Abstract: Water instead of carbon dioxide is substituted for part of the volatile organic blowing agent, e.g., pentane, resulting in extruded foams having a smooth, lustrous drum side skin compared to foams containing only organic blowing agent or organic blowing agent plus carbon dioxide.

Abstract: The present invention is directed to a process for the production of matte, non-blocking, thin-walled molded articles, films or tubes from polyurethane elastomers prepared from high molecular weight polyols which contain dispersed polyadducts based on polyisocyanate polyaddition products. The use of these high molecular weight polyols contained dispersed polyadducts allows for the preparation of thin-walled, molded articles which have reduced surface tackiness. The present invention is additionally directed to the molded articles produced by this process and to their use for forming polyurethane foam composites.

Abstract: In a filament winding technique, filaments are wound around a mandrel, and the mandrel remains in the structure and becomes part, normally a structural part, of the article. The mandrel may be any suitable rigid, light-weight material, but a foamed material such as a structural foam is thought to be most suitable. Metal inserts for attaching other components to the filament wound article can be moulded into the mandrel surface, and locked in place by the filament windings. According to a preferred aspect of the invention a motor vehicle suspension wishbone is made according to such filament winding method and the mandrel on which the filaments are wound remains in the structure.

Abstract: The present invention relates to a process for the production of polyurethane-urea or polyurea-based microcellular of foam moldings by reacting a polyisocyanate component containing aromatically bound isocyanate groups with an isocyanate-reactive component containing at least one compound which has at least three aliphatic ether groups and aliphatically bound isocyanate-reactive groups and wherein a portion of the aliphatically bound-reactive groups are amino groups which have been converted to ammonium carbamate, carbonate or bicarbonate groups.The present invention also relates to the compounds containing aliphatic ether groups and ammonium carbamate, carbonate or bicarbonate groups, optionally in admixture with compounds containing unmodified amino groups or other known isocyanate-reactive compounds.

Abstract: Pipelines for transporting sewage, water, slurries, liquid and gaseous hydrocarbons, and like materials are interlined with a composite tubular lining having an inner skin layer and a foamed layer contiguous with the inner skin layer. The foamed layer is either contiguous also, along its opposite surface, with the inner wall of the pipe or may be spaced therefrom by an outer skin layer of the composite lining. The lining may be applied either before the pipeline is placed into service or afterward, whether in situ or removed for maintenance or repair. For application in situ the lining is preferably more flexible than will suffice for insertion into new pipes.

Abstract: A steering wheel having the hand wheel part thereof formed of an injection molded foam of thermoplastic synthetic resin, which injection molded foam has a substantially solid outer surface and is covered with a coating. This steering wheel is produced in attractive appearance without requiring use of any specially formulated resin material or exercise of rigid control of molding conditions.

Abstract: A method of re-shaping polyimide and modified polyimide foam sheets into selected shapes. Polyimide foam sheets can be made by any of a number of methods, some of which produce sheets of selected thicknesses directly and others of which produce blocks or buns of foam which are sliced into sheets. A sheet is placed in a mold having the desired configuration, such as a half-pipe. The sheet is compressed to about 0 to 99% of the original thickness with heating of one or both major surfaces of the sheet to a temperature of from about 250.degree. to 320.degree. C. for about 0.5 to 5 minutes. Upon removal from the mold, the polyimide foam is found to be self-supporting and to have taken on the mold shape. A moisture impervious densified skin is found on the heated side(s).

Abstract: The invention relates to a process for the preparation of cellular, microcellular and noncellular polyurethane polyurea molded parts through the reaction of organic polyisocyanates, polyols having at least 2 reactive hydrogen atoms, and a chain extender containing at least 70 percent by weight of a mixture of aromatic diamines comprising from 80 to 50 weight percent of at least one primary aromatic diamine whose amino groups are sterically hindered relative to reaction with polyisocyanates, and 20 to 50 weight percent of at least one unsubstituted or substituted reactive primary aromatic diamine whose amino groups do not exhibit reduced reactivity to polyisocyanates.These reactive mixtures produce polyurethane polyurea polymers with excellent demoldability without the use of external mold release agents.

