There are many methods for measuring the strength of zippers, and the following methods can be used to test the quality of zippers for different purposes.

1.Flat-Pull With Intensive Force

This method is the most basic strength indicator：a zipper chain is interlocked,clamp the zipper with the test tool and align the chain teeth foot with the jaw of the test tool.

The zipper chain is pulled lateral at a constant speed,and the strength is measured.

2.Open-end Flat-Pull With Intensive Force

Use upper and lower clamps to fix the left and right sides of the open end.The edge of the clamp should be falls into line with the inner of the the pin separable,and the clamp mouth should be close to the pin separable and box retainer,then can be measured the strength.

3.Top Stop With Intensive Force

Use the upper clamp to clamp the pull tab, and the lower clamp to clamp one end of the zipper.The zipper chain teeth are interlocked, and the slider is pulled up to the top stop. 

At this time, the strength of the top stop of the zipper can be measured.

4.Bottom Stop Flat-Pull With Intensive Force

Clamp the zipper with bottom stop in the upper and lower clamps, and make the end face of the clamp be in line with the inner surface of the bottom stop, and the jaw is close to the bottom stop,then the strength can be measured.

5.Single Teeth Shift With Intensive Force

Remove two chain teeth from the cutting point of a single-sided teeth chain tape, leave the third teeth, and buckle it into the lower clamp, and clamp the other end in the upper clamp.

The strength of the single teeth can be measured.