Internal mixer mixing is carried out in a fast, high temperature and high pressure environment, with large glue loading capacity, short mixing time and high production efficiency. The mixing effect of the internal mixer is affected by many factors, in addition to the order of feeding, it is also related to the mixing temperature, glue capacity, rotor speed, mixing time and other factors. Let me share with you the mixing and feeding sequence of the internal mixer and its influence on the rubber compound.
1. The influence of the sequence of rubber materials on the rubber materials
Mixing is to fully mix various rubber materials and compounding ingredients in a rubber mixer. Improper addition of rubber materials during the mixing process will directly affect the quality of the mixed rubber, which will lead to uneven dispersion of the compounding ingredients, burning, degumming, over-refining, early vulcanization, frosting, etc., so mix and feed in order Make reasonable arrangements.
2.Mixing order
First, the plasticizer, masterbatch and reclaimed rubber are mixed for a period of time before adding the compounding agent. Generally, the compounding agent HY4S1J2Y-MXF with small dosage, strong effect and difficult to disperse is added first, and the compounding agent with large dosage and easy to disperse is added first. Principles added after agents are added.
Since the solid softener generally disperses slowly, it is directly added into the internal mixer together with the raw rubber during mixing. A small amount of medicine has a very important effect on the rubber, and should be added after the raw rubber is added to ensure sufficient mixing time and uniform dispersion, such as activators, accelerators, anti-aging agents, anti-scorch agents, etc. It should be added later together with the vulcanizing agent. Adding anti-aging agent immediately after the raw rubber can protect the raw rubber.
The dispersion effect of carbon black is the key to ensure the quality of the rubber compound, and the dispersion of carbon black is related to its own structure. The larger the particle size of carbon black, the lower the structure, the lower the heat generation of mixing, the easier it is to mix into raw rubber, but the more difficult it is to disperse; the smaller the particle size of carbon black, the higher the structure, the lower the heat generation of mixing The larger it is, the more difficult it is to mix into raw rubber, but it is easier to disperse further.
The liquid softener is added after the carbon black is basically dispersed, which is beneficial to mixing, improves the mixing effect and shortens the mixing time. The liquid softener must be added after the carbon black, otherwise it will reduce the hardness and shear stress of the rubber compound, make it difficult to disperse the carbon black, increase the agglomeration phenomenon, and reduce the physical and mechanical properties of the rubber compound. The addition time of the liquid softener can be determined by the partition coefficient K.
Vulcanizing agent and ultra-speed accelerator must be added after cooling the rubber on the tablet press, otherwise scorching and blooming will easily occur. The order of feeding has a great influence on the quality of the rubber compound. To produce rubber products with an internal mixer, the order of feeding should be arranged reasonably to achieve the best quality of the rubber compound.
