Abstract: This invention provides a novel, rapid method and device for determining the relative phase retardation of different layers of a multi-layered specimen, which is related to the thicknesses of its layers and walls, and the orientations of its optical axes. An intact wood pulp fibre is a typical multi-layered birefringent specimen. This new method is based on the change of polarization of polarized light that passes through a specimen composed of birefringent layers with different optical axis orientations, such as directions of cellulosic microfibrils oriented differently in various layers of wood fibres. In particular, a novel solution is found to relate the emerging light intensity from an intact wood fibre to the incident light intensity, the wavelength of the light, and the relative phase retardations of various layers and orientations of their cellulosic microfibrils, such as fibril angle, in a circularly polarized light system.

Abstract: The invention relates to a fluorescence microscopy technique for measuring physical and chemical properties of individual fiber-like particles. Fluorescence intensity per unit length is shown to be proportional to the fiber coarseness. In addition, other fiber properties such as fiber length, width and wall thickness can be obtained from fluorescence images, and lignin content from fluorescence spectra. The present invention will provide a process for determining the uniformity of pulp samples in terms of the physical and chemical properties of the individual fiber-like particles, particularly wood pulp fibers.

Abstract: The invention relates to a fluorescence microscopy technique for measuring physical and chemical properties of individual fiber-like particles. Fluorescence intensity per unit length is shown to be proportional to the fiber coarseness. In addition, other fiber properties such as fiber length, width and wall thickness can be obtained from fluorescence images, and lignin content from fluorescence spectra. The present invention will provide a process for determining the uniformity of pulp samples in terms of the physical and chemical properties of the individual fiber-like particles, particularly wood pulp fibers.