Test method for tension of protective mask: Theory Provisions of the sample size of the clamp (there is a seam in the middle of the part of the clamping), along the direction perpendicular to the stitch at a constant tensile elongation rate, until the joint damage. Record the most strongly values achieve joint damage. 1) take samples of five masks;
2) according to the provisions of GB/T13773.2.The stretching speed is 100mm/min. The test hook is installed on the stretching instrument. During the test, the mask belt is vertically suspended on the test hook.
3) test hook, made of steel, strip, width (10±0.1) mm, thickness (2±0.1) mm, one end bent into a right Angle hook, hook part length at least (12±0.1) mm, hook edge should be smooth.The test hook shall be conveniently installed in the clamp of the tensile testing machine.