Ultrasonic Cleaning Small Holes and Crevices

Due to the increasing complexity of precision mechanical products, cleaning these workpieces is becoming an ever greater challenge. Especially small (tap) holes are often a source of annoyance. Below you can see how the surface tension of the cleaning liquids contributes to the solution of this problem.

Customers Criteria: Free from all contamination
Component: Seal
Material: Ceramic
Contamination prior to cleaning: Lapping slurries

Machines used for cleaning Cleaning Agent Temperature(s) Concentration
1. Versa 120+ 30Khz ultrasonic Rodaclean 2018 70°C 5%
2. Rinse tank Tap water 25°C 100%
4. Rinse tank Deionised water 45°C 100%
5. Hot air dryer N/A 70°C N/A

Process for cleaning small holes and crevices from ceramic parts

Rodaclean 2018 was used as its formulated for uses with ceramics and is very good at removing stubborn contamination. The tank was diluted with a 5% concentration of Rodaclean 2018 and allowed to reach to the required temperature of 70°C whilst degassing. A single part was tested initially, the ceramic seal was suspended in the basket and cleaned in the Rodaclean 2018 for 10 minutes. The part was then rinsed in tap water for 2 minutes. To remove any minerals which may cause staining the part was then rinsed in DI water for 2 minutes. Finally, the part was dried in the Versa hot air dryer for 5 minutes at 70°C.

An important function of the cleaning agent is to reduce the surface tension of the liquid (often 25 - 30 mN / m). However, depending on the quality and the temperature, water has a surface tension of 63 - 72 mN / m. It is therefore difficult for water to penetrate into small spaces. Thanks to the low surface tension, the cleaning fluid penetrates more easily into complex parts of the workpiece. The contamination is thus removed from the workpiece surface by the action of the cleaning fluid and the ultrasonic energy. Heating the liquid lowers the surface tension even more and also shortens cleaning time.

Note: This is a one stage wash process, to achieve optimal results we would follow up with a second wash in a finishing product.

Before cleaning

Before cleaning small holes and crevices

Below x50 microscope

Before cleaning crevices

After cleaning

after cleaning small holes and crevices

Below x50 microscope

After cleaning  crevices