Drying and curing by UV, generated by LED

Vilnius Baldai has been an Acustomer of Bürkle for many years. For more than 20 years, both companies have been closely connected with each other, also through the local representation of the Freudenstadt plant manufacturer Lintera. The close relationship started in 2004, when Bürkle designed and built two large printing and coating lines for Vilnius Baldai. In the last few years, several individual machines have been purchased and replaced. Vilnius Baldai also owns Bürkle veneer press lines.

The first layout for the line was created at the beginning of 2019, the final concept in April, and the contract was then concluded in July. The current investment is a complete greenfield project, a new plot of land with an area of 73 000 m² was purchased and equipped with a new factory. This has now made it possible to double the previous capacity. The most important targets set by Vilniaus Baldai for the new production line were the already mentioned 50 m production speed with complete UV-LED drying at the highest possible coating quality. In addition to LED technology, technical highlights of the system include a high-quality trowel coater for optimum coating results and corresponding roller coaters for precise coating application. The UV system in modern design (with high output and long lamp life) is combined with high-performance UV LED technology, which generates cost advantages thanks to the lower energy consumption through the use of the UV LED modules. In addition, all machines are equipped with energy-efficient motors and are designed to be operator and maintenance friendly. According to the manufacturer, this is the first complete UV-LED system ever: drying and curing are done by UV, which, however, is not generated by gallium but by LED. Basically, a UV lamp can be used in many different ways in industry. Through the targeted use of the right UV radiation, work processes can be optimised, which in turn leads to an increase in profitability. The luminaires of the UV LED family are particularly suitable for curing inks, coatings and lacquers.

Fully automatic adjustment of the machine parameters during operation

In the phase of project preparations, there was a continuous, intensive cooperation between the customer, the lacquer supplier and the machine manufacturer Bürkle. Already in the run-up to the project, the Bürkle specialists were able to carry out extensive pre-tests and various rejections of customer parts in the Technology Centre in Freudenstadt and to provide the furniture parts manufacturer with the corresponding material. Permanent jour fix appointments were held in order to discuss the progress with the customer at any time and to be able to make changes if necessary. The engineering was carried out as a complete 3D planning using the latest digitalisation tools, simulation models and the use of dual twins. The scope of the project also included the interlinking of the coating system and the customer's loading and unloading system using the latest technology. In addition to Siemens' "Profi Net", the latest version of "Tia" was also used in the PLC area.

The operating side of the machine is designed as a central control with recipe management for various products (furniture parts). Among other things, it also allows the fully automatic setting of the machine parameters during operation. The line cycle begins with the sanding of the workpiece blanks on the wide-belt sanding machine integrated into the control system and provided by the customer, including cleaning, before the application of a water-based primer by a first roller application machine. This is followed by curing and annealing of the primer by a UV LED system. The workpieces are now prepared for filler application by filler application machines with 20 - 30 g/m². Two machines are connected in series, each with a temperature control unit for water and a subsequent UVLED system for trying and curing. This is followed by intermediate sanding with the customer's second wide belt sanding machine, including cleaning of the workpieces. The workpieces are then coated with the top

coat by three roller coaters arranged one behind the other in the line, each of which is followed by a UV-LED system that ensures that the basecoat gels. The final 3 - 8 g/m² of basecoat is applied by two further roller coaters, each followed by a UV system with two lamps and one with three lamps for curing. Belt conveyors are located between the production units to ensure smooth, synchronised transport of the workpieces. The central line control is equipped with the Bürkle Remote Service System. This system ensures access to the line elements for troubleshooting, i.e. direct access to the line control by the Bürkle technicians in Freudenstadt via remote desktop. All single machines were accepted by Bürkle experts in Freudenstadt. The subsequent transport of the line to Lithuania was unproblematic without any special incidents. The only problem was that the lorry driver could not find the customer's address at the first attempt, as it was located in the completely new industrial area, which was not yet listed on Google Maps or in the memories of the navigation devices. All machine parts (of course) still arrived on time at the installation site at Vilniaus Baldai in September 2019. All machine parts (of course) still arrived on time at the installation site at Vilniaus Baldai in September 2019. Two Bürkle fitters were on site for final assembly at the beginning of 2020. They were supported by (at least) five employees of the customer. An installation time of eight weeks was estimated, but the installation had to be forcibly interrupted in March due to Covid 19 quarantine regulations. Finally, in late November to early December 2020, staff were trained to carry out theperformance run with material on 8 December, which went without incident and achieved the warranty. The customer is very satisfied with the plant performance in production practice so far.

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