About Zips - 关于拉链

Basics Structure Strength Functions Sliders Platings

How to Determine the Quality of a Zipper

Tape
The dye for the tape should be even without stains or scars. The tape should be soft to touch.

Teeth
The surface of the teeth should be smooth and there should be no noise when they are used.

Slider
The slider should go smoothly, freely and be secure.

Cord
The cord should fit the tape well and be secure.

Top Stop
The top-stop must come together with the first tooth on the zip. However the distance must not exceed 1mm.

Bottom Stop
The bottom stop must secure the teeth.

Allowable Tolerance of Zipper Length

Due to the friction caused by machinery during the manufacturing process, zippers require an "allowable tolerance". The longer the zipper the bigger the allowable tolerance will be. Industry standards are as follows:

Zipper Length	Allowable Tolerance
Below 30	± 5mm
30 - 59	± 10mm
60 - 99	± 15mm
100 +	± 3%