Patents by Inventor Richard K. Roberts

Richard K. Roberts has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Multilayer heat shrinkable polymeric film containing recycle polymer
    Patent number: 5128212
    Abstract: The use of multilayer heat shrinkable film for advantageous high shrinkage but low shrinkage force is combined with the use of recycle scrap of such film to provide multilayer heat shrinkable film retaining these advantageous properties. Exemplary of the film is a core of a blend of certain linear low density polyethylene with certain highly branched low density polyethylene sandwiched between two relatively thin outer layers of propylene/ethylene copolymer, with the core also containing recycle scrap of the multilayer film.
    Type: Grant
    Filed: May 2, 1991
    Date of Patent: July 7, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Timothy M. Kneale, Richard K. Roberts, John D. Snyder
  • Tough monolayer shrink film for products containing moisture
    Patent number: 5112696
    Abstract: A blend of an ethylene-alpha olefin linear copolymer having a density of about 0.890 to about 0.914, a tubular low-density polyethylene, and optionally a copolymer of ethylene with at least one copolymerized vinyl alkanoate, alkyl acrylate, or alkyl methacrylate and a linear low density polyethylene provides a shrink film particularly useful for packaging e.g. fish or poultry.
    Type: Grant
    Filed: March 15, 1991
    Date of Patent: May 12, 1992
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Richard K. Roberts
  • Monolayer polyethylene shrink film
    Patent number: 4760116
    Abstract: This invention relates to a heat-shrinkable film consisting essentially of a blend of 99.5-98.5 weight % of linear low or medium density polyethylene and 0.5-1.5 weight % of one or more copolymers of ethylene with a monomer selected from vinyl acetate and acrylic acids or esters, where said film has been cross-linked to the degree induced by an irradiation dosage of about 1 to 5 megarads.
    Type: Grant
    Filed: November 26, 1986
    Date of Patent: July 26, 1988
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Richard K. Roberts