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HANNOVER MESSE 2020, 20 - 24 April

Exhibitor Press Releases

PIAB Vakuum

Everyone is today talking about additive manufacturing or 3D printing as one of the future technologies to meet the increasing demand for personalized or customized products. Originally used as a simpler solution in prototyping, more and more unique pieces are being produced using this technology. But while it sets standards in the realization of products, many process steps are still manual. This includes, in particular, the loading of the production equipment with the corresponding plastic or metal powder. An ergonomic workplace design is needed to prevent back pain from employees handling the weight of the containers as well as exposure to the particulate matter itself. The use of vacuum conveying technology can help to protect people, the product itself and the environment. As a supplier to the pharmaceutical, chemical and food industries, Piab faces this issue daily and draws on 40 years of experience. Accordingly, the piFLOW® vacuum conveyor was developed as a closed system to solve this problem. Filters in the vacuum conveyor as well as additional exhaust air filters on the vacuum pump prevent fine dust from entering the system in the workspace and thus causing employees to come into contact with these substances. This ensures a clean working environment where the health burden is reduced as far as possible. At the same time, the powder is protected against contamination by environmental influences with corresponding loss of quality. The use of metal powders in additive manufacturing poses particular challenges, starting with the high bulk density. Metal powders can weigh up to eight kilograms per liter (kg / l), while powders in the pharmaceutical or food sector are generally between 0.8 and 1.2 kg / l. This requires significantly more powerful vacuum systems to keep the metal powder moving. At the same time, only relatively small quantities are needed for a production process, usually no more than 100 kilograms per hour - that is 12.5 l in volume conveyed. Due to the high bulk density and the large filter in the system as well as the additionally required exhaust air filter, a correspondingly large-sized vacuum pump is required to achieve the necessary suction power. The production time in the 3D printing process is relatively long and the active conveying times are low. Thanks to the automatic shutdown of the vacuum pump at idle, the piFLOW® vacuum conveyor is very energy-efficient, especially in comparison to mechanical pumps, which must continue to run at idle. Thus, the energy costs for the automated delivery and filling remain low. Alternatively, it is also conceivable that the vacuum conveyor on a mobile platform feeds several 3D printers that use the same powder. Explosion protection must also be taken into account when producing metal powders, as these are generally subject to the ATEX regulations. For the configuration of a suitable vacuum conveyor, this means that appropriate seals and filters must be used and additional grounding points must be taken into account. All plastic and rubber parts in the ATEX version are made of antistatic nitrile butadiene rubber (NBR). In principle, all ATEX-relevant powders and gases can be transported in the vacuum conveyors as long as they do not undergo electrostatic charging under a gas atmosphere and do not exceed a specific volume resistance. Vacuum conveying transports powder in the air stream. Another peculiarity in conveying metal powders is that they are usually conveyed under inert gas atmosphere, usually nitrogen or argon. This means that these gases have to be fed into the system, which requires highly complex control. At the in-house test center in Butzbach, Piab conducts its own nitrogen-conveying experiments and, together with the customer, develops a vacuum conveying process tailored to the particular powder used. In addition to the conveying of the new powder, the vacuum conveyors are also used to return excess powder from production back to the production cycle. In this case, the remaining powder is taken up by means of a suction feed wand with the vacuum pump of the conveyor and emptied through a sieve into a container. From there, the powder is fed back to the production cycle via the vacuum conveyor via a hose. In this way, the cycle is closed, resources are saved and waste is avoided. This reduces costs and protects the environment. Piab's piFLOW® vacuum conveyors are designed to be easy to disassemble and reassemble for cleaning and maintenance. In an inert gas atmosphere, it must be ensured that these gases do not escape into the atmosphere, both for reasons of cost and occupational safety. Piab is currently working on approaches to develop appropriate solutions that will allow a quick change from one metal powder to another in a flexible production process. The integration of piFLOW® vacuum conveyor systems into Industry 4.0 is another development topic at Piab. These are bundled under the piSMART® product brand and coupled to the vacuum pump used. In addition to an I / O link, cloud capability and the ability to preset, Piab is currently developing an auto-tuning process specifically for the vacuum conveying area. As a result, the vacuum conveyors in fully automated process chains are to independently adjust to different requirements, to optimize the conveying cycle.. For Piab itself, additive manufacturing as a production technology is very interesting. Already today custom grippers for the handling of bags in the packaging of food are produced by this process. In particular, the lightweight construction potential is a great advantage for Cobot applications in addition to the individual design possibility.

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