Abstract: An installation for producing a polymer melt for a porous film, in particular for a membrane film, comprises a planetary roller extruder. Said extruder is used to produce a flowable polymer melt from thermoplastics. The planetary roller extruder has a filling opening and a discharge side for delivering the polymer melt. A melt pump is further provided. The discharge side of the planetary roller extruder is connected to a downstream inlet side of the melt pump for further conveying the polymer melt. The connection is in the form of a pressure channel shielded from the ambient atmosphere or a pressure line shielded from the ambient atmosphere. The planetary roller extruder and the melt pump are designed and/or can be driven in such a manner that the polymer melt is applied or can be transferred under pressure at the melt pump on the inlet side.

Abstract: Described is a system for controlling the sizing of a rising foam emulsion web travelling on a conveyor. The system includes a plate arrangement and an actuating arrangement. The plate arrangement includes at least a first and a second plate, each having a web-facing lower side and an opposite upper side. The second plate is configured to be located downstream of the first plate with respect to the direction of travel of the foam emulsion web. The actuating arrangement includes a base portion and a top portion. The top portion is movable relative to the base portion and operatively connected to the plate arrangement. The actuating arrangement is configured to individually adjust for each plate a separating distance relative to the base portion, for controlling the rising of the foam emulsion web along at least a part of its travel.

Abstract: The present invention includes: a connector unit configured to disconnectably connect an injection container unit and a lid member; and a vertically driving mechanism configured to cause the injection container unit and the lid member to move up and down together when the injection container unit and the lid member are connected together and to cause the lid member to move up and down when the injection container unit and the lid member are not connected together.

Abstract: Open celled membranes from thermoplastic polymers are prepared from foamed polymer melts by extrusion through a die.

Abstract: A method for manufacturing polyolefin foam beads by a continuous process is disclosed by which the polyolefin foam beads can be produced with increased efficiency and productivity. The method comprises a step of impregnating foaming agent into polyolefin resin by mixing polyolefin resin particles, water and the foaming agent in a impregnation chamber under heat and pressure, followed by a step of storing the polyolefin resin containing the foaming agent in a storing chamber under heat and pressure. Thereafter, the resin particles are subjected to a foaming step by continuously or intermittently discharging the resin particles from the storing chamber to a low pressure expansion chamber by utilizing a discharging device, in the same time period when a next batch of polyolefin resin is added and mixed in the impregnation chamber after being supplied with the resin particles from a resin supply chamber.

Abstract: A process and apparatus for producing polyurethane foam, comprising bringing together under pressure one or more foam components and a gaseous CO2 auxiliary blowing agent and discharging the combination through a permeable discharge head in the form of plural individual wire meshes sintered together to form at least one composite element having a structure such as to require repeated division, divergence and convergence of flow paths and impingement of the individual flows with the sintered wire mesh and the flows through adjacent pores in three dimensions within its axial thickness, and at which the pressure is reduced for forming a froth, wherein the combination of the foam components and gaseous CO2 is arranged to be in a non-homogeneous state containing gas bubbles prior to passage through the discharge head.

Abstract: A method for producing a foamed granulate, wherein a thermoplastic synthetic material is placed in an extruder, the synthetic material is melted, a pressurized expanding agent is fed through one or several injection nozzles, the molten material enriched with the expanding medium is foamed as it exits through a perforated plate arranged at the outlet of the extruder and is granulated by a cutting device arranged behind the perforated plate. Also disclosed is a device for implementing the method and the foamed granulate.

Abstract: A blowing agent composition includes a blowing agent consisting of liquified carbon dioxide and 1,1-difluoroethane, or a mixture consisting of liquid carbon dioxide and at least one other liquid or pressure-liquified component selected from the group consisting of ethers with a total of 2 to 4 carbon atoms; ketones with 3 to 5 carbon atoms; alcohols with 1 to 5 carbon atoms; aliphatic hydrocarbons selected from the group consisting of propane, butane, pentane, hexane, heptane; cyclic hydrocarbons with 3 to 12 carbon atoms; fluorohydrocarbons selected from the group consisting of trifluoromethane, 1,1,1-trifluoroethane, 1,1,2-trifluoroethane, 1,1,2,2-tetrafluoroethane, 1,1,1,2-tetrafluoroethane, 1,1,1,3,3-pentafluoropropane and 1,1,1,3,3-pentafluorobutane; phosphate esters and phosphonate esters containing three C1-C4-alkyl groups optionally substituted by one or more halogen atoms. The composition comprises 5 to 50% by weight of liquid carbon dioxide.

