Abstract: An improvement is described in a prior art process and apparatus for the preparation of continuous polymer bunstock having substantially rectangular cross-section which employs a panel member having its downstream end pivotally mounted above a conventional moving trough-shaped mold, the underside of said panel member floating freely in tangential contact with the rising foam in the area immediately following the gel point of said foam but before the point at which the foam is no longer sufficiently mobile to be molded without distortion of the cells thereof. The improvement, which is particularly designed for use in those cases (e.g.

Abstract: The invention relates to equipment for the continuous production of foam boards, which may be laminated between facings, from a liquid foamable reaction mixture. The apparatus broadly comprises(i) a conveyor,(ii) an inclined table at one end of said conveyor, the incline of said table sloping downwardly toward said conveyor,(iii) a foam mixture application device located above said downwardly sloping surface, and(iv) a transverse foam mixture distribution device located downstream of said application device and located above said downwardly sloping surface thereby forming a space therewith. When sheets or relatively thin foam boards or sandwich boards are produced, the device used is generally additionally equipped with an upper conveyor. This invention primarily relates to such double conveyors. The liquid reaction mixture must be applied over the entire width in a particularly uniform layer in order to obtain a perfect final product.

Abstract: A method and apparatus are disclosed for the manufacture of a web of foamed thermoplastic material. The material web is extruded to form a tubular member and then expanded by action of a compressed fluid so that the outside of the tubular member is forced against a calibrating element arranged adjacent the tubular member. The tubular member is then cooled to a temperature below the softening temperature of the material and then is cut and converted into web form.

Abstract: In a method of producing blocks of a foamable reaction mixture having an adjustable surface and sharp edges wherein the reaction mixture is discharged from a mixing chamber onto a forwardly moving surface path in a continuous mass of varying height, the improvement therein includes applying forces to the discharging mass opposing formation of differences in the height thereof.

Abstract: A method of and a device for adjusting the capacity and the diameter of an electric conductor provided with an insulation coating of foamed plastics material in an extruder press. The press is provided with an adjustably rotating feed screw and adjustable heating means. The deviation of the capacity of the insulated conductor from a preset capacity and the deviation of the diameter of said conductor from a preset diameter are measured at the path of movement of the conductor. The rotation speed of said screw is adjusted in response to said capacity deviation and said diameter deviation and the temperature of said heating means is also adjusted in response to said capacity variation and said diameter deviation in order to correct said deviations.

Abstract: An apparatus for producing a corrugated foamed plastic sheet includes an extruder and a die provided at the extrusion end of the extruder. The die has a plurality of grooves provided on one of its surfaces which make contact with the foamed sheet being produced. The grooves extending from the resin feed inlet toward the resin exit of the die.

Abstract: The present invention relates to equipment for the continuous production of foam boards, and particularly rigid foam boards, which may be laminated between facings. The apparatus broadly comprises a conveyor, which at the pouring end is equipped with an inclined table and a transverse distribution device, and a foam mixture application device provided above the table.

Abstract: A method and apparatus for making flat topped foamed buns (e.g. polyurethane) in a continuous foaming process. In accordance with the method, continuous thin film tubular members are guided onto each side of the central trough defining conveyor of a continuous pouring system, and a central trough defining film member generally covering the central conveyor is guided thereover prior to the dispensing head. The edges of the tubular members are subsequently guided upward over guides at each side of the trough so that the tubular define upward sloping side walls traveling at an angle and rate determined in accordance with the rate of longitudinal travel and the rate of rise of the foaming reactants so as to encourage the sides of the bun to the same height of rise as the center region of the bun. Continuous slitting of the tubular members at an appropriate elevation allows the material thereof to progress longitudinally with the cured bun.

Abstract: An extruder for simultaneously extruding two plastics materials without intermixing thereof prior to exiting the extruder. The extruder barrel has two feed hoppers at one end and an outlet at the opposite end and contains a rotatable screw with two spaced screw threads of the same handedness which form two helical channels, each fed from one of the hoppers. One channel extends from a hopper to the outlet and the other channel is blocked in advance of the outlet so that substantially all the material therein is forced to enter a passage in the screw which extends to the outlet. Also, a process for extruding the two plastics materials and for coating a wire with two layers with a die having a single material receiving channel.

