“Develop a highly functional and environmentally friendly automated packaging solution for furniture parts in batch size 1. This was the big goal when developing a new packaging system from G. Kraft Maschinenbau GmbH“, says Jürgen Sandmeier. Jürgen is head of design at Kraft Maschinenbau and one of the many people who came up with the idea for such a novel and patented packaging system.
The new, approx. 50 m long manufacturing line is modular in design and like all automated lines made by Kraft, was completely assembled and commissioned in the approx. 26,000 m² production and assembly halls in Rietberg-Mastholte in East Westphalia. True to its manufacturing heritage, Kraft Maschinenbau created this automation solution with the goal of delivering quality, high performance and the highest degree of automation. "To date, the furniture industry still lacks automated packaging in batch size 1. We have taken a big step forward in solving this challenge," says Michael Tigges, the sales representative responsible for the packaging system.
"In the beginning, the task was to develop a packaging design that would not only meet all the requirements of sustainable furniture packaging for the future, but also fulfill all the prerequisites for highly efficient machine and system technology," explains project manager Markus Gelhäut.
Kraft succeeded in doing this by cleverly combining a modified Fefco 401 as the outer carton with the functionality of using four-sided separate edge protection, all from continuous corrugated board. In addition, an environmentally friendly bio hot melt adhesive was used for gluing the edge protectors and the carton. Finally, a wet adhesive tape made of renewable raw materials and natural glue was used to seal the carton. This combination of materials has made it possible to develop an increasingly popular, sustainable and recyclable single-material packaging.
For Michael Tigges, one thing is certain: "The development of the edge protection with the customer was the initial spark for this unusual system".
Everything happens in a continuous flow
Another desirable characteristic featured by this line is each furniture component is packed in a continuous flow at constant speed.
Kuka's ConveyorTech organizes the cooperation of robot and material transport. The software automatically adapts the robot actions to the transport speed. This enables the robot to place parts on the running transport. "In the current line concept with continuous automation, packaging in a continuous flow achieves a cycle rate of 5 furniture parts per minute in a virtually unmanned operation," says design manager Jürgen Sandmeier. Other system concepts with higher cycle rates are of course conceivable.
When the furniture parts enter the line, the required part dimensions are recorded via a barcode and transferred to the "VPS 100", a corrugated cutting machine which was developed earlier by Kraft. The VPS 100 is not only sold and used as a stand-alone machine, but is also increasingly being integrated into interlinked large-scale plants. The corresponding outer cartons are then cut to size in the corrugated cutting machine. The machine operates fully automatically from the raw corrugated board store and selects the appropriate board with the lowest waste for the component. If a required corrugated board width is used up during the production process, the VPS100 automatically selects the next wider corrugated board preventing any production interuptions.
The finished corrugated carton, in sheet form, now runs over the belt conveyors in the direction of the transfer station. The carton is aligned in a running direction and then a clamping device pulls the carton onto a conveyor and positions it centrally.
A specially developed vacuum process in the conveyor system ensures that the workpiece and the carton are transported safely and accurately in position during the further packaging process.
Edge protection is manufactured endlessly
The Kraft company has paid special attention to the production of edge protection. Parallel to the carton packaging process, endlessly folded edge protection pieces are being made and cut to the appropriate length. A major advantage of this process is that no waste is produced.
A robot then picks up both longitudinal edge protection pieces and places them next to the component in a continuous flow by means of a width-adjustable suction beam. A further robot performs the same operation for the cross pieces.
After the top and sides of the edge protection have been coated with bio-adhesive, the component passes through the automatically width-adjustable folding station. The component is now securely packed between the edge protector pads and the outer carton.
In the subsequent process, the finished carton is automatically sealed with a wet adhesive tape. The so-called C-closure secures the carton again at the front against unintentional opening. In order to enable the customer to open the carton safely and quickly, a tear-open thread is integrated in the wet adhesive tape.
Sustainability in mechanical engineering
"Sustainable solutions in mechanical engineering are becoming increasingly important and for this reason it was important for us to develop a resource-saving product. We attach great importance to taking the issue of sustainability into account when designing our systems," says Markus Gelhäut.
For the plant developers at Kraft Maschinenbau, this packaging design made of folded and glued corrugated cardboard is an intelligent solution that takes into account the increasing demands of consumers as well as the German Recycling Management Act.
This innovative packaging line is only the beginning, because Kraft sees great potential for similar line concepts in many industries. A global trend is heading towards environmentally friendly packaging produced in batch size 1 and Kraft is now implementing such automation solutions into the market.
Press report: HOB Die Holzbearbeitung 9 (September) 2020