Discuss the discoloration of zipper

March 19, 2018 BY TRIMS CO.,LIMITED zippers Knowledge

Metal Zipper is a popular and durable zipper. But after prolonged use, you may find that the teeth and sliders of metal zippers (red copper zipper, Brass Zipper and copper-nickel-zinc-zinc alloy zipper) are discolored or the dyes of the fabric are transferred. In this article, we will analyze the cause of the problem and propose solutions to eliminate or prevent the problem.

Discoloration of metal:

The chemical properties of copper alloys in metal zippers are that they react chemically when they meet acids, alkalis, oxidants, or reducing agents, and they easily change color. When the chemical residue on the fabric reacts with the fastener elements, the slider or the open end of the metal zipper, the zipper may become discolored. This chemical reaction is more likely to occur under high temperature and high humidity conditions. This situation does not belong to the quality of the zipper.

How to prevent discoloration of metal zipper?

1. Avoid contact between metal zipper and acid, alkali, oxidant or reducing agent.

2. Avoid long-time ironing or long-term sealed packaging of plastics in plastic bags, because the chemicals remaining on the clothing are more likely to chemically react with the metal zipper teeth, sliders and tail openings under high temperature and high humidity Causes discoloration. If necessary, use moisture-proof paper and moisture-proof agent to reduce the degree of chemical reaction of metal zipper.

3. Correct washing method: Before washing or putting in the dryer, close the zipper and fix the slider. If the washing is left on, the top of the top stop will damage the fabric and the tape will shrink. Alkaline detergents or chlorinated bleach will remove the paraffin or oil film on the metal zipper.

Wool and cotton products are dyed:

Discoloration will occur if the zipper that contains copper alloy is attached to the wool fabrics which have been bleached.

Generally speaking, the following three methods can be applied to the bleaching of the wool.

Processing using the oxidative bleaching agent (For example, Hydrogen Peroxide)

Processing using the reductive bleaching agent (For example, dithionite)

Chlorine treatment applied to the shrinkproof processing of the finished products (chlorinating agent in the chlorine group)

Chemical gases(for example, chlorine) will be introduced if the chemicals involved in the above-mentioned treatment methods (the second and the third methods in particular) are not fully cleansed or neutralized. In addition, the chemicals will react with the zipper surface in the damp environment. Discoloration will occur with the teeth, slider, top & bottom stops and retaining box & pin of the zipper that contains copper alloy due to the chemicals and gas volatilization if the finished products are packed in the bags immediately after ironing.

Tips:The fabrics used should be fully cleansed and dried.The chemicals involved in the washing process should be fully cleansed and neutralized.

Packing should be not performed immediately after ironing.