Abstract: A method selectively recovers a useful substance from waste including a chlorine-containing synthetic resin and metal copper in a mixed state. Metal copper is recovered from coated copper-wire waste. The method includes the steps of heat-treating the waste in form of coated copper wires, each having a coating material made of a chlorine-containing synthetic resin, in oil or under a non-oxygen condition. Here, the coating material is carbonized and a chlorine content of the coating material is reduced. Then the coating material and the copper wire are separated from each other the copper wire is recovered. The chlorine-containing synthetic resin can be treated without generating dioxin.

Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.

Abstract: A sheet of paper, plastic or the like on which an image has been formed using a toner that is photochemically decolorizable by absorption of near infrared rays is illuminated with near infrared rays under the state wherein the image is heated to a temperature equal to or higher than the glass-transition temperature of a binding resin of the toner. The color of the toner can thereby be easily and rapidly eliminated. This enables the reuse of the sheet to be realized easily and at a low cost.

Abstract: A roller for running a flat belt is formed at its surface by an elastic body. Short fibers are mixed with the elastic body. The short fibers are averagely oriented in a direction radially or peripherally inclined to the roller with a small angle and protrude at their tip portions from the roller surface. Owing to a grip force of the protruding short fibers, the flat belt is running, while decreasing a friction coefficient and obtaining a stability to a variation of temperature and humidity. The short fibers may be oriented in a direction axially, peripherally inclined thereto with a specific angle. When a belt guide member is provided to the roller or flat belt, accurate running of the belt is performed.

Abstract: Pin tractors which are used in various printers, typewriters, etc. for use as output devices for electronic computers, especially for personal computers. This pin tractor has a synthetic resin frame around which a belt carrying pins is wound revolvably and a presser member made of synthetic resin supported revolvably by said frame. Blank paper having feed perforations at its both edges is held between said frame and said presser member. Pins of said belt carrying pins are engaged with feed perforations of blank paper for feeding blank paper. Said presser member has pawl parts and said frame has concaves to correspond to said pawl parts. Said pawl parts are fitted in said concaves to keep said presser member opened in the specific degree.