Why does the transparent Bing Dwen Dwen silicone shell turn yellow?

The mascot of the Olympic Games this time is also the first time that silica gel material is used as an auxiliary part. Bing Dwen Dwen is the first mascot that uses silica gel material. Natural silica gel material is also the focus of our friends. Why does the shell of bingdundun turn yellow?

1. Color masterbatch of raw materials:

Color masterbatch is the main material for debugging the color of silica gel products. The main materials are composed of toner, silicone oil, dispersant and silica gel raw materials. However, this phenomenon can be avoided because Bing Dwen Dwen silica gel shell is a pure color silica gel shell product without any color glue!

2. Raw material problems:

The yellowing of silica gel products is mostly caused by transparent or white products. Under the action of the catalyst of many white like silica gel products or transparent products, the yellowing and discoloration of products will occur due to the high processing temperature or the high operating ambient temperature and the influence of heat.

The main reason for this phenomenon is that tetramethylammonium hydroxide in the catalyst is used as the main material. If it fails to pass through the influence of environment, temperature, humidity and oxidation correctly in the mixing stage, it is likely that the prepared raw material will lose its anti yellowing effect, and the product will turn yellow after passing through the catalyst. Therefore, it is necessary to see whether the raw rubber formula of the material is correct in raw rubber production.

3. Vulcanizing agent problem

In fact, if there is no vulcanizing agent, the yellowing effect will occur. Therefore, the yellowing of the silica gel shell of Bing Dwen Dwen that you buy also has a certain reason with the vulcanizing agent in the silica gel material!

Generally, vulcanizing agents can achieve certain anti yellowing effect, but each brand of vulcanizing agent has different anti yellowing effect according to its debugging formula, because vulcanizing agents not only need to be prepared for anti yellowing effect, but also need to achieve good sulfur adding effect, odor problem and material dispersion effect.

When mixing other properties, you can't control several properties at the same time to achieve the best state. Therefore, the silicone products you buy are likely to have good tensile toughness, but they turn yellow over time.

4. Caused by use:

Silica gel product manufacturers can not completely avoid this phenomenon. It mainly depends on how consumers use it. The oxidation reaction caused by placing the product in places with high temperature or strong ultraviolet rays may cause yellowing. Long term storage in dark, humid and strong light may cause yellowing. Therefore, we remind you to put the product in a constant temperature and dry and ventilated environment as far as possible.