Abstract: In the manufacture of foamed plastic slab by introducing foamable fluid from a mixing head into a moving conveyor-type mold, the improvement wherein supplemental quantities of the fluid are conducted from the mixing head longitudinally to locations where the main body of the material has foamed to partly expanded condition and friction between the sides of the mold and expanding material has caused the upper longitudinal side edges of the expanding material to assume a rounded shape which curves away from the mold sides leaving a space. The supplemental material is introduced into the spaces while the mold moves and upon expansion substantially fills the spaces and thereby greatly reduces the amount of the slab which must be cropped off prior to cutting it to form saleable articles.

Abstract: A method for the continuous fabrication of blankets or sheets of expanded phenolic resin displaying a hard skin on each of their sides, according to which a mixture, comprising in particular a resole resin, a blowing agent and a hardening catalyst is placed on an essentially flat surface of a moving conveyor, is completely expanded, and is conformed eventually between two parallel surfaces entrained in the same direction, the second surface being located above and substantially parallel to and able to move at the same speed as the moving surface, characterized in that, in a first stage, after having been distributed at the surrounding temperature and in the liquid state along the whole width of the surface of the transport component, in such a way so as to comprise a blanket of expandable liquid mixture essentially uniform in thickness, the expandable mixture is conveyed in the open air towards the conformation surfaces while being submitted to a heating so that it expands, the degree of heating and the lengt

Abstract: A conveying and supporting surface is provided with a plurality of coanda effect nozzles for providing a directional film of gas along the surface to support and/or convey a plurality of articles, in indefinite length web, or material along the surface. The directional coanda effect nozzles will produce a conveying film of gas and a film of gas that will produce a suction spaced from the surface to hold the articles closely adjacent the surface while at the same time produce an air bearing to prevent the articles or web material from contacting the surface.

Abstract: An improvement in the manufacture of flexible densified polyurethane foam wherein the partially cured freely risen foam is fed through a crush conveyor to minimize the density gradient throughout the vertical cross section. The crush conveyor includes an upper crushing section which is arcuate and has a radius of a dimension such that the ratio of the radius of the arc to height of the partially cured freely risen foam is 1.1 to 1 or greater. The crush conveyor has a bottom crushing section which may be arcuate with a radius of a dimension such that the ratio of its radius to the height of the partially cured freely risen foam is also 1.1 to 1 or greater. The radius of the bottom arcuate crushing section may be the same or larger than the radius of the top arc. As an alternative, the bottom crushing section may be planar and may be horizontal, or inclined with respect to the horizontal.

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: A pad, especially an athletic pad, and particularly a pad for use in contact sports to protect the wearer, in which a film of plastic material is deposited on a support and then a body of the same material with a blowing agent therein is placed on the film and the pad member is then cured (gelled and fused) with simultaneous blowing of the added body of material. The pad member is formed so that different regions thereof are different in thickness to provide for increased protection in the thicker regions while flexibility is maintained in the thinner regions of the pad member. The addition of at least one elastic strap element to the pad for retaining it in position on the body completes the construction of the pad member.

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: In a method of continuously producing rectangular foam blocks wherein a foamable polyurethane-reaction mixture is deposited on a bottom web moved by a conveyor belt, the surface of the rising foam is covered by a cover web which is withdrawn from the foam surface by a deviating device disposed near a location at which the foaming of the mixture is terminated, and the cover web is further advanced by means of a deviating roller, a method of synchronizing the movements of the cover web and the bottom web includes driving the deviating roller, through a transmission coupled to the conveyor belt, at a peripheral speed that is synchronized with the conveyor speed of the conveyor belt, and passing the cover web between the deviating roller and a roller adjustable in elevation and in pressure contact with the deviating roller.

