Efficient painting for modern brand kitchens
A good price-performance ratio and design are among the decisive criteria for buyers of brand kitchens when choosing their kitchen. Nolte Küchen meets these requirements with a sophisticated range of colors and appealing surface concepts. To this end, Venjakob was asked for a spray coating lines with drying, which works economically even with small batch sizes and saves resources.
For 60 years, Nolte Küchen from Löhne in East Westphalia has been producing high-quality fitted kitchens with a focus on people. For this, the company has been named Germany's most popular kitchen brand for the third time in a row. Consumers give the brand very good marks for design and a good price-performance ratio. The award was presented by the German Institute for Service Quality.
Nolte Küchen invests continuously
The need for individuality is increasing. "The kitchen fronts shape the look of a kitchen. Style-conscious and design-oriented consumers want an ever-increasing selection of colors and color combinations," says Raphael Gottschalk, Project Manager at Nolte Küchen. This variety needs to be produced in the shortest possible time and in the most diverse quantities - from batch size 1 - in a customer-oriented manner. In order to meet these criteria in the future, the kitchen manufacturer is continuously investing. In this case in a spray coating lines with drying, which was planned together with Venjakob, the mechanical engineering specialist for surface processing.
The project objectives included cost optimization, quality aspects, reduction of throughput times and greater flexibility in the production process," explains Raphael Gottschalk. Before deciding to paint the surrounding materials (side panels, visible sides, plinths, etc.) internally, Nolte Küchen turned to external partners. As the general contractor, Venjakob took on the complete implementation of the spray painting line for coating and drying matt surfaces. With the exception of the sanding machine, all system components and conveyor systems were planned, produced and installed by Venjakob. The external sanding machine was integrated into the system control. The system was to be designed so that kitchen furniture components of the smallest sizes up to a maximum length of 2,800 mm and width of 1,300 mm could be coated automatically in a continuous process.
Color management system shortens set-up times
Nolte Küchen defined specific requirements for the performance of the system. Only water-based paints are used. "The challenge was the variety of colors. The system had to be able to run economically in small batch sizes and allow up to 20 color changes," says Reinhard Prus, head of the surface department in Löhne. as each color change takes time, a color management system was used. This keeps set-up times as short as possible. Painting is carried out by four spray guns in high-performance linear operation. The gun speed is infinitely variable and fully automatically controlled. a scanner in front of the spray booth determines the shape, number and position of the workpieces. The guns are switched on and off precisely above the workpiece. Each individual workpiece is recorded separately. The workpiece measurement is automatic and can be parameterized to a large extent. All relevant adjustable parameters can be preset in any quantity at a central control point in front of the spray booth via a touch screen computer and called up as a spray program. The individual programs are easy for the operator to change and can be stored in the system. "All relevant process parameters are stored in the recipes," explains Christian Schulze, sales engineer at Venjakob.
Drying process with rising temperatures
Another customer requirement: short throughput times so that the kitchen fronts are completely dry after the industrial finishing process and the backs can be painted immediately afterwards. The drying process was coordinated with the manufacturer of the 2-component water-based UV paint used. In addition, a number of test series were carried out in venjako's own technical center. Drying takes place with rising air temperatures: after industrial finishing, the workpieces first pass through a calming zone for two minutes. This is followed by a jet dryer with an air temperature of 30-35 °C. The components are continuously conveyed on closed belt conveyors. They then enter the nozzle drying channel with a temperature of 40-50 °C. After drying, the paint surface is cured with UV light. The uv curing systems has its own electrical control cabinet, but is controlled via the control system of the overall system. A built-in active power control compensates for voltage fluctuations that occur in overloaded or unstable power grids, ensuring a consistently high-quality result.
Best painting results thanks to special air supply
The required process air is supplied by two central supply air systems, which were planned by Venjakob and integrated into the overall concept. In the spray painting area, the supply air system works with humidification. The incoming air is heated, cleaned and humidified before being discharged, ensuring optimum air quality for the best industrial finishing results. A second supply air system without humidification supplies the areas of the sanding machine, the dust extraction system and the drying section.
Sanding machine can be used individually
The conveyor systems had a special feature. The sanding machine integrated into the system needed to be able to be used separately. For this purpose, a movable belt conveyor on flanged rollers was installed between the sanding machine and the spraying machine. when extended, this allows the sanding machine and the coating lines to be used individually. For combined operation (sanding + industrial finishing), the belt conveyor is in line and allows line operation.
Successful production start thanks to trained team
Production at the Löhne site started immediately after the in-house training in July 2021. The output of the coating lines has been continuously expanded in 2-shift operation to date. Venjakob has another good reference in Nolte Küchen. "Our requirements were fully met according to the specified parameters. The support and service after the final acceptance were also very flexible and top in every respect!", Reinhard Prus and Raphael Gottschalk confirm the good performance of the Venjakob team.
