METHOD FOR DETERMINING BAST FIBER FLEXIBLE RIGIDITY Russian patent published in 2023 - IPC G01N33/36 

FIELD: fiber production.

SUBSTANCE: assessing the quality of bast fiber materials used in calculating the bending stiffness of bast fibers during their qualimetry and standardization. The strand is placed on supports of circular cross-section with a diameter of 2R at a center-to-center distance of 2L, followed by a deflection by a constant valueΔ. Flexural stiffness EJ, depending on the resulting force F, is calculated numerically using the shape of the curved axis of the strand in the form of dependence:

f is the coefficient of friction of the strand on the surface of the supports;ϕ is the angle between the vertical and the radius of the support, drawn from the center of its section to the point of contact of the strand with the surface of the support; R is the radius of curvature of the support. Under the conditions of touching the axis of the strand to the surface of the supports at points having coordinates y_B =Δ-R(1-cosϕ ) and x_B =L-Rsinϕ and so that the tangents to the axis of the strand and to the point of contact on the surface of the supports coincide and are located at an angleϕ to the X coordinate axis.

EFFECT: simplification of analysis and increase in accuracy in determining the flexural stiffness of the fiber.

1 cl, 2 dwg