5.1.3 Testing a) The test shall be carried out in the laboratory atmosphere. b) Place the steel plate (3.3.4) on a convenient rigid horizontal surface and locate the specimen on it with its surface layer uppermost. The specimen shall be configured on the test apparatus using the underlay material t
43、hat is recommended by the supplier and delivered with the sample. If the sample already contains pre-attached underlay material, it is tested as delivered. If the supplier does not specify any underlay material or no underlay material is pre-attached to the elements, the test shall be carried out us
44、ing the polyethylene foam described in 3.2 as the underlay material. The test specimen shall be loosely clamped on the steel plate so as to immobilize the specimen but not to compress the underlay material. BS ISO 24335:20068 c) Fix the impact tester (3.3.1) in its support fixture (3.3.3), load the
45、tester, place the assembly on the specimen and release the impact bolt. Start the preliminary test with a spring force of 8 N and increase by 5 N on each occasion to determine the minimum spring force at which the surface of the specimen shows damage due to impact stress. d) Test each of the remaini
46、ng four specimens for the final determination of the maximum force at which no damage occurs. For this purpose, start with the spring force determined in the preliminary test and reduce it in suitable stages, for example 1 N, after every five strikes. e) To make any damage more easily visible, the s
47、urface of the specimen shall be rubbed with a contrast medium (3.3.5) after the test. f) The distance between points of impact shall be at least 20 mm and the distance between points of impact and the edge of the specimen at least 30 mm. g) Examine the surface tested for damage at the points of impa
48、ct. For the purpose of this test, damage is defined by the presence of fine hairline cracks (which are frequently concentric), continuous cracks or flaking of the decorative surface. Indentations without cracks do not count as damage. Examine the test specimen by viewing it at an eye-to-specimen dis
49、tance of approximately 750 mm to 900 mm and at an angle of approximately 45 to 75 from the horizontal (table surface). The specimen shall be viewed from all directions. Direct sunlight or other angle light sources, which will accentuate or minimize the effect, shall be avoided. h) If the test is conducted only to determine whether the impact strength of a material exceeds a limiting value, the specimen shall sustain no damage after five successive individual impact strikes with the prescribed spring force. 5.1.4 Factors influencing a
