New ROWASOL Cleaning Agent Speeds Up Color Changes
The peristaltic pump remains the dosing system of choice in many applications for easily coloring plastic products with liquid. The advantages of a quick hose change are particularly evident when dealing with a wide variety of colors and frequent color changes in a short period of time, since no peripheral equipment needs to be cleaned or flushed. Even with the relatively new and highly precise piston pumps, a color change can be carried out quickly because, here as well, a set consisting of a piston and connecting hoses is replaced for each color. The investment costs for a so-called piston set are many times higher than for a hose, possibly with quick-connect couplings.
However, there is now a wide range of other modern dosing systems to choose from when, for example, high precision is required, high pressure is needed to inject the liquid ink, or the use of a hose is undesirable. Depending on the application, innovative micro-toothed ring, eccentric screw, or gear pumps can be used. To flush these pump heads of the liquid ink from the previous production run, the proven ROWACLEAN, a liquid cleaning concentrate based on modified fatty acid esters, which in turn can be very easily displaced by the new liquid ink for the upcoming job.
To optimize cleaning performance, ROWASOL has further developed ROWACLEAN and added a color-neutral, gently abrasive special mineral. The resulting product, called HM 1108.01 ROWAPURGE, flushes the paint to be removed from the pump head even faster and more thoroughly, thereby minimizing both paint carryover and setup times. ROWAPURGE also delivers impressive results on the processing machine, as shown in the adjacent illustration: For comparison purposes, polypropylene was blended with approximately 1% Pigment Red 254—an organic pigment that is difficult to flush out—and then displaced from the injection molding machine using the virgin plastic. The process was then repeated with approximately 1% ROWAPURGE, resulting in a significant reduction in the number of flushing cycles.
Of course, even better results are achieved if the colored plastic is first continuously discharged into the open air, the screw is then fed with plastic and ROWAPURGE, and the mixture is allowed to act for two to three minutes so that the fatty acid esters it contains can dissolve paint residues and other contaminants.
No chemical reaction or foaming occurs, so ROWAPURGE itself can be quickly removed. Another advantage over chemical cleaning compounds is the comparatively low manufacturing costs and, consequently, the retail prices. All ingredients in the formulation are FDA-compliant, meaning the product can be used without hesitation in the manufacture of food packaging or toys, for example. The new ROWAPURGE is now available from stock.