Patents Assigned to The Research Association for the Paper and Board Printing and Packaging Industries
  • Patent number: 4326912
    Abstract: The method removes a contaminant, such as adhesive or ink particles, from wastepaper pulp. The method includes the steps of dispersing a monomer in the pulp so as to form droplets or beads which take up the particles e.g. by a process in which the particles are coated, absorbed or dissolved by, or adhere to the droplets or beads of monomer. The monomer is then polymerized to increase the rigidity of the droplets or beads, and the droplets or beads are separated from the pulp, e.g. by screening. The monomer or a mixtures of monomers are dispersed in the pulp by strong mechanical agitation and the agitation can be controlled to provide droplets or beads of monomer within a certain size range. Suitable monomers includes styrene, vinyl acetate, methyl methacrylate or mixtures of the same. The viscosity of the monomer phase may be increased by dissolving a homopolymer in the monomer to reduce the effect of shear forces caused by agitation. Benzoyl peroxide may be added to initiate polymerization.
    Type: Grant
    Filed: September 30, 1980
    Date of Patent: April 27, 1982
    Assignee: Pira, The Research Association for the Paper and Board, Printing and Packaging Industries
    Inventor: Christopher C. Mollett
  • Patent number: 4184218
    Abstract: A method of producing a fastback book including the steps of providing a block of pages and a cover for the block, both the block and the cover having a respective spine, the spine of the cover being thin compared with the front and back portions of the cover; and bonding the spine of the block to the spine of the cover.
    Type: Grant
    Filed: December 2, 1977
    Date of Patent: January 22, 1980
    Assignee: The Research Association for the Paper and Board, Printing and Packaging Industries
    Inventor: Charles V. Hawkes
  • Patent number: 4005165
    Abstract: A method of producing book covers, which method includes cutting at least one elongated notch along the length of one side of a sheet of comparatively rigid plastics having a "memory" (as herein defined) and stretching the plastics defining the floor of the notch to alter its molecular structure so as to provide a readily foldable hinge, said stretching being effected by pressing the plastics defining the floor of the notch outwardly from the notch to raise a ridge on the other side of said sheet.
    Type: Grant
    Filed: July 9, 1975
    Date of Patent: January 25, 1977
    Assignee: The Research Association for the Paper and Board Printing and Packaging Industries
    Inventor: Charles Vivian Hawkes