Abstract: A pre-shaped aluminum plate is held against the flat end wall of an inverted mold cavity by vacuum pressure communicated through bore holes in the wall leading to a vacuum chamber in the mold body. A high temperature PTFE gasket shaped to match the plate fits in an annular recess in the wall to provide a seal between the wall and plate. Polyurethane foam expands and hardens in the mold cavity to further press the plate against the wall and to form a foamed plastic water ski having a flush aluminum deck. The mold cavity has a curved side wall to produce a ski having a radiused edge about the deck.

Abstract: A mold for use in heat expanding prefoamed polystyrene beads to form a part of a predetermined shape is disclosed. The mold comprises a cavity defined by separable mold wall portions. Each mold wall portion has on its exterior a chamber into which a heating medium is introduced to heat the mold walls and also into which cooling medium is introduced to cool the walls. A plurality of nozzles are provided in the mold walls and a corresponding plurality of tubes interconnect the nozzles to a manifold located in the corresponding chamber. A pressurized heating medium is introduced to the manifold whereby the heating medium is injected into the cavity to expand prefoamed polystyrene beads in the cavity. A device is provided on the manifold for the selective removal of condensate from the manifold. The mold construction provides for an economical, readily manufactured unit.

Abstract: Crimped foamed fibers are produced by a process which eliminates any mechanical deformation steps. The process comprises the step of forming foamed fibers having a plurality of randomly arranged cells distributed asymetrically over a given cross section and occupying at least about 10% of the cross sectional area of the fiber, and heating the foamed fibers while maintaining the fibers under no load condition to produce a crimped foamed fiber. The crimped foamed fibers are used in apparel, carpet fibers, thermal insulation, acoustic and filtration.

Abstract: Polymer compositions and methods of making them are provided. Selected surface layers of the polymers, integral with the polymer body, possess pressure sensitive adhesive properties. The polymers are cured with the selected surfaces in contact with a cross-linking inhibition agent which controls the amount of cross-linking of the polymer taking place at the surface. The polymers are useful as, or in conjunction with, prosthetic appliances which are adhered to skin or other substrates.

Abstract: The present invention is directed to a process for the production of optionally cellular, polyurethane and/or polyurethane-urea moldings having an impervious skin by reacting in a closed mold a reaction mixture containing(a) at least one organic polyisocyanate,(b) at least one compound which has a molecular weight of about 400 to 12,000 and at least two isocyanate-reactive groups, and(c) optionally at least one compound which has a molecular weight of from 32 to 399 and at least two isocyanate-reactive groups,wherein before the reaction takes place a surface-improving additive (e) is added containing(e1) a liquid and sedimentation-stable polymer dispersion which is produced by the free radical addition polymerization or copolymerization of one or more olefinically unsaturated monomers in a high molecular weight compound having isocyanate-reactive groups of the type mentioned in (b),and optionally(e2) a metal salt of a monocarboxylic acid having at least 8 carbon atoms in the moleculewherein additive (e) is us

Abstract: The invention relates to a process for the preparation of elastomeric molded parts having urethane or urethane and urea linkages which comprises reacting(a) an organic polyisocyanate,(b) a polyhydroxyl compound selected from the group consisting of(i) polyester polyols with molecular weights of 1000 to 3000 and hydroxyl numbers of 170 to 35 produced by polycondensation of organic dicarboxylic acids and a polyol mixture of at least 3 polyols;(ii) polyether polyols having terminal ester groups, molecular weights of 1000 to 8000 and hydroxyl numbers of 170 to 15; and(iii) mixtures thereof;(c) a chain extenderwherein components (a) through (c) are processed according to reaction injection molding techniques in open or closed molds.The reaction is preferably carried out as a one-shot process and may also be carried out in the presence of blowing agents (d), auxiliaries (e), and additives (e).

Abstract: A bicycle wheel assembly prepared by a process comprising the steps of:(a) Inserting a bicycle rim assembly comprising a central hub, a plurality of radially extending spokes joined to said hub at one end and a rim having a channular cross section joined to the opposed ends of the spokes into a mold cavity configured to form a bicycle tire around the rim;(b) Injecting a foamable polyurethane composition into said mold cavity;(c) Foaming and curing the polyurethane composition in the mold cavity; and(d) Cooling the so-foamed polyurethane composition to cause it to shrink fit around the rim.

