Abstract: Described is a process for preparing extruded functional fluid and solid-containing thermoplastic foamed particles using chemical blowing agents or direct gas extrusion processes, uses of such foamed particles and articles produced from said foamed particles. The process described involves the use of a single screw or double screw extruder wherein the resin particles are added upstream from the functional fluid or solid which, in turn, is added to the extruder upstream from the point of addition of the liquid or gaseous blowing agent.

Abstract: A method for preparing a multi-cellular foamed board of thermoplastic resin which comprises forming under pressure in a die a thermoplastic resin melt containing a foaming agent to give the resin melt a shape of a flat board having a broad width compared with a thickness thereof, extruding the resin melt from the die having the convex forward end with a middle portion in the width direction thereof protruding the greatest toward the extruding direction, introducing thus extruded resin melt immediately into a moulding passage having a concave end engaging with the said convex forward end of the die, allowing the resin melt to expand in the thickness direction at the portion adjacent to and extending along the concave end of the passage, and thereafter allowing the resin melt to expand in both the thickness and width directions of the board in the passage.

Abstract: A method for forming a molded thermoplastic foam structure comprising partially filling a mold with solvent imbibed particles of a thermoplastic resin, pressurizing said mold under conditions such as to prevent vaporization of said blowing agent during subsequent polymer melting, heating said polymer to a flowable state, releasing the mold pressure to permit foaming of the melt and expansion of the foamed polymer within the mold.

Abstract: A method for forming a molded polymer foam structure comprising expanding solvent imbibed polymer particles selected from the group consisting of a polyetherimide, a polycarbonate and a polyphenylene oxide-polystyrene blend and fusing the expanded particles together in a mold.

Abstract: The invention relates to a process of making articles of foamed polymethyl methacrylate (PMMA). In a first process stage a mixture comprising monomeric methyl methacrylate, plasticizer, preferably liquid foaming agent and catalyst is polymerized by heating and/or irradiation to form a foaming agent-containing solid body. In the second process stage this body is foamed by heating to the softening temperature of the plastic material. Either of these stages may also be performed continuously. The final product is clear-transparent and has large closed cells, a smooth surface, is light- and weather-resistant, readily workable, has good thermal insulation properties also in combination with plastics or glass coatings and may be used in a variety of applications, especially as a transparent insulating slab or plate.

Abstract: The use in conventional polyolefin extrusion foaming processes of a stability control agent (e.g., stearamide, EAA copolymer, etc.) in conjunction with certain mixed blowing agent systems, the mixed blowing agent system containing 60-95 weight percent of 1-chloro-1,1-difluoroethane or 60-95 weight percent of 1,1-difluoroethane. These compounds have a shorter atmospheric lifetime and lower stability than the saturated chlorofluorocarbons presently used as blowing agents or in blowing agent systems.

Abstract: Process and apparatus are disclosed for manufacturing foamed articles such as tubes used as pipe insulation, which tubes are of a high impermeability and flexibility and are formed of a polymer, such as polyethylene or polypropylene, containing up to about 25% of an elastomer.

Abstract: Described is a process for preparing extruded functional fluid and solid-containing thermoplastic foamed particles using chemical blowing agents or direct gas extrusion processes, uses of such foamed particles and articles produced from said foamed particles. The process described involves the use of a single screw or double screw extruder wherein the resin particles are added upstream from the functional fluid or solid which, in turn, is added to the extruder upstream from the point of addition of the liquid or gaseous blowing agent.

Abstract: A one-part activator and blowing agent system for foaming plastics comprising an alkali metal borohydride and a salt hydrate blended in a single pellet or as separate pellets with a dry inert resinous polymer carrier. The one-part system is blended with a resinous polymer and then the blend extruded at a temperature at which the blend becomes molten such that the salt hydrate releases its water of hydration to hydrolyze the borohydride and produce a cellular article.

Abstract: The invention provides a method for producing permeable polymeric membranes comprising decomposing, in a polymeric matrix, molecular moieties, bound to the polymer or contained in compounds dispersed therein, into smaller, discrete, molecular units, whereby the smaller, discrete molecular units, which are formed, spontaneously leave the polymeric matrix and a membrane of defined permeation characteristics is obtained.

Abstract: The aim of the invention was to find a method of producing a sorptive body, to be used especially with objectives such as the elimination of odors and air freshening. In the invented process a granular or powdered solid component consisting of a sorptive material, e.g. active carbon, or a compound containing such a material, is mixed with a binding agent, by which it is generally fixed to a carrier substance. The essence of the invention is that at least part of the finely-ground solid component is mixed with a liquid sorbate; only then it is combined with the dissolved binding agent. In a subsequent operation heat is applied to the mixture, thereby expelling the sorbate. The heat causes pores and capillaries to form within the binding agent, thus enabling air to enter into the sorptive substances deposited in the binding agent and so effecting an increase in the active area of the surface of the body.