Abstract: The present invention is directed to an agitator-free mixing head and a method for agitator-free production of a reaction mixture from an isocyanate and a higher-viscous polyol formulation, wherein both constituents are fed to a mixing zone and mixed with each other therein, whereby a polyol formulation with a viscosity of at least 3000 mPa.s is fed at low pressure into the mixing zone and at least two flows of low-viscosity constituents (isocyanate and optionally low-viscous polyol) are injected into the flow of high-viscous polyol formulation at high pressure.

Abstract: There is provided pre-expanded particles of a propylene resin having a high expansion ratio and excellent molding adhesion without using a volatile blowing agent or increasing an expansion pressure. The pre-expanded particles of a propylene resin are prepared by the process comprising dispersing resin particles comprising a propylene resin composition, which contains 100 parts by weight of (A) a random copolymer of ethylene and propylene having an ethylene content of 1.5 to 4.5% by weight and 0.

Abstract: The inflatable, non-collapsible, flotation device (INCFD) utilizes foam mng chemicals within a flotation chamber where the materials react and harden to form a layer of pliant foam, such as polyurethane. The foam, during reaction, conforms with the shape of the wearer and hardens to provide both flotation and physical protection from exterior objects.

Abstract: The present invention pertains to improved alkenyl aromatic polymer foams (and processes for their preparation) having increased heat distortion temperature and improved dimensional stability while maintaining good tensile/tear, creep and environmental dimensional change properties.The closed cell low density alkenyl aromatic polymer foams exhibit increased heat distortion temperature, when substantially random interpolymers of about 21 to about 65 mol % styrene are blended in. When these same alkenyl aromatic polymer foams are made without these interpolymers, the heat distortion temperature is not improved.

Abstract: Disclosed herein is an improvement in microcellular or supermicrocellular polymer extrusion systems. Both conventional and microcellular systems employ an extruder which plasticates polymer pellets into a polymer melt; a gas metering system, whereby a gas is injected directly in the polymer melt flow in the extruder; a mixing and homogenizing section of the extruder, which creates a single-phase solution of the polymer and the gas; and a nucleation device at the outlet end of the extruder. In this invention, the improvement to the conventional system comprises the nucleation means attached to said extruder which is a gear pump acting as a throttle rather than a pump. With this improvement, the discharge pressure is dictated by die resistance and flow rate as delivered by the gear throttle, and the pressure drop of the polymer/gas single-phase solution is nearly instantaneous.

Abstract: An apparatus and process for producing polymeric foam, wherein reactive foam components and a low-boiling point frothing agent are brought together, sufficient pressure is applied to maintain the frothing agent in a liquid state and the mixture is passed through a permeable discharge head through which the mixture is discharged and wherein the pressure is reduced and froth is formed. The discharge head comprises one or more diffuser elements (80) having a structure such as to require division, divergence and convergence of flow paths in three dimensions within the axial thickness of the diffuser element, considered in the direction of flow therethrough. The diffuser element (80) is made of bonded, or sintered or sintered composite material, such as sintered wire.

Abstract: In the process and an extrusion device for producing a foamed polymer, a polymer is melted and a foaming agent is added to the polymer melt. After the polymer melt and the foaming agent have been mixed, a throttle generates a pressure drop for nucleation for gas bubbles or cells. The mixture is then shaped, foamed and cooled. In order to produce high-grade foamed polymer with a microcellular or sub-microcellular structure continuously without any shaping limitations, the throttle controlling the flow rate has a passage control so that the flow rate can be adjusted independently of the pressure drop.

Abstract: High quality, consistent polyurethane froth foams, both filled and unfilled, are prepared by directing polyol, isocyanate, and optionally other polyurethane-forming ingredients to a high pressure mix head prior to introducing the mixture to a froth foaming head. Changes in stoichiometry may be made rapidly without shut-down. An in-line blender incorporated filler into the polyol stream minimizing density differentials normally encountered in the holding tank, maintaining low and reproducible viscosity, and allowing for greater amounts of filler than otherwise possible.

