Dunst GmbH Paste Extruders
  Extrusion process with Dunst Paste Extruders
 
 
 
Paste extrusion is a process for the production of thin hoses, thick tubes (linear), wire insulation and unsintered tapes of PTFE. For the PTFE paste technique exclusively emulsion polymerization powder is used. The paste is a mixture of these spongy PTFE powder types with wetted organic fluids like gasoline, light oil, etc.

The process is done in batch quantities: The PTFE lubricant mixture firstly is pre-pressed to so-called billets (pre-form, candles) and then put into a paste extruder which works on the principle of the ram extrusion.
Then the billets are pressed through a conic nozzle in cold or slightly pre-heated condition (approx. 40-60 °C). The extrudate is separated from the still containing lubricant within the drying zone and then sintered.

 
 
 
 
 

Advantages of Dunst Paste Extrusion Systems

low wall thickness tolerances through special equipment
extrusion cylinder to be heated additionally for better extrusion quality
measurement transducer of pressure, force and ram speed for permanent control of the extrusion process and extrusion speed
hydraulic closure with high closing force for quick extruder loading
quick loading with special loading carriage - also possible with several pre-forms
(no manual touch)
electrically adjustable mandrel
control system for constant extrudate speed
operation through touch screen and recording of the extrusion process parameters