Abstract: A new process for foaming cellulose acetate rods consists of blending the cellulose acetate with a suitable plasticizer, a nucleating agent, cyclic ethylene carbonate, and a co-reactant for the ethylene carbonate and extruding into a foamed rod. Suitable co-reactants include aromatic diol polyesters, polycarbonates, and poly(ester-carbonates) and monomeric or polymeric materials containing the ##STR1## group, which have melting or flow points of less than about 250.degree. C.

Abstract: A core material for automobile bumpers which is composed of a molded article of foamed particles of a polypropylene-type resin. The molded article has a density of 0.015 to 0.045 g/cm.sup.3 and a compression stress at 50% compression of at least 1 kg/cm.sup.2. The core material simultaneously has excellent energy absorbing property and dimensional recovery and a low density.

Abstract: Aromatic polymer materials, such as polyethersulphone, polysulphone or polycarbonates in granular or porous forms with a solvent such as acetone or butanone. The resultant mixture is thereafter compressed and compounded to significantly increase its density producing a pre-form substantially free of large irregular voids. The preform is then capable of being formed in a foamed structure under heat.

Abstract: Process and composition for single step production of foam by utilizing a blowing agent, organic peroxide cross linking agent and a silicone block copolymer.

Abstract: A method of providing cured latex-based compositions is disclosed which permits in situ curing of latexes disposed in plastic container closures or other heat sensitive receptacles without adverse effect on the closure or receptacle. The method comprises heating a fluid latex composition to gel the latex and effect removal of at least a portion of the water initially contained therein and subjecting the resultant composition to modulated microwave energy to effect curing thereof. Modulation of the microwave energy is achieved by applying same in an intermittent or pulsed fashion. The method is of particular interest for the in situ formation of cured latex-based gaskets in polyalkylene container closures.

Abstract: A one-part activator and blowing agent system for foaming plastics comprising an alkali metal borohydride and a salt hydrate blended in a single pellet or as separate pellets with a dry inert resinous polymer carrier. The one-part system is blended with a resinous polymer and then the blend extruded at a temperature at which the blend becomes molten such that the salt hydrate releases its water of hydration to hydrolyze the borohydride and produce a cellular article.

Abstract: Styrenic foams are prepared with water as a blowing agent component and polyhydric alcohol as a corrosion inhibitor.

Abstract: Resilient foam particles and moldings are obtained employing a lightly crosslinked polymer such as a styrene polymer with volatile fluid foaming agent that has low permeability through the polymer. Multiple expansion will permit low density particles for molding.

Abstract: The present invention relates to a process for preparing a polyolefin foam by heat-molding pre-expanded beads of an expandable polyolefin resin containing a foaming agent in a mold, said process being improved in preparing beads having a peak expansion rate at pre-expansion equal to 1.3 to 3 times the expansion rate of beads to be packed into the mold, adjusting the beads to a pre-expansion rate depending on an expansion rate of the desired foam, and packing and molding the pre-expanded beads in a mold without any further addition of expandability thereto. The polyolefin foam prepared by the process of the present invention is evenly fused to the interior and is less liable to shrink or deform.

Abstract: The present invention is directed to a method of preparing a phenolic foam that has cell walls which are substantially free of perforations. The method comprises using certain anhydrous aryl sulfonic acids as the foaming and curing catalysts. The useful anhydrous aryl sulfonic acids are those which have a pKa of less than about 2.0 and which change the compatibility of the phenolic resole with water. The preferred anhydrous aryl sulfonic acid is a combination of toluene sulfonic acid and xylene sulfonic acid. The invention is also directed to a phenolic foam having cell walls which are substantially free of perforations and to foamable phenolic resole compositions for preparing the phenolic foam.

Abstract: A process for preparing a poly(p-methylstyrene) polymer foam including extruding a poly(p-methylstyrene) foam structure from a melt at a temperature which will yield an open cell percentage less than that formed in general purpose polystyrene foamed under the same general conditions. It also includes performing the extrusion from a melt at a rate which will yield a foam structure at least comparable to that of general purpose polystyrene foam, wherein the extrusion rate is greater than the extrusion rate for said polystyrene foam.

