Injection Mold Maintenance and Care
Injection molds are one of the main equipment in injection molding production. Methods for mold inspection and maintenance are established to effectively maintain mold precision and stable production operations, ensure the quality of molded products, reduce failures during production, and extend service life.
I. Pre-Installation Mold Inspection
Before installing a mold on the machine, perform the following checks:
- Open the mold slowly in stages and check whether the core, slider positioning beads, guide pillars, side locks, sliders, and angled surfaces are abnormal.
- Check whether the mold is leaking water and whether there is material debris on the parting surface.
- If oil stains are found on the core or cavity, spray mold cleaning agent onto cotton, wipe the oil-stained areas, and blow dry with an air gun. Note: Mirror-polished or electroplated molds must not be wiped with cloth; they must be gently wiped with clean cotton.
- Clean the sliders, guide pillars, ejector pins, and return pins thoroughly, then evenly apply grease. If hot mold production is required, use high-temperature resistant grease.
- Open and close the mold continuously multiple times to observe whether the mold is abnormal. If no abnormality is found, close the mold without applying high pressure.
II. In-Production Mold Maintenance
Normal Production
- During normal production, the mold parting surface must be kept clean. Mold setup workers should wipe the mold surface once every 5-8 hours to avoid plastic strings and foreign objects from damaging the mold surface and to ensure smooth product venting.
- For molds in production, operators must lubricate their molds every 12 hours to ensure normal production and prevent moving parts from seizing.
Short-Term Shutdown (5 min to 1 hour)
Close cooling water, lower material temperature, turn off the motor.
End-of-Shift or Short Holiday Shutdown
- Close water valves and blow clean residual water inside and outside the mold.
- Produce a few more shots to heat up the mold.
- Spray sufficient wax-based anti-rust agent.
- Keep front and rear molds in a closed state but without high-pressure clamping, maintaining a distance of 1-3 cm between them.
- Turn off the motor.
Long-Term Shutdown or Mold Removal
Evenly spray anti-rust agent on the mold surface, especially on rib areas, to prevent mold rust. Distinguish between short-term anti-rust oil (for shutdowns less than one week) and long-term anti-rust oil (for shutdowns exceeding one week).
III. Mold Maintenance After Continuous Production
When a mold has been in continuous production for more than one month, due to wear of moving parts, lubricant deterioration, water leakage corrosion, and other issues, the mold needs to be removed for maintenance. Maintenance content includes:
- Rust removal: Appearance, PL surface, mold cavity, core, ejection, sliders, etc.
- Re-lubrication: Ejection mechanism, sliders, etc.
- Replacement of worn parts: Springs, pullers, bolts, core rods, pressure heads, etc.
- Repair of defects: Flash, ejector marks, drag marks, etc.
IV. Anti-Rust Oil Application Procedure
- Open the mold and clean the mold core interior with mold washing water.
- Evenly spray anti-rust oil on the mold core, sprue plate, and sliders.
- Shake the can before spraying; spray at a distance of approximately 20-30 cm from the object.
- Ensure every corner is evenly sprayed; do not apply too thickly.
Molds are key production tools in the injection molding workshop. They are specialized, precise, and susceptible to damage. Proper mold safety protection is extremely important.
