Abstract: This invention relates to reaction injection molded elastomers derived from high molecular weight amine terminated polyethers and/or high molecular weight polyols, a chain extender, a polyisocyanate, a chloro and/or isocyanate silane coupling agent, and untreated filler material. The reaction injection molded (RIM) elastomers of this invention are useful, for example, as automobile body parts.

Abstract: A first reaction mixture, prepared from (a) isocyanates with isocyanate contents of from 5 to 50% and (b) compounds with molecular weights of from 32 to 10,000 which contain at least two isocyanate-reactive hydrogen atoms, in an equivalent ratio of component "a" to component "b" of 0.8:1 to 5:1, from 0.1 to 20% of a blowing agent and, optionally, other known additives, is introduced into the rigid cavity of a closed mold. After this mixture has become resistant to permeation, but is still compressible, a second reaction mixture, either the same or different from the first reaction mixture, prepared from (c) isocyanates having isocyanate contents of from 5 to 50% and (d) compounds with molecular weights of from 32 to 10,000 which contain at least two isocyanate-reactive hydrogen atoms, in an equivalent ratio of component "c" to component "d" of from 0.

Abstract: A two part RIM nylon-based urethane block polymer consists of an anionic metal salt catalyst in minor proportions and a prepolymer consisting of the reaction product of a diisocyanate with a mixture of a polymeric triamine having primary amine groups and a polyether diol in a large excess of a ring lactam which serves as a reaction diluent. The prepolymer preparation process is characterized by the immediate formation of a visible high molecular weight polymer gel which redissolves with continued agitation. No free or extractable polymers, diols or isocyanate is observed in the polymer product.

Abstract: A machine for manufacturing foam building blocks (39) and the like wherein a plurality of two-piece forming molds (21) are continuously moved by a conveyor mechanism along a closed path-of-travel (22) is disclosed. Filling, curing and injection stations (31, 32 and 33) are located along the path-of-travel (22). As a mold (21) enters the filling station (31), the nozzle (37) of a foam gun (35) enters a hole (34) in the top of the mold (21) and moves with the mold (21) as that mold continues to move along the path-of-travel (22). At the end of the filling station (31), after the foam gun (35) has injected a suitable amount of resin, curing and foaming agent materials into the mold (21), the nozzle (37) rises from the hole (34). Thereafter, a cap-latch (36) is moved into a hole closed position. In addition to closing the hole (34), the cap-latch (36) forms one of two latches that latch the two mold pieces (21a and 21b) together. The other latch (38) is located on the opposite side of the forming molds (21).

Abstract: Disclosed is an improved process for the production of organic polyisocyanate-based molded polymers prepared from at least one organic polyisocyanate and at least one polyol wherein there is employed an internal mold release agent comprising an amino-polysiloxane having at least one group of the formulaRNH-alkylene--O--bonded to a silicon atom of a polysiloxane, wherein R is selected from the group consisting of hydrogen, lower-alkyl, cycloalkyl, and ECHR"CHR'-- wherein E is an electron withdrawing group and R' and R" are independently selected from the group consisting of hydrogen and methyl.The molding process can be repeated many times before the mold surfaces must be cleaned or treated with release agent. The ease of release of the molded polyurethanes makes the process particularly suitable for RIM production methods.

Abstract: A method and apparatus for producing a molded article comprising covering at least a portion of the mold wall with a thin smooth surfaced soft lining as an integral permanent lower part of the mold cavity, thereafter loading a preformed grained vinyl shell against at least a portion of the soft lining; closing the mold and injecting a reactive plastic formulation into the mold such that the reactive plastic material forms a rigid backing layer that is strongly bonded to the vinyl shell without distorting the vinyl.

