Rowasol: New Rowapurge cleaning agent for coloring plastics

The peristaltic pump is still the dosing system of choice in many applications for the simple liquid coloring of plastic products. The advantages of a quick hose change are obvious, especially with a large variety of colors and many color changes in a short time, as no peripherals need to be cleaned or rinsed. Even with the relatively new and very precise piston pumps, a color change can be carried out quickly because here, too, a set consisting of pistons 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 couplings. However, today there are many other modern dosing systems to choose from, for example if high precision is required, high pressure is needed to inject the liquid paint or the handling of a hose is undesirable. Depending on the application, innovative micro annular gear, progressive cavity or gear pumps can be used. To remove the liquid paint from the previous production from these pump heads, the proven Rowaclean, a liquid cleaning concentrate based on modified fatty acid esters, was previously recommended, which in turn can be very easily displaced by the new liquid paint for the upcoming application.

In order to optimize the cleaning effect, Rowasol has further developed Rowaclean and added a color-neutral, gently abrasive special mineral. The resulting product, called HM 1108.01 Rowapurge, rinses the paint to be removed from the pump head even faster and more thoroughly, minimizing both paint carryover and set-up times. Rowapurge is also convincing on the processing machine, as the adjacent illustration shows: For comparison purposes, a polypropylene was mixed with approx. 1% Red 254 pigment, an organic pigment that is difficult to rinse out, and displaced from the injection molding machine again with the natural plastic. The process was then repeated with approx. 1 % Rowapurge, which led to a significant reduction in the number of rinsing cycles. Of course, even better results are achieved if the colored plastic is first continuously ejected into the open air, the screw is then fed with plastic and Rowapurge and the mixture is allowed to react for two to three minutes so that the fatty acid esters it contains can dissolve color residues and other contaminants. There is no chemical reaction and no foaming, so Rowapurge itself can be removed quickly. Another advantage over chemical cleaning compounds is the comparatively low production costs and therefore also the sales prices. All recipe components are FDA-compliant, which means that the product can be used without hesitation in the manufacture of food packaging or toys, for example.