Operation Method of internal mixer

Mixer, also known as kneading machine, mainly used for rubber molding and mixing. The internal mixer is a machine with a pair of rotors of a specific shape and relative rotation, which is used to plasticate and mix polymer materials intermittently in a closed state with adjustable temperature and pressure, it is mainly composed of mixing chamber, Rotor, rotor sealing device, feeding and pressing device, unloading device, transmission device and machine base. 1. Calculate the rubber content and the actual formula according to the volume of the internal mixer and the suitable filling coefficient (0.6 ~ 0.7) . 2. Accurately weigh the raw materials used in the formula according to the actual formula, the raw rubber, small materials (Zno, SA, accelerator, antioxidant, solid softener, etc.) , reinforcing agent or Filler, liquid softener, sulfur are placed separately, arranged in order on the shelf; 3. Open the power switch and heating switch of internal mixer, preheat the internal mixer, check whether the wind pressure, water pressure and voltage meet the process requirements, check whether the temperature measuring system, timing device and power system indication and record are normal; 4、 after preheating the internal mixer, stabilize for a period of time, prepare the rubber; 5、 lift the top bolt, put the raw rubber which has been cut into small pieces into the internal mixer from the feeding mouth, drop the top bolt, refine the rubber for 1 Min; 6、 lift the top bolt, add the small material; 7. Lift the top plug, add carbon black or filler, drop the top plug and mix for 3 min. 8. Lift the top plug, add the liquid softener, drop the top plug and mix for 1.5 min. 9, using thermocouple thermometer to measure the temperature of the rubber, record the initial temperature of the mixing chamber, the temperature of the mixing chamber and the temperature of the rubber discharge at the end of mixing, the maximum power, the rotation speed of the rotor, make the mill run, open the circulating water valve, then put the rubber material discharged from the internal mixer into the packing roll of the internal mixer, wait for the temperature of the rubber material to drop below 110 °C, add sulfur, cut knife about twice each time, wait for the sulfur to be eaten, the rubber material surface is relatively smooth, cut off the rubber. 11. Adjust the open mill roller pitch to 0.5 mm, put in the rubber material thin pass, make triangle pass, thin pass 5 times, adjust the roller pitch to about 2.4 mm, put in the rubber material roll, wait for the surface to be smooth without bubbles, next piece, weigh the total mass of rubber material, place on a flat, clean metal surface and cool to room temperature. Label with Formula Number and mixing date. Leave aside. Mixing process test report for each batch of internal mixer, should record: The temperature at the beginning of mixing, mixing time, rotor speed, top plug pressure, temperature of discharging, power consumption, the difference between the quality of mixing rubber and the total quality of raw materials, and the type of mixer. Note: At the beginning of the mixing experiment, a compound with the same formula as the test compound can be mixed to adjust the working state of the internal mixer before the formal mixing.