Abstract: Heating and extruding a polymeric sheet having a predetermined thickness and introducing it into and through a gap between cooling rolls, measuring directly by laser beam and without reflection the gap between the cooling rolls, and controlling the gap to control minimal pressure on the softened and heat-plastified sheet.

Abstract: Heating and extruding a polymeric sheet having a predetermined thickness and introducing it into and through a gap between cooling rolls, measuring directly by laser beam and without reflection the gap between the cooling rolls, and controlling the gap to control minimal pressure on the softened and heat-plastified sheet.

Abstract: Heating and extruding a polymeric sheet having a predetermined thickness and introducing it into and through a gap between cooling rolls, measuring directly by laser beam and without reflection the gap between the cooling rolls, and controlling the gap to control minimal pressure on the softened and heat-plastified sheet.

Abstract: Accurately and uniformly cooling a preformed plastic sheet that is formed at elevated temperature in an elongated plastic sheet die, using upper, middle and lower vertically arranged cylindrical cooling rolls closely spaced to one another to engage the sheet between them, and providing one or more auxiliary cooling rolls connected to provide additional cooling for the sheet.

Abstract: An apparatus for heating and extruding a polymeric sheet having a predetermined thickness and introducing it into and through a gap between cooling rolls, measuring directly by laser beam and without reflection the gap between the cooling rolls, and controlling the gap to control minimal pressure on the softened and heat-plastified sheet.

Abstract: Heating and extruding a polymeric sheet having a predetermined thickness and introducing it into and through a gap between cooling rolls, measuring directly by laser beam and without reflection the gap between the cooling rolls, and controlling the gap to control minimal pressure on the softened and heat-plastified sheet.

Abstract: A sheet processing system for continuously producing plastic sheet which is continuously supplied to an intermittent take-up device, utilizing a sheet forming apparatus, a conveyor, an accumulator and take-up apparatus, the sheet being fed along the conveyor to an accumulator positioned integrally with the conveyor, the accumulator being controlled in a cyclic operation which provides for the accumulation of the continuously fed sheet material to permit intermittent operation of the take-up apparatus, and the edge trimming of the sheet subsequently to the action of the accumulator.

Abstract: A sheet processing system for continuously producing plastic sheet which is continuously supplied to an intermittent take-up device, utilizing a sheet forming apparatus, a conveyor, an accumulator and take-up apparatus, the sheet being fed along the conveyor to an accumulator positioned compactly beneath the conveyor, the accumulator being controlled in a cyclic operation which provides for the accumulation of the continuously fed sheet material to permit intermittent operation of the take-up apparatus.

Abstract: Apparatus for extruding and cooling a polymeric sheet incorporating an extruder connected to feed polymer through a rigid conduit and to and through a sheet die, and a roll stack including a plurality of cooling rolls having nips arranged adjacent the sheet die to continuously receive and cool polymeric sheet emanating from said die. Polymeric sheet feed control apparatus for tilting the stack to arrange the roll nips at various angles between and including the vertical and the horizontal, a pair of spaced-apart swivels positioned between the extruder and the sheet die, one swivel being connected to permit independent swinging movement of the sheet die up and down, and another swivel being connected to permit independent tilting movement of the sheet die angularly up and down to relate the tilt of the sheet die to the tilt of the stack.

Abstract: A food container thermoformed from nucleated polyethylene terephthalate sheet. The food container comprises an opaque or colored tray formed from nucleated polyethylene terephthalate in a crystalline state so that the tray remains rigid at elevated temperatures. The food container also comprises a substantially transparent cover formed from nucleated polyethylene terephthalate in an amorphous state. The food container also comprises a hinge that connects the cover to the tray.

Abstract: A food container thermoformed from co-extruded polyethylene terephthalate sheet, a portion of which contains a nucleating agent. The food container comprises an opaque or colored tray formed from nucleated polyethylene terephthalate in a crystalline state so that the tray remains rigid at elevated temperatures. The food container also comprises a substantially transparent cover formed from non-nucleated polyethylene terephthalate in an amorphous state. The food container also comprises a hinge that integrally connects the cover to the tray.

Abstract: A rod of heat-plastified material is extruded and passed through an adaptor section, during delivery to a sheet extruder. In the adaptor section, another material or substance is fed into the interior of the just-extruded rod, such that, upon the rod subsequently being expanded in one direction, and reduced in thickness in another direction, in a sheet-extruder, a multiple-layered laminate may be provided, in that the substance introduced into the rod may differ from the material of the rod. Variations may be made in the manner of introduction of other material into the rod, in order to obtain various numbers of layers, and desired distributions of introduced material through the rod.

Abstract: A die having a controllable lip opening, through which flowable material is forced to form a sheet, film or tube. Lip opening control means including an elongated member which expands and contracts thermally and adjusts the lip opening to control the product thickness, and heating means is provided for controlling this expansion and contraction.