Setting Up Shop, Part IV

Systemizing mold maintenance must include ameans to efficiently and safely clean mold plates and tooling. While the vast majority of mold cleaning is still performed at the bench, many shops are looking at ways to isolate this stage of noise and mess to promote a safer, cleaner and quieter area for their skilled employees to clean a stable of expensive molds.

Solvent tanks, maxi-blasting units, ultrasonics and dry ice blasting are the main equipment we rely on to remove the variety of residue, rust and grime. As discussed in previous articles, there is no single solution that works for all molds. It normally requires a combination of these methods to remove a large variety of mold residue.

Most types of cleaning equipment generates some type of residual funk or grit that when used in an open shop, leave deposits on exposed molds and tooling, computers, toolboxes, floor and benches. Incorporating a 15’ x 20’ long cleaning room in our layout will provide an effective alternative to above issues.

There are a few things to consider when designing a cleaning room:

• Location of the clean room in relation to benches and expansion
• Installation of a small hoist (500-1,000 lbs) to hang plates in the solvent tank and ultrasonic washer
• Transporting method and traffic flow getting mold plates and tooling to and from the room
• Types of cleaning equipment to include in the layout
• Ventilation

Our cleaning room will be located in the front part of the shop, which will place it in a good position for shop expansion should it become necessary to add more benches, and keeps the clean room in full view of the repair techs working at their benches. They will be able to see if the ultrasonic tank is in use, which will improve timing between washes.

The clean room walls will be constructed of concrete blocks with a ceiling height of 15 feet. This will allow for easy mounting of a single I-beam (mono-rail) and two-speed electric hoist to be located directly over the center of the ultrasonic and solvent tanks. With this type of setup, tall, heavy plates with tooling installed can be easily and safely lowered into each tank, and, if necessary, the majority of the weight supported by the hoist during cleaning.

It will be necessary to construct or purchase a mobile cart to move plates and baskets of tooling to and from the benches and clean room. For our size of molds, this cart need only be 30” wide by 36” long. Having at least two mobile carts will allow continous flow of parts, optimizing the cleaning process.

Also included in our clean room will be a self-contained glass bead blaster and a dry ice cleaner. The self-contained compressed air media blasters are notorious for creating a waste stream of grit that seems to travel for miles, attracted to everything you’ve just cleaned. If your molding operation uses rubber or other thermosets that requires continuous use of a maxi blaster type unit, it would be advantageous to add a divider around the unit to contain the grit even further and allow for easy clean-up. If use is only occasional on heavily contaminated or rusted surfaces, just keeping the unit behind closed doors will keep the entire shop and molds grit free.

Anytime cleaning equipment is used in a small, enclosed area, ventilation will be required to filter the air and keep the humidity level down (if using ultrasonics).

If you use a caustic solution to clean with, then ventilation becomes a really big deal. Be sure to contact the supplier of your solution to determine any ventilation issues, and use only a certified HVAC technician to determine necessary hood configurations and placement, cfm (cubic feet per minute) requirements and local code restrictions.

Other Considerations

• It is highly recommended that the ultrasonic generator and power supply be located directly outside of the cleaning room as over time, the humidity/vapors from 180-degree water will contaminate and corrode sensitive circuits. Treat the generator as you would your home stereo.
• Outfit the clean room with double-action doors with windows.
• Construct a pegged or wall board with hooks to hang cleaning baskets when not in use.
• Store a mop and bucket in the room for quick clean-ups.
• Hang a clipboard on the wall to record solution usage, wash tank cleaning dates and necessary instructions to remove and clean all appropriate filters and screens in cleaning equipment.
• If room allows, add a small, tall (40”) bench to disassemble and clean small sub-assemblies.

The cleaning stage of mold repair is just messy business. Keeping this mess quarantined in a smaller, well-ventilated area provides for reduced costs in housekeeping hours and issues with contaminated molds and tooling. An advantage you can’t put a price on is the added benefit of improved employee attitudes, morale and sense of professionalism and craftsmanship.