Baskets and trays used to support products in an ultrasonic cleaner solution have an effect on ultrasonic cleaning efficiency. Ultrasonic cleaner baskets and trays are necessary to keep the products being cleaned from coming in contact with the tank bottom and walls. The design of the ultrasonic cleaner basket or tray should have minimum impact on the level of ultrasonic cavitation. This is because anything placed in an ultrasonic cleaner bath, including the baskets, affects cavitation action by absorbing ultrasonic energy. The goal is selecting a basket or tray design that helps maximize cavitation action on parts being cleaned.
Comparing Basket Design
The October 2005 issue of Managing Infection Control reported on a study of four basket designs and how the design impacted ultrasonic cleaner efficiency. While there are several tests to evaluate the efficiency of an ultrasonic cleaner, including the aluminum foil test and the ultrasonic activity detector, one of the easiest and most cost effective is the SonoCheck™ cavitation check test. It consists of positioning SonoCheck tubes in the basket, the number being determined by the size of the basket. When subjected to ultrasonic cavitation the tubes change in color to yellow from green. The time that elapses for this change gauges the efficiency of the ultrasonic cleaner.
This is the testing method that was used to gauge the impact of basket design on cavitation action. In all cases tests were conducted using baskets segmented into 9 sections, each with a tube, and using a degassed ultrasonic cleaning solution. Three tests were conducted on each basket design and each test was timed to determine the average overall time, the average minimum time and average maximum time for the tubes in each section (a total of 27 tubes per tray) to change color.
Open weave, solid side, small weave and plastic trays were subjected to the test, summarized as follows:
- The open weave tray had the best overall results for the best penetration of cavitation action to contents that are placed in this type of tray.
- Solid-side trays came in second, although they appear to be the most popular in the central sterile departments of healthcare facilities.
- The small weave trays had the best average minimum time but an overall rating of third.
- The plastic tray placed last in all categories.
The study suggests that open weave trays support the most efficient cavitation action on parts being cleaned. But what also must be taken into account is the size of the parts. Small instruments and components such as screws and bolts are usually cleaned in mesh immersion baskets to keep them from falling through open weave trays to the bottom of the cleaning tank.
Contact the ultrasonic cleaning pros at Tovatech for expert advice on cleaning baskets and cleaning procedures for your operations.