The closed plastic mixing machine is referred to as the internal mixer. The main component of the internal mixer is the internal mixing chamber, also called the plasticizing chamber. The upper part is the feeding device and the lower part is the unloading device port. There is a bolt on the upper and lower parts; when the upper and lower ejector bolts are closed, a Closed molding room. There is a pair of rotors rotating in opposite directions in the mastication chamber. The cross section of the rotor is pear-shaped and the longitudinal direction is a Z- shaped spiral. The rotor speeds are slightly different. There is a fixed speed ratio between the rotors and between the rotors and the wall of the mastication chamber. There is a cooling (heating) jacket on the outer wall of the plasticizing chamber to heat and cool the materials.
Introduction
The closed mixer is referred to as the internal mixer. In a closed cylindrical container, a mixer is used to give the material a shearing effect by means of the rotation of a paddle wheel. Both the container and the impeller have small holes, and the temperature of the material can be adjusted by heating or cooling, and is used for mixing plastics or rubber. The advantage of this mixer is that there is minimal risk of dust and fumes spreading. Banbury mixer is a typical representative.
Working principle
When the internal mixer is working, first the upper ejector bolt is lifted up, and the material is added through the feeding port. The upper ejector bolt presses the material into the mixing chamber driven by air pressure. During the working process, the upper ejector bolt always presses the material and gives the material a certain force. effect. After mixing is completed, the lower top bolt is opened and the material is discharged from the discharge port. The material refined by the internal mixer will be a sticky mass when it is discharged. It must be rolled into a sheet with a mixer and cooled before proceeding to the next step.
Effect
Rubber products cannot be made only from pure rubber. In order to make the products have specific physical and mechanical properties and facilitate the processing and molding of the products, a certain amount of other inorganic and organic compounds must be added to the raw rubber. These compounds are the so-called rubber compounding agents., the process of using mechanical methods to completely and evenly disperse rubber compounding agents into raw rubber is called compounding and mixing of rubber materials.
It is difficult to disperse the compounding agent evenly into the raw rubber because it is affected by many factors, such as the wettability of the compounding agent to the rubber material, the agglomeration of the compounding agent itself during the mixing process, the The viscosity of the material, the purity, humidity, fineness and order of addition of the compound itself, the temperature and time of mixing, etc.
The function of mixing is to increase the plasticity of the rubber when the temperature rises, and the healthy compounding agent is more easily distributed evenly in it. In order to prevent the rubber from self-crosslinking and forming a body structure when the temperature is removed, the mixing time must be reduced. In order to obtain the expected effect, the plasticity should not be too large during mixing to cause the so-called “over-plasticizing” phenomenon, which will cause the vulcanized rubber to have too low strength in the future.
Tire production
Production process flow
Tires are composed of three parts: casing, inner tube, and pad. During the production process, several processes such as beating, rubber coating (or dipping), and casing molding are more dangerous.
Mixing process
Mixing of rubber materials is generally carried out in a closed mixer. The refined rubber material is fed into the open mixer through a pipeline, and then the sulfur compounding agent is added. During the mixing process, volatilized dirty oil and carbon black powder often accumulate in pipe mouths and pipelines. Therefore, when inspecting and repairing welded transportation pipelines, the pipelines must be disassembled, flammable substances must be removed, and then moved to a safe location.
