Overlap both ends in the long direction of the test piece with PVC film facing outside, insert an area of 5 mm to be clamped by a test piece holder, and install it to the cold resistance tester of the clamp so that the fold of the test piece is at the center of the anvil. After five minutes, push button to release the catch of the stand. Immediately after the falling weight is dropped, remove the weight, take the test piece out of the holder, and check for cracks or breaksge.