Injection mold cleaning can reduce part defects and improve cycle times. If injection molds aren’t cleaned properly, however, residual materials can cause part discoloration and require rework. If the cooling channels of an injection mold become clogged, slower cooling rates may result. Over high volumes of molded plastic or rubber parts, even seconds of longer cycle times can add up to hours of lost productivity.
Three Main Injection Mold Cleaning Methods
There are three main ways to clean injection molds in place.
- Dry ice blasting
- Laser mold cleaning
- Chemical cleaning
Ultrasonic cleaning and plastic media blasting can also be used to clean injection molds, but these methods typically require removing the tool from the injection molding machine – and that reduces productivity and increases expenses.
The following sections compare dry ice blasting, laser mold cleaning, and chemical cleaning. As you’ll learn, dry ice blasting provides important advantages.
Dry Ice Blasting for Cleaning Injection Molds
Dry ice blasting uses compressed air to propel a stream of dry ice particles at injection mold surfaces. This non-abrasive process is effectively media-less because when dry ice hits a target surface, it turns into a gas and evaporates through sublimation. As a result, dry ice cleaning can remove fouling from mold cavities without leaving any media inside. For both tight spaces and large surfaces, it’s clean, fast, and efficient.
The benefits don’t end there either. Dry ice blasting won’t harm mold surfaces, an important consideration with tight-tolerance parts that require expensive steel molds. This FDA-approved process is a good choice for medical molders, and it’s USDA-approved for companies that serve the food and beverage industry. Importantly, dry ice blasting also lets operators clean molds that are hot and still in place.
Laser Mold Cleaning
Laser mold cleaning uses a short, pulsed laser beam to burn off residues and contaminants from injection mold surfaces. Some systems are portable for in-place cleaning, but others are stationary and require the removal of the tool from the injection molding machine. Regardless, cleaning speeds depend upon the contaminant’s ability to absorb laser energy. Plus, fumes and particulates must be removed with a filter.
With laser mold cleaning, there’s a risk of damaging mold surfaces and stripping the tool of its protective surface coatings. Over-cleaning like this can reduce injection mold life, require expensive repairs, or take an injection mold out-of-service when it’s needed for production. Lasers also need line-of-sight access to areas that need cleaning, and that’s a problem with molds that have complex geometries.
Chemical Cleaning for Injection Molds
Chemical cleaning for injection molds can range from chemical baths or manual scrubbing to connecting the mold’s cooling channels to a chemical recirculation circuit. Chemicals raise environmental health and safety (EHS) concerns and may require specialized disposal methods. Some cleaners are also expensive. Buying them in bulk can reduce their purchase price but increase storage costs.
Manual cleaning with chemicals can be especially problematic. In addition to posing EHS risks to workers, scrubbing with abrasive cleaners or materials can damage mold surfaces. Although these cleaners can support in-place cleaning, failure to remove chemicals completely can affect overall part quality or cooling times, causing the very problems that injection mold cleaning is supposed to avoid.
Choose Nitrofreeze® Dry Ice Blasting for Injection Mold Cleaning
Nitrofreeze® Cryogenic Solutions of Worcester, Massachusetts (USA) provides dry ice blasting services and sells dry ice blasting equipment for cleaning injection molds. Whether you’re a plastic injection molder or a rubber injection molder, and whether you mold parts in low or high volumes, talk to the experts at Nitrofreeze®. The consultation is free of charge, so contact us at the phone number or email below.
(508) 459-7447 x 105 | firstname.lastname@example.org