Abstract: A structural foam billet made from a plurality of blobs of foam forming stock which are spaced from one another in a predetermined order and expanded into the structural foam billet.

Abstract: An apparatus and method for producing a continuous slab of polymeric foam uses an open topped trough with an upper pour plate adjacent to a moving conveyor. A liquid reactant foam mixture is continually introduced into the bottom of the trough and allowed to rise and partially expand until the mixture flows over the pour plate and onto a moving conveyor to complete its expansion and cure as it is conveyed. The inner surfaces of the trough are chilled to reduce the reaction rate of the liquid foam mixture and thereby prevent the undesired build-up of cured foam on the surfaces of the trough. The chilled trough may be formed from a plurality of hollowed panels fitted with interior baffles to define inner fluid passageways. A chilled fluid, such as water, is pumped through the passageways. Longer production runs with fewer defects are advantages of this apparatus and method.

Abstract: A support surface is formed into a trough, a liquid polymer which expands on reaction is dispensed onto the support surface, and the support surface is inclined to cause flow of the polymer to a region in which the polymer expands. The polymer is introduced onto a supporting liquid which supports the polymer in a zone which is substantially coextensive with at least a major portion of the expansion region. The supporting liquid has a specific gravity higher than that of the polymer, whereby the polymer floats on and advances across the supporting liquid in the form of an expanding mass having left and right sides, a flat bottom and a top which slopes upwardly in the direction of the advance. Conveyors support the expanding mass at the respective left and right sides thereof. The conveyors are submerged in the liquid at their upstream ends, and the direction of advance of their polymer-supporting active surfaces is substantially parallel to the sloping top of the polymeric bun as it expands.

Abstract: A method of continuous production of foamed material, wherein foam forming materials are fed from below at a controlled rate and the foamed material is drawn away from above at a corresponding rate. Foaming takes place in a diverging expansion enclosure bounded by moving sheet material in the form of webs or in tubular form constrained to follow a diverging path and drawn away from above so as to travel with the foaming material at a rate corresponding to its rate of travel. The enclosure is defined above by foam already expanded, at the sides by the sheet material, and below by a feed zone sealed to contain the foam forming materials. The enclosure leads into an upwardly directed take off path for the foam. Appropriate machines for practicing the method utilize either webs of sheet material or sheet material in tubular form, which tubular form may itself be made by the machine from webs.

Abstract: An apparatus for manufacturing continuous webs of polymer foam obtained from a mixture of liquid reagents, wherein the volume of a container is determined to form a zone of retention of the mixture of reagents in liquid phase and wherein the level of this mixture is maintained at a level slightly higher than the plane upon which the mixture in the liquid state flows, so that the primary phase of expansion of the mixture and its further expansion are produced outside the container on a moving surface of the conveyor, which surface is maintained in a substantially horizontal plane. The invention is particularly applicable to the production of webs of supple foam or of panels of rigid foam.

Abstract: Polymeric foam, particularly polyurethane foam block, is produced in a stationary, longitudinally-extending, channel-shaped, mould (1a). A mixture of foam reactants partially expands in a vessel (40) and overflows down a fall plate (41) to the bottom of the mould. The vessel and fall plate are progressively transported from one end of the mould to the other to lay down partially expanded foam over the bottom of the mould (FIG. 1). The ends (11,12) of the mould may be opened to permit entry and exit of a foam lay-down unit (6) and transporting means (7) and to permit removal of the expanded foam strand (61) (FIGS. 6 and 7). The mould may be covered (14) after foam lay down and means (5) may be provided for removing gases emanating from the foam (FIG. 1).

Abstract: A method of continuous upwards production of foamed material by feeding foam forming materials from below and taking foamed material away from above, wherein foaming takes place in diverging expansion enclosure (1) the walls (13, 14) of which are provided with surfaces (15, 17) travelling with the foaming material, which enclosure (1) is defined above by foam already expanded, at the sides by said walls (13, 14) and below by a feed zone for the foam forming materials, and leads into an upwardly directed take off path for the foam.

