YMK-Zipper Size

Methods to Determine Zipper Strength

There are various methods by which to evalute zippers strength. The basic strength can can be determined based on the result of the following inspection methods, from which all around strength appropriate for respective uses can be juged. (Based on JIS-S3015)
*Tensile tester: Tensile velocity is 300mm/min, Clamp with is 25mm.

Crosswise srength of chain (per 2.5cm)
To determine ordinary zipper strength: a zipper chain is interlocked, pulled at a fixed speed at s rigth angle to the chain interlocked direction,and the resistance is measured.

Vertical tensile strength of the top stop
The lower part of an interlocked ziper is fixed and the slider is pulled up to the top stop.Holding strngth is measured bu pulling the slider top stop firmly.

Bottom stop tearing strength
A slider is pulled down to the bottom stop and single chains are opened to the right and left sides. Bottom stop holding strength and resistant of the elements inside the slider are measured.

Horizontal tensile strength of the box
The open part is fixed to the tensile tester (only the open part as shown in the figure) so that the end of the last element falls into line with the clamp edge and the tensile strength and resistance of the elements inside the slider are measured.

Slider lock strength
A slider is locked at teh middle of a zipper chain and single chains are oped to the rigth and left sides.Locking strength and resistance of the elements inside the slider are measured.

Overall atrength of the slider (90 degree)
For a completed slider,resistance of the slider is measured when power is put on the pull and the lower port of the body. In addition to the 90 degree method of measuring shown in the figure at left, there is one of 45 degree.

*YKK zipper meets UK standards of durability and passes the above JIS strength tests.

YKK® is registered Trade Mark of YKK Corporation

YMK-ZS