ANISOTROPIC TRANSPARENCY OF POLYSTYRENE FILM WITH CRAZES

A crazing method was developed to create regular crazes in a polystyre ne film. The crazes penetrated completely in the direction of film thi ckness. The tensile strength of the crazed films in both perpendicular and parallel directions to the processing direction was almost unchan ged after the crazing-processing, regardless of crazing conditions. Yo ung's modulus in the parallel direction decreased with the film tensio n during the crazing-processing. If suitable crazing-processing was us ed, transmittance of incident light decreased between the incident ang les of 0 to 20 deg, and increased above the angle of ca 20 deg with an increasing incident angle, which gives a W-shape to the light transmi ttance curve.