Ever since Binderholz entered the cross laminated timber sector 13 years ago, the company steadily expanded its capacities and became the world’s biggest supplier of CLT. With the start of production at Plant 2 in Burgbernheim, the Tyrolean timber company currently produces more CLT than the entire industry did ten years ago.
The production technology and thus also the adhesive systems have evolved massively during these past years. However, the basic ingredients used by Binderholz – spruce wood and Loctite Purbond PUR adhesives – are still the same. For the company’s managing director Thomas Aigner, the advantages of using a 1-K-PUR adhesive for CLT are clear: “Due to the considerable dimensions of the elements, cold-curing adhesive systems have advantages in the production of dimensionally stable and low-distortion cross-laminated timber panels. 1-K-PUR adhesives with short pressing times are highly suitable for this purpose.”
For the sake of innovation
For more than ten years, Binderholz has been using 1-K-PUR adhesives by Henkel Engineered Wood. The dormitory Adohi Hall in the US is one of the numerous CLT projects which the Tyrolean timber company helped to build © Binderholz
With the start of the first CLT production site in Unternberg in 2006, Binderholz also began working with Henkel. “Back then, we started with a product containing fibers and we have always used Henkel’s most innovative adhesives ever since. The consistent development effort in this area was certainly one of the reasons for the rapid growth of the industry.” Aigner describes the cooperation with Henkel as extremely fruitful: “Henkel’s Engineered Wood team always responds to our demands in a way that is satisfactory to us. Of course, negotiations are tough sometimes – but for the sake of innovation, we have always worked together well and we have further evolved together.”
In recent years, key developments have been the steady improvement of the press time ratio and the switch to the fiber-free Loctite HB-S system which is much easier to use. When it comes to speed, not only Aigner but also Europe Sales Manager Christoph Sturmlechner see further potential: “Under controlled production parameters, we still see room for improvement in the press time ratio, which can be exploited in the future.”
For its CLT production, Binderholz currently uses seven different adhesives from the Loctite HB-S Purbond line. These are used for surfaces as well as for finger jointing. Depending on the technical equipment, Henkel adapts its HB-S line adhesives to the needs of each customer. Possible open times range from two to 70 minutes.
Safe adhesive
According to Aigner, another advantage of 1-K-PUR adhesives is that they are emissions-free in their cured state, which is indispensable for a building material which is also used indoors and thus makes the product safe for users.
A second adhesive system
At the Derix Group, the situation is completely different. In its new, big cross-laminated timber plant in Westerkappeln/DE where production started just a few months ago, the company uses a PUR adhesive for the first time in decades. For glulam and in the existing CLT plant in Niederkrüchten, the company uses a MUF adhesive. “We did not make it easy for ourselves, but in the end we opted for the Henkel Loctite HB-S line for economic and technical reasons”, explains executive partner Markus Derix, adding that it is mainly the process as a whole which needs to be taken into account. The 1-K-PUR adhesive – the Loctite HB-S 109 Purbond to be specific – is uncomplicated and can be used not only on surfaces but also in finger jointing.
Additionally, Derix focused on easy solutions when planning its production site: “A high-performance unit was a bit too complex for us. In case of problems, we would have been dependent on external experts and we did not want that. Also, the pressing of entire panels was a central concern for us.”
Smooth production start
Henkel’s HB-S line is easy to use and highly cost effective © Oest
According to Derix, the production start was largely smooth thanks to the new adhesive system. Together with Oest’s adhesive application experts, Henkel accompanied the start-up of the machines. According to Henkel project manager Alexander Sauer, this is extremely important especially when it comes to new customers. It is a free additional service offered by the adhesive experts. Sauer sees potential for saving time after the stabilization of production processes at Derix as well: “We can certainly further optimize the open times, thereby making it possible for Derix to significantly increase output.”
