BS EN-1941:1996 pdf download.Self adhesive tapes Measurement of elongation at break.
BS EN-1941 specifies a method to measure the elongation of a self adhesive tape when it is subjected to a tensile force sufficient to cause it to break.
The elongation at break of the adhesive tape is of value as an indication of its unifomiity and quality, as well as a rough indication of its ability to conform to curved and irregular surfaces. It is usually determined at the same time as the breaking strength.
The maximum width of adhesive tape tested by this method is 25 mm. For adhesive tapes of this width or less, the elongation at break measured corresponds to that as supplied commercially, with factory-cut edges. For adhesive tapes wider than 25 mm, this test method provides for the tape to be cut down to 25 mm with a well-sharpened instrument. In such cases, because of the better cutting of the edges, the results can be higher than would be found on conunercial adhesive tape.
4 Apparatus
Tensile testing machine, with the following characteristics:
— the force shall be indicated with a maximum error
of2%
— the speed of the moveable clamp shall
be 3tXJ mn’i/rnin ± :30 mm/mm;
— the scale shall be such that the readings obtained
are between 15 % and 85 % of the complete scale;
— the clamps shall be serrated to prevent, slipping or
tearing of the adhesive tape;
— if a iwnduhiiii machine is used, ensure that the pendtiiuiii can swing freely.
6 Procedure
6.1 The test shall be earned out at the Stan(lar(I COfl(litiOflS of 23°C ±2 °C an(I 54j % ±5 % flhlatjve humidity.
6.2 Remove the test pieces radially from the roll at an approximate speed of 300 nuu/s, then condition for a further 2 ii in the standard test conditions in order to remove all strain and distortion due to unwmduig.
6.3 Set the clamps 100 nmi apart. Clamp the test piece firmly so that the longitudinal axis is vertical and in line with the direction of the applied force.
Check that the cLamps move in the same plane and I)arall(l to the ap)1ied force and that the spee(l of SeparatlOfl s 300 mm/mm ±30 mm/mm.
Reject all test pieces which break within 5 nun of the clamps and carry out sufficient further tests to obtain 5 test. pieces which break in the correct maimer Measure the (listance between the clamps at break.BS-EN-1941-1996