Abstract: A filter element comprising a hydrophilic organic polymeric microporous filter membrane having a preformed substantially non-porous sealing area and a filter housing having, preferably, a hydrophobic thermoplastic sealing surface in thermoplastic sealing relationship with the sealing area. Preferably, the filter membrane is a pleated cylindrical membrane and the housing includes endcaps thereto. The preferred membrane is nylon.The preferred pleated cylindrical membrane is produced from an elongated porous filtration area longitudinally bordered by substantially non-porous sealing areas. Such a membrane may be produced by a specific casting method or collapsing the pores along the longitudinal borders of the filtration area. The filter element is particularly useful for the filtration of aqueous liquids, particularly parenteral or body liquids.

Abstract: The present invention is directed to a process for the production of a molded article having a compact surface layer and a gross density above 900 kg/m.sup.3 via the reaction injection molding technique, comprising introducing a reaction mixture into a closed mold, said reaction mixture comprising:(a) a polyisocyanate component consisting of at least one polyisocyanate in which all the isocyanate groups are aromatically bound,(b) compounds having molecular weights of from 400 to 12,000 and having at least two isocyanate reactive hydrogen atoms,(c) water, in a quantity of at least 0.

Abstract: A machine for molding sheets of foamed material includes an upright stationary steam chest having opposing perforated external faces, and a pair of movable assemblies abuttable with the opposite faces of the steam chest to define mold cavities therewith. Each cavity forming assembly includes a mold frame extending normal to a face of the steam chest, and a platen positioned within and coupled to the mold frame. Jackscrews move each mold frame into and out of abutment with the steam chest, and also move each platen relative to its respective mold frame toward and away from the steam chest. A method of molding sheets of foamed material is also disclosed wherein heated polystyrene beads are squeezed by the movable platens to a predetermined thickness to provide a board having the desired dimensions and density.

Abstract: A method of producing thermoplastic resin foams is disclosed. The method comprising extruding an expandable resin through a plurality of holes bored in a die in the inside of a frame fitted to the extrusion end surface of the die in an adjacent relation therewith and fusing together the thus-extruded materials while they are expanded and still softened, wherein the inner surfaces of the frame are inclined at an angle of inclination ranging between 5.degree. and 30.degree., so that the cross-sectional area of the frame is increased toward the outer end thereof, and the extruded materials are fused together while kept in contact with the inner surfaces of the frame.

Abstract: An inexpensive, cellular plastic mold and method of preparation, wherein the plastic mold comprises male and female mold elements which define a mold cavity therebetween, each of the elements comprising a rigid thermoplastic foam or cellular board material having a smooth, integral, solid layer of a plastic material forming the facing surface of the mold cavity and a relatively thick, solid, supporting layer of a plastic material forming the back surface of the mold elements.

Abstract: A method of manufacturing a thermally insulated building block (54a) comprises foaming a quantity of foamable plastics material in an enclosed space (56) between a building block (54) and a closure means (52), the quantity of material being sufficient to fill the enclosed space (56). The foamable material may be injected into a cavity in the block onto an outer surface of the block (54) or onto the closure means (52) prior to locating the block (54) and closure means (52) relative to each other to form the enclosed space (56) therebetween. The block (54) is transported between upper and lower parallel endless belts (55, 50) during foaming and either belt (55, 50) may provide the closure means (52). If the lower belt (50) provides the closure means (52) the upper belt (55) maintains the block (54) in contact with the closure means (52) during foaming.

Abstract: The invention relates to a process and apparatus for manufacturing adapter blocks with channels and making a mold system for producing the blocks. The adapter blocks have channels in at least one surface and connection openings running through the thickness of the blocks.For forming the connection openings the mold has anchoring pins and it is designed for producing more than one adapter block at a time. The casting material is supplied into the mold from below and along one long side thereof. Gasket plates with nipples are placed on the connection side or sides, such nipples being received in conical connection openings.

