Modular coating technology for maximum flexibility
The magic formula for cost-effectiveness and flexibility in the coating of furniture elements is based on the clever interaction of high-performance individual machines that are customised to the customer's requirements. From surface cleaning to industrial spray coating and drying. Venjakob's pioneering modular concept utilises all possibilities to create solutions tailored to the customer's needs.
Strong double in the spray coating lines
This example involves a modular overall system for coating furniture fronts. At the centre of the coating line is the VEN SPRAY VARIO spray coating machine, which is characterised by high productivity. The reason for this lies in the technology used by Venjakob: a combination of spray painting robot and surface spray painting system. Another plus point is the flexible use of the spray painting machine. Depending on the furniture element, only the surface mode or only the robot mode can be selected.
High system availability and reliable process data
When selecting and technically equipping the individual components, the customer's desire for high performance and high system availability was met. In addition, when planning the process chain, the focus was on the high surface quality to be achieved and the variable utilisation of individual machines. For example, traditional, high-quality solvent-based PU wood coats as well as water-based coats can be used. The status data of the individual machines can be recorded centrally and analysed using software. This provides the plant operator with important data at all times, e.g. to be informed about possible wear parts at an early stage or to be able to better plan requirements and productivity. Reproducible process data at all times, which also serves to give the trust between producer and supplier a measurable basis.
Surface quality starts with cleaning
Cleaning comes before the actual coating process in the automatic spray painting unit. This plays an important role in achieving a good finishing result. As very fine particles are released during the processing of wood, which cannot always be completely removed even with good extraction systems, a dust extraction device with an ionising system is used to clean the furniture fronts. After pre-cleaning and extraction of the swirled-up particles, the static surface charge is neutralised using an ionising system. The workpieces leave the pre-cleaning process in a clean and charge-neutral condition.
Continuous industrial finishing of furniture components
The workpieces are transported to the spray painting area via a closed belt conveyor system. While the ABB robot arm thoroughly pre-coats the outer edges of the furniture elements, the conveyor belt continues to run continuously in order to then evenly coat the surfaces and edges of the workpieces with four spray guns. During the transport from the robot zone to the surface coating area, the first coat of paint is already applied so that the paint can be added a second time to the edges. As the belt does not stop here, but continues to run continuously, the coating performance (area/minute) is 50 per cent higher than with other robot coating systems," says Oliver Milde from the East Westphalian family business Venjakob.
Colour change and cleaning are carried out automatically
The high performance of the VEN SPRAY VARIO is complemented by the automatic colour management system. In conjunction with the higher-level system control, a colour change including the necessary cleaning is carried out automatically. Using a central control panel, which controls the entire system via an Ethernet connection, each colour can be prepared in parallel to ongoing production and activated within a very short time. This increases the flexibility of the system. The system can process 1-, 2- and 3-component coating systems. Nine paint pumps, two hardener pumps and three cleaning agent pumps are available for this purpose.
Paint consumption is significantly reduced
The paint consumption can be optimised for each spray gun via the machine control system. To do this, the furniture elements are scanned on the infeed side and the format and position data is fed to the control system. The spray system is also equipped with an application-adapted extraction system which, in conjunction with an adjustable fresh air supply, ensures optimum removal of the resulting overspray. For coat recovery, the coat that falls onto the conveyor belt during the coating process in the offset area is recovered using a belt cleaning system. The spray coating machine can be equipped with a second, decouplable cleaning unit so that the necessary scrubber cleaning can be carried out in parallel with production operation and thus the changeover can be completed in the shortest possible time, increasing productivity by another.
Drying process important for the surface result
After industrial finishing, the furniture fronts are moved on to the dryer by the conveyor belt. The temperatures can be freely configured and adapted to the coats used. The air speed and optional humidity can also be set within the drying system. To stabilise the sensitive industrial finishing, the freshly lacquered elements are pre-dried in filtered air in a laminar flow jet dryer for approx. five minutes. They are then transported in batches to the Ven Dry Vario Time shelf dryer, where they are stored on 62 shelves 5,500 mm long for curing and dried individually and continuously according to a predefined schedule. At the end of the drying process, the furniture elements leave the dryer via the conveyor belt. They are removed at the output point or coated again. A UV channel can be retrofitted for UV-curing coating systems if required.
Venjakob's modular system concept leaves plenty of room for manoeuvre to meet a company's needs. Both the individual machines within the process steps required for industrial finishing and the overall system can be expanded at any time and adapted to new customer requirements.
