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: 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: An open container includes an outer part formed of molded polyurethane and an inner liner of preformed plastic material, the polyurethane being placed in an open mold cavity and a center core plug having a plastic liner disposed thereabout is inserted into the open mold cavity to occupy a predetermined positional relationship therewith so that when the polyurethane is allowed to foam, rise, set and cure, the liner is securely bonded thereto to form a mechanically strong heat insulated container for displaying consumer items such as soft drinks immersed in ice water disposed within the container.

Abstract: A cushion article, such as a seat cushion or the like, for snapping in place onto an appropriate seat support without additional attaching means. The seat cushion has a foam body with a snap-ring member molded integral with a peripheral portion of the body, the snap-ring member providing means for snapping the seat cushion over the seat support. A process and a mold assembly are disclosed for molding the seat cushion, utilizing the snap-ring member as an integral part of the process and mold assembly to evacuate entrapped air from the mold cavity.

Abstract: A method and apparatus for forming insulated concrete blocks in which at least two and preferably three concrete blocks are fed concurrently to the inlet end of the apparatus having a pair of opposed, continuous upper and lower conveyors for concurrently passing said blocks through the apparatus, and a foam injection system for delivering foam to the cavity or cavities formed between the blocks, wherein continuous strips of an impermeable material such as polyfilm are fed to bottom, ends and upper sides of the cavity or cavities to form an impermeable barrier between the foam and conveyors to substantially prevent escape of said foam from the said cavity or cavities. Former plates secured to end frames carried by the lower conveyor and former plates secured to transverse segments comprising the upper and lower conveyors interact with the former plates secured to end frames to provide a desired shape to the foam insulation.

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 and apparatus for manufacturing a cup formed of a thermoplastic resin foamed sheet material and having a lip, the side wall and bottom of the cup being integrally formed, the lip extending outwardly from the mouth portion of the cup and being bent at its end radially inwardly towards the side wall. The method includes forming a rim extending outward from the mouth portion of the cup and having a downwardly extending end, providing a bending furrow on the outer periphery of the side wall at a level below the rim, and bending the rim, as it is heated, at the bending furrow. The apparatus comprises a mandrel block adapted to hold cups and rotatable and axially slidable, a hot blade or cutting blade movable toward the mandrel block and adapted to form a bending furrow for bending the rim, and a lip forming tool having a lip forming groove adapted to be heated.

Abstract: A method and system are described for manufacturing molded packings used in the shipment of articles such as computers, typewriters and the like. The system employs a plurality of mold plugs positioned on a rotating platform whereby the mold plugs are alternately moved between work stations. At one work station a separator sheet is manually placed over a mold plug. At another work station a foaming material dispensing gun is automatically operated in a predetermined pattern over a mold which encloses the mold plug. The pattern is manually adjustable to fit any particular mold plug. Control over the system is obtained with a microprocessor programmed to operate with sensors and actuators associated with the system.

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

Abstract: 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: 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 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 and associated apparatus for forming a foam plastic article using a mold with a mold cavity and a pair of electrodes across which an RF field may be impressed. The foam material that is to be processed is inserted into the mold and is then compressed. The compression may be at least on the ratio of 2 to 1 and perhaps as high or higher than 8:1. An RF heating field is applied while maintaining the foam material compressed and after the heat is terminated, the foam material is permitted to expand to conform to a mold shape as the material cools. This pre-compression step enables substantial reduction in processing time.

Abstract: This invention relates to insulated pipe and methods and apparatus for making the same. There has been difficulty in placing foamable insulating materials in the narrow elongated space between a casing pipe and a core pipe. According to the instant invention, a miniaturized mix head is inserted in this elongated space. Constituents of the foamable insulating material are simultaneously mixed and disseminated by the mix head in a manner to create a moving foam front which displaces air within the elongated space and permits the formation of a layer uniform, low density insulating material therein.

