The tearing test of the tensile machine is to determine the tear strength value. Generally, the electronic tensile tester is used to continuously stretch the rubber product with or without cutting at a prescribed speed until the rubber product is torn. The break strength value is obtained so that the tear strength value is obtained.
We first select the electronic tensile testing machine to be tested, we recommend WBE-9909B electronic universal material testing machine
The tear strength value is generally related to the shape of the sample, the stretching speed, and the test temperature.
A, select the pants sample:
The use of a pant sample is insensitive to the length of the cut, while the cuts of the other two samples require strict control. In addition, the results obtained are more likely to be related to the basic tearing ability of the material, but less affected by the tensile stress (generally ignored), and the rate of tear propagation is directly related to the stretching speed of the holder.
B, select the non-cut straight angle sample:
A cut-free, right-angled specimen is a combination of tear initiation and tear propagation. The stress at the right angle points rises enough to cause an initial tear, and then the stress is further increased until the sample tears. However, only the total force required to destroy the specimen can be determined. Therefore, the measured force cannot be decomposed into two component forces that produce tear initiation and tear propagation.
C. Select a straight-angled sample with a cut:
A straight-angled specimen with a cut is a pre-cut of the specimen to determine the force required to expand the tear, but it should be noted that the direction of the tearing cut should be consistent with the direction of the calender because the expansion speed and the stretching speed are not directly The relationship is related to the cutting method and the rolling direction of the sample.
D. Select the crescent sample:
The crescent-shaped specimen is to cut the specimen in advance and measure the force required for the expansion of the specimen. The specimen cutting, measurement and test shall be carried out continuously. If the test cannot be carried out continuously, the specimen shall be tested according to the specific conditions. Store to the test under the specified temperature test. The interval between the cut and the test shall not exceed 24 h, and when the aging test is carried out, the cut and the cut shall be performed after aging.