Slot heater

Warm compaction of metal powder.

Warm compaction gives a major advantage compared to the conventional "cold" compaction by producing changes in the pore morphology of sintered parts.

The result is that higher density levels are achieved and, at the same time, warm compaction products have more even density distributions, i.e. less variation in density within a component.


The warm compaction process is applicable to most powder/material systems. This will lead to higher strength and better dimensional tolerances. A possibility of green machining is also obtained by this process partly due to high green strength.


The Slot heater can be fitted to all press types and is manufactured and marketed under licens from Höganäs AB, Sweden.

The process offers:

  • an increase in green density and strength 
    between 0,1-0,3g/cm3
  • improved powder flow
  • reduction in green scrap caused by damage
  • increased potential for machining in green state

Lower compacting pressures will:

  • extend tool life
  • reduce the likelyhood of tool breakage
  • facilitate multi-impression tooling

Technical specifications:

  • capacity at 130°C – max 4,5 kg/min
  • +/- 2°C temperature control
  • pre-heating timer, approx. 1 hour
  • 3x400V 50Hz 32A power requirement

Simple installation of the heating elements (max 3,5 kW/unit) and thermocouples converts the system ready for production.


In addition to the powder heater, temperature regulators and tyristor units are included for:

  • punch
  • die
  • fillshoe
  • bottom plate

Safety features:

  • separate breakers for all heating circuits
  • overheat protection for thr oil system
  • low temperature alarm
  • earth fault switch
  • emergency stop

Read more here...