Abstract: A cooling/mixing device having no moving parts is interposed between the extrusion head and the screw barrel of the extruder. The device comprises a cooled metallic block having a pair of large opposed faces and a plurality of rows of through-passages interconnecting said faces. Inlet and outlet manifold channels for the melt extend along the rows of passages so that a lateral wall of a manifold channel is formed by its respective face of the block. Partial flows of melt obtained from the flow in the inlet manifold channel are individually cooled in the passages and emerge from the latter substantially perpendicularly to the outlet flow in the output manifold channel to produce turbulent mixing. Preferably a further similar cooling block is provided, acting in series with the first block. The blocks are preferably in form of cylindrical sleeves with through-passages directed radially while the manifold channel are directed axially at the inside and at the outside of the sleeves.

Abstract: A centrifuge is disclosed for prefoaming liquid polyurethane-foam generating reactants prior to introducing the reactants into a continuous slab mold. A preferred embodiment of the invention is adapted to produce continuously slabs of polyurethane foam of substantially rectangular cross section.

Abstract: A process and die are disclosed for preparing a foamed article of thermoplastic resin having a particular cross section configuration. The die of the invention is provided with a plurality of apertures in its face through which the resin is discharged. The apertures in the face of the die are distributed in a shape corresponding to the cross section of the foamed article which is produced. The apertures are further divided into a plurality of groups in which there is at least one zone which is void of apertures so that the apertures in the same group are actually restricted to a narrow band. The zone on the surface of the die which is void of apertures has a thickness more than twice the average distance between two adjacent apertures belonging to the same group.

Abstract: In a process for producing a foamed polyolefin article which comprises melting and mixing a polyolefin, a volatile organic blowing agent, a cell size-controlling agent, and an ester of a long-chain fatty acid and a polyhydric alcohol in an extruder comprising a feed zone, a compression zone and a metering zone, and extruding the resultant molten gel into an area having a lower pressure than the pressure of the inside of the extruder, the improvement wherein said ester is at least one ester of a long-chain fatty acid having 8 to 20 carbon atoms and a polyhydric alcohol having 3 to 6 hydroxyl groups, and said ester is fed in the molten state into the molten gel within the metering zone and mixed with it.

Abstract: Rigid synthetic foam is expanded, molded and cured in an endless mold formed by opposed spaced horizontal belt conveyors with side dams. To obtain a smooth finish on the products, a top cover belt and a bottom cover belt are employed to span the rigid slats of the conveyors, respectively. The top cover belt is stretched tightly and smoothly when the endless conveyors approach each other at the entrance to the pressure mold, by means of a downwardly depending continuous wedge shaped member along each side margin of the cover belt that cooperates with an upwardly opening correspondingly wedge shaped recess in the side dam. To obtain different thickness products, spacer blocks may be employed between the side dam and the lower conveyor.

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 pipe insulation is made between an inner and outer mold core from a liquid which foams and then forms a solid. The foaming action may cause movement in the inner mold which is detected and then adjusted accordingly to maintain concentricity between the inner and the outer wall of the pipe insulation. The insulation may be used alternatively as pipe.

Abstract: Extrusion apparatus for manufacturing blow moulded sheets of expanded polystyrene wherein, following an extruder there is a static cooler/mixer member comprising inner and outer cooling surfaces defining between them an annular passage, the inner cooling surface having a star-shaped outline when viewed in cross-section with the points of the star extending at an oblique angle to the longitudinal axis. Preferably the star-shaped outline is provided by folded metal strips several of which are provided alternately angled and staggered with respect to one another.

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: The instant invention is directed to a process for the continuous production of block-shaped foam and to the equipment used therefore. The process of the invention broadly involves the heating of the bottom film prior to application of the foamable mixture. In this way, the undesirable crust generally formed on the bottom of the foam blocks is substantially reduced and/or eliminated.

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.

Abstract: A method and apparatus is provided for forming a cushion from foam plastic material by first depositing separate masses of foam material, each having a predetermined configuration, onto a moving transfer surface at a depositing station. While the masses of material are being transferred to a forming station, they rise to a tack-free state and reach substantially full expansion during a predetermined time period which is less than the time which it takes the foam material to set. Then, before the foam material does set, each mass of foam material is individually shaped at the forming station into a predetermined configuration by employing force-applying elements to press each of the masses of foam material into the predetermined configuration while on the transfer surface. Once the mass of foam material has been shaped and set, the force-applying elements are released.

