Method and apparatus for the production of sheet on block of agglomerated granules of polystryrene

Claim 2

The method of claim 2, said cooling being continued under pressure, until the agglomerated pellets have a temperature sufficiently low to maintain their agglomerated form without expansion under atmospheric pressure.

Claim 3

The method of claim 2, said heating period being inversely proportional to the temperature, within the range selected.

Claim 4

Process for the continuous manufacture of panels, slabs and the like, of cohered synthetic resin cellular material such as polystyrene foam, from pearls thereof previously expanded, comprising: a. In a first zone forming the expanded contacting pearls into a layer and heating them to softening temperature under essentially atmospheric pressure; b. Moving the layer to a second zone and there subjecting the same to compression above atmospheric, to impart theretO reduced thickness and definitive density; and c. Moving the compressed layer to a third and cooling zone and cooling the same while subjecting it to continued pressure sufficient to maintain said reduced thickness.

Claim 5

Apparatus for forming pellets of expanded thermoplastic into predetermined agglomerated shape, comprising, housing means, a first conveyor including a first pair of foraminous belts in said housing means, and having substantially parallel coextensive adjacent first passes spaced a first distance, means for circulating heated gas into said housing means, through said belts and material confined between said first passes thereof, a second conveyor in said housing means and including a second pair of foraminous belts having substantially parallel coextensive adjacent second passes spaced a second distance less than said first distance, and positioned to receive material directly from said first passes, cooling means mounted contiguous to said second passes over and along the downstream ends thereof, and means operable to feed material to and between said first passes at the upstream ends thereof.

Claim 6

The apparatus of claim 6, and means in said housing means, for heating said second pair of belts at and along the upstream ends of said passes thereof, and upstream of said cooling means.

Claim 7

The apparatus of claim 7, partition means in said housing means, defining first, second, and third discrete compartments along and encompassing said first passes, upstream to downstream, said means for circulating heated gas directing the same upwardly through said passes traversing said first compartment, downwardly through said passes traversing said second compartment, and directly into contact with each respective pass traversing said third compartment.

Claim 8

The apparatus of claim 7, said cooling means comprising first and second chambers each having a heat exchange surface contiguous, parallel with, and substantially coextensive with the respective downstream ends of said second passes, and means circulating coolant into and through said chambers.

Claim 9

The apparatus of claim 6, said distance between said second passes slightly decreasing in the downstream direction of movement thereof.

Claim 10

The apparatus of claim 7, said heating means for said second pair of belts comprising a pair of radiant heaters each conforming to and closely adjacent the return curvature of a respective belt at the upstream ends thereof.

Claim 11

The apparatus of claim 6, said housing means comprising a first casing enclosing said first pair of belts, a second casing enclosing said second pair of belts, and upper and lower sets of rollers between said casings and confining material emerging from between said first passes and positively directing the same to and between said second passes, the belts of said two conveyors being drivable at the same or different linear speeds.

Claim 12

The apparatus of claim 6, said material feeding means being operable to feed material to and between said first passes, at a rate to fill the space therebetween without voids and without substantial compression of material.

Claim 13

The apparatus of claim 13, said second distance being sufficiently less than said first distance to exert a predetermined pressure upon material passed from said first passes to said second passes, when all said belts are driven at substantially the same linear speed.

Claim 14

Apparatus for the continuous production into panels, sheets, slabs and the like, of cohered synthetic resin cellular material, such as polystyrene foam, from pearls thereof previously expanded, comprising, a first pair of foraminous conveyor belts having contiguous spaced parallel runs between which the expanded pearls are introduced and translated, heating means adjacent the contiguous runs of said first pair of belts, for circulating heating fluid through the runs and the pearls being translated therebetween, a second pair of conveyor belts having contiguous runs spaced a distance less tHan that between the contiguous runs of said first pair of belts, and arranged to receive and translate the heated pearls from between said first pair of belts and to compress and agglomerate them to a desired thickness, means for heating the upstream portions only of the contiguous runs of said second pair of conveyor belts, and means juxtaposed with the downstream portions of the contiguous runs of said second pair of belts, for directing cooling fluid into heat exchange relation with the agglomerated pearls being translated by and between said downstream portions.