Here’s a prototype cleaning unit I built for and electronics company with a highly specialized problem. Automated glue dispensers use nozzles that can be removed for cleaning. The problem is that cleaning is inconsistent and occasionally damaging depending on the skill of the operator. Damaged nozzles don’t work properly and are costly to replace. This proof-of-technology prototype uses pressurized alcohol or another preferably specialized glue solvent to dissolve the contaminants in the nozzle. The system allows for consistent results based on time. and the use of fluid keeps the nozzle from being damaged by overly-zealous manual cleaning.
EXPLANATION:
Pressurized solvent is stored in a pressure tank. These are common in electronics industry, used mainly for wave flux application. A custom timer (2-channel) is connected to an air solenoid and sealed (VOC-compatible) fluid solenoid. The fluid line from the pressure tank is connected to the solenoid, and the solenoid is connected to a Tee-fitting with an interchangeable nozzle fitting on the end. Once an operator attaches a dirty nozzle to the fitting and closes the door, the timer can be started. The timer opens the solenoid and and pressurized solvent is forced through the nozzle, slowly dissolving hardened epoxy/glue (~1 min). Timer would then switch off fluid solenoid, and open air solenoid for about 15sec. After this dries the nozzle, system shuts off, and the operator can remove the cleaned nozzle from the housing. Efficient, consistent, and safe.
DESIGN:
The fully automated unit was never built, but it’s relatively simple. The system can be ordered with fittings for any type of nozzle from various manufacturers. Fittings can easily be replaced if a particular company runs several different types of dispensers. The 2-channel timer should probably be an old-style contact-disk timer for durability. PLC control here would be overkill. Waste is simply collected in a bucket beneath the unit. The system needs to be well-sealed, so use of alcohol would be safe. Alcohol use is important because alcohol is a waste stream that doesn’t require EPA regulation. Some custom epoxy solvents are a regulated waste stream, and the unit needs that flexibility in a company for both types of application. The unit only requires 110v for timer and solenoid to open the fluid flow, and an air supply for fluid pressurization. Lights are just optional.
Honestly, it’s one of those things that only companies like Nordson, Panasonic or Fuji would have any real interest. Similar systems could easily be incorporated into the dispensing machines themselves. Maybe even sold as a retrofit kit! Hmmmm. Whatever else happens to this idea, I know it still worked.
