There are two process methods for mixer mixing: one stage mixing and stage mixing. For rubbers with a high rubber content or a combination of natural rubber and a small amount of synthetic rubber, and a small amount of reinforcing fillers, the one-stage mixing method is usually used. For rubbers that use natural rubber and more synthetic rubbers and have a large amount of reinforcing fillers, a two-stage mixing method can be used to mix the two rubbers with the compounding agent more uniformly. Whether it is one-stage mixing or two-stage mixing, during the mixing operation, the raw rubber, masterbatch or combined rubber is first added along the driving end, and then various compounding agents are added for mixing according to the formula.

There are two methods for mixing and adding medicines: rubber feeding and rubber changing and feeding. Suction feeding is suitable for those with high raw rubber content, and the compounding agent is added in the middle of the roller. Replacing and adding materials is generally suitable for those with low raw rubber content, and the compounding agent is added at one end of the roller. Be careful not to cut the knife when eating powder, otherwise the powdery compounding agent will invade between the front roller and the inner surface of the rubber layer, so that the rubber rubber roller will also be squeezed into a hard piece through the roll gap, which will cause mixing difficulties. After all the ingredients have been eaten, add the remaining glue and mix.

The main methods of refining operation include:

(1) Thin pass method: This method is to adjust the roller pitch to 1～1.2mm, let the rubber material pass through the roll gap, and let it fall into the receiving tray. The rubber material is twisted 90° to pass thinly. This is repeated until the specified number of times. Then increase the roll distance (about 10mm) to allow the rubber material to wrap the roll and unload the film. This method is characterized by fast heat dissipation of the rubber, low labor intensity, and safe operation. However, the compounding agent is not easy to be uniformly dispersed, especially along the axial direction of the roller.

(2) Triangular bag operation method: This method adopts a smaller roller distance (1～5mm) or a larger roller distance (2～2.5mm), and the rubber material wrapped on the front roller is cut transversely during operation. The rotation of the rollers continuously folds the left and right side rubber into a triangle bag, and repeats this until a specified number of times, so that the rubber between the rollers is continuously folded from the two sides to the middle, and then dispersed to the middle to mix on both sides. Then enlarge the roller distance (about 10mm), wrap the roller and unload the film. This method has good compounding agent dispersion effect and uniform rubber texture, but due to high labor intensity and poor operational safety, it is generally only suitable for mixing with open mills below KX-400 specifications.

(3) Oblique knife method (eight knife method); this method is to cut the knife at a 75° bevel angle with the horizontal line of the roller on the roller of the open mill. And rolling 8 times, that is, 4 times on each side. The roller pitch is generally 7-8mm. In this method, the compounding agent is more uniformly dispersed and the operation efficiency is high. However, due to the high labor intensity, the production is only suitable for mixing with an open mixer below the KX-550 specification.

(4) Twisting operation method and cutting operation method: The twisting operation method is to cut the rubber material wrapped on the roller laterally and attach it to the front roller. As the roller rotates, the rubber material is fan-shaped. Move from right to left or from left to right, and then put one side of the film into the rubber mixer to mix it. The cutting operation method is to cut the rubber wrapped on the roller to the left and right until there is still a certain width of the roller rubber, and then turn the blade to 90° to continue to cut the film, so that the rubber on the roller falls on In the receiving tray, when the accumulation of glue on the top of the roller is almost exhausted, stop the cutter, make the rubber in the tray enter between the two rollers with the remaining tape on the roller, and move the rubber to the left or right. Repeat several times to make the rubber compound evenly mixed. The button-pressing operation method and the inverted operation method have low labor intensity and are suitable for mixing on large-scale open mills. The cutting operation method can also be equipped with an automatic cutter device instead of manual operation, but the mixing effect is not ideal, so it is generally not used alone, but combined with other methods.

(5) Rolling operation method: This method can be divided into oblique rolling operation and horizontal rolling operation. The roll pitch is generally 7-9mm. The slanting operation is to roll the roll diagonally from left to right. When the accumulated glue on the roller is almost eaten up, push the film to the right, and then roll it diagonally from right to left. Repeat this to make the mixing uniform. The horizontal winding operation is to cut off the rubber and then rotate with the roller to roll. When the accumulated rubber is almost eaten, the film is twisted 90° and placed between the rollers, and then re-rolled, and so on until the mixing requirements are met. This method has good mixing effect, high production efficiency, but high labor intensity.

In production, several methods are usually carried out concurrently.

The above is for reference only, and does not mean that any process is applicable!