1. Basic process flow
There are many kinds of rubber products, but the production process is basically the same. The basic process of rubber products with general solid rubber-raw rubber as raw material includes six basic processes: plasticizing, mixing, calendering, extrusion, molding and vulcanization. Of course, basic processes such as raw material preparation, finished product finishing, inspection and packaging are also indispensable. The processing technology of rubber is mainly to solve the contradiction between plasticity and elastic properties. Through various technological means, the elastic rubber is turned into plastic masticated rubber, and then various compounding agents are added to make semi-finished products, and then the plastic semi-finished products are turned into rubber products with high elasticity and good physical and mechanical properties through vulcanization.
2. Raw material preparation
The main raw material of rubber products is raw rubber as the basic material, and raw rubber is collected by artificially cutting the bark of rubber trees grown in the tropics and subtropics.
Various compounding agents are auxiliary materials added to improve some properties of rubber products.
Fiber materials (cotton, hemp, wool and various man-made fibers, synthetic fibers and metal materials, steel wires) are used as skeleton materials for rubber products to enhance mechanical strength and limit product deformation. In the process of raw material preparation, the ingredients must be accurately weighed according to the formula. In order for the raw rubber and compounding agent to be homogeneously mixed with each other, the material needs to be processed. The raw rubber should be softened in a drying room at 60–70℃, and then cut and broken into small pieces. The compounding agent is lumpy. Such as paraffin, stearic acid, rosin, etc. to be crushed. If the powder contains mechanical impurities or coarse particles, it needs to be screened to remove liquid ones such as pine tar and coumarone, which need to be heated, melted, evaporated, and filtered. Bubble formation during uniform vulcanization affects product quality.
3. Plasticizing
Raw rubber is elastic and lacks the plasticity necessary for processing, so it is not easy to process. In order to improve its plasticity, it is necessary to masticate the raw rubber, so that the compounding agent can be easily and uniformly dispersed in the raw rubber during mixing, and at the same time, it is also helpful to improve the permeability of the rubber and penetrate into the fiber fabric during the calendering and forming process. and molding fluidity. The process of degrading the long-chain molecules of raw rubber to form plasticity is called mastication. There are two methods of plasticizing raw rubber: mechanical plasticizing and thermal plasticizing. Mechanical mastication is a process in which the long-chain rubber molecules are degraded and shortened from a high elastic state to a plastic state by the mechanical extrusion and friction of the plasticizer at a low temperature. Hot plasticizing is to pass hot compressed air into the raw rubber under the action of heat and oxygen to degrade long-chain molecules and shorten them to obtain plasticity.
4.Mixing
In order to adapt to various conditions of use, obtain various properties, and in order to improve the performance of rubber products and reduce costs, different compounding agents must be added to the raw rubber. Mixing is a process in which the masticated raw rubber is mixed with the compounding agent, and the compounding agent is completely and uniformly dispersed in the raw rubber by mechanical mixing in a rubber mixing machine. Mixing is an important process in the production process of rubber products. If the mixing is not uniform, the effect of rubber and compounding agents cannot be fully exerted, which affects the performance of the product. The rubber material obtained after mixing is called mixed rubber. It is a semi-finished material for the manufacture of various rubber products, commonly known as rubber material, which is usually sold as a commodity. Buyers can use the rubber material to directly process, shape and vulcanize it into the required rubber products. . According to the different formulations, there are a series of different grades and varieties with different properties to choose from.
5.Forming
In the production process of rubber products, the process of prefabricating various shapes and sizes by calenders or extruders is called molding.
6.Vulcanization
The process of converting plastic rubber into elastic rubber is called vulcanization. It is to add a certain amount of vulcanizing agent such as sulfur, vulcanization accelerator, etc. The linear molecules of the raw rubber are cross-linked to each other to form a three-dimensional network structure through the formation of “sulfur bridges”, so that the plastic rubber compound becomes a highly elastic vulcanizate.
Post time: Mar-29-2022
