DPP-4 and DPP-8 glue delivery pumps

The Baumer hhs presentation in Hall 13 (Stand C16) at drupa 2016 includes the DPP-4 and DPP-8, two new double-piston pumps for its adhesive application systems that come up with improved performance features, thanks to a new working principle. For instance, the new electronic control system permits exact pressure management at all production speeds, meaning that a material pressure regulator can be dispensed with. Instead of generating high pressure in the delivery pumps and then reducing it by means of material pressure regulators, as in the past, the new pumps always generate only the pressure currently required, and thus a constant delivery flow. As a result, the adhesives are handled more gently and delivered to the application heads with the viscosity intended by the adhesive manufacturers. This can improve the gluing results when using sensitive adhesives, since the glue dots run less and penetrate more slowly. In addition to which, the new double-piston pumps are very robust. They need little maintenance and have extended options for diagnosis. Another advantage is their convenient operation. Colour displays allow the machine operators to rapidly identify all operating statuses. The DPP-4 double-piston pump achieves an adhesive pressure of up to 20 bar, and the DPP-8 twice that figure. Visitors to the "drupa eXtended" days, which Baumer hhs is holding at its hhs solution-center in Krefeld throughout the 11 days of drupa 2016, can convince themselves of the performance of the new double-piston pumps in live presentations in the company's ultra-modern test laboratory, which is just 15 to 20 minutes away from the exhibition grounds in Düsseldorf.

"Glue delivery pumps developed by Baumer hhs are known on the market for their particular efficiency and reliability. But, thinking that even the best can get better, a member of our Development Department came up with the idea for a new glue delivery pump that is gentle on even the most sensitive adhesives, even easier to service, and also offers an expanded range of options for diagnosis and for communication with the Xtend3 controller. When we then actually developed the new double-piston pumps, we ultimately achieved even better results than we'd expected at the start," says a happy Thomas Walther, Head of Engineering & Technology at Baumer hhs, talking about the new products.

The DPP-4 and the DPP-8 work with two mutually independent pistons, whose movements are ideally coordinated with each other. The sum of the capacities of the two pump sections yields a constant delivery flow. Since this new working principle of the delivery pumps eliminates a number of undesirable influencing

variables that cause non-linearity of the adhesive pressure in other pump designs, the new delivery pumps achieve better control performance in this respect, compared to the usual products on the market. Months of extensive test series demonstrated exact and largely linear pressure control – the situation that control engineers most like to see.

Another feature of the new double-piston pumps is their ease of operation and clarity. The colour display indicates all operating statuses at a glance. Should faults occur in exceptional instances, despite the great operational reliability of the delivery pumps, the machine operators can quickly identify these faults and thus minimise the downtimes of their machines. If everything is running smoothly in the production process, the display is green and shows key delivery parameters. In the event of faults, it turns red and indicates them, being easy to see even from a long way off. This enables the machine operators to intervene quickly and take targeted action. Since most malfunction messages and the warning thresholds can be configured individually, the operators can, within certain limits, decide for themselves when they want to be notified. The delivery pump is even capable of eliminating certain faults on its own, without the operators having to intervene. That likewise avoids production disruptions. Moreover, the DPP delivery pump automatically records its operating time. These data can serve as a basis for preventive maintenance.

Speaking of maintenance: while most of the delivery pumps customary on the market have lubricating points that need to be filled with oil, this is no longer necessary on the DPP pumps. That reduces the maintenance effort for the machine operators.

Delivery pumps are often installed on the drive side of production machinery, thus being out of the machine operators' sight. In the case of the DPP delivery pumps, an interface to higher-ranking control systems permits data communication, including malfunction indications, with central operating terminals. So, the machine operators can additionally monitor the delivery pumps from their accustomed workplaces.

One of the primary development targets was to design a delivery pump that is as robust and reliable as possible. Extensive field tests by customers show that this target was reached. After all, the new pumps were intended to be fit for the future and open to the market demands lying ahead. This target, too, was reached. For instance, the adhesive pressure can be adjusted within certain limits, in order to cope with the steadily rising performance of production machinery.