Abstract: A process for producing a shaped article of a non-cellular or microcellular polyurethane elastomer by reaction injection molding by using at least two components of (A) a polyol component comprising a high molecular weight polyol and a chain extender as essential ingredients and (B) an isocyanate component comprising a polyisocyanate compound as essential ingredient, characterized in that substantially all or at least 80% by weight of said high molecular weight polyol is composed of a polyoxyalkylene polyol, and the polyoxyalkylene polyol is a single or mixed polyoxyalkylene polyol which has an average hydroxyl number of from 2.0 to 3.5 and an average hydroxyl value of from 15 to 60 and contains at least 5% by weight, in an average, of oxyethylene groups at the terminal portions of the oxyalkylene chain and in which the total oxyethylene group content is, in an average, less than 21% by weight and the average unsaturated monool content is at most 0.085 meq/g.

Abstract: Cushioned automotive strap handles with spring steel base strips, cushions, and wrapped and sealed covers are made by injection molding resin cladding directly onto steel base strips before assembly with the cushion and cover. The base strips 10 are cut to length with formed end regions 11 which are mounted on a mold part 15 so that a midregion of base strip 10 spans an injection mold cavity 18. Pins 21 within mold cavity 18 locate base strip 10 in a plane spaced from the cavity walls so that the cavity surrounds the midregion of the base strip. The injection molded resin cladding 25 also surrounds the midregion of base strip 10 and provides raised resin shoulders 20 extending along longitudinal side edges of the base strip. The surrounding engagement of cladding 25 secures resin shoulders 20 against transverse movement relative to the base strip.

Abstract: An adapter block having fluid channels is made up of at least two parts bonded together. At least one of the parts is made up of an integral skin foam material, more specially polyurethane. A foam-molded core of this material is covered over by an integrally molded, unfoamed skin. At the faces that are to be bonded the skin is first machined away by a roughening tool. A mold for producing the adapter block is made up of two mold end parts with hollows to take up mold pins so that mold pins or stoppers may be put therein. The mold end part opposite to the end part with the pins is made of an elastically soft material. The mold pins may have concave end faces.

Abstract: An improved foamable vinyl aromatic polymer composition and a process for preparing a vinyl aromatic polymer foam having incorporated therein a blend of alpha-olefin polymers are disclosed. The blend of alpha-olefin polymers may be virgin material or a portion of recycle feedstream, the recycle feedstream being prepared from adhesive film faced extruded vinyl aromatic foam laminate scrap. Foam materials having improved solvent resistance, ultraviolet light stability, and adhesive characteristics are prepared from the composition and process.

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: An adapter block having connection openings provided in and extending normal to a surface thereof is produced by a process which includes the steps of foaming a resin compound such as a polyurethane in a mold cavity which has a shape complementary to the adapter block, the resulting component having an integral skin on the exterior surfaces thereof; then allowing the component to harden; then machining the integral skin off the mentioned surface and a surface on the opposite side of the component; and then applying an adhesive to and placing further components against the machined surfaces so that the further components become secured to the first-mentioned component.

Abstract: A process of producing a moulding by introducing thermoplastics material into a mould space through gate means having a passageway, which process includes the formation of a sprue in the passageway. A retractable member cuts off the sprue before the material solidifies and closes the passageway at its junction with the mould space, the sprue being subsequently ejected from the passageway of the gate means before the next moulding cycle. A holder provides the gate means and the retractable member which is preferably inclined to the passageway. The gate means may also provide air ejecting means for removing the sprue and may conveniently be bolted onto an otherwise conventional injection moulding machine. The retractable member may incorporate a feed pipe for injecting a fluid into the plastics material.

Abstract: The invention comprises a method and apparatus to quickly heat a mold cavity surface or portions thereof just prior to the injection of a foamable plastic resin. The apparatus comprises one or more thin metal surface sheets or bands of high electrical resistivity in the mold cavity covering those portions of the mold where a smooth surface finish on the product is desired. In an alternative form the surface sheets may be plated or sprayed metal of high resistivity on a layer of thin electrically non-conducting plastic in turn adhered to the mold cavity surface.The thin metal surface sheet is resistance heated approximately 300.degree. F. in a few seconds or less by a low voltage high current source of electric power just prior to the injection of the foamable plastic. The high current passing through the metal of high resistivity causes conversion of electrical energy into sensible heat very quickly to accomplish quick heating of the mold cavity surface sheet.

