Method and apparatus for measuring fiber orientation anisotropy

摘要

Apparatus for measuring fiber orientation anisotropy in a web of fibrous material includes a microwave generator, a waveguide through which a microwave signal is propagated axially and in which an electric field is established in one direction perpendicular to the waveguide axis, the waveguide having a gripping means which provides a gripping means for specimen insertion, a detector for measuring intensity of the microwave signal propagated through the waveguide and a metering means for numerically evaluating the intensity of the propagated signal. The intensity of the propagated signal is measured (1) with the waveguide empty, (2) with the specimen inserted in the waveguide in a plane normal to the axis and with its machine direction aligned with the electric field and (3) with the specimen inserted in the waveguide in the normal plane and with its cross direction aligned with the direction of the electric field. The ratio of attenuations by the specimen in the two orientations is a measurement of fiber orientation anisotropy.