How did you come up with the idea of producing cross-laminated timber from silver fir?
Jörg Kübler: Actually, the idea was born in different places at the same time, and we started discussing it by chance. The project was sparked off by a feasibility study from the Forum Weißtanne [note: an association dedicated to the promotion of silver fir]; Manuel Echtle was a board member at the time.
Manuel Echtle: The aim of the Forum Weißtanne is to promote the silver fir in the construction sector. Our companies are located in the central and northern Black Forest which is right in the middle of its ideal growth area; we want to utilize this regional advantage.
How did the idea of a cooperation between the three companies come about?
Kübler: The sawmill industry in our region consists of rather small-sized plants. To be able to meet our high quality requirements and still achieve profitability, however, a certain plant size is necessary. With our collaboration, we are well positioned in terms of raw material supply and investments. We could even be completely self-sufficient; however, this is not our goal. Furthermore, each of the three equal shareholders brings his strengths to the table. The Streit sawmill stands for high-quality fir lumber, the Echtle sawmill is already producing three-layer boards for interior construction, and my company handles the joining work for over 1000 construction projects a year.
What are the specific characteristics of cross-laminated timber production when
using silver fir?
Echtle: Based on our experience, of course we are aware of the challenges that come with processing silver fir. This is why it was a central objective for us to have the entire process – in-cluding lumber drying and grading – under our own control. With this measure as well as thanks to some special features in the production process we will be able to achieve the desired high surface quality both with silver fir and spruce. This already starts with the separate grading system. Of course, we are aiming for single-variety purchasing, but there is always a certain margin for error which we have well under control thanks to our grading line.
Why did you choose Weinig as your complete supplier?
Kübler: The project is a great challenge for us. In order to tackle it, we need a partner who can handle the setup and resolve the interface issues and who is not only capable on the technical side of things but can ultimately also take on the agreed schedule and financial scope. Weinig has handled all of these aspects extremely well so far. In particular, we were very impressed with their approach to the question of the master computer.
Echtle: After visiting several CLT plants it was clear to us that we want to press single-layer panels with the highest possible quality so that we would no longer have to think about intermediate processing before the block press. Drawing on the experience from our panel plant we knew that Weinig could do it. Since we want to produce for construction, it was also essential to install a line that was as flexible as possible. Weinig has solved the batch size 1 issue very well.
Which innovations did Weinig implement in this project?
Kübler: This already starts at the grading station. Here, Weinig employed a new principle which allows the stacking of up to four qualities and three waste boxes in a confined space. The production process involves a very small num-
ber of personnel with Weinig guaranteeing a high level of system availability. One new development is the chaotic single-layer panel warehouse, from which two preparation stations and subsequently the lay-up unit are fed. There are numerous additional solutions custom-made for us that I will not elaborate on in detail
here.
So far, how has the project been coming along, and what will be the next steps in the coming months?
Kübler: Despite challenging circumstances we have been able to keep to the schedule so far. Even though Weinig had to reschedule some things internally, they were able to meet all final deadlines.
Often, we didn‘t even notice that we were dealing with different companies of the Weinig Group. In September, all stand-alone machines were tested and at the end of the month we were able to press our first panels. In October, the master computer was then superimposed, and the start-up was launched as planned. In other words, the entire plant should be running fully automatically in the near future already.
Thank you very much for the interview!