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 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: Polyamide-polyurea containing polymers are disclosed that are derived from the reaction of (A) an organic polyisocyanate; (B) an organic compound having at least two active hydrogen containing groups; and (C) about 15 to about 160 parts per 100 parts of said (B) of a chain extender combination comprising (i) a particular enamine and (ii) an aromatic diamine and optionally (iii) an extender diol wherein the ratio of equivalents of (A) to total equivalents of (B) and (C) is within the range of about 0.90:1 to 1.10:1.The polymers find particular utility in the preparation of RIM parts having excellent physical properties. At the same time, the polymers are characterized by slower gel times than prior art aromatic diamine extended polymers thereby allowing the filling of larger molded parts.

Abstract: An apparatus and method are disclosed which greatly facilitate molding of plastic material in the form of structural foam. The invention contemplates the provision of a valve-like mixing nozzle assembly which is selectively operable to control the flow of plastic material into an injection mold. Significantly, the nozzle assembly includes a mixing turbine rotatably mounted in the flow path of the plastic material. Notably, the turbine is driven by the plastic material itself as the material is driven into the mold assembly, and thus desirably provides intense mixing of the material during injection. This mixing action can be advantageously employed for effecting dispersion and/or expansion of the blowing agent carried by the plastic material for greatly enhanced control and flexibility in molding structural foam articles.

Abstract: Polyurethane, polyurea and polyureaurethane resins having improved mold release properties are made by including with the reactive ingredients certain internal mold release agents which are polysiloxane polymers having pendant organic groups which contain at least one hydroxyl, amino or mercapto group.

Abstract: Reaction injection molded elastomers made from polymer polyols derived by reacting a liquid terephthalic polyester polyol with an organic polyisocyanate in the presence of a polyether polyol solvent are described. The liquid terephthalic polyester polyol may be made by reacting residue or scrap polyethylene terephthalate (PET) with an oxyalkylene glycol. The oxyalkylene glycol is preferably either diethylene glycol alone or a mixture of diethylene glycol and at least one other oxyalkylene glycol. The liquid terephthalic polyester polyol is preferably distilled to remove ethylene glycol. RIM elastomers made from these polymer polyols have improved hot tear (green strength) and final tear properties than prior art elastomers.

Abstract: A first reaction mixture, prepared from (a) aromatic isocyanates with isocyanate contents of from 5 to 50%, and (b) compounds with molecular weights of from 32 to 10,000 which contain at least two isocyanate-reactive hydrogen atoms, in an equivalent ratio of component "a" to component "b" of 0.8:1 to 5:1, from 0.1 to 20% of a blowing agent and, optionally, other known additives, is introduced into a closed mold with a rigid cavity. After this mixture has become resistant to permeation, but is still compressible, a second reaction mixture, prepared from (c) aliphatic and/or cycloaliphatic polyisocyanates having isocyanate contents of from 5 to 50% and (d) compounds with molecular weights of from 32 to 10,000 which contain at least two isocyanate-reactive hydrogen atoms, in an equivalent ratio of component "c" to component "d" of from 0.

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 mixing and extruding nozzle for two reactant components has a housing formed with a mixing chamber, a pair of parallel and oppositely directed faces flanking and turned away from the chamber, respective injection passages having inner ends opening into the chamber and outer ends opening at the respective faces, and respective outwardly open grooves in the faces offset from the passages. A valve-type rocker pivotal relative to the housing about an axis perpendicular to and traversing the two faces and offset from the passages and grooves has two like halves each formed with a face confronting the respective housing face and a feed passage opening at the respective rocker face offset from the axis.

Abstract: A packaging system for encapsulating an article within a solid foam material. An article to be encapsulated is supported on a base. A wall enclosure is disposed on the base to form a mold cavity. At the top of the base and above the article to be encapsulated is a cover. Expandable plastic foam in liquid form is introduced into an orifice of the base and the expandable plastic foam advances through a passageway in the base and is discharged from an orifice in the base into the mold cavity to encapsulate the article. The foam material in liquid form solidifies into a solid plastic foam material for packaging the article.

