This method uses UHF heating to produce the final product using the heat conductance property of the rubber material. The Magnetrones in the curing equipment are located in a tunnel. These Magnetrones transmit radio waves with a frequency of 2450 MHz, which cause whirl currents in the electrically conductive materials and oscillate polar molecular structures in the material when the rubber profile passes through the conveyor belt. The heat produced so far is then maintained in a long hot-air tunnel where the actual curing process takes place. The air temperature in the tunnel is over 200°C.
Once the product has come into the desired shape, the cooling and the wind-up process is carried out, which is similar to the process followed in the Salt Batch Continuous Cure Rubber Extrusion process.
Basic Rubber Requirement
As rubber is not a good conductor of heat, to ensure this method works efficiently the rubber material must be electrically conductive and have polar molecular structures. The black reinforced rubber has carbon black filler, so it is capable of conducting heat through the induced whirl currents.
However, if you need to produce the light colored rubber products via this rubber extrusion method then ensure adding some polar material to the raw rubber compound. For example, you can add Nitrile, chloroprene polymer, or Polyethylene glycol. Adding the polar material will help conduct the heat, but in comparison with the black carbon filled rubber, it will be less.
When to use Microwave Continuous Cure Rubber Extrusion
This method takes a long time to produce the final products; hence, it should be used to develop thick-walled products. In the case, the raw material has pollutants like metal filings or poorly distributed carbon black they may result in hot spot when the rubber profile is being produced.
Pros - This method produces less environmental hazards than the other methods of extrusion.
Cons - It takes more time in the production.