ISO 505 pdf download.Conveyor belts — Method for the determination of the tear propagation resistance of textile conveyor belts
1 Scope
This Standard specifies a method of test for the measurement of the propagation resistance of an initial tear in textile conveyor belts, either in full thickness or of the carcass only. This test is intended for application to textile belts in installations where there is a risk of longitudinal tearing.
2 Normative references
This European Standard incorporates by dated and undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. ISO 61 33:1 998 Rubber and plastics – Analysis of multi-peak traces obtained in determinations of tear strength and adhesion strength
3 Principle
The test consists in measuring, by means of tensile testing at a given speed, the force necessary to propagate an initial tear made in a test piece.
4 Apparatus
The apparatus consists of a dynamometric tensile testing machine with the following essential characteristics: a) the machine shall be chosen so that the forces to be measured come within the upper 90 % range of its full rated capacity; b) the speed of separation of the jaws shall be capable of being adjusted to (50 ± 1 0) mm/min; c) the free distance between the jaws shall be capable of being adjusted to at least 300 mm. The machine shall be provided with a device for the graphical recording of the force necessary to continue tearing the test piece.
5 Test pieces
5.1 Method of sampling Test pieces shall be taken from the sample in the longitudinal direction of the belt and at a minimum distance of 50 mm from the edges of the belt. 5.2 Shape and dimensions Shape : rectangular. Length: 300 mm. Width : (1 00 ± 1 ) mm. Thickness: Full belt thickness or without covers. NOTE. If it is found that weft threads are pulled out of the test piece instead of breaking, the width of the test piece should be increased to 300 mm. 5.3 Number Two test pieces shall be used : one in sense A and one in sense B (see Figure 4). 5.4 Preparation Where the test is to be conducted without covers, the covers of the test pieces shall be removed by stripping or by buffing. If there is a breaker ply, strip the corresponding covers without cutting the breaker ply over a width of 20 mm only, i.e. 1 0 mm on each side of the longitudinal axis of the test piece with the exception of the zone held in the jaws of the machine (see Figure 1 ).
If necessary, the width of the test piece (cut-edge) may be adjusted to the gripping width of the jaws by tapering the edges symmetrically on a length at most the same as that of the cut, as indicated in Figure 3, with the width at the end of the cut part as great as the width of the jaws permits.
6 Method of test
6.1 Conditioning of test pieces The tests shall start not less than 24 h after manufacturing. This time includes 8 h for conditioning. The conditioning atmosphere shall be one of the following: temperature (20 ± 2) o C with (65 ± 5) % relative humidity, or, temperature (23 ± 2) o C and (50 ± 5)% relative humidity, or, temperature (27 ± 2) o C and (65 ± 5) % relative humidity. The tests shall be conducted in the same atmosphere as used for conditioning. The atmosphere at which the test pieces were conditioned and tested shall be reported in the test report. In the event of dispute the period of conditioning shall be 72 h.