A major printer of business forms feeds viscous, pressure-sensitive glue onto a web press for application to check stubs. The silicone-based glue is pumped from a floor-mounted container to a height of six feet. Two separate pumps feed into a tray that holds approximately two quarts of the glue. A porous pick-up cylinder transfers the glue to the paper as it speeds through the press. It is absolutely critical that the tray is kept full and that the cylinder stays coated with the glue. Farther down the line, the paper runs through a folder where the applied pressure activates the glue.
A web press is an extraordinarily complex and expensive piece of machinery requiring constant monitoring and adjustment. Stopping the press for an equipment failure is costly in terms of both money and time. Critical components that are reliable and that require minimal attention from the press operators are worth their weight in gold.
The printer had previously been using centrifugal pumps in this particular application. The centrifugal pumps were prone to clogging due to the nature of the glue. A clogged pump required disassembly, cleaning, and rebuilding—a process requiring at least an hour. Consequently, the life expectancy of the centrifugal pumps was poor.
Now the presses run much more smoothly with Masterflex® I/P® process drives, I/P Easy-Load® pump heads and Masterflex® Norprene® pump tubing. The drives offer consistent flow and reliable, continuous–duty operation. The Norprene tubing is chemically compatible with the silicone-based glue and also offers excellent suction and resilience to lift and deliver the viscous glue. Norprene pump tubing also suits this particular application due to its long pumping life—further reducing the maintenance load on the operators. And when new tubing is needed, the Easy-Load pump head requires only minutes for a tubing change.