Planing is an important step in parquet production. Depending on the product and material, there are one or more planing steps: The aim of pre-planing is often to make wood defects more visible. This is a prerequisite for the subsequent quality sorting. In the subsequent actual planing process, the aim is to produce perfectly level, flat workpiece surfaces that are at right angles to each other.
There are two planing processes in the production of solid planks: First, only the top and bottom sides of the planks are pre-planed, so that wood defects become more prominent. Some manufacturers also plane on four sides, i.e. even the narrow sides are processed. Depending on the nature of the material to be processed and the quality of the pre-planing, four-sided planing may be carried out again before pre-sanding and profiling. Afterwards holes and cracks can be filled again.
When planing the friezes/blanks in the production of two-layer parquet and three-layer parquet (the blanks are later cut into lamellas on thin-cutting saws), guiding the comparatively short workpieces can be a challenge. Some concepts provide for grooves to be milled into the underside of the workpiece for this purpose.
The four-sided planing machine used for planing has at least four spindles; depending on the output, there may be more. Sometimes individual spindles are set at a slight angle to allow for greater precision when workpieces are very curved.