Problems and solutions in the use of silica
1、 Silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber: silica in rubber
1), the reason why the breaking strength is not enough: silica is lower than the surface area; mixing is not enough, so that silica can not be well dispersed in the rubber; there are a lot of difficult to disperse particles in silica, mainly composed of silica gel.
2). There are white dots in the compound: there are a lot of difficult to disperse particles in silica, mainly composed of silica gel.
3). The color of the compound is gray and black: the content of iron and manganese in silica is high; the silica contains dust, which is mainly caused by the rupture of the heat exchanger tube.
4). The elongation of rubber is not enough: it is inversely proportional to the breaking strength. It is inversely proportional to the hardness. Generally speaking, high transparent sole requires higher hardness.
1). The matting effect is not good: the modifier is added too much (for some paints, the modifier is not good); the ultra-fine particles are too fine; the oil absorption value of silica is not high, and the particle size distribution is uneven
2). Abnormal paint color: iron content in silica is too high, or product whiteness is not enough-
3). Insufficient paint strength: low oil absorption value of silica DBP, poor structure)
4). Coagulation phenomenon: the mixing sequence of raw materials needs to be corrected, especially the sequence of silica addition; silica needs to be modified but not modified; the mixing is not uniform; materials reacting with silica are added.
1). This kind of general requirements for white carbon black is not high, but need good fluidity, to granulate white carbon black
2. For those that need sustained release and high oil absorption value, for example, for the carrier of micro elements such as vitamins, the higher the oil absorption value, the better, and play the role of anti caking and easy dispersion
4、 Others
1). In silicone rubber, silica will react in silicone rubber. For general silicone rubber, ordinary superfine silicone rubber is needed. For high-quality silicone rubber, low iron (high iron, yellow and red product color) products are needed. Low iron products with high oil absorption value and large specific surface area are the best choice, which can better react with silicone rubber raw materials.)
2). For plastics and plastic products, it's better to need products with large specific surface area and high oil absorption value, and it's better to need modification, so that the obtained products have wear resistance, aging resistance, good transparency, and maintain the natural color of pigments.
3). For hard rubber pad, silica needs low surface area and low oil absorption value.
4). For toothpaste friction agent, it needs ultra-fine products with low specific surface and low oil absorption value; for toothpaste thickener, it needs ultra-fine products with high specific surface and high oil absorption value. Some people take the intermediate products of the two as mixed additives, which is not desirable.
5). For absorbent silica, such as diapers, need high oil absorption value of the product, which can better absorb urine, instead of absorbent resin. In use, the air in the silica powder should be removed to make the volume compressed.