Bürkle has integrated the "Multi-Line" coating line for PUR hotmelt adhesives into the production of the Swiss door factory. The collaboration between Bürkle and Türenfabrik Turbenthal began at the Ligna trade fair in 2019. Shortly after the trade fair, Bürkle's engineers began planning and the order was placed in January 2021. The system was installed in the same year, and the first doors were coated at the end of 2021. The line coats and laminates the surfaces of the workpieces. The centerpieces of this coating line are the hot melt adhesive application machine and the roller press. Each system is developed and built on a customer-specific basis, as the configuration often depends on the local conditions. At Turbenthal, a gantry was added to support the 25 meter long and eight meter wide system. This arrangement fitted perfectly into the planned hall structure, and only details had to be coordinated to ensure the required room height for loading.


Customer information
For over 40 years, TT Türenfabrik Turbenthal in the Swiss municipality of Turbenthal has been synonymous with first-class doors, mainly made of wood. Its product range includes interior and exterior doors as well as custom-made special designs according to the customer's wishes. Those responsible are proud of their location in Turbenthal, which combines tradition with the highest quality - a philosophy they share with Robert Bürkle GmbH from Freudenstadt.

The "Multi-Line" in Turbenthal enables the coating of workpieces with dimensions from 900 x 250 to 3,050 x 1,300 millimetres and a thickness of 10 to 105 millimetres. The line is designed for a maximum panel weight of 215 kilograms. Workpieces with a width of 600 to a maximum of 1,300 millimetres and a length of 1,500 to 3,050 millimetres can be fed and stacked automatically. Smaller workpieces are placed manually and removed again after coating. The "Multi-Line" in Turbenthal achieves a cycle output of around two and a half cycles per minute, depending on the optimum processing temperature of the hot melt adhesive used.

In Turbenthal, a PUR HOTMELT adhesive is used that is water and heat resistant and cannot be reactivated after processing. This means that once bonded, components can no longer be separated. Cleaning the hot melt adhesive application machine at the end of a production day takes around 15 to 20 minutes due to the special design to ensure consistent quality and service life of the application roller.

Another strength of the PUR coating in Turbenthal is that different materials can be applied to the door blanks. For example, plastic coatings can be applied on one side and different surface materials on the other, which are bonded together by the pressure of the calender roller alone.

The "Multi-Line" is designed so that it can be operated by a single machine operator who monitors the feeding and removal of the raw stacks and surface materials. Machine operators are trained during installation and commissioning to understand and operate the machine in the best possible way right from the start.

Each coating line is a customized solution, adapted to the customer's needs. Details such as the requirements for the surface finish or special requirements for the end products determine the design of the system.

The coating line in Turbenthal has been in operation for over a year and has proven to be extremely reliable. The "Multi-Line" enables the company to produce more efficiently, shorten delivery times and increase the quality of the doors, says Steffen Denker from Bürkle.