Ultrasonic Cleaning of Injection Moulds: Perfect Cleanliness Even in Hard-to-Reach Areas

Why is regular mould cleaning important?

During plastic injection moulding, residues of polymers, release agents, lubricants, oils and deposits created at high temperatures gradually accumulate on moulds, inserts and ejector pins. Even a small amount of contamination can cause surface defects on moulded parts, blocked venting channels, irregular movement of ejector pins, higher reject rates or unplanned downtime. Cleaning must therefore be thorough, repeatable and gentle on sensitive mould surfaces.

Why are conventional methods not always sufficient?

Manual cleaning with brushes and wipes is time-consuming, depends on the operator’s experience and cannot reliably reach deep holes or internal channels. Dry ice blasting cleans accessible surfaces effectively, but as a directional technology, it has limited effectiveness in blind holes, curved channels and concealed areas. The ongoing costs of dry ice and compressed air must also be considered. Laser cleaning is precise, but it also requires direct access to the area being cleaned, involves a higher initial investment and requires expert adjustment of the parameters according to the material and surface sensitivity.

How does ultrasonic cleaning work?

During ultrasonic cleaning, the mould or its dismantled components are immersed in a specially selected cleaning fluid. Ultrasonic transducers generate high-frequency pressure waves in the liquid, creating microscopic bubbles. These bubbles rapidly form and collapse in a process known as cavitation. Their collapse produces an intense local cleaning effect—millions of tiny “micro-explosions” that separate contaminants from the surface.

The key advantage is that the cleaning fluid surrounds the immersed component from every side and penetrates blind holes, threads, narrow gaps, grooves, fine surface structures and internal channels that can be filled with liquid. This makes it possible to clean dismantled ejector pins, inserts and other complex components thoroughly, including areas that manual, laser or blasting technologies can only reach to a limited extent.

The process can be adapted to the material, surface sensitivity and type of contamination. Once started, cleaning proceeds automatically, allowing employees to focus on other tasks. Standardised parameters also provide more repeatable results than manual cleaning.

Results before and after cleaning:

The specific result depends on the mould design, material, type of contamination and selected programme. A practical cleaning trial is therefore recommended before implementing the technology.

Safetykleen ultrasonic solutions

Safetykleen offers several models and sizes of ultrasonic machines for applications ranging from small precision components to larger and heavier mould parts. The appropriate machine size, ultrasonic frequency, temperature, cleaning fluid and process time are selected for each application.

Effective ultrasonic cleaning in practice: a system with automatic basket movement and an overflow tank.

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Ultrasonic cleaner sizes up to 2,000 liters with a load capacity of 1,000 kg.

For the most flawless process and mold cleaning results, we offer ultrasonic cleaning in a package with an automatic rinsing washer.

Customers receive more than just a machine—they receive a complete service. Safetykleen analyses the existing cleaning process, performs a practical trial and recommends the most appropriate solution. It then provides delivery, installation and commissioning of the machine, regular supplies of cleaning fluid, operator training, servicing and maintenance. The service also includes the replacement and collection of used fluid, professional waste management and all the necessary documentation. Customers therefore do not have to manage the equipment, servicing, cleaning chemistry or administration separately—every part of the process is handled by a single partner. For most companies, this offers the advantage that it is not considered an investment, meaning the funds do not fall under CAPEX (capital expenditures). Another benefit is not only a worry-free, turnkey solution, but also the fact that the customer is not the generator of hazardous waste.

More than 50 years of experience

Safetykleen has been providing professional parts-cleaning services since 1973 and works with small businesses, medium-sized manufacturing companies and multinational organisations across many industrial sectors. In Central Europe, Safetykleen operates in the Czech Republic, Slovakia, Hungary and, most recently, Poland. Customers in the plastics industry primarily use its ultrasonic solutions to clean injection moulds, inserts, ejector pins and other complex components.

Safetykleen helps increase productivity, cleaning quality, occupational safety, and sustainability for over 20,000 customers worldwide.

A cleaner mould means more stable production

A correctly configured ultrasonic cleaning process reduces manual work, improves process repeatability and removes contamination from areas that are difficult to reach. A cleaner mould can contribute to more consistent product quality, lower reject rates, shorter downtime and longer tool life.

Would you like to find out whether ultrasonic cleaning is suitable for your injection moulds and ejector pins?

Safetykleen ultrasonic cleaning machines