Abstract: Plastic materials are dewatered in an extruder by applying heat and pressure and venting out vaporized water; before the plastic is extruded through the die orifice a gas is injected under high pressure into the plastic and this causes gas explosions when the plastic is released through the die orifices. The particles produced have micropores which provide improved workability, and form bales of controllable density.

Abstract: A slit extrusion die with a modified entry port which allows extrusion of a low denier tape at high draw down ratios is disclosed. The die has an entry port wherein the depth of the slit is greater at both ends than at the middle by an amount equal to 0.1 to 0.4 times the length of the slit.

Abstract: In a molding apparatus employing opposed endless belt conveyors to mold a non-rigid material into a rigid material, the problem of one conveyor being driven at a slightly greater speed than the other conveyor to produce harmful shear stresses within the molded product is avoided by driving both conveyors at generally the same speed during start-up until the rigid product extending between the two conveyors will tend to drive the slower conveyor at the speed of the faster conveyor, at which point the drive for the slower conveyor will be disconnected. One-way clutches may be placed in the drive of both conveyors so that it does not matter which conveyor is slower, or a one-way clutch may be placed in the drive of only one conveyor and the other conveyor constructed so that it will inherently tend to run faster than the one conveyor, or a selectively releasable coupling, such as a clutch, may be placed in the drive of one conveyor so that the drive of the one conveyor may be disconnected.

Abstract: An apparatus for producing a foamed sheet of material has a mixing head mounted on a frame which is positioned on a track for longitudinal movement. The mounting head also engages a worm gear for vertical movement. Below the mixing head is a sloped portion of a conveyor. The sloped portion of the conveyor comprises a pair of stationary central panels and a right and left pair of panels. Each pair of panels is hinged together and slide toward and away from the longitudinal axis of the central panels. A paper sheet slides over the panels onto a level bottom conveyor. Vertical side fences are adjacent the side edges of the bottom conveyor panels. A paper sheet slides along the inside surface of each side fence at the same speed of the bottom sheet of paper. A worm gear adjusts the distance between the side fences. The sloped portion of the conveyor has a height adjustment mechanism at its upper and lower end and at the hinged portion of the panel. The central panels have air passages therethrough.

Abstract: A method and apparatus for continuously fabricating three-dimensional (3D) filament reinforced foam insulation slabs. Rows of X or longitudinal filaments are fed longitudinally into a machine in spaced, stacked horizontal planes. Rows of Y or transverse filaments are fed transversely into the machine in spaced, stacked horizontal planes. Z or vertical filaments are fabricated into units of four vertical spaced lengths of strands which fit into each of the vertical column squares formed by the X-Y filaments to form the continuous X-Y-Z orthogonal array. Urethane or equivalent foam is discharged onto a moving belt beneath the filamentary array which is moved in the same direction and at the same rate as the belt carrying the foam. The foam material froths or foams upwardly through the filamentary array as they move along to the next station for curing. After sufficient cure, the foamed array is cut from the frames and into desired length, forming planks.

Abstract: The manufacture is carried out by impregnating bundles of filaments of fibrous-reinforcing material in a bath made up of an emulsion of a thermoplastic resin and a blowing agent. The emulsion-impregnated reinforcing filament bundles are then squeezed and dried to form resin coatings, and then collected to provide a single bunch of the fiber-reinforced thermoplastic resin material. This bunch is subsequently heated and allowed to expand in a tunnel and also cooled in a tunnel to produce a fiber-reinforced thermoplastic resin of a cellular structure. During the impregnation with the emulsion in a bath, the bundles are slackened and repeatedly beaten in the condition of free tension to cause the filament bundles to be substantially frayed to facilitate the impregnation. An apparatus utilizable in the practice of the above method is also disclosed.

Abstract: A metering pump whose speed is controlled in accordance with product data is provided between an extrusion press and the extrusion die. The speed of the worm is controlled by a pressure/speed regulator and the temperature at the outlet side of the press is maintained constant within .+-.10.degree. C.