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: A method and a mold for fabricating an aerodynamic airframe structure or the like. The method using foam material introduced into the mold having split halves. The mold constructed for receiving a prefabricated stiffener skin. The mold acts as a backup restraint for the airframe structure or any other part being produced. The foam injected into the cavity adheres to the stiffener skin thereby forming an elastic foundation of continuous support for the stiffening element.

Abstract: What is disclosed is a method of producing molded polyurethane articles by a reaction injection molding process which includes mixing one or more polyols, polyisocyanates and catalysts with an organopolysiloxane containing at least one --COOA group, wherein A is an alkali metal, and molding the curing the mixture.

Abstract: A method for producing a reinforced composite racket frame having an outer shell made of a fiber reinforced thermosetting plastic material and a foam core comprising the steps of: (a) placing an open-ended tubular shell of fiber reinforced thermosetting plastic material in a racket frame mold with two valve members respectively provided at an outlet and an inlet of the mold; (b) heating the mold to a first predetermined temperature for curing the tubular shell; (c) causing one of the valve members to be open and the other valve to be closed; (d) applying compressed air through the open valve to force the shell into intimate contact with an inner surface of the mold, the shell thereby assuming the shape of the mold; (e) cooling the mold to a second predetermined temperature at which the tubular shell becomes set to the mold shape; (f) opening the closed valve; (g) introducing a predetermined amount of a foamable material through at least one of the valves and into the shell; and (h) closing both of the valve m

Abstract: Shaped articles are provided containing a polymer which is capable of exhibiting anisotropy in the melt characterized in that the ratio of the stiffness in any two directions at right angles in the shaped article differs by at least 10%, and preferably by at least 50%, from the ratio in the same two directions for a control sample made from a melt consisting entirely of the polymer in anisotropic form.These may be obtained by a variety of methods including disturbing the normal flow pattern of flow into a mould by including obstacles to flow in the mould, disturbing the pattern of flow by foaming in the mould, by including fillers or by using polymers capable of existing as a bi-phase anisotropic and isotropic melt and forming shaped articles in which this two-phase disposition is retained.

Abstract: A process and apparatus for injection-molding a foamed article including a foamed core and an outer solid skin layer of unfoamed synthetic resin are provided. A first molten flow of the unfoaming synthetic resin is at first injected into a mold to form the outer solid skin layer. Subsequently, a second molten flow of a synthetic resin containing a foaming agent is fed into the first molten flow without stopping the first flow and is then mixed and kneaded to form a kneaded mass. The kneaded mass is then injected into the mold to form the core portion. Since the first flow is continuously fed during one operation cycle, the product molded article has no hesitation marks.

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: Method for casting a base directly on an electron tube comprising a stem and stem leads sealed in and extending out from the stem includes: A. detachably coupling a mold to the leads and stem, B. producing a temporary pressure seal between the mold and the stem including applying static pressure in a direction that is substantially normal to the surface of the stem and C. injecting liquid castable material into the mold at substantial hydraulic pressure while maintaining the static pressure at the temporary seal.

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: The addition of a small amount of a halogen compound, e.g. chloroethyl phosphate, in a process producing elastomeric polyurethane RIM parts using tertiary amines as the chief catalyst component results in scavenging the residual amines after the part has been cured by annealing. The parts from such a process can be coated with a wide variety of enamels having a high solids content and completely cured to result in a higher degree of adhesive between the coating and the part's surface than those parts from a process without the use of such a halogen.

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 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: 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: Disclosed is an improved process for the production of organic polyisocyanate based molded polymers prepared from at least one organic polyisocyanate and at least one polyol in the presence of an internal release agent wherein the improvement comprises employing as said agent a polysiloxane having at least one unit of the formula ##STR1## wherein R is selected from the group consisting of lower-alkyl and aryl, R.sup.1 is a divalent hydrocarbon radical, and R.sup.2 is selected from the group consisting of lower-alkoxy, aryloxy, particular hydroxyalkyleneoxy, alkoxyalkyleneoxy, amino, and hydroxyalkylamino radicals.The molding process can be repeated in many cycles before the molds require cleaning or treatment with release agent. The ease and rapidity with which the present process can be carried out makes it particularly suited to RIM production methods.

