1、CEN EN*25978 93 3404589 0051190 b5T EUROPEAN STANDARD EN 25978 NORME EUROPENNE EUROPISCHE NORM September 1993 UDC 677.077.65 : 687.066 : 677.017.424.25 : 620.1 Descriptors: Textiles, coated fabrics, fabrics coated with rubber, fabrics coated with plastics, adhesion tests English version Rubber- or p
2、lastics-coated fabrics - Determination of blocking resistance (IS0 5978 : 1990) Supports textiles revtus de caoutchouc ou de plastique - Dtermination de la rsistance au blocage (IS0 5978 : 1990) Gummi oder Kunststoffbeschichtete Textilien - Bestimmung des Blockwiderstandes (IS0 5978 : 1990) This Eur
3、opean Standard was approved by CEN on 1993-04-05. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references conce
4、rning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own
5、language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland
6、and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels O 1993 Copyright reserved to CEN members Ref. No. EN 25978 : 1993 E CEN EN*25978 93 M 3404589 005LLl1 596 M Page 2 EN
7、25978 : 1993 Foreword Introduction This European Standard is the endorsement of IS0 5978. Endorsement of IS0 5978 was recommended by CEN/E 248 Textiles and textile products under whose competence this European Standard will henceforth fall. This European Standard shall be given the status of nationa
8、l standard, either by publication of an identical text or by endorsement, at the latest by March 1994, and conflicting national standards shall be withdrawn at the latest by March 1994. The Standard was approved and in accordance with the CENKENELEC Internal Regulations, the following countries are
9、bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. Blocking tests at elevated temperatures are designed to estimate the relative resist
10、ance of rubber- or plastics-coated fabrics to blocking. For this purpose, the coated fabric is subjected to a specified load over a defined area at a specific temperature* CEN EN*25978 93 m 3404589 005LL2 422 m Rubber- or plastics-coated fabrics blocking resistance 1 Scope This International Standar
11、d specifies a method for the determination of the resistance of rubber- or plastics-coated fabrics to blocking. The method specified is acceptable in most cases. If it is desired to use conditions other than those specified, these may be mutually agreed between the contracting parties but such varia
12、tions shall be stated in the test report. 2 Normative reference The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the edition indicated was valid. All standards are subject to revision
13、, and parties to agreements based on this International Standard are encour- aged to investigate the possibility of applying the most recent edition of the standard indicated below. Members of IEC and IS0 maintain registers of cur- rently va l id l n te rn at ion a I Stand a rd s. IS0 2231:1989, Rub
14、ber- or plastics-coated fabrics - Standard atmospheres for conditioning and testing. 3 Definition For the purposes of this International Standard, the fol lowi ng de fin it ion a p pl es . blocking: An unintentional adherence between ma- terials. Definition taken from IS0 472:1988, Plastics - Vo- ca
15、bulary. 4 Apparatus 4.1 Glass plates, measuring approximately 150 mm x 150 mm x 3 mm. Page 3 EN 25978 : 1993 - Determination of 4.2 Wefght-piece, of mass 5,O kg. 4.3 Cfrculating-air oven, of such a size that the total volume of the test assemblies does not exceed 10 O/O of the free space in the oven
16、. Provision shall be made for placing the test assem- blies on shelves so they are not less than 50 mm from each other or from the sides of the oven. The nature of the source of heat is optional but the source shall be located in the air supply of the oven. Provision shall be made for circulation of
17、 air through the oven at a rate such as to provide a minimum of six air changes per hour. The temperature of the oven shall be thermostatically controlled to maintain the temper- ature of the test assemblies within f2 “C of the specified temperature. Baffles shall be used as required to prevent over
18、- heating and dead-spots. 5 Time interval between manufacture and testing 5.1 manufacture and testing shall be 16 h. For all purposes, the minimum time between 5.2 For non-product tests, the maximum time be- tween manufacture and testing shall be four weeks, and for evaluations intended to be compar
19、able, the tests, as far as possible, shall be carried out afler the same time interval. 5.3 For product tests, whenever possible, the time between manufacture and testing shall not exceed three months. In other cases, tests shall be made within two months of the date of receipt by the cus- tomer. CE
20、N ENx25978 93 D 3YOLi589 0051193 3b9 D Page 4 EN 25978 : 1993 6 Samples and test pieces 6.1 Samples shall be taken not less than I m from the end of the roll. 6.2 The test pieces for each sample to be tested shall consist of six specimens, each 150 mm x 150 mm. 6.3 Test pieces shall be representativ
21、e of the ma- terial being tested. They shall be taken from the working width of the sample. They shall be cut with one edge parallel to the longitudinal axis of the sample. The longitudinal and lateral axes shall be maked on the test pieces. 7 Conditionlng of test pieces The test pieces shall be con
22、ditioned in one of the standard atmospheres as defined in IS0 2231. 8 Procedure 8.1 Arrange the test pieces in pairs, back to back, face to face and back to face, to form a pile 150 mm square. Place the test pieces thus arranged between two glass plates (4.1). Place the 5,O kg weight-piece (4.2) on
23、the top plate in a position to ensure an even distribution of pressure. 8.2 Expose the test assembly for 3 h at a temper- ature of 70 “C f 2 “C in the oven (4.3). 8.3 At the end of the exposure period, remove the test assembly from the oven. immediately take the test piece from between the plates an
24、d allow it to cool for 1 h. Then carefully separate the test pieces and examine them for adherence or peeling of the coatings. 8.4 Rate the resistance of each test piece to blocking by the scale given below: 1 - No blocking: coated surfaces separate with- out any evidence of adhering. 2 - Sllght blo
25、cking: some adherence of coated surfaces takes place on separation, but without detriment to the coating. 3 - Blocklng: coated surfaces are difficult to separate; the coating or part of the coating is removed during separation. 9 Test report The test report shall include the following partic- ulars:
26、 a) a reference to this International Standard; b) all details necessary for the identification of the sample; c) the conditioning atmosphere used (see clause 7): d) the total mass on the test piece: e) the rating for resistance to blocking, in accord- ance with 8.4: 9 any departure from the procedure specified.
