Process and apparatus for fixing images

Abstract

In a process and apparatus for fixing thermoplastic image material onto paper, wherein the image material in thermally softened condition is transported through a pressure zone while being pressed between and in contact with the paper and belt moving together through said zone, and upon leaving said zone the paper and belt are separated from each other by forced movement of the belt along a path curved away from the paper, the fixing of the image material to the paper is achieved reliably in a simple manner, with little sensitivity to variations of temperature or of the character of the belt surface, by maintaining the thickness of the belt, the speed of movement of the belt and the radius of curvature of said path in a relationship defined by the formula: (D .times. V/R).gtoreq. 0.05, in which D represents said thickness (in meters), V represents said speed (in meters per second), and R represents said radius (in meters). The process serves effectively for papers of various kinds and thicknesses without need for adjustment of other operating conditions, when the heat softening of the image material is provided by keeping the belt heated to a suitable temperature range between 120.degree. and 170.degree. C. and limiting the time of contact of the paper with the belt to not more than 0.1 second.