Cleaning Injection Molds with Ultrasonics

Ultrasonic cleaning has been used on injection molds for decades. The technique has a number of advantages over other cleaning methods:

• Ultrasonic cleaning is non-contact, so there is no chance of damage to mold detail.
• The higher level of cleaning also results in easier, complete releases after the process.
• Longer production runs
• Less scrap
• Extends the life of expensive molds
• Complete removal of residual polymers and mold release
• Removal of residue from internal cooling ports
• Less maintenance, freeing up man hours for other work
• More shots between breakdowns
• Reduced scrap and waste

How it Works

Ultrasonic energy is released into the tank, producing cavitation - a formation and subsequent collapse of tiny vacuum bubbles. This causes the release of kinetic energy which creates high rates of movement in the area of the bubble. This is what gives us the scrubbing action needed to clean the mold.

Because the scrubbing action occurs on a very small scale, we can clean out blind holes, tiny crevices, and fine detail. Literally anywhere we can get the cleaning solution, there will be scrubbing.

Ultrasonic Equipment

For larger parts, you'll need a separate tank and generator, or a large integrated machine. Smaller molds can be cleaned in a tabletop unit. We'll look at these choices below:

Tabletop units are available up to 5.5 gallons, and these will handle smaller molds and inserts. The tank is 19.5" long by 11.5" and 6" deep. Longer parts can be cleaned by doing half the part, then flipping it around to do the other half.

Larger molds can be cleaned in IC Series integrated industrial cleaners, which are available up to 21 gallons. The tank is 16" x 20" x 16" deep. The IC series includes the tank with integrated digital controls, power supply, cover, and parts basket.

For the largest pieces, you'll want to look at separate tanks and powersupplies. These units are available up to 80 gallons, and provide more flexibility in equipment placement. Branson’s S8000 line of industrial cleaners fit the bill perfectly:

• S8300 power supplies offer high power levels and precise process control
• 25 or 40 kHz piezoelectric transducers
• All 304 stainless steel means durability and longevity
• Temperature controls add to ultrasonic effectiveness. Heat available up to 69C.
• Ports are provided for pump and filter systems. Use Branson’s or your own.

A typical system:

Chemistry

While you always want to choose a chemistry that does two things (has an affinity for the soils / will not harm the part), most molds can be cleaned with a buffered alkaline solution. These are easily available, and testing will lead you to the best possible cleaner for your molds.

Sonics Online offers a wide range of best ultrasonic cleaning equipment for sale. All our ultrasonic cleaner systems are environmentally friendly. For more details visit our website http://www.sonicsonline.com/