Abstract: The present invention is directed to a process for separating polyester, and particularly polyethylene terephthalate, from various contaminants and impurities. In general, the process includes the steps of contacting materials containing polyester with an alkaline composition to form a mixture. The mixture is heated causing some of the impurities to be chemically modified into a more separable form. During heating, a portion of the polyester may also be saponified. After heating, the mixture can be washed with water and the polyester can be easily separated from the remaining impurities. Through the process of the present invention, polyester can be separated and recovered from waste materials containing polyvinyl chloride and aluminum. The process is also effective at removing coatings adhered to the polyester and at removing entrained organic and inorganic compounds contained within the polyester.

Abstract: A method for treating polyesters comprises combining discrete particles of a polyester with an alkaline composition such that the alkaline composition coats the polyester particles. The particles are then heated in an environment that is at least substantially free of water. The method can be effectively used in cleaning, decontaminating and even increasing the intrinsic viscosity of polyester materials. Moreover, when used in the recovery of polyester materials containing contaminants and/or impurities, the method can provide a superior polyester product both in terms of intrinsic viscosity and color.

Abstract: The present invention is directed to a process for separating polyester, and particularly polyethylene terephthalate, from various contaminants and impurities. In general, the process includes the steps of contacting materials containing polyester with an alkaline composition to form a mixture. The mixture is heated causing some of the impurities to be chemically modified into a more separable form. During heating, a portion of the polyester may also be saponified. After heating, the mixture can be washed with water and the polyester can be easily separated from the remaining impurities. Through the process of the present invention, polyester can be separated and recovered from waste materials containing polyvinyl chloride and aluminum. The process is also effective at removing coatings adhered to the polyester and at removing entrained organic and inorganic compounds contained within the polyester.

Abstract: A process for recycling polyester contained in waste materials is provided. The polyester is converted into a corresponding acid salt of a polybasic organic acid and a polyol. The process steps generally include first combining materials containing polyester with an alkaline composition to form a mixture. The mixture is heated, causing the polyester to convert to the acid salt and polyol. The polyol is evaporated and separated from the acid salt.

Abstract: A process for recycling polyester contained in waste materials is provided. The polyester is converted into ethylene glycol and terephthalic acid. The process steps generally include first combining materials containing polyester with an alkaline solution to form a slurry. The slurry is heated, causing ethylene glycol to evaporate which can then be collected. The remaining product stream is then mixed with water and filtered to remove any undissolved impurities. The aqueous filtrate can be acidified causing terephthalic acid to precipitate. Further, if silver is contained within the materials fed to the process, the silver can also be isolated and recovered.

Abstract: Photoemulsion is reduced with a combination of reducing sugar and sodium borohydride, resulting in increased silver recovery.

Abstract: A novel composition for use in reducing and recovering metals, such as silver, and for use in stripping adhesive polymer layers from various polymer bases, such as polyester, and processes for using same are provided. The composition and variations thereof can be useful in separating an adhesive polymeric layer from the film for recovery of either. The composition comprises a reducing sugar/alkaline solution that is particularly useful for recovering silver from polyester photographic film where a silver halide light-sensitive emulsion layer is adhered to the polyester film by a polymeric adhesive resin, such as resins containing copolymers of polyvinylidene chloride and polyvinyl chloride. Processes for separation and recovery are also disclosed and claimed.

Abstract: A novel composition for use in reducing and recovering metals, such as silver, and for use in stripping adhesive polymer layers from various polymer bases, such as polyester, and processes for using same are provided. The composition and variations thereof can be useful in separating an adhesive polymeric layer from the film for recovery of either. The composition comprises a reducing sugar/alkaline solution that is particularly useful for recovering silver from polyester photographic film where a silver halide light-sensitive emulsion layer is adhered to the polyester film by a polymeric adhesive resin, such as resins containing copolymers of polyvinylidene chloride and polyvinyl chloride. Processes for separation and recovery are also disclosed and claimed.