Abstract: Method and apparatus for injection molding plastic articles having solid exterior surfaces and porous interior cores wherein a molten mixture of a chemically reactive foaming agent and a thermoplastic resin is injected into a mold so as to fill the mold cavity with unfoamed resin and form an outer solid skin on the molded article. Immediately prior to injection, an activator additive is introduced into the mixture, the additive reacting chemically with the foaming agent after a time delay of no more than a few seconds to provide for cellular expansion within the core of the molded article. The result is a molded body with a solid unfoamed skin which accurately relicates the surface of the mold and a cellular inner core.

Abstract: Microcellular foam materials having void fractions of about 5 to 30 percent and uniform void sizes on the order of 2 to 25 microns are produced by pre-saturating the material to be processed with a uniform concentration of a gas while controlling temperature and pressure to avoid cell nucleation. Processing is also done under pressure to avoid nucleation. After processing, pressure is released and cell nucleation occurs at or near the glass transition temperature of the material; it is then cooled quickly to preserve the microcellular structure.

Abstract: A method and apparatus for continually metering a gaseous blowing agent in an accurate and precise manner into a molten resin charge, such as polystyrene. This is accomplished by a free piston-cylinder combination which is actuated by the gas blowing agent and which continually meters discrete uniform volumetric charges of the gaseous agent into the molten resin. The blowing agent is uniformly distributed throughout the resin charge and extruded into a region of lower pressure to yield a foamed structure.

Abstract: Disclosed is a process for extruding thermoplastic resinous compositions, comprising the steps of heat plastifying the resinous composition in an extruder; cooling the heat plastified resinous composition exiting from the extruder to a uniform temperature desired for extrusion through an extrusion die, including conveying the resinous composition through at least one enclosed flow path in a cooling device, circulating a cooling medium about the entire circumference of each of the resin flow paths and controlling by the means of orifices the flow of thermoplastic at the inlet and the outlet of the cooling device across substantially the entire cross-section of each of the resin flow paths; and, extruding the cooled thermoplastic resinous composition through an extrusion die downstream of the cooling device.

Abstract: The invention is a method for making reaction injection molded polyurethane of improved properties and decreased catalyst usage. The product is formulated by placing the tin catalyst in the A-component (isocyanate component) rather than in the B-component (polyol side). Reaction injection molded elastomers are useful as molded articles of commerce including, but not limited to, vehicle body parts.

Abstract: There are provided methods for making heat-resistant, foamed, crystalline plastic materials. For example, polyethylene terephthalate may be foamed with a polycarbonate, extruded into a foamed sheet and this foamed sheet may be thermoformed by being subjected to crystallization annealing. The thermoformed, foamed, crystalline plastic sheets prepared by this process are particularly useful for forming light weight, ovenable food containers.

Abstract: A method of forming reinforced synthetic articles of polyester resin by reaction injection molding techniques comprising combining a set of reactants including a major base mass of polyester resin in fluid form, at least one polyester cure accelerator, a selected quantity of isocyanate, a surfactant, and an additive that is highly exothermically reactive with at least one other component in the mixture. The isocyanate is added in sufficient quantity to react with at least one other component in the mixture to provide mold filling and shrink-resistant quantities of carbon dioxide throughout the mixture. The resultant mixture is injected into a mold prior to substantial reaction. The additive is allowed to react and the heat produced by this exothermic reaction is effective to trigger and accelerate gas forming soon after injection. The gas formation generates pressure to expand the polyester base resin mass and maintain pressure through the curing reaction of the accelerator with the polyester resin.

Abstract: There are provided heat-resistant, foamed, crystalline polyesters, such as polyethylene terephthalate foamed with a polycarbonate and subjected to crystallization annealing, which are particularly useful for forming light weight, ovenable food containers.

Abstract: The invention relates to an earplug, produced with the use of a polysiloxane which is made foamable and cross-linkable by the use of expanding and cross-linking agents. The method for producing such an earplug comprises preshaping the polysiloxane together with the additives, then finally shaping the earplug in the foaming process and then tempering the finally shaped product.

Abstract: A method and apparatus for producing a foamed polymeric sheet having comparatively high density skin layers. Molten polymer containing a foaming agent is extruded from a die into a post-extrusion region defined by the die and a spaced pair of rotating chill rolls which are spaced from the die. The post-extrusion region is maintained at a pressure sufficient to at least inhibit expansion of the foamable molten polymer through the use of cooled sealing elements which occupy a substantial portion of the space between the die and the chill rolls, and are spaced from the chill rolls. The rolls and the sealing elements are cooled so that foamable molten polymer in the space between the sealing elements and the rolls becomes solidified, completing the seal. The chill rolls are maintained at a temperature below the temperature of the molten polymer to aid the skin formation on the surfaces of the polymer. If desired, the polymer can pass directly from the chill rolls into a water bath.