Abstract: A process for the continuous foaming of plastics, especially polyurethane, of the type in which the foaming space is delimited by flexible material bands which are fed together with the bun of foamed material being formed. As flexible material for these bands a composite web is used which comprises a support paper band and a thin impermeable band of plastics, preferably polyethylene having a thickness from 5 to 40 microns. The two bands of which the flexible is composed have a reduced adhesion to one another. The paper band is then detached from the bun of foamed material by disengaging it from the band of plastics which is left permanently adherent to the foamed material or is detached from this latter in an operation subsequent to the detachment of the paper band. In this way, losses of material are avoided, and the paper of the paper bands can be recovered.

Abstract: In the continuous production of block-foam from liquid reaction components, the danger of over-rolling exists in installations having low throughputs and in installations having high throughputs, which over-rolling results in faults in the finished block. These over-rolling phenomena are avoided by providing a conveyor belt in the mixture charging zone which belt transports on its conveying surface a foil which has trough-shaped indentations which can correspond to trough-shaped indentations in the conveying surface. The reaction mixture is portioned into the indentations of the foil. These portions are only spread out once the reaction mixture has reached the creamy phase.

Abstract: An apparatus for making cylindrical polyurethane foam blocks, including an upstanding trough with a weir structure at the upstream end of a fall plate in a molding apparatus, means for passing a first web of a separation sheet below the trough and between a gap formed between the weir and the fall plate leading edge, means for forming the first web into a U-shaped configuration as it advances with the foaming material, and second means for feeding opposite webs of sheet material immediately upstream of the conveyor through molding means for forming the cylindrical block.

Abstract: In the preparation of polyurethane foam by the provision of foamable urethane composition to a trough and subsequent overflow of the trough to a conveyor belt for final foaming and curing of the urethane composition, improved product is obtained by maintaining temperature uniformity laterally across the trough.

Abstract: The densified area commonly formed during the manufacture of blocks of pliable polyurethane foam on a web of continuous material in a foaming tunnel is eliminated by controlled heating of the conveyor belt in the tunnel to a range between the densification temperature and the cracking temperature of the foam during the reaction period. An improved apparatus for this purpose comprises an enclosed, insulated housing and means for heating the conveyor belt such as hot air, infrared radiation, steam coils or electrical resistors. A preferred embodiment comprises heating the bottom of the foam block after it emerges from the foaming tunnel to a temperature considerably higher than that in the foaming tunnel. This eliminates completely any need for trimming off irregularities after removal of the web of continuous material.

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: A method and apparatus in a panelboard processing line is disclosed for controlling the application of smoothing pressure to a facing sheet of a laminate comprising at least one such sheet and a layer of plastic foam. Smoothing pressure is applied to the facing sheet during continuous production of the laminate in a conventional nip-roll, free-rising foam panelboard system. To this end, provision is made for adjustably suspending a belt-like member generally parallel to, but in variably spaced relation above, the processing line at a region downstream of the conventional nip-roll in the typical free-rising foam system. The belt-like member is flexible along its longitudinal axis but is relatively stiff transversely thereof, and is so suspended as to produce a depending loop or sag intermediate its ends.

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: 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: 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: 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 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 method for the continuous production of foam blocks or foam sandwich panels involving the application of the liquid foamable reaction mixture to the continuously moving shaping support in a manner which avoids large gas inclusions in the final product produced. The liquid foamable reaction mixture is preliminarily distributed by the use of a particular distributor channel means in a traverse direction to the continuously moving shaping support, permitted to flow in the form of a descending film exposed to the atmosphere to an intermediate storage means and then conveyed to said continuously moving shaping support. The distributor channel means may also be pivoted to control the outflow of the mixture.

Abstract: A process and apparatus are disclosed for the continuous production of polyurethane foam. The invention is directed to the use of a laterally translating mold, the first portion of which has divergent side walls, including a "V"-shaped mold having divergent straight vertical side walls. A polyurethane reaction mixture is deposited at or near the apex of that mold. The deposited mixture can be a partially-expanded prefoamed fluid mixture formed, for example, by a centrifugal mixing means. Typically, the mixture is permitted to substantially complete its rise after being conveyed past the extremeties of the divergent side walls of the first mold portion. The invention contemplates use of a ratio of conveyor velocity to foam product height lower than those of the prior art. Both rectangular and circular cross sectional products can be produced.

