mold maintenance for operation and downtime

Plastic Injection mold plays one of the most important roles in plastic molding process, its quality is directly related to the quality of products. Moreover, since plastic mold building occupies a large cost proportion of the production for a plastic mold company, and its life time directly affect injection products cost. Therefore, improving the quality of injection molds, conducting good maintenance and extending its life cycle, are important issues for any injection molding companies
Due to product variety, frequent mold exchange on injection machine and longtime storing after production, there are many chances that mold get damaged. However, some plastic molding companies don’t pay much attention to mold maintenance, which invite corrosion on the mold, poor surface finish, and result in lower-quality product and high rejection rate. Statistics show that the usage and maintenance accounted for 15% to 20% in the mold life, the injection mold life in general can be up to 1 million times, mold under good maintenance maybe own a longer life extension of 2 to 3 times. However, as for some other plastic molding companies, due to the poor maintenance, injection mold life is relatively short,, only about 1/5 to 1/3 times of good maintenance mold. Therefore, the plastic injection mold maintenance is very important. The following words would discuss some mold maintenance methods:

Mold running maintenance

Maintenance technician should check the following items and make a complete record before mold installment;
  • Check the molds for rust, if any, it should be cleaned;
  • Check the mold surface for oil or stains, if any, it should be cleaned;
  • Check the locks for damage, if any, it should be changed;
  • Check the water channel and/or oil channel for thru;
  • Check the mold P/L locker for miss or damage;
  • Check the hydraulic cylinder for work;
  • Check the spring for break;
  • Check the mold surface for damage, if any, fix that and clean;
  • Check the slider for smooth movement, and lubricate it;
  • Check the ejector pins for seize or miss;
  • Check the guide pins and guide bushing for lubrication
Check daily whether all the align guide pins, guide bushing get damaged, including mold guide pins, sliders, lifters and other components, regularly lubricate them twice on 2 shifts
Check whether there is scale build up, foreign material and oil stains on the P/L and vent slot; check the ejector pins and lubricate that regularly. Clean the P/L and runner twice a day. Lubricate the EGP, EGB and dowel pin twice a day.
Regularly check whether the water channel is thru, and tighten all the screws.
Regularly check whether the limits switch, lifters, cam pins work well. Click for more mold maintenance tips

Mold downtime maintenance

Before shutoff the machine, stop the cooling system and blow the water channel free of residual water, then check whether there is foreign material on mold surface, if any ,remove them ,spray with approved rust preventive and finally record.
Key points for plastic mold maintenance:

  1. Cleaning the mold surface, cavity, core and other parts of the mold;
  2. Cleaning and lubrication of moving components of mold, and fastening screws;
  3. Checking water pipelines for corrosion preventative and the electrical components for short circuit.
  4. Conducting a regular maintenance in a continuous production. As to short time production, in the end of a batch, the mold should be in an optimum maintenance state when removed from the injection machine. The mold should be conducted daily maintenance and regular maintenance. All should be in accordance with mold maintenance regulation and all maintenance should be performed and recorded

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