Material to use inside ultrasonic cleaner

Question

I am trying to create a couple of holders for my ultrasonic cleaners. They are supposed to be used for parts that don't fit in the holder that came with the cleaners. I was wondering what material is best to use for this.

My initial thoughts are:

• Material should hold up to the cleaning solution, I have a wide range of them from degreaser, deruster, and so on. I would say PETG or PLA should be a safe bet as it reacts with almost nothing
• Material should not have issues with warm (not hot) water, I'd say something along the lines of 60-80 °C. This already eliminates PLA, but I think PETG should still be OK-ish (I am aiming more towards 60 °C than 80 °C).

Is there something I am missing? Does anyone have any input? I am anyway just going to do a few tests, but I assume starting with PETG is a good start.

Answer 1

ABS and PLA arn't very chemical resistant. PETG is better, but PET is probably your best option, however it is also a little harder to print in. PET also has a higher melting point than PLA, and shouldn't soften up too easily. PET is more durable as it tends to flex rather than crack, unlike ABS.

Answer 2

The materials you list suggests you could also print PETG. PETG is probably you best option without having specialized options on your printer.

1. PLA is the easiest to use, but loses its shape at lower temperatures than your other options. Moisture also makes it more brittle and more likely to crack sooner under ultrasound.

2. ABS is flexible (when thin) and survives temperatures as high as the boiling point of water. But, it dissolves in acetone and isn't resistant to solvents.

3. PETG is reasonably flexible (also when thin) to survive the ultrasound and more chemical resistant, but somewhat harder to print as mentioned.

Printing PETG

PETG can have issues with the filament jamming. If you print too fast, it jams because it doesn't have time to adequately melt in the nozzle. If you print to slow, you get heat creep. The solution I found was to use the maximum hot end temperature recommended, usually 250 °C,, and increasing the airflow through the heat sink and across the printer bed as much as possible.

One is tempted to leave the bed at room temperature to help prevent heat creep. PETG will stick at room temperature. However PETG sticks too well. Heating the bed to 80 °C will help the print release from the bed when it cools down. PETG will also tend to damage the surface it's printing on. Thus, a sacrificial layer such as a glue stick layer is useful to protect other layers on the bed.

Also import to the quality of the print for PETG, the filament must remain dry. Moisture in the filament will cause bubbles in the print. For your application the bubbles would make the print more porous, exactly what you want to avoid. The best results is to print from a dry container and minimize the time the filament is exposed to open air over 20% relative humidity.

Keeping water out of the print

You may need to check if you can get enough exterior layers to keep the cleaning liquid from filling up the spaces in the fill. People often use paint to seal the surface, but most paint is not resistant to solvents. Thus, it would take socialized paint such as epoxy paint. Paint will also tend to peal in an ultrasonic cleaner.