Abstract: A method and apparatus for making flat topped foamed buns (e.g. polyurethane) in a continuous foaming process. In accordance with the method, continuous thin film tubular members are guided onto each side of the central trough defining conveyor of a continuous pouring system, and a central trough defining film member generally covering the central conveyor is guided thereover prior to the dispensing head. The edges of the tubular members are subsequently guided upward over guides at each side of the trough so that the tubular define upward sloping side walls traveling at an angle and rate determined in accordance with the rate of longitudinal travel and the rate of rise of the foaming reactants so as to encourage the sides of the bun to the same height of rise as the center region of the bun. Continuous slitting of the tubular members at an appropriate elevation allows the material thereof to progress longitudinally with the cured bun.

Abstract: The instant invention relates to a process and an apparatus for applying a layer of liquid, foamable reaction mixture to a continuously moving support, such as for the production of foam blocks or foam sandwich panels having a thick foam core.

Abstract: Apparatus for forming sheets of foamed synthetic plastics material, comprising a screw extruder, a nozzle head having an extrusion passage therein and a nozzle core positioned in the extrusion passage so as to form an annular nozzle, a cooled calibrating mandrel of a diameter larger than that of the annular nozzle, disposed downstream of the screw extruder having regard to the direction of extrusion and mounted on a stand, blowing means for applying internal pressure to an extruded tube between the annular nozzle and the calibrating mandrel to expand the extruded tube to the diameter of the calibrating mandrel, cutting apparatus for cutting open the increased-diameter cooled foamed plastics tube and apparatus for laying out flat the cut-open tube, wherein the nozzle core is rigidly connected to the stand of the calibrating mandrel and is connected to the inner wall of the extrusion passage by a single web aligned with the cutting apparatus whereby weakened and marked regions of the laid-flat cut-open tube are

Abstract: A method and apparatus for directing a foamed material, such as a foamed binder, across the lateral dimension of a moving surface in a uniform and controlled metered flow. In accordance with the method the foamed material is fed into an interior compartment of an applicator unit and is spread laterally as it moves through the compartment toward a laterally extending metering flow gap. After being laterally spread the foamed material is metered in a uniform, controlled manner across the lateral dimension of the moving surface. The applicator unit of this invention has a housing that includes a body portion and a door portion movable relative to each other to form, in a closed condition, the interior compartment that receives the foamed material. The body portion and door portion also aid in forming the laterally extending metering flow gap in communication with the interior compartment, and a passage extends through a wall of the housing to permit the foamed material to be introduced into the applicator unit.

Abstract: The invention relates to an apparatus for the continuous production of continuous plastics foam webs from extruded polyolefin webs containing peroxide and blowing agent by cross-linking on a perforated conveyor belt with subsequent foaming, suspended freely in space into a continuous heating furnace.

Abstract: A centrifuge and centrifugal process are disclosed for prefoaming liquid polyurethane-foam generating reactants prior to introducing the reactants into a mold. A preferred embodiment of the invention is adapted to produce continuously slabs of polyurethane foam of substantially rectangular cross section.

Abstract: Continuous method and apparatus for treatment of a solid material submerged in a body of liquid wherein the material is sticky and/or has weak tensile strength. The material is supported, while it is so submerged, by a dynamic layer of the liquid lying between the material and a moving surface. The method is illustrated by heating and thereby foaming a strip of heat foamable thermoplastic resin while it is held submerged in a denser heat transfer liquid by a dynamic layer of that liquid generated by a moving belt above the foaming material. In an example, expandable high density polyethylene strip is foamed continuously while it is so held submerged in molten salt.

Abstract: The technique uses an extruder for delivering a supply of softened thermoplastic resin material containing a foaming or expanding agent, the resin material being under pressure and therefore unexpanded in the extruder, but being delivered into an unconfined zone of lower pressure for partial expansion. The partially expanded resin material is drawn by a puller mechanism through a chilled shaping or sizing die of a cross sectional dimension smaller than that of the material in the unconfined zone. The material drawn into the sizing die continues its expansion in the interior of the profile with resultant development of porosity in the core of the profile while the surface layer is cooled and hardens as a substantially unexpanded structural shell.

