New vacuum system with blast air enhancement reduces particulates and lowers energy consumption
When Europe’s leading filter systems manufacturer teams up with the research institute that boasts the world’s cleanest room, the results are bound to be a clean break with conventional thinking. A two year research project between the company Schuko and the Fraunhofer IPA in Stuttgart faced the challenge of reinventing the process for removing the dust and shavings produced while shaping fiber composite materials. This challenge was met with a resounding success! The result: less fine particulate matter, lower energy consumption and a satisfied first customer.
The economic development agency for lightweighting Baden-Württemberg is proud to present this innovation as its ThinKing for October 2017. Leichtbau BW GmbH awards this label each month to promote innovative products and services in the lightweighting sector from Baden-Württemberg.
Shavings and chips are produced whenever a plane tool is used. While carpenters might use a broom or vacuum cleaner to tidy up afterwards, industrial production requires a larger more automated solution. This applies to fiber reinforced plastics the same way it applies to wood. Manual cleanup is not only expensive, but it also reduces a machines production time and interrupts the manufacturing cycle of serial productions. As a rule, employees should avoid contact with particulates and fiber dust which can pose potential health hazards.
For these reasons, high power suction systems are often used to remove shavings and dust material from the machine and extract it through a filter. Conventional systems quickly reach their limits because the range of the airstream is limited. Simply increasing the suction power often leads to a significantly higher energy bill with only minimal improvement in performance.
A complete new approach by Schuko and Fraunhofer IPA
In order to overcome these limitations, Schuko and the Fraunhofer IPA came up with a completely new approach. The idea was to design the suction system to use part of the filtered airstream to blow the chips and dust towards the extractor hood. This strategy allows the suction airstream to cover a space 30 times the size of the space directly below the extractor hood. The principle is similar to blowing out a candle – easy to do by blowing, much harder to do when breathing in!
In order to utilize this new approach, two usually separate units needed to be combined – the filtering system and the processing machine itself. To completely collect all the dust, the airstreams need to be optimally adapted to the geometry of the machine and the shaping process. This complex coordination was the focus of the two-year publicly subsidized project organized by the Central Innovation Program for SMEs (ZIM).
Vacuum system with rerouted airstreams significantly increases the performance range
Blowing the dust to a spot where it can be vacuumed up can be very helpful when manufacturing the complex shapes often formed out of modern fiber composite materials. One problem facing the designers is that chips and dust are thrown in all directions by the work tool – usually a router. The extraction hood is usually attached to a high ceiling or to the casing of the machine to stay out of the way of the cutting tool. This positioning is of course far from optimal for maximum suction performance. As any cook can tell you, the further the pan is from the exhaust hood, the less effective it becomes. Industrial applications have typically attempted to address this through more powerful suction systems or expensive custom solutions.
This is where the new vacuum system shows its prowess. Due to its use of additional airstreams, it has a much larger range. This allows the power of the main fan to be reduced while still improving the overall dust and shaving collecting performance. Another advantage of the new system is that the distribution of the airstreams into blowing and sucking streams means that only 20 percent of the drawn air needs to pass through a fine filter and into an exhaust channel. The remaining 80 percent passes through a coarse filter and is reused as blown air. This enables a further reduction of energy consumption and reduces the air intake required for the system to operate.
Pilot machine in Goschsheim puts in a convincing performance
The company Polytec in the southwestern German city of Gochsheim manufactures glass fiber reinforced plastic components using a range of routers and robotic production machines and was quickly convinced of the advantages of the new vacuum system. The company now houses the first pilot machine implementing the airflow vacuum system which was installed in late 2016 at the end of the research project. The project was supported by the Baden-Württemberg Ministry of the Environment which recognized the system’s potential for improving energy efficiency and reducing fine particulates.
It quickly became evident that the system would be able to fulfill the requirements of industrial mass production. Polytec’s manufacturing manager praised the new device noting, “The dust pollution in the workspace has been reduced by the new suction system which improves our health protection and is popular among employees. Cleaning the other machine components has also become much easier.” The new system has proved to be beneficial to both the company and its employees. Dr. Wolfgang Seeliger, managing director of Leichtbau BW GmbH, emphasizes the groundbreaking impact of this innovation. “The routing and cutting stage is an essential part of the production chain in manufacturing components out of fiber reinforced plastics (FRP) or wood materials. This makes this new suction system a milestone for lightweight technology as well and shows – once again – that the collaboration between research and industry is a true success story.”