Blackwell Plastics partners with OEM manufacturers and sub-tier suppliers in South Texas including Houston, San Antonio, Austin and Corpus Christi to provide plastic injection molding and plastic extrusion of engineering grade resins that satisfy demanding industrial applications. Blackwell Plastics supports plastic injection molding and plastic extrusion projects from design to fulfillment.

Thursday, October 27, 2011

Mold Maintenance: Hidden Costs Often Overlooked – Jeff Applegate

Injection molds are a big investment and in many circumstances represent a substantial portion of assets on the balance sheet of a company. Tooling assets are similar to a car that is used for transportation. Maintenance is essential to keep the vehicle running efficiently and continuing to be dependable transportation. Injection molds are like any other mechanical asset requiring maintenance to ensure efficient and dependable performance.

When water lines become clogged, vents become blocked, or mechanical parts begin to wear, the efficiency, quality and overall performance of the tool begins to decline. In an effort to produce parts process technicians may make adjustments to the manufacturing process such as increasing pressures or extending cycle times to accommodate normal wear and poor maintenance. Seldom does the loss of production efficiencies get noticed and are more often are overlooked as minimal variances to the process. There is truth in the saying that “small leaks sink ships” and the accumulation of many of these variances add up to big dollars.

It is not uncommon for shops to simply blow out the water lines and spray down the cores and cavities with rust inhibitor and call that maintenance. For the purpose of this article I will address the two general terms referring to maintenance that take place in most shops.
Preventative Maintenance – Routine maintenance that is done on a tool that is out of the machine. Preventative maintenance is routine and should be prescribed by the individual tool. Materials processed, moving parts, complexity of part are some of the factors that will influence the maintenance interval. Typical tasks in routine mold maintenance include:
• Cleaning and descaling of the water lines
• Disassembly of the tool to inspect and Lubricate the ejector pins and leader pins
• Inspection and lubrication of slides or moving components of a mold
• Inspection of cores and cavities for wear or damage
• Cleaning of vents
• Inspection of hot runner systems

Predictive Maintenance. – This is typical of high volume production tools to ensure that there is minimal unexpected downtime. Predictive maintenance accounts for predicted life cycle of components and production performance history of the mold. The idea is to study and record the performance of a mold so that you can predict the normal wear patterns. Once these are identified an intelligent preventative maintenance program can be implemented. This program would include all of the above PM as well as the specific plan for critical wear or performance components.

There are many programs that can help manage the preventative maintenance for tools. At Blackwell Plastics we use a Preventative Maintenance software package that is an added option to the IQMS ERP system. This system allows us to create a custom PM plan for each tool that automatically triggers a work order upon reaching the prescribed number of cycles. Companies such as Tooling Docs also have Preventative Maintenance software and training that can do this as well. Tooling Docs also offers valuable training programs in maintenance, repair and management of the tool shop.

Don’t let “small leaks sink your ship”. Investing in Preventative or Predictive maintenance is described as a “last frontier” in improving performance and profitability. Proper maintenance will yield consistent processing, consistent quality, and consistent profits.

For more information on injection molding, mold building or mold maintenance, please contact Blackwell Plastics engineering 713 643-6577, email: or our website at