Preparatory studies on the use of beech in industrial OSB production

Project background

Oriented Strand Boards (OSB) are currently mainly made from pine and spruce in Central Europe. However, climate change and the associated situation in German forests are increasingly are increasingly leading to a reduction in the availability of softwood and an an increase in the amount of beech. The background to the project is therefore the use of beech wood as the most important hardwood species in Europe in the production of OSB. However, the use of beech is difficult because strands (large chips) made from beech largely curl up after the machining process.

Project objective

The overall objective of the planned project is to develop the process engineering principles for the use of beech in industrial OSB production. To this end, the project is dedicated to a holistic view of the process chain from logging to the finished board, taking into account the special requirements of beech wood.

Beechwood is considered unsuitable for the production of OSB in industry, as beech strands curl to a large extent after chipping (also known as the "curl effect" or "cigar effect"). Such strands cause various problems in an industrial production process. For example, they are difficult to dry and handle. Above all, they cannot be properly glued and thus cause defects in the boards produced from them.

The planned project therefore aims to investigate the causes and influencing factors of the curling of beech strands in terms of raw materials and process engineering, to develop suitable measures for minimizing curling on an industrial scale, to identify suitable technology to separate rolled strands from the flakes, and to develop a chipping technique for the most gentle possible re-chipping of such strands, so that this re-chipped material can be reintroduced into the production process at a suitable point. In addition, the project will investigate the process conditions and quantities under which such processed beech chips can be used to produce OSB that meets the relevant standards.

Project procedure

The project is divided into the following four subprojects:

Subproject A is dedicated to the procurement of raw materials and the production of strands and chips. Work package A1 deals with the procurement and characterization of raw materials. In work package A2, the procured roundwood is debarked and machined using various processes. At the same time, the machined strands are analyzed in work package A3.

Sub-project B is dedicated to the separation and processing of rolled strands. To this end, work package B1 will initially investigate ways of separating the rolled strands. Then, in work package B2, various approaches will be investigated to process the rolled strands in such a way that they can be fed back into production.

Subproject C deals with the recycling of material processed from rolled strands and the production and testing of OSB. In work package C1, the recycling of the re-ground material into the production process is investigated. Work package C2 is dedicated to the production of OSB from strands with and without recycled material and with different proportions of beechwood. In work package C3, the OSB produced is tested according to DIN EN 300.

Finally, subproject D will create a material flow diagram (process concept) for OSB production with the highest possible proportion of beechwood.

Innovation

The successful completion of the project will provide a comprehensive process engineering concept that will enable industrial OSB production with the highest possible proportion of beechwood.