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Main Advantages of the Microwave Heating

  • Speeding up: minutes instead of hours!!
  • Volume Energy transmission - cold vessel
  • ENERGY Savings, Room Savings
  • Efficiency 70%
  • Automatization
  • Safety *
  • Environment *

Comparing to the processes using the combustion


REFERENCES

Rubber

Dielectric heating

Covers both radio frequency heating and microwave heating. Elastomers pose typically very low thermal conductance. Conventional heating requires external heating of surface first, creating of thermal gradient enabling the heat transfer into the material volume that can possibly deteriorate its properties. On the other side dielectric heating enables immediate affecting into the depth of material. Various natural and synthetic rubbers are using different fillers posing variable dielectric properties reacting in effect very diversely in high frequency electromagnetic field.

Continuous microwave vulcanization

Vulcanization of extruded profiles is far most usual application of MW in rubber industry. The profile section, properties of the selected rubber material, required production output – that all affects shifting velocity of the profile, process control and namely the required installed MW power. (Typical value is 1kW for every 30 kg product output/hour. In extruder the temperature is increased to 80°C-90°C while ahead of the vulcanization tunnel the MW preheating section is deployed to increase the temperature aprox. to 130°C. Entering the tunnel the material reaches quickly the vulcanization temperature (i.e. 180°C, according to the blend composition). After passing the MW tunnel it is kept on the vulcanization temperature for the period of 60-90 seconds conventionally, i.e. hot-air method. Afterwards it is cooled. Despite the vulcanization of moulded material that undergoes under the pressure here is sufficient the atmospheric pressure.  It enables more universal design and processing of different profiles without substantial line (technology) modifications. 

Microwave waste rubber regeneration

Rubber recycling requires disrupting the bridges on vulcanization level sustaining the bridges on polymerization level... The major difficulty is the fact that devulcanization and depolymerization temperatures are quite close each other. This is due to the similarity of atomic structure to be broken: it is S-S and C-S bounds to be disrupted during devulcanization, while C-C bounds are disrupted in de-polymerization.  That is why very high level of uniformity and homogenity of the process is required in the whole volume.