First, a gang saw cuts the logs into planks: Several parallel saw blades produce several planks in one process. Then, the wood can be stacked with gaps between planks and dries for 1 to 2 years. Beech wood is steamed like in a pressure cooker to improve its mechanical properties. Thereby, the wood turns darker and acquires the typical brown-reddish colour.
The dried planks are raw with some cracks, with the bark still forming the edge. In order to minimise waste, each plank is inspected. A sawing machine is programmed to cut long laths from the planks. The laths are needed in different lengths: The sawing system automatically recognises the length of each raw batten and cuts out a suitable length if possible. The laths whiz along a long conveyor belt and are automatically ejected from the belt at a specific point depending on their length: The result is a stack of laths of the same length.
The result is rough-sawn laths on which the strong marks of the saw teeth are still visible.
The raw laths still have imperfections such as knotholes or missing edges. These are marked with fluorescent paint. The automatic saw recognises the markings and cuts the slats to a new, suitable length.
The cut laths are now placed in the planing machine, where they are given the required shape. For the Hangbird frame parts, the planing machine planes all four sides straight and breaks the edges, called “to chamfer” in the slang of the trade. The extraction system ensures that the work is free of wood chips or crumbs.
There are several planing stations in the planing machine, which process the different sides of the laths. Four stations are required for the Hangbird laths: one station for each side. Each station has a cutterhead with four blades. For Hangbird, the knives are flat with a ‘nose’ protruding on one side to break the long edge. For decorative laths, the knife blades form the profile accordingly.
How the lath looks after planing depends on the planing knife used. There is a wide variety of planing knives for the different laths. The workshop collects the knives assigned to the different customers in a little filing box.
After planing, the frame parts are sanded. In the sanding machine, the wood is processed from all four sides at the same time.
Planing, sawing and sanding produces chips – but here they are neatly captured! This is done by the huge extraction system. Suction hoses ensure that all the wood residue ends up in a large silo. They can later be processed into litter for small animals or wood pellets, for example.
