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How efficient is your mold maintenance? Part two.

* Last month we discussed how mold performance and mold-maintenance efficiency are different things, but they work hand in hand to affect the profitability of a molding company. We discussed the first three steps (Clean-up and Organize, Stop the Bleeding, and Assess the Damage) of a six-step process to optimize maintenance efficiency.

Last month's article included a chart that demonstrated how to assess the damage by tracking all unscheduled mold-stop reasons to determine the most serious issue (based on tooling and labor or corrective-action costs) that shut down production, along with the total number of these occurrences. It is important to remember that tool-room corrective-action costs do not reflect press downtime and lost production, which could add greatly to the overall cost of an unscheduled mold stoppage.

Knowing the frequency, conditions, and contributing issues surrounding these stoppages represents the most rudimentary of initial steps to begin improving mold performance. When you acquire the ability to track and target unscheduled downtime events, you then begin the process of moving from a completely reactive culture into a more profitable proactive one.

Data as a resource

In the U.S., the vast majority of mold-maintenance shops do not have the luxury of being "over-staffed" and must learn how to use every tool available to troubleshoot effectively and optimize bench hours, whether scheduled or unscheduled. Again, data is necessary to determine exactly where and how repair hours are being used.

Unfortunately, many companies are stuck in the frame of mind that if their repair techs would work a little faster and little harder they would be able to stay ahead of the mold issues that cause unscheduled breakdowns and they could simply "catch-up" if they focused on doing so.

This rationale will not prevent the same type of issue from recurring later on--possibly to a different mold under completely different circumstances. The typical reaction to unscheduled breakdowns is panic, frustration, and the urge to immediately assess blame. The reaction should be to use available data to "work the problem" to identify root causes, if possible, or at least to understand better the variables involved. This is the payoff for the data-gathering effort. You simply cannot rely on memory or random journal entries to set priorities. Now we can complete the six-step improvement process:

Step 4: Count the issues: Once unscheduled mold stops are categorized, the next step is to count all occurrences to see where your problems really lie. Unscheduled mold stops should be documented at the press by processing personnel and the data entered into a computer system that organizes and tallies the frequencies.

Right here, most shops in the early stages of data assessment are shocked at what they learn. The greatest and least problems are never what they assumed. It is human nature for people to remember some maintenance events more vividly and differently than others, based on their own interaction with the event. Repair techs easily recall events that cause physical pain such as skinned knuckles and pinched or cut fingers. Molds or components that are unwieldy or tedious to work on create anxiety that can bias opinions concerning the labor hours required to perform simple tasks. Conversely, issues that are readily corrected through a simple procedure or by installing new tooling are easily forgotten, even though the collective dollars spent should put them at the top of the list of problems to be addressed.

Step 5: Prioritize: After you have accumulated enough mold-stop data to create a list of targets, the next step is to figure out what you want to go after first. Prioritizing a maintenance schedule for your shop will depend first on your production requirements. Those are not something a toolroom supervisor will readily know (unless the plant has mostly long-running jobs) without first meeting with production and process personnel.

I am amazed at the number of mold shops that do not even attempt to develop a work schedule related to the plant's production plans, relying instead on a "shoot-from-the-hip" approach to projecting their workload. Even a couple days' notice of an upcoming mold run would give many repair-shop managers the ability to more wisely utilize the time they have a mold on a bench.

In last month's sample chart of mold-stop causes, mold damage was at the top of the list in both frequency and dollars spent on corrective action. That ought to make it the #1 target for improving maintenance efficiency. At this point the mold-damage occurrences would be sorted by distribution to see exactly which molds were stopped because of damage, when it occurred, what tooling was involved, and so forth, as we did in this month's chart on Mold Damage Distribution.

Optimizing mold performance and maintenance efficiency should be taken one step at a time in order not to be overwhelmed and to maintain focus. The accompanying chart (sorted by mold-repair cost) helps us narrow the field down to a manageable goal, which would be to address first the 51895-CN mold. This type of report also makes it easy to sort and filter by different column headings to find information that might be related to various mold-stop occurrences regardless of mold type.

In prioritizing secondary targets, always look for maintenance items that could be eliminated or significantly reduced by simply making repair techs aware that an issue exists, such as the maintenance issues listed at left These involve incorrect installation techniques or oversights that cause much heartburn for the molding department. Though they may not be in the top five mold-stop causes by repair cost, these preventable problems always get a lot of attention in the corner office. Set priorities for correcting these maintenance issues based on frequency of occurrence and simplicity of the corrective action required.

Step 6: Act: Now that you have targeted issues for your shop to investigate, follow through with mold-maintenance plans that directly address these issues. Publicize frequencies of problems, corrective-action costs, and lost production time to give repair techs a sense of value for their actions.

Changing cultures

Many repair-shop cultures today are so rooted in reactive thinking that spending time on an issue that nobody is hollering about might seem at first a waste of shop time. Changing a maintenance culture to value proactive thinking depends on systematically choosing targets based upon accurate data, pursuing them diligently, and then continuing to monitor these defects for improvement or change.

Steven Johnson worked as a toolmaker for 26 years, rebuilding and repairing multicavity molds for Calmar Inc. and then as mold-maintenance engineer for Hospira Inc., a medical device manufacturer. Today, he is the maintenance systems manager for Progressive Components and has his own business, MoldTrax in Ashland, Ohio, which designs and sells software for managing mold maintenance (www.moldtrax. com). He can be reached at or (419) 289-0281.


