Home

TPR (Thermoplastic Rubber)

Typical Machine Settings: Subject To Polymer Grade

Nozzle

Front

Centre

Rear

Barrel Temperature

190 - 200oC

180 - 190oC

175 - 185oC

170 - 185oC

Melt Temperature

190 - 210oC

Must be measured with a pyrometer by taking an airshot through the injection machine nozzle.

Hot Runner Temperature

190 - 210oC

Mould Temperature

15 - 75oC

Run at upper end of range for best flow.

Injection Rate

Fast

Specific Injection Pressure

700 - 1400 Bar (10,000 - 20,000psi)

Screw Back Pressure

3.5Bar (50psi)

Screw Speed

Fast

Processing Features

Structure

Amorphous

Specific Gravity

1.00

Viscosity

Low

Needs small runners.

Shear Rate Susceptibility

High

Needs small gates to reduce viscosity through shear.

Temperature Window

Narrow

Needs accurate & stable control

Residence Time

Medium

Aim for short residence time

Start-Up Precedure
  • Ensure all heaters are thoroughly baked dry - do not rely on brief ‘soft start’ systems to do this.
  • Fast Heat controllers automatically and safely bakeout wet heaters - ask for details.
  • Turn on water lines to stabilise tool and manifold temperatures.
  • Turn on manifold control zone(s) and allow to warm up until measured value is within 10oC of setpoint.
  • Now turn on tip zones and allow to settle at setpoint for 5 - 10 minutes before starting production.
  • Take an airshot from the machine barrel and check that the melt temperature is correct.
  • Start moulding parts on a semi-automatic cycle until suitable machine settings are established.
  • Avoid lengthy delays between cycles during this setting procedure.
  • Switch to automatic cycle when parts are being produced, and fine tune the machine settings

Shut-Down Precedure

The machine and mould may be shut down normally, without purging the TPR from either the barrel or the hot runner.