High-quality rubber seals have the problem that customers encounter whitening of rubber parts. What is the reason? Seals are a kind of rubber parts that are more common nowadays, and we often encounter them in daily life. What problems will rubber parts encounter in daily life? Let's take a look at it together!
1. Excessive cooperation
The solubility of various additives in rubber is also different. The smaller the solubility of the additives in the rubber, the more likely the over-mixing will cause the blooming. The frost caused by the excessive blending tends to drive the other groups together, even though these sprays are far from saturated in the rubber.
2. Temperature change
Additives usually have a solubility in rubber that varies with temperature. Generally, in this case, the solubility will increase when the temperature is high, and the solubility will decrease as the temperature decreases. Since rubber products are generally used at room temperature, once the outside temperature is lower than room temperature, some of the additives in the formulation are close to their solubility, resulting in blooming. For example, the rubber shoes produced in the summer are qualified for inspection at the factory, but they are found to be sprayed in the winter.
3. Under sulfur
The dissolution of the additive in the rubber is affected by the vulcanization. Taking NR as an example, under the condition of normal vulcanization, the density of cross-linking is the largest, the free sulfur is gradually reduced, the probability of sulfur spraying is gradually decreasing, and the chances of other additives moving through the three-dimensional network are also reduced a lot, so the frosting The probability of the gradual decrease will be gradually reduced. On the contrary, in the state of sulfur sulphur, the network crosslink density will be relatively small, and the probability of blooming will increase accordingly. The seal is an unusual rubber piece, but it is usually There will also be some problems. Let's see what problems are there?
Wear: The wear of the seals involves the smoothness of the surface of the mated parts, the speed of the movement, the transmission medium, etc., and the speed at which the different sealing materials are adapted is also different;
Hardening: The seal is actually a material and then hardens after being affected by the temperature. When the degree of hardening is too high, the seal cannot fill the gap between the mating parts, and the leak will occur slowly;
Corrosion: The situation that is manifested is generally that the seal softens and dissolves. The reason is that the seal is invaded by the medium, and the selected material has an error. If the medium contains water or solvent, special attention is required;
Extrusion: Each time the seal is subjected to excessive pressure, it will be squeezed into the gap of the metal. If the seal is damaged, it will leak. This situation involves the hardness of the seal and the gap of the metal. Whether it is too large, if it is improperly handled during design, processing, selection or installation, it will be damaged.