Patents Assigned to Wietek Holding GmbH
  • Patent number: 7696255
    Abstract: Process for recycling soluble or dispersible plastics from a waste product containing plastics by treatment with an organic solvent, concentrating the plastics solution thus obtained to more than 40 wt % of plastics, preconditioning the concentrated plastics solution to a pressure of at least 2 bar using a first pump and a temperature of 1-10° C. below the boiling temperature of the solvent at that pressure, bringing this preconditioned concentrated plastics solution above the critical point of the plastics solution using a high-pressure pump and a high-pressure heat exchanger, spraying the concentrated plastics solution above the critical point to recover the plastics through evaporation of the organic solvent, and recovery of the organic solvent. The process has advantages over known processes in that higher concentrations of plastics can be processed, without the danger of cavitations, and the need for solvent and energy can be reduced.
    Type: Grant
    Filed: July 28, 2006
    Date of Patent: April 13, 2010
    Assignee: Wietek Holding GmbH
    Inventors: Richard Dräger, Ulrich Schurr
  • Publication number: 20080234399
    Abstract: Process for recycling soluble or dispersible plastics from a waste product containing plastics by treatment with an organic solvent, concentrating the plastics solution thus obtained to more than 40 wt % of plastics, preconditioning the concentrated plastics solution to a pressure of at least 2 bar using a first pump and a temperature of 1-10° C. below the boiling temperature of the solvent at that pressure, bringing this preconditioned concentrated plastics solution above the critical point of the plastics solution using a high-pressure pump and a high-pressure heat exchanger, spraying the concentrated plastics solution above the critical point to recover the plastics through evaporation of the organic solvent, and recovery of the organic solvent. The process has advantages over known processes in that higher concentrations of plastics can be processed, without the danger of cavitations, and the need for solvent and energy can be reduced.
    Type: Application
    Filed: July 28, 2006
    Publication date: September 25, 2008
    Applicant: WIETEK HOLDING GMBH
    Inventors: Richard Drager, Ulrich Schurr