Abstract: The invention relates to apparatus for moulding a tire for a wheel rim by means of a mould having mould parts, said mould parts being movable between a closed working position in which they enclose a mould cavity with the shape of the tire and an open position in which said mould parts are spaced apart, wherein in the open position of the mould parts a hollow tire core is positioned in the mould cavity while being receivable with respect to said parts, wherein the mould parts are moved into the working position, in which a residual cavity not occupied by the tire core is left free in the mould cavity, said mould defining the residual cavity being adapted to receive synthetic resin foam for moulding a tire body. Preferably the tire core is arranged on the wheel rim before being positioned with respect to the mould parts.

Abstract: Hot runner injection molding apparatus for coinjecting two thermoplastic materials sequentially through separate channels to form at least a two-layer sandwich material is provided. There is a valve means for instantaneously switching the flow of thermoplastic material from one channel to the other channel, the valve means preferably comprising a shuttle ball member.

Abstract: The invention relates to a process for the preparation of polyurethane or polyurethane-polyurea molded parts by reacting organic polyisocyanates, polyols and chain extenders in the presence of monocyclic amidines having the formula ##STR1## as catalyst or catalyst mixtures of monocyclic amidines having the formula (I) and (a) tertiary amines, (b) metal salts having the formula Me X.sub.n Y.sub.m (II), and/or (c) optionally-substituted aliphatic carboxylic acids. R.sup.1 and R.sup.2, Me, X, Y, n, and m are defined herein.

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: 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: A process of reaction injection molding of polyurethanes is disclosed which includes the mixing of one or more of each of polyols, isocyanates, and catalysts, the reaction of the foregoing ingredients, and the molding and curing of the foregoing mixture into the desired configuration, the improvement comprising mixing with the other ingredients a silicone selected from the group consisting ofZ.sub.4-a SiG.sub.a and R.sub.3-d G.sub.d SiO(Y.sub.2-b G.sub.b SiO).sub.n SiG.sub.c X.sub.3-cwherein Z, R, Y, and X are selected from the group consisting of hydrogen, substituted and unsubstituted hydrocarbon radicals, and mixtures thereof; G is a radical of the structure --D(OR").sub.m OH wherein D and R" are selected from the group consisting of substituted and unsubstituted hydrocarbon radicals, and m has a value of 1 to 50; a has a value of 1 to 4; d and c have values of 0 to 3, and b has a value of 0 to 2 wherein d, c, or b has a value of at least 1; and n has a value of 0 to 350.

Abstract: An injection molded bowling pin with a core of thermoplastic plus a blowing agent and a solid skin of thermoplastic per se injected into the mold at one and the same time. The bowling pin is molded by a process wherein a foam material for forming the core is surrounded by and in contact with a nonfoam material and both materials are simultaneously injected into a mold cavity having the shape of a bowling pin. The skin and core may be of the same or of different thermoplastic. The bowling pin is a unitary structure of superior strength and finish with the foamed core and solid skin fused together.

Abstract: High quality plastic foam and the like expanded products and articles are made by incorporating a blowing agent in an acid-containing alkenyl aromatic polymer, such as a copolymer of styrene and acrylic acid; extruding while cross-linking the polymer with a polyfunctional cross-linking agent.

