Reasons for Rubber Frosting in Cold-weather Products.

As the temperature decreases, the phenomenon of frosting of rubber also begins to become serious. For the finished products of Hydraulic Rubber Hose that are ready to be shipped, they have encountered many quality pressures.

According to the description of the Hydraulic Rubber Hose Manufacturers, the rubber produces frost, wax, and oil, and the frosting is a phenomenon in which liquid or solid compounding agent migrates from the inside of the rubber to the rubber surface. Generally speaking, it can be divided into the following three types. One is that the powder spray is a powdery compounding agent such as vulcanizing agent, accelerator, active agent, antioxidant, filler and the like is deposited on the rubber surface to form a layer of powder. The second is wax spraying, in which waxes such as paraffin wax and ceresin are deposited on the rubber surface to form a layer of wax film. The third is that the oil injection is a liquid compounding agent such as softener, tackifier, lubricant, plasticizer, etc., precipitates on the rubber surface, and forms a layer of oil.

The solubility of the compounding agent in rubber generally rises and falls with the rise and fall of temperature; the pressure during rubber storage, the humidity of the surrounding air and the time also affect the solubility of the compounding agent. Although the effect is generally small, If the pressure is large, the compounding agent in the rubber under pressure will form crystal nuclei, precipitate out of the rubber surface, and form frost; if the humidity of the air is too high, the polar compounding agent in the rubber will affect the raw rubber (non-polar The weakening of the effect of the compound reduces the solubility of the compounding agent, which leads to frosting; the longer the storage time, the more obvious the frosting on the rubber surface. Because of the temperature and humidity of the air in the storage environment vary with the season and the difference are very large, extremely It is easy to cause the solubility of the compound to change, resulting in blooming.

Hydraulic Rubber Hose

The causes of frosting are as follows: First, the various additives are excessively mixed. The solubility of various auxiliaries in rubber is different. The smaller the solubility of the auxiliaries in the rubber, the more prone to blooming caused by excessive blending (that is, the content of the auxiliaries in the rubber exceeds its solubility in the rubber). Excessive mixing and frosting often cause other components to spray together (this phenomenon is called passive frosting), although these passive frosting materials are far from being saturated in the rubber.

Second, the solubility of temperature-changing additives in rubber changes with temperature. Generally, the solubility is high at high temperatures, and the solubility is reduced at lower temperatures. Because rubber products are usually used at room temperature, once the outside temperature is lower than room temperature, the content of some additives in the formula will approach its solubility and precipitate, resulting in blooming.

The third is that the dissolution of under-sulphur additives in rubber is affected by curing conditions. Taking NR as an example, under the condition of normal vulcanization, the crosslinking density is the largest, the free sulphur is reduced, and the probability of sulphur spraying is reduced. The opportunity for other additives to shuttle through the three-dimensional network is also reduced, so the probability of frost spraying is reduced; otherwise, in the state of sulphur deficiency, In this case, the network cross-linking density is relatively small, and the frost spray probability increases accordingly.

24 is that it begins to age. Aging means that the three-dimensional network structure of the vulcanizate is partially damaged due to bond breakage, which weakens the ability of the network structure to adsorb and lock the auxiliary additives. The migration of the additives to the surface causes blooming. 

The frosting is caused by a variety of reasons. The frosted rubber can only be effectively treated if the cause of the frosting is analyzed. Medium Pressure Hydraulic Hose are constantly being improved. Welcome your patronage.