Abstract: A thermosetting foam, preferably polyisocyanurate or polyurethane foam, is prepared in an extruder which permits the incorporation of high levels of filler particles. The method includes introducing polyol, isocyanate and filler particles to an extruder screw for mixing. In conjunction with extruding, a catalyst is added. The catalyst may be added either in a last extruder barrel or with the extruder head. Foam with filler particle content in excess of 12% made be readily made. Filler particles, such as aluminum trihydrate, perlite, carbon black, diatomaceous earth, polyiso powders, ammonium phosphate, fly ash, barium sulfate, calcium silicate, and calcium carbonate, may be used. The process described is preferably used for making foam boards or bunstock.

Abstract: A polyurethane foam is produced by mixing foam forming chemicals with the mixing being effected to produce an unfoamed liquid mixture and then feeding the unfoamed liquid mixture into an open-topped trough in which the liquid mixture remains for a dwell time during which an exothermic and gas-forming reaction occurs and the liquid begins to foam and for a partially foamed froth. The volume of the open-topped trough and the dwell time of the foam forming chemicals in the trough are adjusted by tilting the trough. The partially foamed froth is discharged across a curved lip portion at the top of the open-topped trough on to a surface on which the foamed froth is allowed to further react and form a solid polyurethane foam material. The curved lip portion is shaped to minimize shear forces and stresses in the foam and ensure smooth overflow of the foamed froth at different tilt angles.

Abstract: A method for the preparation of flexible polymeric foam by reacting a polyisocyanate component with an isocyanate-reactive component comprising at least 50% by weight of water, the polyisocyanate component comprising at least two polyisocyanate compositions, one of them being a low NCO isocyanate terminated prepolymer and the second being a high NCO polyisocyanate.

Abstract: High quality, consistent polyurethane froth foams, both filled and unfilled, are prepared by directing polyol, isocyanate, and optionally other polyurethane-forming ingredients to a high pressure mix head prior to introducing the mixture to a froth foaming head. Changes in stoichiometry may be made rapidly without shut-down. An in-line blender incorporated filler into the polyol stream minimizing density differentials normally encountered in the holding tank, maintaining low and reproducible viscosity, and allowing for greater amounts of filler than otherwise possible.

Abstract: An apparatus and a process for the production of frothed polyurethane foams: the reactive polyurethane components are mixed with a liquid low-boiling blowing agent and a nucleation gas by a mechanical mixer under pressure controlled conditions in a mixing chamber to keep the blowing agent in the liquid state and cause a fine dispersion of the nucleation gas. The reactive polyurethane components, the blowing agent and the nucleation gas are mixed by reverse flowing the mixture in respect to centrifugal forces generated by a rotor member in the mixing chamber, and by subjecting the same mixture to repeated stirring and whirling actions while it is flowing towards a central discharge outlet and circulating in a radially extending annular path, between facing surfaces of the rotor member and a bottom wall of a mixing chamber provided with intermeshing sets of axially extending pegs.

Abstract: The invention relates to a method and an apparatus for producing polyurethane foam with a controlled number of cells, in which a gas is dispersed in one of the components, i.e. the polyol or the isocyanate, in a dispersing device arranged between the mixing head and the metering pump for the respective component.

Abstract: A low density foam having a density less than 15 pounds per cubic foot (240 kg/m.sup.3) is formed from an amorphous polyethylene terephthalate polymer. An expandable resin composition is also disclosed, comprising an amorphous polyethylene terephthalate polymer and a blowing agent mixture comprising a low permeability blowing agent and a high solubility blowing agent. Unexpanded and partially expanded foam particles, impregnated with the blowing agent mixture are disclosed. Numerous methods are disclosed for producing lightweight foams from amorphous polyethylene terephthalate polymers. One such method utilizes an Accumulating Extrusion Expansion System which avoids problems experienced with the prior art when attempting to extrusion expand polyesters.

Abstract: An apparatus and method for producing foam polyurethane incorporates an apparatus for mixing a nucleating gas into the polyol (part B) fraction and finally dispersing the nucleating gas prior to mixing the polyol (part B) fraction with the isocyanate (part A) fraction. The apparatus and method produce a very fine and uniform microcellular structure in the foam.

Abstract: A method for the preparation of flexible polymeric foam by reacting a polyisocyanate component with an isocyanate-reactive component comprising at least 50% by weight of water, the polyisocyanate component comprising at least two polyisocyanate compositions, one of them being a low NCO isocyanate terminated prepolymer and the second being a high NCO polyisocyanate.

