Rubber mixing process

1. Cleaning

The cleaning of rubber mixing is particularly important. If impurities or other rubber materials are mixed in the process of rubber mixing due to uncleanness of the equipment, the surface of the rubber tube after vulcanization will not be smooth and clean or the air hole will not be uniform

2. Rubber parking

After the rubber mixture is mixed (without vulcanization system and foaming agent), it is better to park it for 24 hours and then use it after refining and adding sulfur. The use of the rubber after parking for a certain time is conducive to the dispersion of the compounding agent

4、 Process

1. Extruder

When starting to feed the extruder, the screw rotation speed should be slow. In order to avoid abrading the screw due to the front end of the screw idling in the barrel.

Extruder temperature control is generally around 70 ℃. The temperature shall increase from the feeding section to the outlet of the rubber hose. The temperature of the extruder can increase the plasticity of the rubber and preheat the rubber.

The temperature of the extruder has a great influence on the rubber tube foaming. Proper preheating can help the microwave section to foam more quickly. However, if the temperature of the extruder is too high, it will affect the scorching of the rubber compound, which will be detrimental to foaming.

The extrusion speed must match the conveying speed of the first section of the curing tank. If the extrusion speed is too fast, the rubber hose will fall to the ground, and if the extrusion speed is too slow, it will form a pull with the conveying speed of the curing tank, which will thin the rubber hose.

2. High temperature of the first section

The first section is called high temperature, which is shorter than the other three sections. Its function is to use the high temperature of this section to peel the rubber tube skin, but it does not affect the inner part of the rubber tube.

3. Microwave section

In the microwave section, there is also hot air, but it mainly uses microwave radiation to heat the rubber tube from inside to outside. A large amount of microwave makes the inside of the rubber material rise rapidly and causes the decomposition of foaming agent to foam the rubber tube. Because this heating is from the inside to the outside, the decomposition foaming is also from the inside to the outside. It avoids the possibility of foaming due to the vulcanization of the rubber tube outside.

4. Hot air

The third and fourth paragraphs are hot air vulcanization. The rubber hose from the second microwave curing tank has been fully foamed, but the curing depth is not enough. It enters the third and fourth stages for final curing. These two stages are mainly the vulcanization of rubber compound, but also accompanied by certain foaming.

5. Cooling and shearing

The rubber hose from the fourth section has completed all vulcanization and foaming, and enters the cooling tank for water cooling. After cooling, cut to the required length according to the size. The finished product is finished.