There are very few manufacturers worldwide of paper impregnation lines to prepare decor and Kraft papers and foils for lamination onto
Vits Systems GmbH, headquartered in Langenfeld, was founded 80 years ago, in 1928, and is a specialist in such “web processing plants”. In terms of impregnation plants supplied, Vits claims an estimated 70% market share. Its impregnators are also used in the filter paper and other sectors of the paper industry.
Vits also makes process plants for the thermal treatment of strips and foils for the metal industry and is a key supplier of rotary sheeters, dryers and finishing machines such as pre-folders or UV-coating units for the web offset printing industry.
In total, Vits has supplied around 900 impregnating lines over the years and has seen a significant increase in demand
during the boom in the laminate flooring industry in more recent years.
Development of those lines continues and the company was carrying out final testing of its latest technology at the time of WBPI’s visit in late October.
This latest impregnation line is capable of running at 100m/min. Running the impregnation process at that kind of speed is not the major problem – stacking the treated sheets fast enough, and carefully enough, at the end of the line is.
If the treated paper were to be rolled at the end of the line, then the problem is less severe, but most panel industry treaters are required to deliver cut-to-size sheets to
a stacker.
The newly-developed system employs an ‘active guidance system’ in a carefully coordinated choreography to lift the sheets as they exit the treatment line and gently but quickly lay them on the stack.
“In this way, we have increased the speed of the line from 50-70 metres per minute, depending on the paper weight, to at least 100 metres per minute,said Thomas Niedermaier, managing director for sales at Vits Systems. “Our target is 120 metres per minute and we are confident of achieving that soon.
“Our latest line, called HIGHLINE, was launched at the Ligna exhibition in Hannover in 2007 as a high-speed line and we are now adding to this by de-bottlenecking the paper stacking system.”
The first such stacking system to be delivered was scheduled to go to panel manufacturer Kastamonu of Turkey and to be running by the year’s end (2008).
“We have seen a lot of interest from other customers as well because of the 30-40% increase in line speed,added Mr Niedermaier.
The current economic crisis must mean that demand for new impregnation lines is going to decrease in the coming months, or maybe even years, and thus Vits is not relying solely on new sales.
“We are now concentrating on upgrading existing lines for our customers – there are at least 600 of our lines out there with potential [for improvement]. It is also important to reduce energy consumption these days, as well as more efficient handling to reduce waste,said the managing director.
“Heat recovery systems, better insulation and optimised exhaust systems will save 30-40% in energy, plus giving a faster running speed for the line. This leads to the possibility for the customer to replace two lines with one high-speed, more efficient line, thus reducing production costs even further.”
With investment in laminate flooring now decreasing for reasons of global capacity, Vits’ management realised there was a need to diversify, using its long experience in overlaying as a starting point. Powder coating lines were the
chosen route.
“Powder coating is not new – it comes from the metal industry but metal is a conductive substrate so giving it an electric charge is easy,pointed out Mr Niedermaier. Imparting opposite-polarity electric charges to substrate and powder so they attract each other is the basis for powder coating.
“Another point is that metal can be heated to high temperatures to make the powder coating melt and flow – wood can’t,said the managing director.
Vits found that no company was offering a complete turnkey line and that they were all utilising components from metal coating lines which did not meet the quality requirements of the panel industry.
“This has led to a decrease in enthusiasm for, though not interest in, the technology,explained Mr Niedermaier.
“We have thus developed equipment for two essential areas of the line: an oven with a very even heat distribution to the whole work piece, which is patent pending; and specially designed spray guns which are also patent pending.”
Vits has long experience in ovens for drying paper and says that its experience in tight control has been transferred to the powder coating line ovens.
“Also, until now, it has only been possible to coat MDF that has been produced with salt crystals in the wood to give it conductivity. This is more expensive than normal MDF and only produced by a few companies. So, working closely with a partner company producing furniture components in Austria, we have a line running successfully with normal MDF. The conductivity comes from the moisture content of the panel,said Mr Niedermaier.
“We build the machinery and install the lines, while our partner company is responsible for the development and implementation of the coating technology.”
Mr Niedermaier suggested that there are two great advantages to powder coating.
Firstly, it is emission-free with no solvents, unlike wet lacquering which either has solvents or is water-based, leading to drying problems. He also said that powder is no more expensive than wet lacquer.
Secondly, the powder is a polyester epoxy resin and Vits claims that this gives a high-quality surface.
“It is very scratch resistant, impact resistant, warm to the touch [unlike melamine] and it offers new design possibilities such as metallic glitter finishes and coating of heavily-moulded surfaces, while surfaces and edges receive exactly the same coating,said Mr Niedermaier. “You can also use the same coating for the MDF panels as for the metal frames – in office furniture for example.”
The powder coating lines are marketed under the name POWTEC. Components to be coated are suspended in the line, which is either 160cm or 80cm high.
Meanwhile, powder suppliers have also seen the potential and have increased their research and development to reduce curing temperatures.
Vits has not deserted its traditional impregnation line markets, as evidenced by the new high-speed line being launched now. Mr Niedermaier also believes that melamine (short-cycle) lamination has a strong future as the only way to achieve structured decorative panels such as realistic wood grain or stone effects.
However, the company is realistic in its assessment of the short-term market and has realised the need to diversify. It also believes it has identified a promising new niche in the market for its powder coating lines.