Does Ultrasonic Cleaning Work with Plastics?

Ultrasonic cleaning systems work best on parts with hard surfaces, such as those made of metal. But can it also clean parts made of plastic?

Most plastic parts have comparatively soft surfaces, and many have other characteristics that make them less suitable for ultrasonic cleaning. Parts made of light, soft plastic with simple shapes can often be cleaned better manually. But for parts with complex shapes with openings and dead-end holes, ultrasonic cleaning may still be the best solution.

The success of cleaning plastic parts using ultrasonic cleaners depends on the kind and condition of plastic.

·         Plastic rigidity – If the plastic is soft and flexible (such as low-density polyethylene), the plastic material will flex with the ultrasonic waves and absorb some of the cleaning power, therefore reducing cleaning performance.

·         Plastic density – Low-density plastics may float in the cleaning solution, which leaves some surfaces exposed and not cleaned. A basket is needed to hold them when cleaning such parts.

·         Surface hardens – When parts surfaces are soft, the ultrasonic cleaner has to operate at a higher frequency to reduce cleaning intensity and avoid surface pitting. The reduced cleaning intensity required to clean soft plastic parts makes cleaning time a bit longer than required and reduces cleaning effectiveness.

·         Degree contamination – The reduced cleaning intensity due to the higher ultrasonic frequency means light contamination can be removed quickly. Heavy contamination will take longer.

·         Plastic composition – To speed up ultrasonic cleaning at higher frequencies, the cleaning solution may be heated or added with mild detergents to remove specific contaminants.

Even if some plastic parts are not ideally suited for ultrasonic cleaning, their shape may require an ultrasonic cleaning solution to get the parts completely clean.

For a specific plastic part cleaning application and a corresponding contaminant, the manufacturer of ultrasonic cleaning systems can often design an effective solution. They can determine which frequencies will be the most suitable and effective and can recommend other cleaning agents (such as heating or adding mild solvents) based on their experience.

Kaijo Shibuya is one of the leading ultrasonic cleaner manufacturers and they work closely with customers to ensure their ultrasonic cleaning needs are met. Their complete article, “Does Ultrasonic Cleaning Work with Plastics?”, goes into further detail. Call them at 408-675-5575 or send an email to info@kaijo-shibuya.com if you have questions or would like to set up a free consultation to discuss your ultrasonic cleaning needs.