Abstract: There is now provided a rigid closed cell polyisocyanate based foam for use as a positive flotation material for watercraft which meets the U.S. Coast Guard immersion test (CGD 75-168, 33 C.F.R. .sctn.183.114). As a blowing agent for this foam, a mixture of 1,1,1,2-tetrafluoroethane (R-134a) as a frothing agent and water is used, where the amount of water is less than 2.5 weight percent based on the weight of the formulated polyol composition. Also, in preferable embodiments, the polyols in the polyol composition are initiated by at least one amine; and the polyol composition contains a delayed action tertiary amine catalyst. The foams used in the invention have excellent dimensional stability. In another embodiment, there is also provided a formulated polyol composition of R-134a and a polyol composition having an average OH# of less than 400 and an average functionality of greater than 4 using R-134a and less than 2.5 wt.

Abstract: The present invention relates to the continuous production of polyurethane and polyurethane urea elastomers by reaction of polyisocyanates with isocyanate-reactive compounds in a mixing nozzle.

Abstract: The present invention relates to an improved process for producing, by means of a portable foaming apparatus having a static mixer, a polyurethane foam by reacting a reaction mixture comprised of a polyol, an organic isocyanate, a foaming/frothing agent, and a reaction catalyst, the improvement comprising employing monochlorodifluoromethane as the sole blowing/frothing agent in said reaction in order to produce a CFC-free essentially closed-cell rigid or semi-rigid polyurethane foam. Also claimed is the foam produced by the above process.

Abstract: A lightweight absorbent foam is produced using a high internal phase emulsion (HIPE), the production of which incorporates the use of capillary viscosity measurements as an in-line diagnostic for HIPE quality. The in-line diagnostics yield measurements of viscosity slope and amplitude. These measurements offer several advantages for monitoring emulsion quality, including stable high resolution measurement of hardware-independent parameters of the whole flow, without the need for sampling.

Abstract: The process for continuous control of cell number in the production of polyurethane foams from polyols, isocyanates and water, where mixing the components is effected in a mixing head with adjustable injection pressure and adjustable mixing chamber pressure, consists in that immediately prior to entering the mixing head the gas content of the isocyanate is continuously increased or reduced.

Abstract: The present invention relates to an improved process for producing, by means of a portable foaming apparatus having a static mixer, a polyurethane foam by reacting a reaction mixture comprised of a polyol, an organic isocyanate, a foaming/frothing agent, and a reaction catalyst, the improvement comprising employing monochlorodifluoromethane as the sole blowing/frothing agent in said reaction in order to produce a CFC-free essentially closed-cell rigid or semi-rigid polyurethane foam. Also claimed is the foam produced by the above process.

Abstract: An apparatus for preparing foams exhibiting a uniformly small cell size, a minimum number of ruptured cell walls and a smooth surface from foamable curable compositions comprises means to transport the ingredients of a foamable, curable composition to the input of a static mixer in which the ingredients of the composition are blended to homogeneity prior to being extruded into an exit zone and through an exit orifice. The length to diameter ratio of the mixing zone and the diameter of the exit orifice are within specified ranges.

Abstract: A method and apparatus for the continuous production of flexible open cell polyurethane foam, where a process air stream is drawn through the interior of the foam material after it has completed its rise to thereby accelerate the cooling of the foam material. The process air stream contains vaporized constituents which are removed by the steps of:(a) collecting the air stream from the foam material;(b) passing the air stream into an adsorption expansion chamber having a cross-sectional area adapted to reduce the flow rate of the air stream;(c) passing the air stream into an adsorption chamber;(d) passing the air stream through at least one activated carbon char filter bed located in the chamber at a flow rate that is adapted to provide sufficient residence time for the removal of the vaporized constituents drawn from the foam material; and(e) discharging the treated air stream into the atmosphere.

Abstract: Through three separate passages opening in a common plane at right angles to one another into a mixing chamber, three components of a reactant polyurethane or polyurea elastomer composition to form in a mold cavity are introduced. One of the components is an aliphatic polyether amine having primary amino function and substantially free from free hydroxyl groups, catalysts with tertiary amino groups, carbon dioxide as a carbamate reactive with the polyether amine and optionally other inert gases and conventional polyurea additives. The second component is a polyisocyanate or prepolymer thereof and the third component C is water. The reacting mixture is formed through a throttle gap into the mold to form low-density foamed products under low fuming conditions and has no unreacted diisocyanates.

