Optimizing Mold Performance and Maintenance Efficiency

by Steve Johnson, Progressive Components

Mold performance and maintenance efficiency are two completely different, yet entirely connected goals of the modern day mold repair shop. Mold performance has been an issue ever since the first part hung up in cavity, with maintenance efficiency – or the approach used when repairing molds – taking a back seat in terms of significance to the overall aspect of producing plastic parts.

In other words, the idea of maintenance efficiency has always been more connected to making sure that a mold is production-ready rather than to the manner in which this is accomplished. After all, that is what this business is all about, right? The goal is to produce quality products on time, with the fewest number of people possible. In the battle against low off-shore wages, it seems as if our mantra should be…Got resources? Who needs ‘em? They’re for sissies!

Judging Efficiency
If a mold shop supervisor has more molds sitting red-tagged (needing work) than getting pulled on a weekly basis (MPP), then is his shop efficient? Probably not. Will anybody notice? Probably not. So why is maintenance efficiency important if the molds are ready when needed? Because as Captain Kirk used to say, “It’s the final frontier.”

Everything in plastics manufacturing gets scrutinized today – from the inception of the part, to the mold design, then the build, and finally production. But maintenance is normally left wide open and to the devices of craftsmen behind the bench.

The rule has been to simply do what it takes to get a mold in the press and keep it running. If this is accomplished, everything else is forgiven. But in today’s market, companies are beginning to look closely at the strategy employed to meet mold performance or production goals. Budget factors such as excess tooling usage, unscheduled mold stops due to maintenance-related issues, excessive labor hours, and the usual array of flashed manifolds, damaged tooling, water leaks, and non-conforming products are no longer being considered “just part of the process.”

Budget Breakdown
With an eye on increasingly shrinking profit margins, mold maintenance is now coming under close scrutiny by the mold owner (customer) and proprietary bean-counter. Common shop issues are having costs associated with them so that they can be measured by the people footing the mold repair bills.

It’s a new day in a new era. No longer can companies be focused solely on meeting orders. To excel in the game, we must raise the maintenance bar. We must concern ourselves with how we maintain molds. Are we systemized in our approach, or are we doing the same thing the same old way over and over and expecting different results? Someone famous once said that is the definition of insanity, but in too many mold shops it’s the definition of reality.

To have a better understanding of how mold performance and maintenance efficiency are diametrically connected to increasing profitability, let’s break them down.

Mold Performance

  • Improve production reliability
  • Increase cavity efficiency
  • Maximize mold/tooling life
  • Decrease cycle time
  • Improve part quality
  • Reduce scrap rates

Maintenance Efficiency

  • Optimize mold repair hours
  • Reduce tooling usage
  • Improve mold knowledge and defect awareness for better troubleshooting
  • Standardize repairs/methods and procedures for consistency
  • Reduce maintenance mistakes
  • Speed up training of new employees
  • Improve shift to shift communication

Typical Barriers to Overcome
As with every process improvement goal, there are challenges or barriers that stand in our way. When putting an unhealthy maintenance shop under the microscope, the “cell structure” is seldom consistent from plant to plant, making the exact treatment less obvious, but the anemic shop is typically stricken by one of these three “viruses”:

1. Time Limitations

  1. MPP (Mold Pull Pace – pulling molds faster than you can get them production ready or green-tagged) is usually the result of shop downsizing, “no hire” practices, acquiring new molds, or a rash of breakdowns.
  2. Tool room supervisor is tasked with other responsibilities besides mold management, typically new mold builds or plant equipment issues.
  3. Repair techs are tasked with other responsibilities, such as ancillary and plant equipment maintenance.