Abstract: A pre-shaped aluminum plate is held against the flat end wall of an inverted mold cavity by vacuum pressure communicated through bore holes in the wall leading to a vacuum chamber in the mold body. A high temperature PTFE gasket shaped to match the plate fits in an annular recess in the wall to provide a seal between the wall and plate. Polyurethane foam expands and hardens in the mold cavity to further press the plate against the wall and to form a foamed plastic water ski having a flush aluminum deck. The mold cavity has a curved side wall to produce a ski having a radiused edge about the deck.

Abstract: A method for forming foamed plastic articles which includes the steps of closing a mold; prepressurizing the mold cavity with gas to prevent premature diffusion of blowing gas from the material injected into the cavity; injecting a short shot of molten synthetic resin material containing a blowing agent into the cavity; venting a portion of the prepressurization gas during the injection step; and venting the remaining prepressurization gas from the mold cavity to a vacuum chamber means to allow expansion of the injected foamable resin material within the mold cavity, the vacuum drawing the resin material throughout the mold cavity. In addition, the vacuum chamber is coupled to the mold cavity through plural spaced passageways so that the vacuum is drawn at various locations throughout the cavity to thereby enhance the complete filling of the cavity with the injected material as it expands.

Abstract: A method of forming a synthetic article by open forming techniques by providing a fluid composition containing a predominant quantity of synthetic resin and having a capability for delayed, substantial gas evolution. To produce reinforced articles, the composition is applied to the reinforcement at a temperature below a predetermined gas evolution temperature and is subjected to fluid spreading conditions to thoroughly wet the elements of reinforcement. Subsequently, the fluid composition reaches the predetermined temperature, the resultant gas evolution effectively expands the composition while it remains in thorough wetting contact with the reinforcement elements, and the resin then solidifies and cures to produce an intimately reinforced, expanded article. In important embodiments the preponderant gas evolution results from the reaction of an organic hydroperoxide with an isocyanate in the presence of a surfactant.

Abstract: A method and apparatus for making a twin-wall internally corrugated plastic structural part provided with a smooth, dense, solid, thin walled, non-cellular skin comprising injecting a thermoplastic or resin material into a pair of closed mold members which define a sealed cavity. A small amount of plastic material is initially injected into the cavity with the material impinging upon and being dispersed over the mold members thereby forming a generally continuous thin skin substantially the mold surfaces. Thereafter, successively and intermittently injecting an inert gas under pressure through one mold member during continued injection of the plastic material into the cavity thereby pressurizing the skin against the walls of the mold cavity and progressively commingling the inert gas under pressure and the inwardly flowing plastic material as both enter the cavity until the cavity is filled with an internal corrugated body integral with and bonded to the skin.

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: A process for producing a highly expanded polyolefin insulated cable comprising the steps of feeding a compound of polyolefin, nucleating agent and volatile liquid to an extruder, heat extruding said compound through said extruder onto an inner conductor passing through said extruder to cover the outer periphery of said inner conductor thereby forming an insulation layer of highly expanded polyolefin foam having a foaming ratio in excess of 2.5 times (60% expansion degree) tightly adhered to said inner conductor.

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: A method for making polyurethanes in a mold that is cooler than usual; i.e., at a temperature less than 120.degree. F., is described. Normally, polyurethanes made in relatively "cold" molds contain numerous surface voids. However, N-alkylmorpholines have been discovered to be effective "cold sink" catalyst additives which permit void-free polyurethane formation even in cooler than average molds. The additive should comprise from about 10 to about 30 wt. % of the entire catalyst portion of the polyurethane formulation.

Abstract: A method of manufacturing a protective and decorative molding for an automobile, comprising the steps of: adding a foaming agent to a starting resinous material comprising a vinyl chloride polymer or copolymer or a blend thereof; kneading the foaming agent and the starting resinous material; successively forming the kneaded mixture into an elongated rod or sheet blank by means of extruder or calender rolls; shearing the rod or blank into pieces having a predetermined shape; and molding the piece in a mold having high-frequency heating electrodes to apply a high-frequency voltage to the piece so that the foaming agent contained in the piece decomposes and foams to provide a product having a predetermined shape.