Abstract: A closed cell, rigid, polymer foam comprising the reaction product of a polyisocyanate and an isocyanate-reactive compound in the presence of (a) a foaming agent, (b) at least about 2 percent by weight of carbon black, based on the weight of the polymer in the foam, and (c) a capped polyoxyalkylene compound which helps bring about a uniform dispersion of the carbon black throughout the foam so that the aged k-factor of the foam is below the aged k-factor of the corresponding unfilled foam.

Abstract: A method and apparatus for dispensing a foamable, pressurized solution of a gas and a high viscosity polymeric material in a manner which produces a foamed bead having a hollow core. Initial foaming occurs in a nozzle through which the solution is dispensed to atmosphere, at a core of the bead. Subsequent foaming of of the bead exteriorly of the core occurs outside the nozzle, and results in an extruded, foamed bead of high viscosity polymeric material having a tubular shape and particularly suitable for form-in-place gasket applications.

Abstract: A process for manufacture of molded, high resiliency, polyurethane foam substantially free of volatile organic blowing agents comprising feeding at least three streams into a mixing device to form a reaction mixture, wherein a first stream contains (i) a polyol, (ii) water, (iii) a catalyst, (iv) a surfactant; a second stream contains an organic polyisocyanate; and a third stream contains (i) water, (ii) a crosslinking/extending agent, and (iii) a process/foam modifier.

Abstract: A method of manufacturing polyurethane foams comprising the steps of mixing a polyol and an organic isocyanate without causing them to substantially react with each other thereby to obtain a nonreacted mixture, mixing the nonreacted mixture with a foaming agent, a catalyst, a foam stabilizer and other necessary additives such as a pigment, a fire retardant and a filler, and injecting the resultant mixture to a mold to cause the resultant mixture to foam and crosslink. The polyol and the organic isocyanate may be preliminarily mixed with a gas such as an inert gas or air. The nonreacted mixture containing the polyol and organic isocyanate may be subjected to aging at a temperature of -10.degree. to 25.degree. C. for 12 to 27 hours.

Abstract: A method of producing a polyurethane foam comprising the steps of dissolving rapidly and substantially completely a non-condensible non-reactive gas in a liquid isocyanate component or a liquid polyol component or both while the isocyanate and polyol components are maintained separate from one another, while controlling the flow of the non-reactive gas to maintain a predetermined dissolved gas to liquid ratio, and while maintaining the component in which the nucleating agent is being dissolved under pressure sufficient to maintain the gas in solution and to hold substantially constant the dissolved gas to liquid ratio and mixing the previously separated isocyanate and polyol components together while reducing the pressure to nucleate the dissolved gas in the isocyanate and polyol components and while impinging liquid streams of the composition together thereby enhancing mixing and permitting the mixture to foam so as to form a fine celled polyurethane foam.

Abstract: The present invention is directed to an apparatus for introducing gas into one of at least two free-flowing components which are subsequently mixed to provide a foam-forming free-flowing mixture by transferring the component to have gas dispersed therein from a supply container to a gas loading area, loading the component with gas and returning the component to the supply area, wherein the gas used in the gas loading area is obtained from a gas cushion maintained in the supply container and wherein the gas is compressed to a pressure higher than the pressure in the gas loading area before it is dispersed into the free-flowing component.

Abstract: The present invention relates to an improved process for the production of a flowable mixture which reacts to form foam from flowable components stored in storage containers, wherein prior to metered introduction into a mixing zone, at least one of the components is charged with a defined quantity of gas, by (i) introducing said one component and gas separately into a gasification chamber equipped with a hollow stirrer, (ii) sucking gas into said component through the hollow shaft of the hollow stirrer, and (iii) stirring the gas into the component, until the desired value is attained, the improvement wherein (a) the component is circulated from the storage container through the gasification chamber and back into the storage container, (b) the gas sucked through the hollow shaft of the hollow stirrer being maintained at a pressure at least equal to the pressure prevailing in the storage container, and (c) the component fraction remaining in the storage container is homogenized during those periods in which ga

Abstract: Viscous liquids containing polymeric materials which will interact with one another upon contact and generate gas for foam expansion are intimately and homogeneously mixed in a very short period of time by passing them successively and continuously through first and second rotary dynamic shearing mixers, the first mixer being considerably smaller than the second mixer, and the mixture experiencing a brief period of respite from shearing between the two mixers. The mixture experiences a much higher degree of shear in the first mixer, where the heat necessary for promoting the reaction is provided through the shearing action but without creating localized hot-spots. The process is particularly well suited for the preparation of foamed polydiorganosiloxanes, on a continuous, commercial scale.

