1、UDC 678.074 ; 678.026 677.074-419.3 z 620.179.4 DEUTSCHE NORM February 1981 Testing of organic materials Separation test on fabric plies bonded together I 53530 Prfung organischer Werkstoffe; Trennversuch an haftend verbundenen Gewebelagen As it is current practice in standards published by the Inte
2、rnational Organization for Standardization (ISO), the comma has been used throughout as a decimal marker. For connection with recommendation ISO/R 36 published by the International Organization for Standardization (ISO), see Explanatory notes. Dimensions in mm 1 Scope and field of application 1.1 Th
3、e separation test (TI is used to determine the adhesion strength of fabric plies bonded together with elastomers or other layers of material. These composite fabrics are used in hoses, belts, conveyor belts or tyre casings, for example. The separation test does not apply to artificial leather cloth
4、to be tested in accordance with DIN 53357. 1.2 The separation test as described in this standard is applicable in cases where the plies to be separated have surfaces which are approximately plane or uniformly cylindrical. This test is not suitable for plies whose sur- faces contain sharp bends, angl
5、es or gross irregularities. 2 Other standards to be observed DIN 50014 DIN 51 221 Part 1 DIN 51 221 Part 3 DIN 53 500 DIN 53 508 DIN 53 521 DIN 53 539 DIN 53 598 Part 1 Atmospheres and their technical application; standard atmospheres Material testing machines; tensile testing machines; general requ
6、ire- ments Material testing machines; tensile testing machines; small tensile test- ing machines Testing of rubber and elastomers; conditioning and test conditions, periods, temperature and humidity Testing of elastomers; accelerated ageing Testing of rubber and elastomers; determination of resistan
7、ce to liquids, vapours and gases Testing of elastomers; evaluation of tear growth, separation and peel tests Statistical evaluation of samples with examples taken from the test- ing of elastomers and plastics 3 Concepts The adhesion strength T is the quotient of the separation force F determined by
8、this test and the test piece width b. 4 Designation of the method Designation of the separation test on fabric plies bonded together (Ti: Test DIN 53 530 - T 5 Test pieces 5.1 Sampling and dimensions of samples The samples from which the test pieces are taken shall comply with the requirements given
9、 in subclause 1.2 and shall have no visible damage or defects and shall be neither folded nor creased. 5.1 .I Sheet-shaped products Test pieces (25 * 0.5) mm wide and at least 150 mm long shall be cut from sheet or strip-shaped products, e.g. conveyor belts or packing sheets with plies. A test piece
10、 consists only of the two plies involved in the separation. In the case of multi-ply test pieces, all the other plies shall be removed from this pair. Should, following a product standard such as IS0 252, a different procedure be exceptionally adopted, this shall be noted in the test report. For exa
11、mple, when peeling off ply by ply, the precise point of separation and the thickness of the layers involved shall be noted (see Ex- planatory notes). The two plies to be separated should be strong enough to be able to transmit the separation force without tearing. Otherwise, they shall be reinforced
12、 by adjacent layers or layers to be applied and this shall also be noted in the test report. The test pieces shall be taken in the longitudinal direction (e.g. direction of warp) and if the width of the products Continued on pages 2 to 4 lesale rights of German Standards (DIN-Normen) are with Beuth
13、Verlag GmbH. Berlin 30 .84 DIN 53 530 Engl. Price group 5 Sales No. 0105 Page2 DIN 53530 so permits also in the transverse direction (direction of the weft) of the fabric. If cutting is difficult without a lubricant, only an agent which does not make the test piece swell or attack it, e.9. soap wate
14、r, may be used. The thickness a of the fabric plies or layers of material (e.g. face covers, rubber or PVC intermediate layers) which are to be separated (see figure I), should not exceed 6 mm. If these layers are thicker because of the structure of the product, they shall, if possible, be reduced t
15、o the permissible thickness by cutting or grind. ing. If they are thicker than 6 mm, this shall be noted in the test report. 5.1.2 Annular products Test pieces shall be taken from annular or hose-shaped products as follows: Rings (25 * 0.5) mm wide shall be cut off. Strips (25 t 0,5) mm wide and at
16、least 150 mm long may be cut in the longitudinal direction (.e. parallel to the longi- tudinal axis) from annular products of sufficient diarn- eter and small wall thickness. If the diameter and wall thickness of the rings permit, they shall be cut through and opened to form strip test pieces. If th
17、is is not possible, the rings remain uncut initially (annular test pieces, see figure 2). For cutting and the thickness of the samples subclause 5.1.1 shall apply. 5.2 Number of test pieces At least three test pieces shall be tested from one product. If it consists of more than two plies, at least t
18、hree samples shall be taken for each pair of plies to be tested. If the dependence of the separating force on the direction is to be established, at least three test pieces taken in the longitudinal direction and three test pieces taken in the transverse direction shall be tested. 5.3 Preparation of
19、 test pieces In the case of strip test pieces consisting of several plies, two plies of fabric or layers of material shall be separated from the composite mass. These two layers shall be separated by hand from the small face parallel to the sur- face for a distance sufficient to ensure correct fixin
20、g in the grips of the testing machine. In the case of closed annular test pieces which cannot be treated as strip test pieces, only the outer layer to be separated is cut first and prepared for fixing in the machine. The subsequent layers or fabric plies shall then be cut off after the previous laye
21、r of ply has been separated (see clause 7). 5.4 Pretreatment of test pieces The test pieces shall be stored for 24 hours immediately before the test in standard atmosphere DIN 50014 - 23/50-2. If the test is carried out in the as delivered condition without prior conditioning, this shall be noted in
22、 the test report. It is often requested determining the adhesion strength of the product after thermal stressing (accelerated ageing) or after storage in various media (e.g. water). In this case, the test pieces shall be conditioned as indi- cated above or treated in accordance with DIN 53 521 or DI
