Mixing and Technology of Rubber Processing Internal Mixer

Compared with the rubber mill, in the rubber mixing process, the internal mixer has a short mixing time, high production efficiency, and easy operation, which can well overcome the dust flying, greatly reducing the loss of the compounding agent and reducing the labor intensity of the personnel. With the continuous improvement of the production process, rubber mixer products are constantly developing and improving.

The mixing process is the process of uniformly dispersing various compounding agents in rubber to form a multi-phase colloidal dispersion system with rubber as a medium or a mixture of rubber and some compounding components compatible with it as a medium, and a compounding agent incompatible with rubber as a dispersed phase.

 The mixing of rubber is the process of mixing raw rubber or masticated raw rubber and compounding agent into compounding rubber by using a rubber mixing machine, that is, the process of uniformly dispersing various compounding agents in rubber by the mechanical force of the rubber mixing machine, that is, uniformly dispersing various compounding agents in rubber to form a mixture with rubber as medium or rubber and some compounding components (compounding agents, etc.) compatible with it as medium, the process of multi-phase colloidal dispersion system with rubber incompatible compounding agent (such as powder filler, zinc oxide, pigment, etc.) as the dispersed phase, the granular compounding agent is dispersed phase, and the raw rubber is continuous phase, which is an important production process for rubber processing.

 1.Mixing Technology of Rubber Processing Internal Mixer

 The process of uniformly dispersing various compounding agents into raw rubber or plastic rubber on the rubber mixing machine is called mixing, and the rubber made by mixing is called mixing rubber. Mixing is a process in which raw rubber or plasticized raw rubber and compounding agent are mixed with rubber mixing machine, which is an important production process for rubber processing. That is, the process of uniformly mixing raw rubber or plastic glue with various compounding agents 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 the production cost. It is necessary to add various compounding agents to the raw rubber or plastic rubber, such as filler, reinforcing agent, accelerator, vulcanizing agent, antioxidant, anti-scorching agent, etc. These compounding agents include solid, liquid and other materials, and the added compounding agents are evenly dispersed to ensure the consistent properties of the rubber.

 The specific technical requirements for the mixing process are: the compounding agent is evenly dispersed, so that the compounding agent, especially the reinforcing compounding agent such as carbon black, can achieve the dispersion degree to ensure the consistency of the rubber material performance. The quality of the compound obtained after mixing has an important influence on further processing and product quality. If the rubber processing and mixing is not good, the rubber compound will have a variety of problems, such as scorching, blooming, etc., so that the calendering, extrusion, gluing, vulcanization and other processes are difficult to carry out normally, and lead to a decline in the performance of the finished product.

 The mixing process of rubber includes four stages: mixing, dispersing, mixing and plasticizing. Raw rubber or plastic rubber is subjected to shearing and stretching in the rubber mixer to produce rheology, fracture and crushing, and is fully contacted with the compounding agent to make it mixed. This process is called the wetting phase or eating the powder phase. The compounding agent after mixing the rubber is further broken into fine particles of a fine size under the action of mechanical force, while increasing the contact surface area and further improving the mixing uniformity. So it is also called micro dispersion. The process of uniform distribution of various compounding agents in raw rubber or plasticized rubber. The so-called mixing refers to only increasing the distribution uniformity of the compounding agent in the rubber compound without changing the size of the particles. This process is also called macroscopic dispersion or simple mixing.

The quality of mixing has a decisive influence on the further processing of the rubber and the quality of the finished product. The mixing method is usually divided into two types: open mixer mixing and internal mixer mixing. Both of these methods are batch mixing, which is widely used at present. General process flow of compound preparation: supplementary processing of compounding agent→Raw rubber and compounding agent weighing→mixing→Quality inspection.

Mixing is a rubber processing process in which rubber (raw rubber) and various compounding agents are uniformly mixed in a rubber mill. In order to be able to add powdered compounding agent to rubber, raw rubber must first be plasticized to improve its plasticity and fluidity.

The mixing process is the basic process of rubber processing, and the quality of the mixed rubber after adding the compounding agent has a decisive influence on the process performance of the semi-finished product and the quality of the finished product. The 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 molecular structure, molecular weight size and distribution of rubber, and the aggregation state of the compounding agent all change. Through mixing, the rubber and the compounding agent play a physical and chemical role, forming a new structure.