Abstract: A closed cell, rigid, polymer foam containing as filler at least about 2 percent by weight of carbon black, based on the weight of the polymer in the foam, the carbon black being uniformly dispersed throughout the foam so that there is present in the cell walls of the foam an amount of carbon black which reduces the aged k-factor of the foam to below the aged k-factor of the corresponding unfilled foam.

Abstract: An impingement mixing device for preparation of plastic parts or objects including cellular foam from at least two reactive synthetic components and an auxiliary component such as liquid foaming agent and including at least two injection ports and a third port for input of the auxiliary component. Inert gas optionally and a foaming agent and further additives are mixed at a point in the cylindrical wall of the component mixing chamber located in or near the vicinity of the radial plane passing through the component openings. The introduction of the inert gas, foaming agent, coloring agent, or further additives is controlled by a cleaning piston which also simultaneously cleans the mixed plastic material penetrated therein from the opening area of the inert gas feeder line. The cleaning piston is part of a control piston, which with its rear segment is located in a metering chamber for the inert gas and optionally also for the foaming agent and the additives.

Abstract: A styling mousse generator adapted to foam a liquid and deliver foamed styling mousse for use in hair treatment and the like having a liquid reservoir in its lower portion, means for filling the reservoir, a fan and motor above the reservoir, a fan inlet and a fan outlet, a foam delivery tube leading from the reservoir to the fan inlet, a liquid inlet duct (coming from the reservoir) and an air inlet duct (coming from a location higher than the reservoir liquid level) at an acute angle to each other (to create a Bernoulli type effect) and leading to the foam delivery tube, and a passageway leading from the fan outlet to a foam outlet. The passageway may be serpentine or include frictional, agitating means to warm the foam.

Abstract: A continuous reactor for forming polymeric materials from reactive components for use in a system for mixing monomeric materials and the process of operation of the continuous reactor and system.

Abstract: Process for manufacture of polyurethane and poly(urethane/isocyanate) foams utilizing higher levels of aromatic polyester polyols in the polyol component through the substitution of CHClF.sub.2 for at least a portion of the conventional blowing agents to provide a foamed product of lower combustibility and lower brittleness.

Abstract: A mixing method and apparatus for preparing multi-component plastic materials, especially polyurethanes, which are mixed before being fed into a mold. According to the invention, a first and at least a second main component are mixed by feeding them into a limited area of a mixing chamber through lateral inlet apertures symmetrically arranged with respect to a plane comprising the longitudinal axis of the chamber and in which a third or secondary component to be mixed is fed through a channel, opening in the chamber upstream of said inlet apertures and orientated so as to direct the flow of the third or secondary component towards said mixing area in the direction of flow of the mixture. A control member is moved toward an advanced position so that it closes the inlet apertures to interrupt feeding of the first and second main components and a coloring agent through respective inlet apertures after a mixing operation.

Abstract: A method and apparatus or system for the continuous manufacture of building element consisting of a self-supporting framework of tightly compressed solid particles and a foaming material in the shape of a foamed plastic material, includes the use of a filling station where mold bottoms are placed in series on a roller conveyor, assembled with sidewalls and passed along a guide section, wherein particle-shaped filler is supplied from a silo while premixed foam material is injected into the material through nozzle tubes and the components are mixed before being injected into the mold and compressed. After placing of a top wall on each of the molds, these are passed under a roller conveyor, and while the molds are moved ahead between the roller conveyors and possibly roller conveyors outside the sidewalls, the foam material binds the particles together to form a monolithic unit which will set before the molds leave the roller conveyors.

Abstract: A thermosetting foam, preferably polyisocyanurate or polyurethane foam, is prepared in an extruder which permits the incorporation of high levels of filler particles. The method includes introducing polyol, isocyanate and filler particles to an extruder screw for mixing. In conjunction with extruding, a catalyst is added. The catalyst may be added either in a last extruder barrel or with the extruder head. Foam with filler particle content in excess of 12% made be readily made. Filler particles, such as aluminum trihydrate, perlite, carbon black, diatomaceous earth, polyiso powders, ammonium phosphate, fly ash, barium sulfate, calcium silicate, and calcium carbonate, may be used. The process described is preferably used for making foam boards or bunstock.