METHOD OF PREPARING A CROSS-SECTION FOR CONTROLLING PARAMETERS OF CELLULOSE-CONTAINING MATERIAL Russian patent published in 2020 - IPC G01N23/2251 G01N21/89 B26F3/16 

FIELD: technological processes.

SUBSTANCE: invention relates to a method of producing a cross-section for controlling parameters of cellulose-containing material. Proposed method comprises preparation of main and surface layers including filler, production of cross-section with thickness of 50–250 mcm by ion cutting at 8–10 kV, duration of cutting from 1 to 2 h, and evaluation of surface properties. Image of the cross-section is obtained using a scanning electron microscope to obtain an elemental composition of the cross-section, after which images with length of 50 to 150 micron are connected to panoramic shots with length from 1 to 10 mm. Then, microscopic images are converted graphically, selecting shades of black, white and gray colors with control of image contrast, roughness is estimated from surface profiles and profile of boundaries of layers in cross section of fibers. Surface profile is created by projections and recesses on surface of cellulose-containing material, and profile of boundary line is formed. On the obtained panoramic image of the cross-section, a cross-section area is selected, it is divided into layers with definition of the profile of the boundary line, then lines of contact of fibers between each other, lines of contact of the fiber walls are marked, a region of fiber cutoff, a region of fibrils, chalk, pores and roughness. Distances from the surface profile to the layer boundary are used to plot the thickness distribution of the layers as to uniformity of forming layers of fibrous material. Along length of contact lines of fibers and length of contact lines of fiber walls, uniformity of their distribution in cross-section and their density of location and length, there is determined linkage of fibers, i.e., mechanical indices of fibrous cellulose-containing material. Fiber section area in each layer is used to estimate density of fibrous material, uniformity of fiber cuts distribution over uniformity of fibrous structure, area occupied by fibrils, determining fiber fibrillation, and by difference between total area and area of cutoff area of fibers and fibrils, porosity is evaluated. According to the calculated area of the area, which is occupied by calcium, which corresponds to a certain color on the map of distribution of element composition, content of chalk filler and its homogeneity of distribution in the cross-section are evaluated.

EFFECT: high accuracy of measuring parameters.

1 cl, 23 dwg