Abstract: A tough board of thermoplastic resin foam provided with skin layers on both surfaces thereof and formed of large cells elongated in the direction of the thickness of said board, wherein an intermediate high density layer thicker than 0.1mm lies substantially halfway between the upper and lower surfaces of said board. The board is formed by extruding thermoplastic resin containing dissolved foaming agent as a sheet, cooling the upper and lower surfaces rapidly to form solid skin layers and then slowly cooling while allowing controlled expansion thereof between expansion restricting members.

Abstract: The pour plate that is inclined downwardly between the side conveyors of a U-shaped continuous molding tunnel is adjustable in width between the correspondingly adjustable side conveyors so as to selectively produce flat-top buns of foamed synthetic resin of a desired width within the range of adjustment. Interdigitating T-shaped fingers are transversely expandible to form the pour plate and have the gaps between the fingers closed by a cover sheet extending completely over the pour plate with sides being folded downwardly between the pour plate and side conveyors where they are attached to a bias that holds the cover sheet in stretched condition over the pour plate. The bottom cover web that travels with the foam may be folded or cut to the adjusted width of the pour plate. The interdigitated finger construction of the pour plate permits adjustment of the pour plate profile so as to correspond to the rise/time curve of the foam as it expands on our pour plate.

Abstract: Two opposed endless conveyor belts, together with side dams respectively mounted on the conveyor belts form a molding tunnel for producing a continuous sheet of foamed and cured resin. A cover sheet, usually of paper, is provided between the molding surfaces of the side dams and conveyors and the product being formed. The side dams are movable toward and away from an abutting surface of the conveyor opposite to the one that they are mounted on so as to clamp the paper therebetween and prevent leakage of foam. A mechanism, particularly a spring bias and cam track, is provided to release the paper clamping pressure to permit the foaming resin briefly to permit the expanding resin to move the paper into conformity with the molding tunnel. The points along the length of the molding tunnel wherein this release occurs are adjustable as desired.

Abstract: An apparatus for the continuous production of prefabricated insulating panels is provided, which includes a feeding station for a lower metal sheet and for an upper metal sheet, a rolling-mill train for shaping the sheets, a furnace for heating the sheets, a device for injecting expandable plastic material between the sheets, a joining unit for joining the sheets together and for holding the expanded plastic material in place, and a cutter for cutting the finished panels. The joining unit has two, link-type upper and lower conveyors for the sheets shaped by the rolling-mills, at least one of which is adjustable, so that the distance between them may be regulated according to the thickness of the panel, with the conveyors being arranged to revolve continuously around rollers which rotate about a horizontal axis. An article produced by the apparatus is also provided.The present invention relates to an apparatus for producing insulating panels and the panels produced thereon.

Abstract: An improved method and apparatus for the preparation of a thermoplastic foam having an enlarged cross-sectional area of a given geometric configuration. A heat-plastified foamable gel of a thermoplastic resin containing a blowing agent is extruded through an orifice of a die into a shaping channel. As the gel expands into a foam generally filling the channel and advances in the longitudinal direction, the foam is supported on a cushion of gas in the area of the channel, relatively near the die orifice, where the surface of the foam is sticky. A sufficient restraining force is applied to the foam in the area, where the foam surface is generally non-sticky, to exert a force in the direction opposite to the normal longitudinal advancement of the foam thereby forcing the foam to expand to a cross-sectional area greater than that of a foam allowed to expand freely. The expanded foam is then cooled to a generally self-supporting condition.

Abstract: An improvement in the manufacture of flexible densified polyurethane foam wherein the partially cured freely risen foam is fed through a crush conveyor to minimize the density gradient throughout the vertical cross section. The crush conveyor includes an upper crushing section which is arcuate and has a radius of a dimension such that the ratio of the radius of the arc to height of the partially cured freely risen foam is 1.1 to 1 or greater. The crush conveyor has a bottom crushing section which may be arcurate with a radius of a dimension such that the ratio of its radius to the height of the partially cured freely risen foam is also 1.1 to 1 or greater. The radius of the bottom arcuate crushing section may be the same or larger than the radius of the top arc. As an alternative, the bottom crushing section may be planar and may be horizontal, or inclined with respect to the horizontal.