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Nine Sure-fire Ways to Beat the Molding Machine Blues

This article was submitted by Dave Dziech, Customer Service Supervisor, Injection Machinery Business, Milacron Inc., Plastics Technologies

1. Make Sure Your Oil is Clean

Oil contamination is the common denominator for a myriad of machine performance problems and component failures. Pre-filter oil to 10 microns before adding it to your system and have a qualified lab analyze your hydraulic fluid every three months. Test for particulate contamination and chemical content to head off serious problems.

Change oil only when analysis indicates it's necessary, not necessarily on the basis of an arbitrary date or number of hours. Every time you change fluid, you increase costs and risk introducing contaminants into the hydraulic system. Likewise, watch out for oil supplied from tanker trucks. Their high-pressure pumps can trigger bypass valves in filters, pushing tanker contaminants into your machine reservoir.

In addition to maintaining the machine's built-in filtration system, consider using an electrostatic oil filter. They are so effective in removing insoluble contaminants that machine performance loss can be reversed. The importance of oil maintenance should never be overlooked.

2. Examine Control Cabinet Filters

Excessive control cabinet temperatures will lead to premature electrical component failures. Check air filters weekly and clean or replace them when dirty. Clean the intake filters a minimum of once every four or six weeks and exhaust filters every 12 weeks. Good air flow is one of the best ways to combat cabinet temperature problems.

3. Check Water Quality

Regularly analyze your water, just like your oil. Mineral-laden or non-pH-neutral well water can clog heat exchangers, leading to damaged hydraulic oil and valves, but a closed water system is not always the answer.

Metals and foreign particles from pumps, manifolds, seals and hoses can build up in a closed system. Mold and hose changes can introduce cleaning compounds or surface rust particles. Here's the bottom line: no matter what type of system you have, you must regularly analyze your water to avoid equipment failures and downtime.

4. Pay Attention to Toggle Link Lubrication

Automatic lube systems certainly are convenient but not always faultless. Visually inspect your machine, "listen" to it, and follow maintenance schedules. An automatic system is no substitute for good old observation and alertness to changes.

5. Monitor Machine Leveling

Periodically inspect machine level, especially if your plant is west of the Mississippi. Everything from rapid clamp cycling to minor earthquakes can change machine level. Out-of-level conditions cause hydraulic seals to leak, and moving components to bind and gall. This is an area where a little maintenance will save costly repairs.

6. Beware of How You Square

Changing ram spacers, dieheight chains, dieheight motors and eject cylinders can alter alignment. Square your machine the right way — use micrometers and a squaring block. Don't expect a mold to act as a squaring block.

7. Inspect Heater Bands

Expansion and contraction from heating and cooling tends to loosen heater bands. This can mean shorted out bands, blown cards and ruined controls. The solution? Check heater bands every month to guarantee they’re tight on the barrel. If you remove the bands, make sure you reinstall them to original specifications. Check and clean them after purging.

8. Watch Safeties

Don’t forget to check safety switches and guards if you remove or readjust them during repairs. The easiest way to avoid trouble is to inspect safety hardware during every shift.

9. Stop, Look, Listen

A routine checklist is no substitute for common sense. An experienced operator can usually tell when a machine is out of “its groove.” Use that sixth sense too.

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Plastics Machining & Fabricating
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