Natural rubber has high elasticity, high elongation at break, and good cold resistance. It is the earliest type of rubber used in the production of rubber products, but its price is high. Therefore, many rubber products manufacturers use rubber fillers in large quantities when conditions permit. To reduce the cost of natural rubber products; filling fillers in natural rubber products not only reduces the cost of raw materials, but also improves the processing technology of rubber products; different types of rubber fillers have different roles in natural rubber products.
The rubber fillers commonly used in the rubber products industry include carbon black, white carbon black, calcium carbonate, kaolin, quartz powder, etc. Each filler has various unique molecular structures and performance characteristics, and has different functions in natural rubber products, such as prolonged vulcanization. Time, improve the reinforcing performance, etc., different fillers need to pay attention to many problems when used in natural rubber products.
White carbon black is a kind of porous material with many odorless, odorless and non-combustible materials. It has good high temperature resistance and electrical insulation. The surface contains highly active OH groups. The adsorption in the rubber compound is strong and can be obviously delayed. Natural rubber vulcanization time; good reinforcing performance, can significantly improve the hardness, tensile strength and elongation at break of natural rubber products; improve the aging resistance of rubber products, and further improve the wear resistance and tear strength of natural rubber . However, the strong adsorption of silica itself will lead to a decrease in the crosslink density of the vulcanizate and increase the compression set of the natural rubber. The particle size is small, the surface activity is large, the reinforcing performance is good, and the excessive amount will reduce the elasticity of the vulcanizate. . Therefore, natural rubber products must be controlled when using white carbon black as filler.
Calcium carbonate is the most non-reinforcing filler in the rubber industry. Its low price and high output can improve the gloss of light-colored rubber products and increase the elongation and tensile strength of natural rubber while significantly reducing natural rubber products. Wear resistance, etc.; but calcium carbonate due to excessive use of its own structure will lead to a decline in physical and mechanical properties of natural rubber products.
The main component of quartz powder is silica, which has good wear resistance and stable chemical properties. It can prolong the scorch time of natural rubber, shorten the curing time of rubber and improve the vulcanization performance of natural rubber. The self-reinforcing property is very weak and natural. The rubber is not easy to disperse, and the modified high-fineness quartz powder has improved reinforcing performance, but the aging resistance is lowered; the quartz powder has higher electrical resistivity, which can improve the electrical insulation performance of the natural rubber product. Quartz powder is also one of the commonly used rubber fillers in the production of natural rubber products. Manufacturers choose according to their needs when selecting, and determine the dosage reasonably.
Kaolin has good high temperature resistance and can be used in natural rubber products which are easy to age under high temperature, which can reduce the cost of raw materials and prolong the service life of natural rubber products. Kaolin has better reinforcing performance than quartz powder and light calcium, but it is second to white carbon black, so it can improve the hardness, tensile strength and elongation of natural rubber to a certain extent; it is between reinforcing filler and non-reinforcing filler. Rubber filler between.
Nowadays, many rubber products manufacturers, especially molded natural rubber products manufacturers, in order to reduce the production cost, will add sub-brand natural rubber or composite natural rubber to the products, which can reduce the production cost and ensure the quality of the products; The molecular structure and performance characteristics of the glue are basically the same as those of the original brand natural rubber. Therefore, when using the brand-name natural rubber to produce rubber products, the low-cost rubber filler is also inseparable. The role of different fillers in the sub-brand natural rubber products can be found in this paper.