Corrugated paperboard strength enhancing process
OwnerScott A. Wallickinventor
Life of this patent
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Abstract
A corrugated paperboard strength enhancing process includes at least one resin application station located within the confines of the corrugator at a position where it is operable to apply a preselected amount of a strength enhancing resin to at least one side of the medium after it has been fluted. At least one liner is adhered to the set of opposed flute tips. Thereafter the combined board with the resin compound on selected transverse portions of the fluted medium is allowed to cure, under selected temperature and moisture conditions and without the application of pressure that would crush the fluted medium. A suitable resin for the intended purpose is an isocyanate compound.
Claims20
A process for increasing the strength of combined corrugated paperboard using a strength enhancing resin, comprising:
- providing a fluted medium directly from an in-line corrugator following fluting of the medium by the in-line corrugator, the fluted medium having side edges and flutes with flute tips, flute troughs and flute side walls, the flutes extending transversely between the side edges and moving the fluted medium in a direction with the flutes extending transverse to the direction of motion of the fluted medium;
- applying a preselected amount of uncured strength enhancing isocyanate resin to the flute tips, flute troughs and flute walls on at least one surface of the moving fluted medium after it has been fluted, the resin being applied at higher concentrations to the flute tips than to the flute side walls;
- applying an adhesive to the surface of the fluted medium to which the isocyanate resin has been applied after applying the isocyanate resin;
- combining the fluted medium with at least a first liner;
- and
- allowing the resin to cure for a period of time sufficient to harden and provide enhanced strength to the paperboard.
A process for increasing the strength of combined corrugated paperboard using a strength enhancing resin, comprising:
- fluting a medium so that it has flutes with flute tips, flute troughs, and flute side walls;
- moving the fluted medium in a direction with the flutes extending transverse to the direction of motion of the fluted medium;
- spraying a preselected amount of uncured strength enhancing isocyanate resin to the moving fluted medium after it has been fluted so as to provide higher concentrations of the resin at the flute tips and flute troughs than on the flute side walls;
- applying an adhesive to the fluted medium after applying the isocyanate resin;
- combining the fluted medium with at least one liner;
- and
- allowing the resin to cure for a period of time sufficient to harden and provide enhanced strength to the paperboard.
Dependencies are inferred from the claim text.