A.Commonly Used Method for Discerning the Quality of GDK Zipper

Tape: The dyeing for the tape should be even and feel soft without any stain or scar. The edge of the tape looks like a wave.

Teeth: The surface of the teeth should be smooth. They should feel soft in use.

Slider: The brace should go smooth and freely, fasten firmly and won’t slide off.

Hem: The hem fits the band well, and won’t break and come off easily.

Separating pin and retainer of the separating unit:

The square bolt should be inserted freely and fastened closely with the band.

Top Stop and End Stop:

a. The bottom stop should come together with the teeth or be fastened on the surface, which should be firm and flat.

b. The top-stop should come together with the first tooth on the metal and nylon zippers. The distance should not be more than 1cm. It should be firm and look fine.

B.Tips for Selecting A Zipper

Different zippers are applicable for different conditions. Hence, the buyers should discuss the following issues with the manufacturers when purchasing zippers.

a. Application of the zipper (such as the leather trunk, footwear, jacket, raincoat, tent, jeans requiring hard washing, leather products with high acidity, etc. ) or any other special requirements

b. Requirements for the content of the zipper- whether the zipper should not contain AZO/Nickel or pass the needle detector.

C.Tolerance of Zipper Length

Zippers will display natural tolerance during the manufacturing process, which is caused by the speed of machine operation, the technique involved and the tensility of the tape. The longer the zipper, the greater the tolerance.

Table of Errors for Germany DIN, Japanese Enterprise and GDK Zipper