Welcome to my new monthly column where I will share best practices for Flexo Wash technology and common flexo challenges. I want to answer your real world questions so be sure to send them to me at: firstname.lastname@example.org and we will feature them in an upcoming column. As your partner, I look forward to handling all your issues as soon as possible and offer lessons learned.
Question: Foam is coming out of my solution tank!
Have you seen foam coming out of the solution tank or chemical spray bar on your anilox cleaner? If so, you know that the foam can leave quite a mess in the unit and on the floor. You will also notice some poor cleaning results. Here are a few things to check if you have been experiencing a foaming issue.
Things to Check When You Have Foam:
- Make sure the cleaning solution is being properly mixed at 50/50 ratio with water. If too much water is mixed with the cleaning solution, this can cause a foaming issue.
- Check your filter. Dirty/clogged filters will impede the amount of cleaning solution that the pump is trying discharge on the roll during a wash cycle. This reduced flow rate can cause the pump to “spit” out cleaning solution as foam.
- Check your cleaning solution temperature! The temperature of the cleaning solution should be set at 128-132 F. There is a temperature drop on all anilox cleaners during the wash cycle. At temperatures below 118 F, the cleaning solution may start to foam due to the agitation of the solution through the diaphragm pump and drain-to-tank process. Starting the wash cycle out at a lower temperature will cause the cleaning solution to reach the lower threshold faster and foam.
- If your start temperature is correct but you see a rapid decrease in cleaning solution temperature to below 118 F, check the speed of your diaphragm pump. If the diaphragm pump is running too fast, then the cleaning solution is turning over too quickly and will foam. The heater in the solution tank cannot keep the temperature at a high enough point to prevent foaming. The diaphragm pump should only run fast enough to keep the roll wet during the wash cycle. If the diaphragm pump sounds like a lawn mower, it is running way too fast. Adjust the flow valve until the proper running speed is reached.
- Check for air leaks. If air is being introduced into the system, that will cause the cleaning solution to foam, regardless of the temperature of the solution. Check the supply lines to and from the pump for leaks. Check the rubber hose in the wash area that supplies the cleaning solution to the spray bar for holes or cracks and make sure the clamps are tight. Check the filter can to make sure there is an O-ring present and that the can is screwed on tightly. On the vast majority of filter cans on anilox cleaning units, there is a black plastic pressure release button on the top of the filter can. If that button is depressed and does not spring back up then air will be getting into the filter can from that location.
If you go through all of these items and are still have a foaming issue, there is more than likely a mechanical issue with the heating element or an internal issue with the diaphragm pump. Give us a call at the shop and we can go through some other items to check.
As always, if you need immediate assistance, call us at Toll Free: 888-493-5396 | F: 888-543-5396