BIRCH BARK PRODUCING METHOD Russian patent published in 2006 - IPC B27L11/02 

FIELD: wood working and wood chemical industry branches, possibly production of birch bark.

SUBSTANCE: method comprises steps of taking birch bark having no wood ingredients, slightly curing and slightly drying taken bark till humidity 20 - 25%; disintegrating bark and sieving disintegrated mass through screen for separating birch bark from bast fibers. If initial humidity degree of bark is less than 20%, it is additionally wetted at water temperature 55 ± 5°C at least for 3 hours and then it is subjected to slight curing and slight drying. Bark is preferably disintegrated in hammer mill at revolution number of its shaft no more than 1800 rev/min.

EFFECT: possibility for producing large quality of biologically active materials, simplified extraction of such matters during further processing.

3 cl, 2 ex