Visit for a link to part two of this article:

* How Efficient Is Your Mold Maintenance? Feb. '07

Mold Description Configu- Start Start
 ration Date Time

51895-CN Ress-Tube- Standard 7/17/ 13:00
 feed "A" 2005

51895-CN Ress-Tube- Standard 1/23/ 0:30
 feed "A" 2005

51895-CN Ress-Tube- Standard 1/4/ 17:00
 feed "A" 2005

51413 Hinged Cap Standard 1/27/ 11:00

61381-BR Break Cap Standard ],/20/ 21:30

61749-BR Top Cup "D" Standard 1/2/ 9:30

61105 Chamber 0.138 8/31/ 21:00

11953 Adapter Green 12/5/ 9:00

61451-BR 15 ML VHC Standard 4/23/ 10:00
 "DD" 2005

61717-BR 3-Hole 61717 3/27/ 20:00
 Rocker (3 Hole) 2005

11953 Adapter Green 2/6/ 3:00

11953 Adapter Green 12/12/ 17:00

61963 Hood, Pin Red 4/17/ 3:00

51912 Ress-Nipple Standard 4/28/ 1:00
 Ring "A" 2005

71104-DE Hosp-Slide Standard 4/29/ 9:00
 Clamp 2005

61721-BR Axe Bottom 61721 3/13/ 12:30
 (Ribbed) 2005

51413 Hinged Cap 51413 8/30/ 11:08

Mold Press Start Stop Stop
 Tech Date Time

51895-CN 02 Aster, J 9/28/ 7:00

51895-CN 02 Mike, Z 6/3/ 16:00

51895-CN 02 Sales, J 1/24/ 8:30

51413 16 Mike, Z 2/2/ 7:00

61381-BR 10 Mike, Z 2/15/ 7:00

61749-BR 08 Streit, T 1/17/ 6:00

61105 04 Mike, Z 9/10/ 12:58

11953 04 Mike, Z 12/11/ 17:00

61451-BR 15 Sales, J 5/21/ 22:00

61717-BR 18 Mike, Z 3/28/ 11:00

11953 04 Mike, Z 2/10/ 14:00

11953 04 Mike, Z 12/19/ 21:30

61963 09 Mike, Z 4/18/ 6:15

51912 17 Lippski, D 4/28/ 7:00

71104-DE 13 Sales, J 5/22/ 17:00

61721-BR 06 Aster, J 3/19/ 9:30

51413 12 Churney, T 8/30/ 11:08

Mold Stop Cycles Run Time Repair
 Tech Hours Date

51895-CN Sales, J 393,512.00 1,746.00 10/7/

51895-CN Sales, J 746,967.00 3,159.50 6/15/

51895-CN Mike, Z 78,981.00 471.50 1/27/

51413 Sales, J 20,239.00 140.00 2/2/

61381-BR Aster, J 118,728.00 609.50 3/3/

61749-BR Mike, Z 190,463.00 356.50 1/25/

61105 Strelt, T 22,044.00 231.97 9/12/

11953 Mike, Z 24,376.00 152.00 12/12/

61451-BR Strelt, T 221,079.00 684.00 5/23/

61717-BR Aster, J 0.00 0.00 3/28/

11953 Sales, J 11,836.00 107.00 2/12/

11953 Aster, J 29,375.00 172.50 12/20/

61963 Mike, Z 0.00 0.00 4/19/

51912 Lippskl, D 0.00 0.00 8/13/

71104-DE Mike, Z 184,312.00 556.25 5/27/

61721-BR Aster, J 0.00 0.00 3/20/

51413 Churney, T 0.00 0.00

Mold Repair Cost Status Repair

51895-CN $15,305.00 Blue Capper, C

51895-CN $11,912.00 Blue Capper,C

51895-CN $6,532.50 Blue Burrougis, L

51413 $2,755.00 Blue Capper, C

61381-BR $1,400.00 Blue Smith, P

61749-BR $1,014.26 Blue Capper,C

61105 $425.00 Blue Capper, C

11953 $409.00 Blue Burrougus, L

61451-BR $375.00 Blue Capper, C

61717-BR $350.00 Blue Smith, P

11953 $309.00 Blue Capper, C

11953 $209.00 Blue Capper, C

61963 $200.00 Blue Smith, P

51912 $150.00 Blue Capper, C

71104-DE $110.00 Blue Capper, C

61721-BR $100.00 Blue Capper, C

51413 $0.00 Red


1. Internal water or oil leaks due to missing, cut, twisted,
 or wrong-size o-rings and seals.

2. Missing, loose, or stripped SHCSs (socket-head cap screws).

3. Repetitive electrical issues such as bad heaters, probes,
 or thermocouples and loose or shorted connections.
 (All stemming from lack of Final Check procedures.)

4. Missing tooling or incorrect tooling/mold assembly.

5. Incorrect cleaning techniques (e.g., using a solvent that
 damages seals or leaving uncleaned vent residue).

6. Incorrect greasing (too much or too little).

7. Repeated sticking of parts or runners (no corrective action

8. Mold damage by improper handling (nicks, dings, or burrs in
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Article Details
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Title Annotation:Mold Shop
Author:Johnson, Steve
Publication:Plastics Technology
Date:Mar 1, 2007
Previous Article:Sticking sprues or parts? Lots of possible causes & solutions.
Next Article:In-mold assembly: the new frontier for multi-shot molding.

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