Patents Assigned to British Technolog Group Limited
  • Tubular materials
    Patent number: 5665297
    Abstract: Tubular workpieces of oriented polymers such as polyethylene polyester and PVC are formed by drawing a workpiece over an expanding former in the absence of any force perpendicular to the axis of the workpiece. The processes do not require the use of any liquid lubricant. They enable greater degrees of expansion and hence orientation in the direction perpendicular to the axis to be achieved and result in products of improved appearance and strength.
    Type: Grant
    Filed: August 24, 1994
    Date of Patent: September 9, 1997
    Assignee: British Technolog Group Limited
    Inventors: Ian MacMillan Ward, Gordon Craggs, Alan Selwood, Ajay Kumar Taraiya