Abstract: Foam extrusion apparatus and methods employing a vacuum chamber at reduced pressure into which foamable material is continuously extruded, hardened and cut to length, means for inventorying a plurality of successively cut lengths in a second chamber then at such reduced pressure, and means for discharging the inventory from the second chamber to the outside after the second chamber has been brought to atmospheric pressure without affecting the reduced pressure in the vacuum chamber. Stacking devices are employed to inventory the cut lengths in either a vertical or horizontal stack for transfer as a stack into and/or out of the second chamber. Provision also is made for accumulating the boards in close but spaced facial relationship with substantially the entire surface areas of the cut lengths exposed to the reduced pressure prior to stacking and discharge to the atmosphere.

Abstract: An extrusion system for the production of foam boards, billets and the like products includes an extruder (20) at a first higher elevation (22) extruding foamable resin through a die in the upper end of an elongated vacuum chamber in the form of an inclined barometric leg (26) which extends at its lower end into a shallow but large surface area pool (39) of liquid such as water. An elongated shroud or hood (44) on the lower end of the leg reduces the pressure head of water above the foam product as it exits the leg and moves out of the pool for processing at a lower second elevation. The large area of the pool reduces its depth for a given volume and minimizes fluctuations in the level of the pool and the pressure head above the product when the vacuum changes. In one embodiment the pool extends beneath substantially the entire floor of the building (30) enclosing the second lower elevation (31) in which the subsequent processing occurs.

Abstract: A foam extrusion apparatus employs one or more extruders mounted on horizontal rails for movement toward and away from the end of a vacuum chamber which is in the form of an elongated inclined barometric leg. The upper end of the chamber is closed by two, substantially concentric in the closed position, substantial bulkheads, each also supported on rails and held in an inclined position to close the upper end of the chamber when moved; one against the chamber and the other against the one. A die is positioned on the inside of the other or smaller bulkhead and aligned with the leg when closed. The extruders are connected to the die through a length of pipe extending through the smaller bulkhead and sealed by a bellows. A shaping mechanism is supported on the interior of the one or larger bulkhead surrounding the die when both bulkheads close the upper end of the inclined barometric leg or vacuum chamber. The die is adjustable externally of the bulkhead.

Abstract: An improved method and apparatus is disclosed for shaping and forming plastic foams as a foamable extrudate is extruded through the orifice, preferably arcuate, of an extrusion die. Immediately adjacent and downstream of the die orifice are opposed sets of curved rollers, each having substantially the same center of curvature as the die orifice. The roller set on one side of the extrudate pass line is adjustable as a set with respect to and substantially parallel to the pass line, while the rollers of the set on the opposite side are adjustable individually each to float with controlled pressure against the extrudate as it expands and moves between the roller sets. Each roller is comprised of a plurality of thin, cylindrical, circular wafers which are drivingly interconnected and journaled on curved core shafts.

Abstract: A foam extrusion apparatus and method employs tandem extruders mounted on horizontal rails for movement toward and away from the end of a vacuum chamber which is in the form of an elongated inclined barometric leg. The upper end of the chamber is closed by a substantial bulkhead also supported on rails and held in inclined position to close the end of the chamber when moved thereagainst. A die is positioned on the inside of the bulkhead and aligned with the leg when closed. The extruders are connected to the die through a length of pipe supported through the bulkhead by a stainless steel bellows. The pipe externally of the bulkhead is provided with a circulating jacket for temperature control. The die is adjustable externally of the bulkhead. The extruders, die and bulkhead are movable as a unit or separately toward and away from the chamber to provide access to the die and the interior of the chamber.

Abstract: A foam extrusion die of the type including a main die body having a face and two spaced, adjustable die lip members having lips defining an elongated, arcuate die orifice through which extrudate moves both laterally and axially outwardly relative to the lip members. The die includes toe and heel clamp assemblies fastened to the die body for biasing the lip members against the face for continuous sealing line contact therebetween. Choker bars secured to the die body at opposite sides of the face define the ends of the die orifice. Provision is also made for specially fabricated heating or cooling passages in the lip members proximate the die orifice.

Abstract: A foam extrusion apparatus and method employs an extruder on an upper level extruding foamable extrudate into the upper end of a large elongated barometric leg which extends at a relatively shallow angle into a pool of water at a lower level. A conveyor in the barometric leg extends through a large radius in the pool to guide the extrudate from the pool for further processing. The leg is in the form of an elongated pipeline fabricated from sections and supported on an inclined ramp. Some of the sections are securely anchored to the ramp to resist axial forces when the leg is evacuated. The sections may be reinforced concrete or fabricated reinforced steel of a variety of sectional shapes. Each section is sealed end-to-end so that a vacuum within the leg will draw water from the pool into the leg leaving a vacuum chamber at the upper end of the leg in which the extrudate expands.