Mixing and Technology of Rubber Processing Internal Mixer
Compared with the rubber open mill, in the rubber mixing process, the internal mixer has short mixing time, high production efficiency, and easy operation, which can well overcome the dust flying, greatly reduce the loss of mixing agent, and reduce the labor intensity of personnel. With the continuous improvement of production technology, rubber internal mixer products are constantly developing and improving.
The mixing process is the process of uniformly dispersing various compounding agents in rubber to form a multiphase colloidal dispersion system with rubber as the medium, or with the mixture of rubber and some compatible compounding components as the medium, and with the compounding agent incompatible with rubber as the dispersion phase.
Rubber mixing refers to the process of refining raw rubber or plasticized raw rubber and compounding agent into rubber mixture with a rubber mixing machine, that is, the process of evenly dispersing various compounding agents in rubber with the help of mechanical force of the rubber mixing machine, that is, evenly dispersing various compounding agents in rubber to form a rubber as medium or a mixture of rubber and some compatible compounding components (compounding agent, etc.) as medium, The process of multiphase colloidal dispersion system with incompatible compounding agents (such as powder filler, zinc oxide, pigment, etc.) as dispersion phase. Granular compounding agents are dispersed phase, and raw rubber is continuous phase. It is an important production process for rubber processing.
1. Mixing technology of rubber processing internal mixer
The process in which rubber disperses various ingredients evenly into raw rubber or plastic compound on the rubber mixing machine is called mixing, and the compound made by mixing is called mixed rubber. Mixing is the process of refining raw rubber or plastic raw rubber and compounding agent into rubber mixture by rubber mixing machine, which is an important production process for rubber processing. Namely, the process of mixing raw rubber or plastic glue with various additives through mechanical action. The mixing of rubber is to improve the physical and mechanical properties of rubber products, improve the processing and molding process, and reduce production costs. It is necessary to add various additives, such as fillers, reinforcing agents, accelerants, vulcanizing agents, anti-aging agents, coke inhibitors, etc., into raw rubber or plastic rubber. These additives include solid, liquid and other materials. The added additives are dispersed evenly to ensure the consistency of rubber properties.
The specific technical requirements for the mixing process are as follows: the mixing agent shall be evenly dispersed to achieve the degree of dispersion of the mixing agent, especially the reinforcing agent such as carbon black, so as to ensure the consistent performance of the rubber compound. The quality of the rubber mixture obtained after mixing has an important influence on further processing and product quality. If the rubber processing and mixing are not good, the rubber will have various problems, such as scorching, frost spraying, etc., which will make it difficult to carry out the calendering, extrusion, rubber coating, vulcanization and other processes normally, and lead to the decline of the performance of the finished product.
The mixing process of rubber includes four stages: mixing, dispersion, mixing and plasticizing. The raw rubber or plastic rubber is sheared and stretched in the rubber mixing machine to produce rheology, fracture and crushing, and fully contacts with the compounding agent to mix it. This process is called wetting stage or eating powder stage. The compounding agent mixed with rubber will be further broken into fine particles of small size under the action of mechanical force, at the same time, the contact area will be increased and the mixing uniformity will be further improved. So it is also called micro dispersion. The process of uniform distribution of various ingredients in raw rubber or plastic compound. The so-called mixing refers to only increasing the distribution uniformity of the compounding agent in the rubber compound without changing the size of its particles. This process is also called macro dispersion or simple mixing.
The quality of mixing has a decisive influence on the further processing of rubber compound and the quality of finished products. The mixing methods are generally divided into open mixer mixing and internal mixer mixing. Both methods are batch mixing, which is a widely used method at present. The general process flow of the preparation of the rubber mixture: processing of the compounding agent supplement → weighing of the raw rubber and compounding agent → mixing → quality inspection.
Mixing is a rubber processing process in which rubber (raw rubber) and various ingredients are mixed evenly in a rubber mixing machine. In order to be able to add powdered ingredients to rubber, raw rubber must be first plasticized to improve its plasticity and fluidity.

The mixing process is the basic process of rubber processing. The quality of the rubber mixture after adding the mixing agent has a decisive impact on the process performance of semi-finished products and the quality of finished products. Rubber mixing process is essentially a process in which the compounding agent is uniformly dispersed in the raw rubber. The granular compounding agent is a dispersed phase and the raw rubber is a continuous phase. During the mixing process, the rubber molecular structure, molecular weight size and its distribution, and the aggregation state of the compounding agent all changed. Through mixing, rubber and compounding agent play a physical and chemical role and form a new structure.