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 process is diclosed for the production of large dimension polyester-derived polyurethane foam. A preferred embodiment of the invention is continuous production of polyurethane foam slabs having a height exceeding forty inches. Such heights are obtained through use of a slow-rise foam formulation. Slabs having a substantially rectangular or round cross section can be obtained using segmented inclined pouring boards. The slow-rise formulation is deposited on one inclined segment and moves down it and another segment more steeply inclined to effect the production of both rectangular or round slabs.

Abstract: A mold is described for the molding of substantially isotropic isocyanate-based polymer foam buns. The mold is a box mold which has sidewalls of which at least one pair disposed in parallel relationship is adapted to move outwardly when subjected to pressure exerted by the expanding foam during the molding operation. The outward movement of the sidewalls is controlled by stops provided on the periphery of the mold floor, said sidewalls being free to slide over the surface of the floor. The lid of the mold is supported in sliding engagement with the upper edges of the sidewalls. The mold and the process of fabricating foam buns therewith is particularly suitable for use in situations (e.g. operation in the field) in which it is not possible or practicable to employ continuous bunstock machines. The mold is relatively inexpensive and readily dismantled for transportation to a fabrication site.

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 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: A polyisocyanate foam having isotropic cells is manufactured by a foaming operation in an apparatus comprising a mold composed of side walls capable of extending and returning, or folding and unfolding, in directions perpendicular to the free rising direction. Mold extending means are provided to spread out the side walls of the mold perpendicular to the free rising direction. While the foamable composition is in a creamy state, it is allowed to rise freely in one direction (the free rising direction), while the side walls of the mold are in their folded condition, until a height detecting means is actuated.

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: 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: Continuous foam blocks with rectangular cross-section are produced on a side-limited conveyor band by feeding a foamable mixture to a cover foil travelling with said conveyor band and covering the free surface of the mixture with a bearing layer not earlier than immediately after the supply of the mixture and not later than before the zone in which a skin would be formed on the free surface of the block.

Abstract: A process and apparatus are described for the preparation of continuous polymer foam bunstock having substantially rectangular cross-section. The novel feature comprises 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.

Abstract: The instant invention is directed to an improved device for the continuous production of foam blocks of rectangular cross-section, comprising an endless conveyor belt with side walls, means for supplying a covering sheet to the upper surface of the upper rim of the conveyor belt and the side walls, a charging device for supplying a foamable reaction mixture to the upstream end of the said upper rim of the conveyor belt, and a plurality of mold covers which are placed along the foaming area and each of which is suspended from a guiding device, the improvement wherein each guiding device comprises first and second links secured to mounting means, a diagonally extending rod pivotally connected at its lower end to the mold cover, a first lever pivotally connected at one end to the first link and pivotally connected at its opposite end to a point on the rod intermediate its ends, and a second lever pivotally connected at one end to the second link downstream of the pivotal connection between the first lever and th

Abstract: The instant invention relates to an apparatus for the continuous production of foam plastic blocks of a rectangular cross-section, in particular based on polyurethane. The apparatus generally comprises an endless conveyor belt whose upper run is provided with side walls, an unwinding device for a bottom and side sheet to cover the upper run of the belt and the side walls, a levelling device in the form of a roller or a doctor, which extends transversely in relation to the conveyor, a mixture application device and an unwinding device for a sheet to cover the mixture applied.

Abstract: A mold is described for the molding of substantially isotropic isocyanate-based polymer foam buns. The mold is a box mold which has sidewalls of which at least one pair disposed in parallel relationship is adapted to move outwardly when subjected to pressure exerted by the expanding foam during the molding operation. The outward movement of the sidewalls is controlled by stops provided on the periphery of the mold floor, said sidewalls being free to slide over the surface of the floor. The lid of the mold is supported in sliding engagement with the upper edges of the sidewalls. The mold and the process of fabricating foam buns therewith is particularly suitable for use in situations (e.g. operation in the field) in which it is not possible or practicable to employ continuous bunstock machines. The mold is relatively inexpensive and readily dismantled for transportation to a fabrication site.

Abstract: Foam plastic is produced by pouring a mixture of liquid foam reactant into a channel-shaped conveyor where the mixture expands to form foam. The mixture is to begin with allowed to flow out beyond the breadth of the conveyor and is guided back to the normal conveyor breadth during the expansion period. An apparatus for such production includes a channel conveyor when the vertical side walls begin first after the cream-line, a scraper device being installed on each conveyor side to guide the foam in between the vertical side walls.