23、N 53508. This shall be noted in the test report. 6 Apparatus A tensile testing machine as described in DIN 51 221 Part 3 with a force recording instrument shall be used. The force reading shall correspond to class 1 in accord- ance with DIN 51 221 Part 1. The testing machine shall have a short dista
24、nce low- inertia dynamometer. Testing machines with pendulum- type dynamometers are not suitable. A gripping device similar to the one shown in figure 2 is necessary for the separation test on closed annular test pieces. The gripping device shall be fitted with a freely rotating mandrel mounted on b
25、earings and the test piece slid onto this mandrel which shall have approximately the same diameter as the annular test piece to be tested. When testing annular test pieces with greatly differing inside diameters, it is advisable to use equalizers which are slid onto the mandrel. 7 Procedure The test
26、s shall be carried out at room temperature directly after removing the test piece from the atmo- spheric chamber, unless otherwise agreed, in which case this shall be noted in the test report. Fix the test pieces prepared in accordance with sub- clause 5.3 in the grips of the testing machine so that
27、 the separation point is positioned in the middle of the two grips (see figure 1). Determine the force required to strip a length of at least 100 mm, in the case of closed annular test pieces, the whole circumference. In the case of closed annular samples, slide them onto the mandrel or onto the equ
28、alizer of the gripping device fixed in a grip of the testing machine as indicated in figure 2. Fix the cut top layer or fabric ply of the annular test piece in the other grip of the test machine. Beginning with the face cover, cut and draw off the rest of the plies consecutively with the sample rota
29、ting on the free-moving mandrel or equalizer. The rate of feed shall be (100 * IO) mm/min. At the beginning of the test, the force reading increases until the separation force is reached. At this point, the plies or layers begin to separate with quite a large drop t t Figure 1. Fixing of strip test
30、pieces DIN 53 530 Page 3 t t where Fand Rn,F are, in N, and b, in mm. 8.2 The adhesion strength of a specific ply (layer) shall be given as the arithmetical mean value of all the medians, their standard deviation and the mean range of all the individual ranges in accordance with subclause 8.1 for th
31、is ply. 8.3 If the type of failure is given as additional inform- ation, the following symbols shall be used: G separation within the elastomer or one of the other material plies; GB separation between the elastomer ply and the ad hesive; BW separation between the adhesive and the fabric ply; V sepa
32、ration within the bonding ply between two fabric plies; W failure of the fabric ply. i Figure 2. Fixing of annular test pieces in force. In the next stressing phase, the same process takes place and is repeated several times with the result that a series of peak values (maximum values) is recorded.
33、Select the measuring range of the recording instrument so that accurate evaluation is possible. 8 Evaluation 8.1 The peak values of the force F in the trace shall be used to determine the adhesion strength T. For this. proceed in accordance with DIN 53 539 and determine the median) Fand the rangel)
34、Rn,. The adhesion strength T of and the relevant range Rn2 for the individual test piece are obtained by dividing F or R,J by the test piece width b: 9 Test report The test report shall include the following, with refer- ence to this standard: al type of product; b) direction in which the test piece
35、s have been taken from the product; c) pretreatment of the test pieces; d) test temperature; e) the following details shall be given for each layer: - number of test pieces; adhesion strength T, in N/mm, and range Rn, in N/mm, for each test piece, standard deviation, mean value T and mean range R; f
36、ailure of the fabric ply; - where appropriate, type of failure, e.g. failure W, f) deviations from this standard; g) date of test. 1) See DIN 53 598 Part 1. Page 4 DIN 53 530 Explanatory notes This standard has been prepared by the Technical Com- mittee Prfung von Elastomeren of the Normenausschuss
37、Materialprfung (Materials Testing Standards Committee). DIN 53 530 is based on IS0 Recommendation R 36 - 1969 “Determination of the adhesion strength of vulcanized rubbers to textile fabrics“. However, the German stand- ard is more general and is not limited to testing the adhesion of rubberhextile
38、bonds. The test procedure is the same as that described in ISO/R 36; however, DIN 53 530 specifies a rate of travel of 100 mm/min, whereas ISO/R 36 also permits 50 mm/ min. This standard does not apply to multi-ply test pieces, as the adhesion strength is dependent on the thickness of the sample pac
39、kage. In exceptional cases (product stand- ards such as IS0 252) stripping ply by ply is permitted with certain limitations. However, even here, the thick- ness of the layers shall not be random as alignment of the line of separatiqn with the stripping plane is also a requirement of IS0 252 and this
40、 can best be achieved by having a thin ply on each side (see figure 3). The sample thickness is a factor both in cases where stripping of a thick package is carried out ply by ply and in cases where a multi-ply package is separated in the middle. Therefore, if there is any deviation from the test pr
41、o- cedure, the thickness of the packages separated shall be given as, with increasing rigidity, the stripping plane is increasingly further away from the ideal position, .e. as close as possible to the line of separation. It shall be taken into account that the results with separa- tion of pairs of
42、plies as in figure 1 need not agree with stripping ply by ply (picture book method); it may lead to considerable deviations. Evaluation is in accordance with DIN 53539, September 1979 edition. However, DIN 53357 applies for testing artificial leather. The two standards differ mainly with regard to t
43、he dif- ferent width of the test pieces. In DIN 53357. a test piece width of 50 mm is specified, compared with 25 mm in DIN 53530. For many products, these different widths lead to different results. It was not possible to agree to a proposal of combining DIN 53357 and DIN 53530, as DIN 53357 has been introduced into some delivery conditions as an acceptance test with specific requirements. -=-+ -. I/ _. -c / r Line of separation Correct Incorrect Figure 3. Alignment of the line of separation