Abstract: A polyamine mixture formed from formaldehyde, an ortho-alkylaniline, and an ortho,ortho-dialkylaniline. The polyamine mixture is prepared by heating one of the anilines with formaldehyde, mixing the other aniline with an acid catalyst, and slowly adding the former to the latter. The mixtures are useful as chain extenders in polyurethane processes including reaction injection molding. The novel mixtures give unexpected mold gel and set times as compared to corresponding unmixed compounds formed from a single aniline or formed by previous typical condensation reactions. Also, the proportion of polyamines made by the novel mixtures may be varied to give excellent physical characteristics.

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: A machine for molding sheets of foamed material includes an upright stationary steam chest having opposing perforated external faces, and a pair of movable assemblies abuttable with the opposite faces of the steam chest to define mold cavities therewith. Each cavity forming assembly includes a mold frame extending normal to a face of the steam chest, and a platen positioned within and coupled to the mold frame. Jackscrews move each mold frame into and out of abutment with the steam chest, and also move each platen relative to its respective mold frame toward and away from the steam chest. A method of molding sheets of foamed material is also disclosed wherein heated polystyrene beads are squeezed by the movable platens to a predetermined thickness to provide a board having the desired dimensions and density.

Abstract: An improved foamable vinyl aromatic polymer composition and a process for preparing a vinyl aromatic polymer foam having incorporated therein a blend of alpha-olefin polymers are disclosed. The blend of alpha-olefin polymers may be virgin material or a portion of recycle feedstream, the recycle feedstream being prepared from adhesive film faced extruded vinyl aromatic foam laminate scrap. Foam materials having improved solvent resistance, ultraviolet light stability, and adhesive characteristics are prepared from the composition and process.

Abstract: A method of improving the physical properties of high density reinforced reaction injection molded microcellular or solid elastomers is disclosed. The method involves placing an inert filler material wholly in the isocyanate component of a two component reaction system where the other component contains predominantly polyol before mixing the components to effect reaction. This modification will result in an improvement in tensile strength and thermal dimensional stability when compared to placing the inert filler material in the polyol component before reaction.

Abstract: Integral skin polymethane foams can be produced in a short time by impingement mixing a solution comprising polyols containing as an essential component a polyol derived from aromatic amine, a blowing agent and a special catalyst of tertiary amine salt having a hetero ring in the molecule, with a solution comprising one or more polyisocyanates, followed by injection into a closed mold and foaming and curing therein.

Abstract: A process for producing injection molded articles of foamed thermoplastic material via injecting of a molten mass of thermoplastic material containing a foaming agent into a mold cavity is improved so as to substantially reduce production time by the utilization of a step introducing a cold compressed gas into the mold cavity internally of the injected mass of material, while it is still at least internally molten. The article produced by the process is characterized by an outer skin of tightly structured material surrounding a body of microcellular foam material having an internal void or voids bounded by material of a tightly structured nature.

Abstract: An electrically heated fluid conduit includes a plastic pipe adapted to carry a flow of fluid subject to freezing at low temperatures, an electric resistance heater disposed around the pipe and extending along the length thereof and a thermal insulating jacket disposed around the heater. The heater is formed as a seamless sleeve of synthetic polymeric material having electrically conductive carbonaceous particles therein and is connected to the lead wires of an electrical power cable by a pair of spaced electrically conductive bands fixed around the sleeve and defining the length of the heater along the pipe. The thermal insulating jacket is formed as a seamless layer of foamed synthetic plastic material having randomly disposed air pockets.

Abstract: An article having a relatively lower density polystyrene core and a relatively higher density polystyrene skin is prepared by a method in which a mold is supplied, simultaneously and/or sequentially with electrostatically charged prepuffs of a relatively higher density polystyrene and relatively uncharged low density prepuffs. The walls of the metal mold preferentially attract the electrostatically charged particles. The uncharged lower density prepuffs concentrate at the core. The thus filled mold is subjected to the heating and cooling cycle to provide a molded article having a core with a lower density than the skin.

Abstract: The present invention is directed to a method of producing phenolic foams comprising introducing into a substantially closed volume a phenolic resole resin foamable composition and allowing the composition to foam in this volume wherein a pressure in excess of ambient atmospheric pressure is achieved within this volume. This pressure in excess of ambient atmospheric pressure generally is in excess of about 2 pounds per square inch, typically in excess of about 5 pounds per square inch, and preferably in excess of about 6 pounds per square inch, gauge pressure.The present invention is also directed to foams produced by the method of the invention.