Before we started with automatic painting, I knew as much about spray painting as I did about synchronised swimming. In the meantime, I have learnt to really appreciate Bürkle spray painting technology.
Remo Albisser, RIWAG

"Before we started with automatic painting, I knew as much about spray painting as I did about synchronised swimming," says Remo Albisser, Head of Machinery at Swiss door manufacturer Riwag Türen AG. He has the laughs on his side.

The passage of the doors through the spray painting system is very complex, as is the sequence of movements during swimming. Other similarities: Communication and data flow must be perfectly harmonised, the performance during sport should be just as inspiring as the perfect function and excellent feel of a Riwag door surface.

Consistent automation

The Swiss door specialist's entire production process is highly automated. Only the fitting process is still carried out manually. The variety of door fittings does not allow for automation here. Riwag purchased the surface finishing of the blanks. In order to achieve even better quality, shorter throughput times and, above all, significantly greater flexibility, Riwag has now taken this process into its own hands. "And if we automate the painting area, then we'll do it right," was the task that Albisser passed on to Bürkle.

Customer information
The Swiss company Riwag Türen AG produces 800 individual, customised doors every week. Exterior and interior doors, wood-metal door fronts, fire, smoke protection and sound insulation doors as well as frames and glazed partition walls are produced in Arth in the canton of Schwyz. Riwag employs 75 people and has well over 100 approvals for the various types of protection (fire protection, burglary protection, etc.).

Batch size one realised

The designed solution is convincing.The Bürkle team automated more than a dozen different work processes in very close cooperation with Riwag. The centralised data provision takes place in the work preparation department.The doors run through all production stages with this data. In the spray coating line, a barcode scanner reads the data into the system. All details, including how the sanding process has to take place, which colour is used, where the spray coating nozzle starts and how quickly the painted door runs through the UV drying process, are taken into account. One-off quantities are realised throughout. The doors are automatically measured, coated and sorted and stacked after painting.

Significantly reduced reject rate

The system operates in a "stop and go" mode with corresponding waiting positions before and after the processing machines. The cycle operation ensures that necessary process steps can be completed and that processing steps on workpieces are not interrupted during a process, resulting in rejects. This approach ensures very good surface quality and improves cost-effectiveness, as the reject rate is close to zero.

Result of good co-operation

The entire system is fully connected to the Riwag production control system. The machine parameter data of all components of the spray painting system are continuously exchanged with the control system. Bürkle realised this complex connection with in-house software experts. "In order to implement the data connection as smoothly as possible, very extensive data processing and preparation was necessary on both sides even before the actual order was placed," explains Martin Brümmerstädt, Bürkle's process engineering expert for the spray coating sector. This resulted in a deep and cooperative relationship of trust between the companies involved even before the order was placed, which contributed significantly to the excellent solution.

Changes possible at short notice

With the new spray coaiting line at Riwag, it is even possible to change the door colour up to two minutes before the barcode is scanned. The overall quality of the system and the good cooperation with a single partner who was able to offer everything from a single source were convincing.

"We are very satisfied. I still don't know anything about synchronised swimming. I have learnt to appreciate the Bürkle spray coating technology very much in the meantime," Albisser concludes.

© 2019 DRW-Verlag Weinbrenner GmbH & Co. KG, HK Holz- und Kunststoffverarbeitung