Patents Assigned to VTT Technology OY
  • Procedure for the manufacture of a foamed plastic product
    Patent number: 5955014
    Abstract: A process for fabricating a foamed plastic product. The process includes a plastic film that is prefoamed in order to introduce lamellar discontinuities such as prefoamed bubbles. The film is pressurized by a gas under a positive pressure causing the gas to diffuse into the film, forming a second film. Further, the second film is inflated in order to form the foamed plastic product. The second film is inflated by heating the second film at a temperature below the melting point of the second film and under a reduced pressure.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: September 21, 1999
    Assignee: VTT Technology OY
    Inventors: Jaako Raukola, Kari Kirjavainen, Hannu Minkkinen