Apparatus for making pressboard from poly-coated paper using relative movement of facing webs

Claim 1

Apparatus for continuously fabricating pressboard with a filler comprising shredded paper coated with a thermoplastic material and a pair of webs comprising: web advancing means for advancing first and second webs toward each other; means for placing thermoplastic coated shredded paper between said webs to form a composite with said webs, said composite having a thickness; and processing means for applying heat to said composite and for simultaneously shifting said first and second webs linearly back and forth relative to each other and to said shredded paper to smear said thermoplastic for bonding said composite together; said processing means including a plurality of heated rolls for operation at a predetermined peripheral speed, and defining a serpentine path through which said composite is passed, such that around each one of said heated rolls one of said webs is in engagement with the said one heated roll to form an inner web which is pulled forwardly to move relative to the other webs; press rolls downstream of said heated rolls, and defining a gap through which said composite passes to reduce said thickness to a desired caliper; and drive means for causing a greater peripheral speed of said press rolls than said peripheral speed of said heated rolls to produce an overdrive relation relative to said heated rolls, resulting in a differential pulling action on said webs to thereby cause said webs to move linearly relative to each other.

Claim 3

An apparatus for continuously fabricating pressboard from a filler comprising shredded paper coated with a thermoplastic material and a pair of webs comprising: means for conveying a first continuous web along a predetermined path; depositing means for depositing shredded polymer coated paper onto said first web; applying means for applying a second continuous web onto the shredded coated paper, whereby a composite is formed with the shredded coated paper located between the first and second webs; processing means for heating said composite, for shifting said webs linearly back and forth relative to each other and relative to said shredded coated paper to cause polymer smearing and web-to-paper rubbing to enhance bonding of the webs and shredded coated paper together; and at least one pair of pressing rolls operated at a predetermined peripheral speed and positioned downstream of said processing means for heating said composite, to press said composite, after said shifting, for bonding said composite and reducing its thickness; and drive means for causing said peripheral speed of said pressing roll means to be greater than that of said heated driven rolls to cause relative linear movement between said webs and inhibit formation of bulges in the webs on said serpentine path.

Claim 4

An apparatus for continuously fabricating pressboard from a filler comprising shredded paper coated with a thermoplastic material and a pair of webs comprising: means for conveying a first continuous web along a predetermined path; depositing means for depositing shredded polymer coated paper onto said first web; applying means for applying a second continuous web onto the shredded coated paper, whereby a composite is formed with the shredded coated paper located between the first and second webs; processing means for heating said composite, for shifting said webs linearly back and forth relative to each other and relative to said shredded coated paper to cause polymer smearing and web-to-paper rubbing to enhance bonding of the webs and shredded coated paper together; and at least one pair of pressing rolls operated at a predetermined peripheral speed and positioned downstream of said processing means for heating said composite, to press said composite, after said shifting, for bonding said composite and reducing its thickness; and drive means for causing said peripheral speed of said pressing roll means to be greater than that of said heated driven rolls to cause relative linear movement between said webs and inhibit formation of bulges in the webs on said serpentine path.