Production of OSB boards
11.10.2019 | Notizie | SWISS KRONO Group
Heiligengrabe. OSB boards are extremely popular especially in timber construction and are regarded as all-rounders. But what is behind the name and what does the production process look like in detail? Product manager Stefan Gottfried has given us an insight into the processes.
The popular coarse chipboard or OSB board has been produced in Heiligengrabe since 2001. OSB is an abbreviation for the English term "Oriented Strand Board", which is derived from the production process in which the veneer strips or strands are aligned ("Oriented"). But more about this later, we start at the very beginning, with the wood.
For OSB production, SWISS KRONO exclusively uses fresh thinning wood from sustainably managed forests, which is sourced from the surrounding area. After delivery via the wood yard, the tree trunks are placed on the feeding section and transported to the plant.
Two large drum debarkers ensure that the bark is removed from the trunks. Now the wood is shredded into strands in the hogger. The veneer strips are then transported on a conveyor belt to the drying plant, where they are dehumidified at approx. 200 degrees Celsius. The resulting water vapour is cleaned and separated via a chimney. The dried wood fibres are then transferred to the screening plant, where they are separated into coarse parts for the top layer and finer parts for the middle layer. Fibres that are too fine are screened out and used to generate energy.
In the next production step, the second important component is used - in the gluing line, the fibres are sprayed with a small proportion of formaldehyde-free glue. The strands are transported to the production line where they are spread onto the belt. In the four-layer scattering process, the coarse fibers are first scattered in the production direction to form a top layer, before two middle layers are scattered across the production direction with the finer fibers. Finally, a further top layer is applied. On its way to the press, the resulting chip cake is preheated in the evaporation plant before being pressed into an endless strand at 200 degrees Celsius. The panel strand is then cut into panels up to 18 meters long by a diagonal saw.
As soon as the panels have been cut to size, they are cooled down in a cooling turner. Now the boards are sanded in the sanding line, as required, or are conveyed unground to the stacking line, where they are stacked into standard packages. Finally, the stacked boards enter the packaging line and are packed ready for transport.