What are the causes of " Incomplete vulcanization" of silicone rubber products?

In the production process of silicone rubber products, we often see "poor vulcanization" of products, which we call "unfamiliar". This is a very serious defect for our silicone rubber products. If it flows into the hands of customers, the consequences are unimaginable. What are the factors leading to poor vulcanization of products?

What are the causes of "poor vulcanization" of silicone rubber products?

First, the proportion of vulcanizing agent is improper

As we all know, the raw materials we purchased are raw rubber and need to add vulcanizing agent Color Masterbatch, etc. These are all strict requirements according to the material formula. They need to be accurately weighed and added according to the proportion required by the formula. If the proportion is improper, it will affect the material characteristics and lead to poor vulcanization of the product.

What are the causes of "poor vulcanization" of silicone rubber products?

Second, the vulcanizing agent is unevenly distributed during mixing. If the vulcanizing agent is too concentrated or dispersed in some areas during mixing, it will also lead to poor vulcanization in subsequent production.

Third: the vulcanization temperature is too high or too low. During molding, the mold surface temperature should be set appropriately according to the different characteristics of materials, and the mold temperature should be evenly distributed. There should be no local temperature that is too high or too low. Generally, the maximum temperature of the upper and lower molds should not be 5 degrees Celsius.

What are the causes of "poor vulcanization" of silicone rubber products?

Fourth: the vulcanization time is not enough. Every material has a vulcanization time that must be met before it can be fully vulcanized. The vulcanization time of the same material formula will be different. In order to pursue productivity, some manufacturers may reduce the vulcanization time during molding. When it is first produced, there may be no problem in the appearance, but in fact, the product is not fully vulcanized and does not meet the actual performance of the material. Thus, the physical properties of the product will be relatively poor, Such as the aging resistance, tear resistance and tensile property of the product.