Cleaning

The machines each process 4 rectangular baskets tightly covered of approximately .85 cubic feet per wash and dry cycle. The machines are computer controlled and are capable of many combinations of wash cycles.

Typically the four baskets are loaded to allow movement of the parts in the basket so as all parts get equal exposure. The baskets are loaded onto a frame that is withdrawn into the machine and a sealed door is closed before starting the cycle.

The parts are tumbled in the basket at variable set speeds and high pressure sprayers wash down the parts of gross degree and oils. The parts are then submersed while tumbling in the cleaner solution or they can be allowed to soak. The cleaners are continuously pumped through a pre-filter for trapping large particles then an absolute filter set to the maximum particle size allowable to meet the standard. Absolute filters are rated to filter out absolutely all particles above the rated particle specification.

The parts can be programmed to ultrasonic irradiation while submersed to facilitate the removal of difficult to reach recessed areas. The cleaning cycles are timed through the computer controller based on the amount it takes to achieve the desired results of cleanliness.

Once the cleaning cycles are complete they are followed by the rinse cycles. The initial rinses are from the contained rinse tank in the machine, which can contain certain types of rust preventatives for plain steel parts or just plain water. This tank can be preheated and is also filtered to the same standards as the cleaners, and is partially replenished with fresh water with every cycle.

The final rinse cycle takes place with high quality deionized water that is filtered as well.

The drying is the final step in the machine, using pressurized heated airflow over the parts while slowly rotating in the machine. The air is recycled thru a blower, and introduces a small amount of outside air to control humidity in the machine, that filters the air to the same quality specifications required to meet the standard of the parts certification process.

Upon completion of the wash and dry cycle, the door is opened and the racks containing the parts are moved to a contained cool down area to prohibit condensation and particles from the air falling on the parts.

At this point the parts are held in containers that will maintain their state of cleanliness, while they undergo testing certification.

Periodic testing of the parts is done to certify that the parts meet the cleanliness specifications and the process is in control.

Testing is done in a clean room environment by taking a specific number of random samples and irradiating them in a known controlled virgin cleaning solution for a specified length of time, and vacuum filtering the wa

sh solution through a weighed certified filter and looking under a microscope and measuring for particle size, number and the net weight gain of the filtered particles.

The qualitative and quantitative analysis of this testing is usually spelled out by the customer or they may refer to an ASTM specification.