Plastic recycling

Plastic Recycling

    Extrusion is a technology for manufacturing products from polymer raw materials based on pushing molten granules through forming holes (annular, slit dies) to give the material a given shape or profile.  
     The heat treatment and evaporation of polymers in vacuum chambers is called degassing. After degassing, the amount of air in the granules is significantly reduced, the percentage of moisture decreases, the raw material gets rid of harmful impurities as much as possible. 
      The water ring pumps of the LRM, LRL series are able to provide high-quality removal of volatile substances at a vacuum of 33-50 mbar abs.

     After the extruder, plastic pipes/profiles pass to a vacuum sizing tank also known as a calibration table. Water is used continuously in a vacuum sizing tank for cooling and lubrication of the plastic profiles. Vacuum is used to improve the shape/profile of the plastics. A vacuum pump used in this step of the process must be capable of handling slugs of water. Kinney’s axial flow design A series liquid ring vacuum pump is proven in this application due to the following benefits:
-  Reduced stress on motor shaft & bearing with the axial flow design.
-  The shrouded rotor does not leave blades exposed and allows the pump to start flooded.
-  Discharge port on the port cylinder has a much larger opening than the flat plate design, this enables it to handle slugs of water and reduces the chance of air being trapped in the pump once the mass flow drops.
-  Axial flow design eliminates valves or balls on the discharge side for ease of maintenance.
-  The typical vacuum requirement is 18 to 22” Hg.