Abstract: This patent application describes a method to produce wood chips with the intention of reducing the energy consumption in the subsequent process steps for pulp production. With the present method wood chipping is done in a wood chipper where the chipping tool (3) has an angle ? (4) within the interval of 75° to 105° between the fibre direction of the log and the side of the tool which faces the chip (2). Angles in this interval will cause an axially directed compression of the chip which will cause a cracking of the wood during chipping.

Abstract: Methods of measuring stress forces in refiners are disclosed in which the refiners include refining disks with a refining surface and refining bars extending across the refining surface, as well as a measuring surface comprising a portion of the refining surface, the measuring surface being movably mounted on the surface of at least one of the refining disks and a pair of rigidly mounted force sensors for producing oppositely directed deflections when the measuring surface is influenced by stress forces, the method comprising resiliently mounting the measuring surface in a direction parallel to the surface of the refining disk and calculating the stress force based on the difference between the deflections measured by the respective pairs of the force sensors. Apparatus measuring stress forces in such refiners are also disclosed.

Abstract: Methods of measuring stress forces in refiners are disclosed in which the refiners include refining disks with a refining surface and refining bars extending across the refining surface, as well as a measuring surface comprising a portion of the refining surface, the measuring surface being movably mounted on the surface of at least one of the refining disks and a pair of rigidly mounted force sensors for producing oppositely directed deflections when the measuring surface is influenced by stress forces, the method comprising resiliently mounting the measuring surface in a direction parallel to the surface of the refining disk and calculating the stress force based on the difference between the deflections measured by the respective pairs of the force sensors. Apparatus measuring stress forces in such refiners are also disclosed.