Home

LCP (Liquid Crystal Polymer)

Typical Machine Settings: Subject To Polymer Grade

Nozzle

Front

Centre

Rear

Barrel Temperature

355 - 365oC

355 - 365oC

345 - 355oC

340 - 350oC

Melt Temperature

350 - 370oC

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

Hot Runner Temperature

355 - 370oC

Mould Temperature

65 - 150oC

Run at upper end of range for best surface finish.

Injection Rate

Very Fast

Specific Injection Pressure

350 - 1000 Bar (5,000 - 15,000psi)

Screw Back Pressure

1.0 Bar (15psi)

Screw Speed

Slow

Processing Features

Structure

Semi-Crystalline

Specific Gravity

1.60

Viscosity

Low

Small runners can be used

Shear Rate Susceptibility

Narrow

Small gates can be used - high shear reduces viscosity

Temperature Window

Narrow

Needs accurate & stable control

Residence Time

Short

Aim for '1-shot' 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
  • DO NOT shut down with LCP in the machine barrel of hot runner system.
  • Purge the barrel thoroughly with glass-filled PET or other recommend polymer.
  • Now start moulding parts in the purging material until all drops are clear of LCP.
  • DO NOT attempt to purge through an open mould, or melt leakage my result.
  • Now purge the barrel with stff HDPe, and continue moulding parts until all drops are clear of PET.
  • Shut down the machine & mould when ALL of the PET has been cleaned out.