BS EN 12773:2000 – Footwear Ð Test methods for outsoles Ð Needle tear strength
Scope This European Standard specifies a method for the determination of the needle tear strength for outsoles, irrespective of the material.
2 Normative references
This European Standard incorporates by dated or 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.
3 For the purposes of this standard the following definition applies:
3.1 needle tear strength
the quotient by division of the maximum force, occurring during tearing-out of the needle, by the thickness of the test piece
4 Apparatus and material
The following apparatus and material shall be used:
4.1 Tensile-testing machine
The tensile-testing machine shall comply with the requirements of EN 10002-2, to an accuracy corresponding to grade B, with a constant rate of traverse of 100 mm/min ± 10 mm/min. Autographic recording of force or a maximum force pointer is
recommended.
4.2 Needle Either a smooth-surfaced steel needle of 1 mm ± 0,01 mm diameter or a corresponding piece of spring steel wire, ground to a point.
4.3 Clamping device Figure 1 shows an example of a clamping device. The distance between the support links for the needle shall be adjustable, so that it can be adjusted to the thickness of the specimen. The clamping device shall be equipped with a suitable protective device to prevent the needle from jumping out.
4.4 Thickness gauge Thickness gauge, standing on a firm base and loaded with a dead weight such that the presser foot applies a pressure of 10 kPa ± 3 kPa. The gauge has a presser foot which is flat, circular and 10 mm ± 0,1 mm in diameter. The gauge has a scale division of 0,01 mm.
5 Sampling and conditioning The test pieces to be tested are taken in accordance with prEN 13400:1998. All test pieces shall be conditioned according to EN 12222 before testing for a minimum of 24 h. Test pieces are strips of 50 mm ± 1 mm length and 20 mm ± 1 mm width. The thickness of the test piece shall be preferably:
BS EN 12773:2000 – Footwear Ð Test methods for outsoles Ð Needle tear strength