Welcome to my 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: service@flexowashus.com 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.
If you’re troubleshooting a narrow web anilox unit, head over to this article: HP Rinse and Air Dry Not Working on Narrow Web Anilox Unit
Have you ever been in the situation where the high-pressure rinse and air-dry passes are not working on your anilox unit? We have run into this situation a number of times over the years. Let’s take a look at what might be causing the issue.
First of all, it is important to remember that the HP rinse and Air Dry do not actually come on until the drain cycle is complete.
An anilox cleaning unit functions in the following order:
So, when you hit start, the unit goes into the wash cycle, and the high-pressure pump is not supposed to come on until after the drain cycle finishes.
If your HP rinse does not come on after the drain cycle, the number one culprit is that the return proximity sensor is stuck on. This means, the sensor is sending a faulty signal to the PLC when it shouldn’t be.
Checking the Inputs:
If you see a red circle on slide right when the spray head is at the start position, that sensor isn’t reading correctly.
On the system pictured above, active inputs are shown as green circles on the screen.
During this period, two different control systems were used, but both relied on normally open sensors.
These units have three sensors in the wash area:
When the spray head is in the start position, the sensor light for the start position will be on. The other 2 sensors in the unit should not be illuminated unless they are flagged.
On the OMRON controls, press the menu button, then press the inputs button. Input 2.06 is for the start position. The circle on the screen should be black if this sensor is working correctly. The input for the slide return is labeled “slide right”. If this circle is also black, then the return sensor needs to be replaced.
On the B&R controls, press the menu button, then press the inputs button.
Below is a picture of the first input screen. When an input is made, the red circle will be green.
On older wide web units (pre-2011), you will need to consult the wiring diagram for your unit and look at the input card on the PLC rack to see which inputs are illuminated. Unfortunately, the inputs vary from year to year for these older units.
We recommend that the sensor and the sensor cable be replaced at the same time.
If your return sensor is good and the unit is going into the rinse cycle but the spray arm isn’t moving or you don’t see any rinse water, then something else is going. There may be a bad traverse motor, traverse coupling, broken timing belt/pulley, dropped output, water inlet solenoid valve, etc. that might be causing the problem. Give us a call at the shop and we can help you troubleshoot the issue.
As always, if you need immediate assistance, call us at Toll Free: 888-493-5396 | F: 888-543-5396
Flexo Wash US
2010 Plantside Drive
Louisville, KY 40299
1-888-493-5396
See what’s happening on our social sites:
Facebook & LinkedIn