Abstract: The method comprises a masking step of closing by masking tapes a gap formed between a roof rail member provided at the inner periphery of an existing roof panel and the roof panel, a linear joint portion between the roof rail and pillar inner panels, and holes provided for securing parts to the roof rail. The method also includes a step of arranging a wire harness assembly at predetermined position a lining skin member below the roof panel by securing and fitting welts provided around the periphery of the lining skin member to the roof panel. A foaming mold setting step is then carried out by mounting a foaming mold having the same shape as a final shape of the lining skin member from a compartment of the vehicle. A heating step is then performed to preheat the whole ceiling portion to a predetermined temperature and a foaming composition injecting step of injecting a foaming composition into a spaced formed between the roof panel and the lining skin member is carried out.

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: The invention is a method of making a molded reaction injection molded elastomer which will release from its mold with reduced frequency of application of external mold release agents. The reaction injection molded (RIM) elastomer is made by injecting exactly two streams via a RIM machine into a mold cavity of the desired configuration, a formulation comprising in the first stream a high molecular weight polyhydric polyether, a low molecular weight active hydrogen containing compound of at least two functionality and an internal mold release agent, and in the second stream an aromatic polyisocyanate and tin catalyst in an amount equal to 100% of the tin catalyst present in the formulation. The resulting RIM elastomer may be removed from the mold easily. RIM elastomers are useful, for example, for automobile body parts.

Abstract: A method for manufacturing a heat-insulating member, such as e.g. a door or housing of a refrigerator, including a shell and a foamed heat-insulating material filled in the shell and a jig used therefor. The jig is intended to hold the shell lest the shell of the heat-insulating member to be manufactured should be deformed when a foamable liquid composition is foamed in the shell. In the jig of this invention, a jig body is formed of a heat-insulating material. The method of this invention comprises the steps of holding the shell in a hollow state by means of two jigs, injecting the foamable liquid composition into the shell to foam the same in the shell. Since the jig body of the jig of this invention is made of a heat-insulating material, the necessity of external heating, which is essential to the conventional method, is substantially obviated.

Abstract: Improved mold structure and method of molding for mechanically frothed urethane foams is presented. The mold is filled from the bottom via an annular runner which communicates with the mold cavity. The connection between the annular runner and the mold cavity is restricted to create a back pressure in the circumferential runner.

Abstract: Foamed thermoplastic resin comprising poly(p-methylenebenzoate) suitable for structural foam injection molded parts.

Abstract: A method of forming synthetic articles of polyester resin by resin transfer molding techniques or the like 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 at least one promoter. The isocyanate is added in sufficient quantity to react with at least one other component in the mixture to produce quantities of carbon dioxide throughout the mixture. The resultant mixture is transferred into a closed mold prior to substantial reaction. The promoter is allowed to react exothermically with at least one other component of the mixture to trigger the isocyanate to react to evolve carbon dioxide gas to generate pressure to fill the mold. Thereafter a curing reaction between the cure accelerator and the polyester occurs to cure and solidify the expanded resin to produce an expanded article.

Abstract: The addition of a small amount of a halogen compound, e.g. chloroethyl phosphate, in a process producing elastomeric polyurethane RIM parts using tertiary amines as the chief catalyst component results in scavenging the residual amines after the part has been cured by annealing. The parts from such a process can be coated with a wide variety of enamels having a high solids content and completely cured to result in a higher degree of adhesive between the coating and the part's surface than those parts from a process without the use of such a halogen.

Abstract: The apparatus molds during each cycle homogeneous plastic material and foam plastic material. It includes a barrel member, a main passageway therein in which is located the screw member. A pair of injecting means for filling molds are provided, one having a homogeneous plastic injection chamber and the other having a foam plastic injection chamber. The first injection means is connected to the screw and barrel member upstream of the place where the inert fluid is introduced into the main passageway whereby homogeneous plastic material is discharged from the main passageway into the first injection means. The apparatus includes means for introducing an inert fluid into the main passageway whereby the rotating screw member mixes the gas with the molten plastic as it moves towards the discharge port which is connected to the second injection means whereby foam plastic material is injected into the foam plastic injection chamber. Each injection means has one or more nozzles connected to a mold located in a press.