PEEK (Poly-etheretherketone) |
Typical Machine Settings: Subject To Polymer Grade |
|
Nozzle |
Front |
Centre |
Rear |
Barrel Temperature |
370 - 390oC |
370 - 390oC |
360 - 380oC |
340 - 360oC |
Melt Temperature |
370 - 390oC |
Must be measured with a pyrometer by taking an airshot through the injection machine nozzle. |
Hot Runner Temperature |
375 - 390oC |
Mould Temperature |
160 - 190oC |
Injection Rate |
Fast |
Specific Injection Pressure |
700 - 1400 Bar (10,000 - 20,000psi) |
Screw Back Pressure |
20 - 50 Bar (300 - 750psi) |
Screw Speed |
50 - 100 rpm |
Processing Features |
Structure |
Semi-Crystalline |
Specific Gravity |
1.43 |
Viscosity |
High |
Uses medium to large runners. |
Shear Rate Susceptibility |
Medium |
Uses medium gates. |
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
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Shut-Down Precedure |
- DO NOT shut down with PEEK in the machine barrel of hot runner system.
- Purge the barrel thoroughly with stiff PE-HD or other recommend polymer.
- Now start moulding parts in the purging material until all drops are clear of PEEK.
- DO NOT attempt to purge through an open mould, or melt leakage my result.
- Shut down the machine & mould when ALL of the PEEK has been cleaned out.
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