It was a board converting plant. The product is not important. It was a continuous process and there was a need to apply a line of PVA adhesive to the edges of the board as it traveled through a series of rollers. The system was pressure fed from a central adhesive supply. The set up was probably designed for a smaller, precision application as there were fine, micrometer type adjustments everywhere. The adhesive application was from a “shoe” type of plate with fine holes at the base. The whole assembly was on a circular bar for lateral adjustment located across the machine.
Unfortunately I didn't take pictures of this set up but it was a nightmare.
The problem being that this was a “rough as guts” plant with operators to match. Typical board widths were around 1200mm (48 inches) and adhesive application rates where not critical. Just get it on and make sure that it sticks. All of the micrometer adjusters had long ago been gummed up with adhesive or damaged so that they didn't work and all of the metal tubing was battered and bent. The circular cross bar was always covered in sediment and of course the assembly would never readily slide across. Fixings where screwed connections and so needed tools. Adjustment was by belting the parts with a heavy spanner, quite amazing the degree of accuracy which could be achieved...... sometimes!
If there was a blockage to the feed shoe (and this happened regularly), it was like a scene resembling a “pit stop tyre change" at a race track, as operators raced in to strip the feed assembly and clear the blockage whilst the board continued to run through the machine and obviously all board going through at this time (without adhesive) needed to be marked and dumped further down the process....hopefully! It was a QA and Safety nightmare.
The fix resulted in a really nice, simple engineered system. See the attached picture and drawing.
I threw away the whole multiple adjustment assembly and replaced the circular cross bar with rectangular flat bar. I designed a simple feed arrangement with a tri clover fitting in the main feed tube for easy make/break without the need for tools. This assembly was attached to an inverted U support bracket with locking hand knob and this allowed easy transverse adjustment and could be lifted off without tools for cleaning.
I fitted a mating tri clover fitting to a nearby tap and a shadow board on the wall. Therefore when a blockage occurred it was a quick and simple task to hinge back the assembly, unfasten the tri clover and replace the blocked end with a clean one from the shadow board. All without the need for tools. The dirty end could then be attached to the tap and flushed out before being put back on the shadow board, ready to be re used. I also fabricated a blank end with a pin. Previously, when the line was down for cleaning or maintenance, the feed shoe would quickly block, but now it could be easily removed, flushed clean and replaced with the blank end. The pin kept the end of the pipe open and the adhesive feed system could readily be brought back on line for the next production run.
If anyone has the same problem, feel free to use the concept. If you need more, I'll help if I can, please get in touch -