Special screw geometries


Spezifische Wärmekapazität von PA6 (30 % Glasfaser)

  

Screw geometry of Polyamid screws

  • L/D ratio: 22:1

  • main characteristics:
    • longer feeding zone to pre-heat and pre-homogenize more PA material because PA processing is a very energy consuming process (see graphic)

  • most common applications:
    • PA6 und PA66

 

Screw geometry LUBRIMELT

    • L/D ratio: 22:1

    • main characteristics:
      • higher throughput
      • low shear coefficient
      • low screw speed possible
      • prevents washing out of lubricant
      • good lubrication properties

    • most common applications:
      • self-lubricant polymers
      • gears, sliding devices, etc.

 

Screw geometry DURO-MELT (free flowing)

  • main characteristics:
    • short L/D ratio
    • low compression ratio
    • wear-resistant execution
    • no non-return valve

 

Screw geometry PIM-MELT

  • main characteristics:
    • L/D ratio: 22:1
    • low compression ratio

  • most common applications:
    • metal and ceramic feedstocks

 

Screw geometry of LIM screws

  • L/D ratio: 22:1

  • main characteristics:
    • spring-loaded non-return valve
    • holes in the first part of the screw flights to improve mixing properties

 

Screw geometry DOUBLEMELT

  • short L/D ratio

  • available for PLUS series only

  • main characteristics:
    • double flighted screw
    • shorter homongenizing length
    • less flight depth in feeding zone to get the resin in contact with the barrel wall as quick as possible

  • most common applications:
    • PA6 und PA66

 

Screw geometry PVC-MELT

  • L/D ratio: 22:1

  • main characteristics:
    • no non-return valve
    • screw flights reach close to screw tip
      (angle of 20°)
    • feeding zone: approx. 1D
    • compression zone: approx. 9D

  • most common applications:
    • rigid PVC processing
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