Injection Mold Maintenance Strategies: Extending the Service Life of Your Tooling

Injection molds are complex tools integrated with many intricate features. The mold-making process is much more complicated than creating a simple cutout of the initial end product design. In fact, product designs are often modified and/or optimized to facilitate an efficient molding process (i.e. design for manufacturability).

From ensuring optimal material flow to promoting easy part ejection, the injection mold’s role is crucial from start to finish. That’s why proper mold maintenance and upkeep is critical in terms of your ongoing product quality.

As the mold surface wears down and degrades, the likelihood of encountering part defects goes up substantially. Meanwhile, your tolerances and dimensions start to fall out of specification. Plus, beyond maintaining quality, keeping your injection molds in good condition also extends the tools’ lifespan which maximizes your capacity and reduces future downtime in your shop.

To that end, we’ve put together a basic guide to mold maintenance strategies that should help you extend the service life of your tool investments. If you need specific guidance or inside tips for your injection mold tooling, get in touch with the experts at Polyshot.

Preventive Maintenance

The first phase of extending injection mold service life comes in the form of preventive maintenance. That means regular cleaning along with inspections and periodic servicing to address potential issues before they lead to production problems or tool failure.

Regularly Scheduled Inspections – You should regularly inspect your molds for any signs of wear, corrosion, or damage. Detailed inspection processes can reveal these issues in the early stages so that you can correct them before the damage spreads.
Proper Lubrication – Always make sure that any moving parts are properly lubricated, such as ejector pins and slides. As the lubrication breaks down or runs dry, friction and wear increase drastically, along with the expected service life.
Regular Cleaning – Regularly clean all surfaces of the mold to prevent the buildup of foreign materials which can affect mold functionality and/or part quality. Thorough cleaning routines should include all mold surfaces with special attention given to runners, sprues, and gate areas.
Temperature Monitoring – Stay on top of thermal monitoring to ensure uniform heating and cooling cycles. Overheating, or heating/cooling too quickly can lead to thermal stresses that can damage mold surfaces. See our previous blog on Injection Mold Temperature Controllers for more information on the importance of precise thermal regulation.

Predictive Maintenance

Often a more intensive maintenance process, predictive maintenance uses performance data to predict when maintenance is required. The goal is to prevent tool failure which can shut down production entirely, as well as minimizing the future downtime you need to commit to ongoing maintenance.

Sensors – Modern injection molding machines rely on a multitude of sensors for monitoring and control. Use this data to stay on top of mold performance and maintenance requirements, paying especially close attention to critical parameters like temperature, pressure, and cycle count.
Data Analysis – You can combine both historical and real-time data to identify patterns that indicate abnormal wear or premature failure. Advanced sensors and analysis allow for a data-driven maintenance process that’s more reliable and effective at preserving mold quality.
Non-Destructive Testing (NDT) – Many of Polyshot’s customers now use advanced non-destructive testing techniques such as ultrasonic testing. These detect internal flaws without damaging the mold, streamlining the predictive maintenance process.

Corrective Maintenance

Sometimes mold damage or other issues arise regardless of how carefully you maintain your tools. That’s where corrective maintenance comes in, addressing issues as they arise to restore your molds to their optimal condition.

Polishing – Surface polishing removes minor defects and maintains the mold’s smooth finish to facilitate proper material flow, curing, and ejection.
Welding and Re-machining – In some cases of relatively extensive damage, cracks or worn areas of the mold can be repaired via welding and/or re-machining the surface.

Proper Handling and Storage

How molds are handled and stored significantly affects their lifespan. Best practices include:

Store in a Controlled Environment – Always store your injection molds in a clean, dry, temperature-controlled environment within your facility. This helps prevent rust, oxidation, and other forms of surface corrosion.
Apply Protective Coatings – Many of Polyshot’s customers utilize special anti-corrosion coatings to preserve the surfaces of their molds and further extend the service life.
Proper Transportation – If you have to transport your molds between facilities, always use protective cases or secure coverings. It’s a relatively simple step to avoid physical damage which can be incredibly costly.

Quality Injection Molding Solutions Since 1989

Polyshot Corporation specializes in the development of advanced hot runner systems to injection molding companies worldwide. Backed by more than 35 years of innovation and experience, our company continues to help our customers remain at the cutting edge of industry.