Abstract: An aliphatic polyketone fiber paper comprising aliphatic polyketone fibers and a polyketone fiber paper core material for a printed wiring board are provided. The polyketone fiber paper and the core material have high strength and modulus of elasticity; excellent dimensional stability, chemical resistance, heat resistance, adhesiveness and electrical insulation; and low dielectricity and water absorbance, and are thin, porous, and uniform. A printed wiring board prepared from the core material having a low dielectric constant, dimensional stability, electrical insulation, and properties of being uniformly bored by laser punching is also provided. The aliphatic polyketone fiber paper and the core material for a printed wiring board comprises 1 to 100% by mass of aliphatic polyketone fibers which comprise the repeating unit of the below-mentioned formula (1), the fibers having an average fiber length of 0.5 to 10 mm, an average fiber diameter of 0.

Abstract: An outer surface of an object 23 is irradiated with visible light from a light source 21, and the reflected light is acquired by a TV camera 24. A two-dimensional image with gradation is Fourier transformed by an image analyzer 20. The brightness and darkness of the image are bipolarized using an emphasis coefficient in a predetermined wavelength range in the process of Fourier transform. The bright regions and dark regions forming closed regions are calculated separately as regions representing gloss irregularity or printing unevenness, thereby outputting a statistical parameter of the areas as a measured result.

Abstract: A method and an apparatus for measuring the thicknesses of film layers of different synthetic resins forming a composite multilayer film or sheet by utilizing infrared rays. Infrared rays of sample wavelengths, each equal to the infrared absorption wavelength of each film layer, and at least one reference wavelength different from the infrared absorption wavelength of each film layer are projected onto the multilayer film to be measured. Ratios are obtained between the amounts of infrared lights of the sample and reference wavelengths transmitted through the multilayer film. An operation is achieved for solving a simultaneous equation including the ratios and the infrared absorption coefficients of the film layers at the sample and reference wavelengths as coefficients and the thicknesses of the film layers as unknowns, thereby obtaining the thicknesses of the film layers.