Abstract: The invention provides a novel method for the preparation of a foamed body of a vinyl chloride-based resin composition having a very fine and uniform cellular structure in a continuous process with outstandingly low costs. The method utilizes a binary volatilizable blowing agent composed of (i) a first volatilizable organic compound which is a halogenated or unhalogenated aliphatic hydrocarbon boiling at 90.degree. C. or below and (ii) a second volatilizable organic compound selected from halogenated or unhalogenated aromatic hydrocarbons, ethers, ketones and esters having a specified solubility parameter in consideration of the compatibility with the vinyl chloride-based resin.

Abstract: Forming polystyrene foam by extruding polystyrene, nucleating agent, physical blowing agent, and water where the physical blowing agent and water are injected into extruder to provide blowing system. The product produced has small cells at junction points between membranes of the foam.

Abstract: A method and apparatus for preparing a substantially uniform thermoplastic foam extruded from an extruder, the molten thermoplastic resin having uniformly distributed therein a foaming agent. A cooling-mixer continuously receives the extruded mass of resin and foaming agent from the extruder and intimately mixes and substantially cools the mass. A substantially adiabatic zigzag mixer is connected to the cooling-mixer and divides the mass into a plurality of separate streams which are at least partially separated and recombined. A die is connected to the zigzag mixer and extrudes the uniformly cooled mass into a lower pressure zone to produce a substantially uniform thermoplastic foam.

Abstract: In a method of producing a plate-like polystyrene resin foam which comprises extruding a molten mixture of a polystyrene resin and a volatile blowing agent from an extruder into a zone kept at a lower pressure than the inside of the extruder, the improvement wherein the volatile blowing agent is a mixture consisting of 50 to 80% by weight of dichlorodifluoromethane and 50 to 20% by weight of ethyl chloride and is present in said molten mixture in a proportion of 8 to 17 parts by weight per 100 parts by weight of the polystyrene resin.

Abstract: An improvement is disclosed in a process for producing foamed articles of thermo-plastic or thermo-setting compounds. The improvement reduces the number of steps normally followed to make a foamed product and cuts down on the time.

Abstract: Fine-celled foams are produced by a process in which a styrene polymer is melted, the melt is mixed with a volatile blowing agent and a nucleating agent under superatmospheric pressure, the mixture is let down to atmospheric pressure, and the foam is cooled. The nucleating agent employed comprises from 0.02 to 2% by weight of the calcium salt of a long-chain fatty acid, and from 0.01 to 1% by weight of a finely divided, inorganic substance which is insoluble in the styrene polymer, a mixture of calcium stearate and magnesium oxide being preferred.

Abstract: A blowing agent composition is provided comprising an azodicarbonamid; zinc oxide, zinc carbonate or a zinc salt of C.sub.1 -C.sub.4 organic acid; and an aromatic sulfinic acid or a metal salt of an aromatic sulfinic acid. For each hundred parts by weight of the azodicarbonamid, the zinc oxide, zinc carbonate or zinc salt is 0.25-25 parts by weight and the aromatic sulfinic acid or metal salt is from 1-2000 parts by weight for each 100 parts of the zinc oxide, zinc carbonate or zinc salt. The total weight of the zinc oxide, zinc carbonate or zinc salt plus the aromatic sulfinic acid or metal salt is from 20-25 parts by weight.

Abstract: A process for obtaining cellular materials from unsaturated polyester resins reinforced with fillers having a density below 0.7 kg/lt by injecting a liquid foam, made from the resins by mechanical introduction of a gas therein into a closed mold, is described. The liquid foam, obtained from polyester resins including additives and optionally a reinforcement of synthetic, artificial, vegetable or mineral fibres having a length lower than 5 mm, and optionally containing a low boiling foaming agent, is injected voluminized and cross-linked in the hot or in the cold in a closed mold containing a reinforcing agent of synthetic, artificial, vegetable or mineral fibers as a monofilament mat, a cut fibre mat, a mono or bidirectional roving woven mat, rovings, fabrics.

Abstract: A process for producing a foamed and molded article of a polypropylene resin, which comprises pressurizing preliminarily-foamed particles of an ethylene/propylene copolymer having a melt index value of from 0.1 to 25, a latent heat of crystallization of not more than 28 cal/g and an ethylene content of from 1 to 30% by weight as a base resin with an inorganic gas or a gaseous mixture of the inorganic gas and a volatile blowing agent thereby to impart an elevated pressure to the inside of said particles, thereafter filling said particles in a mold capable of enclosing the particles but allowing escape of gases therefrom, and then heating said particles to expand them to the configuration of the mold.

