The FP 400 is a new generation of diaphragm pump from KNF combining the traditional advantages of diaphragm pump technology – self priming, can run dry, long life time – with a pulsation level comparable to gear pumps.
This new pump generation has been specially designed to meet the challenges posed by UV inks which are currently witnessing substantial growth across a range of applications in industrial Inkjet Printing (IJP). The five diaphragms of the FP 400 apply a low shear force to UV inks, thus avoiding premature curing – i.e. activating the UV initiators - in the pump.
The new FP 400 delivers 4 to 5 l/min (depending on version) to meet the higher recirculation volumes required by modern printers which utilize a greater number (up to 36) printheads per colour bar. These new bigger printers are to be found in packaging, laminates, textiles, wallpaper, ceramics, glass, metals and wood for instance. Furthermore, the FP 400 is ideally suited to the new high laydown printheads on the market which require much higher recirculation flow rates.
To provide compatibility with different ink types, the FP 400 is available with a choice of material options:
• An EPDM version for less aggressive UV and water-based inks
• A PFTE-coated diaphragm model, primarily for solvent-based inks
• A version with FFKM diaphragm and valves for oil/solvent-based inks and the abrasive pigments used in ceramics and glass printing.
Low pulsation is a key feature of the new FP 400 since it achieves values lower than 150 mbar (at the pump outlet) at nominal flow rate and lower still depending on system configuration and running speed. In this respect the new FP 400 fares just as well as gear pumps used in IJP.
Linear adjustment of flow is another strong feature of the new FP 400. The pump offers an outstanding linearity between 10% and 100% of the nominal flow rate.
On top of that, the new pump is stable against back pressure (up to 1 bar) and against viscosity changes within the range of the commonest inks used in industrial IJP. The FP 400 is therefore a good solution for applying glazes, enamels, hot melt inks, etc.
Last, but not least, the FP 400 has been intensively tested for 18 months at major printer and ink manufacturers in Italy, Spain, Germany, UK and China and has already raised a great deal of interest.