Injection mold preventive maintenance checklist are critical assets in the manufacturing process, especially for industries like automotive, medical, and consumer goods, where high-volume, precise plastic parts are necessary. Proper maintenance ensures molds produce high-quality parts, reduces downtime, and extends the mold’s lifespan. A comprehensive preventive maintenance (PM) checklist is essential for consistent performance and cost-effectiveness.

Keep Molds and Components Clean and Dry

Your mold cavities and components are critical to producing quality products, so you should take special care to plan injection mold maintenance and ensure they’re in the best shape possible. After each production cycle, thoroughly clean each mold with a gentle solvent and use compressed air to remove any debris.

Be sure to remove any moisture from your molds before you store them — moisture left on metal molds could cause rust, damage the molds and produce poor-quality products.

Perform Safety Checks

Injection mold preventive maintenance checklist feature safety limit switches that can become damaged over time as they get bumped, which can cause malfunctions. Include safety checks as part of your regular injection molding machine maintenance routine to keep your operators safe and keep your machines running on schedule.

Also, be sure to check the bolts holding the limit switch in place and that the trip arms are adjusted for your usage. To combat this wear, you’ll want to keep your machine level and parallel to the moving platen and stationary platen. We recommend leveling your machine as part of your monthly preventive maintenance.

Check Your Oil

If you have a hydraulic molding machine, you rely on high-quality oil to keep it running. You should monitor your oil to watch for leaks, maintain levels and keep clean oil flowing through your hydraulic mechanisms.

Oil checks should be part of your regular preventive maintenance schedule, with oil filter changes at the start of every quarter. When you check your oil, you should also check for and replace any worn seals and tighten any loose joints.

Check Electrical Components and Wiring

Hybrid or fully electric injection molding machines rely on strong electrical connections for optimal operation. To maintain these machines, you’ll need a technician who understands the electrical systems. Have your technician check the electrical systems regularly to ensure there are no loose or pinched wires, loose connections or accumulated dust and dirt.

Change Your Filters and Clean Tank Breathers

Maintaining proper airflow allows your mold machine to operate smoothly. A dirty air filter will restrict the air entering and exiting your cabinet, while a blocked tank breather may cause the tank to expand and contract as oil flows to and from the tank. Both circumstances could result in strain on the welds of your reservoir or reduced performance.

Clean Your Machine

Replace your cabinet air filter as part of your scheduled mold machine maintenance and keep your tank breather clean and free of debris by regularly cleaning the top and outside of your machine.

Make Sure Moving Parts Are Lubricated

Your injection molding machine has several moving parts that rely on proper lubrication to move smoothly without significant friction or wear. To maintain your machine, make sure there is a film of grease on all of these important parts, like the rods and skates.

If greased parts aren’t receiving lubrication, check that grease flows properly through the lines and reaches these points. Check for blockages and air bubbles in your lines that may be limiting your grease flow.

Check Your Heater Bands

Malfunctioning heater bands can cause defects in your final products. Inspect your heater bands regularly to ensure they’re reaching the correct temperature in each zone and making proper contact with the barrel.

If it seems like your bands are not maintaining the correct temperature, or the temperature varies along in different zones, consult a qualified electrician who can test the zones to identify where you have a malfunction.

Replace any heater bands that are fluctuating in temperature or not working properly. While you have your machine down replacing one band, consider replacing the whole set. This step could help you avoid future downtime to change other bands as they fail.

Invest in Predictive Maintenance Upgrades

Upgrading your injection molding machine to include predictive maintenance monitoring systems is a great way to stay on top of your preventive maintenance schedule and keep an eye on your machine’s smaller, more hidden components like tiny screws.

These systems include sensors that note changes to your machine’s parts and monitor wear to notify you when a part is near a failure point and needs to be replaced. When you’re actively monitoring the status of these parts, you can be sure to replace them before they fail, preventing unplanned downtime.

Advanced Injection mold preventive maintenance checklist

Daily or twice-daily maintenance on mold machines helps, but certain parts inevitably wear out over time and require replacement. In addition to following the basic injection molding maintenance checklist before and after every cycle, you’ll want to do deeper inspections at longer intervals. You should perform this maintenance at regular intervals determined by what type and how many cycles you’re running.

Check ejection components

All ejection components, including ejection pins, should be inspected. If you notice any damage, replace the parts. Also, make sure all the parts are appropriately lubricated. Do every 10,000 cycles or so.

Check all non-ejection components

Inspect the mold components regularly, ideally every five to ten times after checking the ejection parts. However, avoid limiting inspections only to the ejection components. Check all mold-related parts for wear, damage, and proper lubrication, including gaskets, valves, and springs.

The Value of Injection mold preventive maintenance checklist

As discussed earlier, there is a cost associated with preventive maintenance: downtime of your machines and the manpower to perform the checks. However, this cost is virtually nonexistent when compared to the much higher cost of unexpected and potentially prolonged downtime, rejected parts and other hassles that hinder efficiency.

Conclusion

A thorough preventive Injection mold preventive maintenance checklist is essential for ensuring consistent production quality, minimizing unexpected downtime, and prolonging mold life. Regular maintenance practices—such as cleaning molds, checking safety components, monitoring hydraulic oil levels, inspecting electrical wiring, replacing air filters, and keeping moving parts lubricated—help keep injection molding machines operating efficiently.

Advanced maintenance, including checking ejection and non-ejection components at longer intervals, is crucial for detecting wear and potential issues before they lead to failures. Although preventive maintenance requires resources and scheduled downtime, it is a worthwhile investment. By addressing minor issues proactively, manufacturers avoid costly breakdowns, rejected parts, and disruptions in the production process.

In the long run, consistently implementing a comprehensive preventive maintenance program not only enhances productivity but also gradually ensures high-quality output. Furthermore, it significantly maximizes the overall return on investment in injection molding equipment. Consequently, by proactively maintaining equipment, companies avoid costly repairs. “Additionally, regular maintenance reduces downtime”. Ultimately, this approach supports long-term operational efficiency, reliability, and better resource utilization.