Thursday, January 13, 2022
Prof. Maximilian Ober, faculty of wood technology, Rosenheim University of Applied Sciences has shared his expertise on the surfaces.
What will be your post LIGNA impression about the surfaces? Was there any new product that impressed you during LIGNA?
Prof. Ober: LINGA has once again shown us new paths in the field of surface finishing technologies. The topics of energy and material savings during manufacture were everywhere. I was particularly impressed by the new systems in digital printing, inert hardening, UV-LED, and the “Ven Spray Vario” newly presented by Venjakob. Although in the past it has only been possible to coat difficult geometries using expensive narrow-area coating processes on a clocked line, the “Ven Spray Vario” offers the option of using a robot to coat these geometries in a continuous running mode. The major advantage of this technique is that some of the paint can be recovered and, in addition, it is possible to increase output.
Another impressive novelty is the UV-LED system for two-dimensional hardening in rolling lines offered by Bürkle. If we take a rolling line for “IKEA White No. 5” as the reference, conventional UV systems require an overall power of 512 kWh. With UV-LED, this power can be reduced to 99 kWh. Venjakob offers the UV-LED system for three-dimensional hardening for workpiece heights of up to 50 mm of the spraying machine. The new UV system permits a reduction in power from about 40 kWh to about 7 kWh.
Both novelties offer significant cost savings and resource reduction of about 80%. In addition, surface heating is significantly reduced and yellowing of the paint is avoided. Amortization times are 3 – 5 years, still relatively long due to the rather expensive UV-LED elements, although their service life is extended from the conventional 2,000 hours to about 15,000 hours.
The technology of inert hardening may not be new, but its refinement and the offerings from Bürkle and Cefla have made it possible to put it on the market. In this process, paint can be applied in relatively thick layers of about 40 – 60 m. The resulting rolled texture is smoothed using the applied foil and/or by the first roller. The foil also keeps the oxygen in the surrounding air away from the paint layer, preventing inhibition from ambient oxygen. This allows the quantity of photoinitiators and even the energy costs for UV hardening to be reduced.
The surface structure of the foil can give the paint surface a texture from high gloss to matte to other textures as well.
Do you think there’s the possibility of immense change in terms of design, raw-materials and sustainability?
Prof. Ober: Even before LIGNA, the topic of digital printing was getting a lot of press.
Different companies like Bürkle, Cefla, Dieffenbacher, Hymmen, Wemhöner, and others have significantly improved it in terms of quality, printing width, feed velocity (output) and price per square meter. The right system can be selected depending on application demands. This provides new opportunities throughout the entire production process. How significant the changes will be, only time can tell.
Which technological aspects, according to you, are going to stay for long in the industry?
Prof. Ober: Digital printing changes the opportunities available for logistics and production. It might be a little too much to talk of a revolution, but it’s not entirely out of the question. A new day is dawning. UV-LED is still in its early days, but it will certainly have a future due to the further development of LED lamps and will significantly reduce its amortization time.
Do you think printing on 3D surfaces is going to be the next talk of the surface industry?
Prof. Ober: We still didn’t see anything at LIGNA in the field of printing three-dimensional parts. I talked to two well-known manufacturers of digital printing systems who still can’t imagine that this will be possible. It’s simply very difficult to operate a print head in three dimensions with enough accuracy to obtain a high-quality print. That doesn’t mean that it will never happen, however.
State-of-the-art technologies are coming to the rescue of surface inspection and quality checks. Do you have any recommendations in this field?
Prof. Ober: For the wood industry, which we represent, there have not been many developments in this field. There are some trends towards the automobile industry or automobile inspections. We have already examined our options for transferring them to the wood industry. These attempts are generally unsuccessful due to the fact that there is less investment in the wood industry. Unit counts are also generally not yet sufficient or the unit counts come at such high speeds that these testing methods used in other systems cannot be used in the wood industry. So there’s still relatively little there.
Tags: Maximilian Ober, wood technology, woodworking USA