2. Corner Office Culture

  1. Not maintenance-oriented.
  2. No clear reporting structure concerning mold repair.

3. Employee Resistance to Change/Accountability (tooling and process…salary and hourly)

  1. Employees do not want to give up the freedom and monetary benefits that come with:
    1. Freelancing repairs (do what I want)
    2. Time commitment (when I want)
    3. No accountability (not my problem…not my fault)
    4. Being “the shop king” (knows the most about all the molds)
    5. Hero worship (the firefighter of the day)

So How Do You Begin?
As you can see, there are several areas of opportunity, so we must begin with a strategy for improvement. There is no silver bullet and we must be careful not to start out making rash decisions based on perceived issues or unproven facts and innuendo. Remember that you are dealing with seasoned, skilled tradesmen who don’t favor being “jerked around” on an assumption of overnight success. Many fitness programs have been attempted in maintenance, only to fail because the repair techs know that if they weather it out, things will soon return to normal – normal being zero expectations and zero accountability. Begin by choosing the parameters that you want to improve, and then establish a baseline of measurable data to use as a barometer.

For this article we will discuss the first three steps of a six step process:

1. Clean and Organize Your Shop
It is hard for anyone to believe that efficiency will be improved in a repair shop that looks like a pigpen. Clean up shelves, benches, floors, and empty chip trays and put the tools away. Tag and organize tooling that has been removed from molds. Once the shop is clean, take an hour every Monday morning and keep it that way.

2. Stop the Bleeding
First, let everyone know through meetings, board posts, email, and the grapevine that monitoring of mold stop reasons is taking place and will be measured for change on a monthly basis. Simply publicizing the fact that the issues will be monitored and posted will immediately help reduce the personnel-related stop reasons attributed to inattention or carelessness. The message is that accountability begins now.

3. Assess the Damage
Keep it simple. Utilize your CMMS (computerized maintenance management system) reports or manually count occurrences to find out where the hang ups are in the process. Categorize your unscheduled mold stop events by:

  1. Stop Reason Description
  2. Frequency
  3. Corrective Action Costs (by labor, tooling, and total)

Let production know you are monitoring the issues. Can the tool room help or correct a reoccurring mold stop issue, such as parts or runners sticking, gas burns, non-fills/shorts, finish, or problems requiring extreme process changes/tweaking?

Eliminating mental mistakes, combined with targeting the most frequently occurring stop reasons for reduction, will begin the decline in unscheduled downtime. A decrease in the unscheduled mold stop frequency count accomplishes several things quickly:

  1. Allows more time for you to concentrate on pro-active maintenance.
  2. Provides measurable data in which to demonstrate improvement to the non-believers.
  3. Reduces operational costs (labor, press downtime).
  4. Improves your ability to meet production quotas and schedules.
  5. Improves relations between tooling and process (this alone is worth the price of admission).

Drilling Down
After compiling the list of unscheduled mold stop reasons (schedule one to six months depending upon your MPP), post them in the tool room and send an email to process and other concerned teammates concerning your targets. Many of these will be easily corrected with a little attention. The challenge is then to agree upon an action plan and assign responsibility, as required, to eliminate or reduce the frequency of targeted stop reasons.

The Chart (6 Month Study)
The X-Unscheduled Mold Stop Reason chart on page 7 shows that our shop stopped production for 21 different reasons. Mold damage (shown in red) was our #1 issue based on total money spent on corrective actions. This will be our target focus, requiring a full investigation of the 17 occurrences (Stop Count) broken down by mold, description, mold configuration, tooling damaged, shift stopped, personnel, press number, etc. We also will target and publicize the shop issues (shown in blue), as these are simply mental mistakes and will show that the tool room is serious about improvement.

Steven Johnson works as the maintenance systems manager for Progressive Components. His tooling maintenance experience includes eight years as senior tooling engineer for Abbott Laboratories, a leading medical device manufacturer, and 24 years as a toolmaker at Calmar, Inc., rebuilding high cavitation, close-tolerance multi-cavity molds. Prior to Calmar, he served four years in the U.S. Navy training reservists as a jet mechanic on the A4L Skyhawk. He has designed and developed MoldTrax™, a documentation software system for tracking mold performance and maintenance, and authors “Across the Bench” and “Mold Shop” columns for Moldmaking Technology and Plastics Technology magazines, respectively. Johnson can be reached at [email protected].

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