In the production process of PVC hollow tile equipment, raw material mixing is one of the most important processes in PVC processing. PVC, calcium carbonate, stabilizer, moistening agent and other raw materials are weighed first and then put into the high-speed mixer. Through the self friction heating of raw materials and the high-speed mixer, the raw materials can be mixed evenly. In fact, many problems in the production process of PVC hollow tile equipment are related to the mixing of raw materials, some of which are direct reasons. Therefore, enough attention must be paid to the mixing of raw materials in the process of PVC hollow tile equipment, and the operation should be standardized according to the requirements.
The most intuitive function of raw material mixing in the process of PVC hollow tile equipment is to mix all kinds of additives in the formula evenly in the PVC resin through the mixing equipment, so that the additives can play a full role and ensure the products have excellent performance.
In the process of PVC hollow tile equipment under general conditions, powder additives cannot be dispersed and mixed evenly in PVC resin. They will exist in the mixing system in the form of aggregates, and plasticizer molecules can not be completely dispersed in PVC resin. Under the shear action of the mixer, the PVC particles are repeatedly broken into primary particles, and the powdery auxiliary aggregates are further dispersed. The additives and resins become smaller particles with larger contact surface, which is easier to absorb and "combine" with each other. In the mixing process of PVC hollow tile equipment process, shear heat or / and external heating will increase the temperature of the mixed materials, the molecular chain of PVC will become more active with the increase of temperature, and the swelling amount of particles will increase, which is convenient for the diffusion and absorption of plasticizer and increase the absorption amount of additives. Low melting point additives, such as lubricants, will become liquid with the increase of temperature and disperse into the pores of resin particles like plasticizers. Therefore, one of the most important points of PVC hollow tile equipment process is to mix raw materials with high-speed mixer and reach a certain mixing temperature, which can make the PVC formula components organically disperse and mix evenly, and ensure the consistency of subsequent plasticization and molding of materials.
At room temperature, the particle size of PVC resin is different, and it is easy to cause uneven plasticization during extrusion molding of PVC hollow tile equipment. In the process of high-speed mixing, PVC resin has the shape change of particle refinement, re bonding and particle size increasing, and has the effect of increasing apparent density and partly gelatinization. The apparent density increases, and the extrusion rate can be increased. The reunion and homogenization of particles are favorable for the uniform plasticization of extrusion process in PVC hollow tile equipment. Some gelation can accelerate the plasticizing process when the material is extruded. Only when PVC hollow tile equipment produces SPC floor can good finished products be made.