HARDNESS MEASURING METHOD FOR POLYMERIC MATERIAL

PURPOSE:To provide a method for measuring the hardness of a polymeric material in which a pair of polymeric materials are press fitted to the opposite end faces of an ATR crystal, infrared rays are projected at a predetermined incident angle toward one polymeric material from one end of the crystal, and then the hardness of the crystal is determined based on the spectrum of light emitted from the other end. CONSTITUTION:Polymeric sample materials 13, 14 are polished, on the predetermined end faces thereof, up to surface roughness of 0.2-0.8mum. The polished surfaces are then applied tightly to an ATR crystal 12 while opposing each other and sandwiched by press boards 1, 4. A predetermined fastening pressure is then applied thereto by regulating male screws 19, 11. The fastening pressure is set in the range of 1.9-2.0kg/cm . Subsequently, infrared rays from an infrared light source are passed through a polarization filter to produce a vertically polarized light. Infrared rays hvi thus obtained are then projected to the crystal 12 from one end thereof and the spectrum of reflected light emitted from the other end is measured thus determining the hardness. This method optimizes the roughness and press fitting power of the press fitting faces of the materials 13, 14 and the crystal 12 thus enhancing the accuracy in the determination.