Additive manufacturing or 3D printing is one of the technologies of the future to meet the increasing demand for personalized and customer-specific products. However, many process steps are still manual. This includes loading the production systems with the appropriate plastic or metal powder. In addition to the weight of the containers and an ergonomic workplace design to avoid back pain, the fine dust exposure of employees plays a particularly important role.

The use of vacuum conveying technology can help to protect people, the product itself and the environment. Piab has therefore developed the Piflow vacuum conveyors as a closed system. Filters in the vacuum conveyor and additional exhaust air filters on the vacuum pump prevent fine dust from the system from entering the work area and prevent employees from coming into contact with these substances.

The use of metal powders in additive manufacturing poses particular challenges, starting with the high bulk density. This is because metal powders weigh up to eight kilograms per liter, whereas powders in the pharmaceutical or food sector are usually 0.8 to 1.2 kilograms per liter. This requires more powerful vacuum systems to get the powders moving. At the same time, only relatively small quantities are required for a production process, so that usually hardly more than 100 kilograms per hour - i.e. 12.5 liters in volume - are conveyed. Due to the high bulk density as well as the large filters in the system and the additional exhaust air filters, a correspondingly large 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 short. The Piflow vacuum conveyor is energy-efficient thanks to the automatic switch-off of the vacuum pump when the system is at a standstill, and the energy costs for the automated conveying and filling of the systems remain low.

Explosion protection must also be taken into account when conveying metal powders, which are generally subject to ATEX regulations. For the configuration of a suitable vacuum conveyor, this means that appropriate seals and filters must be used and additional earthing 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 become electrostatically charged in a gas atmosphere and do not exceed a specific volume resistance. as