Abstract: Methods of converting essentially unpolymerized precursors into polyimides in which the precursors are exposed to microwave radiation. Preheating, thermal post-curing, and other techniques may be employed to promote the development of optimum properties; and reinforcements can be employed to impart strength and rigidity to the final product. Also disclosed are processes for making various composite artifacts in which non-polymeric precursors are converted to polyimides by using the techniques described above.

Abstract: A blowing agent composition is provided comprising:(a) zinc formate, and(b) a compound having the formula M.sub.m X, wherein M is sodium or potassium; X is chlorine, bromine, iodine, CO.sub.3, HCO.sub.3, SO.sub.4, SO.sub.3, S.sub.2 O.sub.3, NO.sub.2, SCN, OCN, BO.sub.2, HBO.sub.3, HPO.sub.4, PO.sub.4 or H.sub.2 PO.sub.4, and m is an integer representing the valence of X; or a compound having the formula M.sub.n.sup.1 R.sub.p, wherein M.sup.1 is alkali metal, calcium, lead or zinc, R is organic mono- or polybasic acid having 1-18 carbon atoms and from 0 to 2 nitrogen atoms, or a benzenesulfonyl or toluenesulfonyl radical; and n and p are integers representing the valences of R and M.sup.1, respectively or whole fractions thereof.

Abstract: Mechanically stable styrene polymer foams having highly desirable physical properties are prepared employing as a blowing agent a mixture of lower alcohols with chlorofluoromethanes.

Abstract: A method and apparatus for entraining gas as a blowing agent in a thermoplastic melt to provide a foamed thermoplastic extrudate wherein an annular sheet-like flow of gas under pressure is impinged on a tubular configuration of melt to entrain the gas in the melt is disclosed. Also disclosed is an improved method and apparatus for controlling the pressure in the thermoplastic melt.

Abstract: A heat-insulating paper container having good heat-insulating property which can be prepared easily at low cost is disclosed. The paper container is prepared by heating a paper container comprising a body member and a bottom member, wherein one surface of at least the container body member is coated or laminated with a thermoplastic synthetic resin film and the other surface of the body member is coated or laminated with the same or different thermoplastic synthetic resin film or an aluminum foil, to thereby foam the thermoplastic synthetic resin film and form a heat-insulating layer on at least one surface of the container.

Abstract: An open-cell foamed article of a cross-linked polyolefin having a high open-cell ratio and a high degree of expansion is produced by a method which comprises the steps of preparing a foamable and cross-linkable polyolefin composition, forming the composition into a desired shape maintaining its gel percent at zero, decomposing the cross-linking agent and blowing agent concurrently by heating the composition under atmospheric pressure in such conditions that the peak of the ratio of the degree of cross-linking to the degree of decomposition of the blowing agent is not more than 20 and exerting a mechanical deformation to the resulting polyolefin foam to rupture the cell membranes.

Abstract: This invention provides a method of continuously manufacturing a cross-linked polyvinyl chloride resin foam sheet which has a low density, uniformly fine cell, excellent thermal moldability and high heat resistance and is neither deformed nor deteriorated even by long storage characterized by uniformly kneading the polyvinyl chloride resin with a blowing agent, stabilizer, plasticizer and cross-linking promoter without causing the blowing agent to decompose itself, thereby providing an unfoamed kneaded composition in which the polyvinyl chloride resin is gelled and forming said composition into a continuing sheet, irradiating said sheet with ionizing radiation to cross-link the resin; and thermally foaming the cross-linked sheet.

Abstract: A process for preparing an open-cell structure from a vinyl chloride resin. The process includes mixing a vinyl chloride resin, stabilizer, plasticizer, surface active agent, azodicarbonamide and 4,4'-oxybisbenzenesulfonyl hydrazide to form a vinyl chloride resin paste. The vinyl chloride resin paste of step (a) is rendered alkaline, and mixed to form a uniformly-mixed paste. The paste is permitted to expand, and then heated to cause gelation.

Abstract: The present invention is directed to a process for producing foamable polyolefin particles comprising adding a mixture of 3 to 15 parts by weight of a blowing agent and 0.5 to 5 parts by weight of a blowing aid to 100 parts by weight of polyolefin particles maintained in a fluid state. The addition of the mixture of blowing agent and blowing aid is conducted under substantially anhydrous conditions, which result in the blowing agent being present in the particles in a gas phase and not a liquid phase. Polyolefin particles comprise polyolefin resin with vinylaromatic resin chemically bonded thereto.