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: A method of manufacturing rigid frame building elements filled with hard foam plastic, said method comprising the use of prefabricated, rigid, dimensionally stable, hollow skeleton frames, the hollow interior spaces of said skeleton frames are foamed and filled with closed cell hard foam plastic serving as heat insulation, and the elements are subjected in a press to compression pressure which overrules the foaming pressured exerted on the frame of an element from inside. For continuous-action manufacture, the used press is a (known as such on the basis of size presses) continuous-action press machine whose lower frame is equipped with lower conveyor means (4) and upper frame with upper conveyor means (5), said conveyor means confining between themselves a conveying gap, in which the passing elements are maintained subjected to compression pressure by means of pressure members (7) carried by said conveyor means.

Abstract: An extrusion die having a die face with plural apertures therethrough, the die face having a contour such as to mate with a non-linear cutting edge of a rotary cutter mounted for rotation about an axis parallel to the die face.

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: 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: 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: A mold assembly for molding a cushion article, such as a seat cushion or the like, for snapping in place onto an appropriate seat support without additional attaching means. The seat cushion has a foam body with a snap-ring member molded integral with a peripheral portion of the body, the snap-ring member providing means for snapping the seat cushion over the seat support. A mold assembly is disclosed for molding the seat cushion, utilizing the snap-ring member as an integral part of the process, and a mold assembly to evacuate entrapped air from the mold cavity.

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 method for the manufacture of shaped articles of polyurethane foam, which comprises pretreating metal molds for at least two types of shaped articles of polyurethane foam conveyed on conveyor units connected to heater units, forwarding said metal molds on the conveyor units according to the types of shaped articles to be produced, adjusting temperatures of said metal molds, feeding relevant polyurethane dopes to said metal molds, conveying said metal molds containing the dopes on conveyor units into the heater unit containing hot water, and immersing said metal molds in the hot water thereby allowing the dopes to foam and set within said metal molds.

Abstract: An apparatus is described for use in a urethane foam molding process to make a molded packing that is employed in the packaging of an article. A generally air tight housing is placed in cooperative relationship with a box in whose chamber the molded packing is to be made with one housing port located for air flow communication with the chamber and another housing port being located for air flow communication with ambient air. A pair of motor driven air blowers are mounted inside the housing with each air blower operatively positioned at a housing port. When one air blower is energized it causes the evacuation of air from the chamber of the box through one port to draw and hold a polyethylene sheet into the cavities of the chamber and of a mold form located therein. The air is exhausted past the other air blower and port. When the other air blower is energized, air flow through the ports is reversed so as to blow air into the box chamber for the release of the molded packing.

Abstract: The invention relates to a factory prefabrication method for hollow panels for the on-site erection of insulated constructions.This method employs a three-dimensional framework 1 composed of thrust bars arranged in two parallel planes and of link bars linking the former. The method consists in placing said framework in a mold 13 containing a pulverulent material 16 wherein the framework is embedded by part of its thickness, in molding an insulating synthetic material 4 in the empty part of the mold so as to embed the visible parts of the framework 1, in placing above the mold a form sheet 2 so that the insulating material shall make contact with it and adhere to it during hardening, and after this hardening, in extracting the pulverulent material and in ejecting the obtained panel. The panel so manufactured can be provided after ejection with a second form sheet opposite the first.

Abstract: Process for producing polyurethane-foam moldings and apparatus for the same; the polyurethane-foam moldings are produced through the steps of pre-treating molds and injecting a foamable polyurethane resin reaction mixture into the molds; carrying the molds with the foamable polyurethane resin reaction mixture injected therein to a reservoir tank containing a heated liquid such as hot water or oil and dipping them into the liquid; and carrying the dipped molds out of the reservoir tank and opening them to take out the moldings thus produced.

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 microwave lens is constructed of a homogeneous body of closed cell rigid polyurethane foam with aluminum flakes dispursed throughout and having a configuration defining an axis and opposed lens surfaces. The method of the invention includes selecting a mold having a cavity of the appropriate configuration, preheating the mold, and filling the mold with a mixture of low density polyurethane foam components and fine aluminum flakes evenly dispersed throughout the foam structure allowing the mixture to cool and form a body of the appropriate configuration.

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 for insulating a water heater with foamed insulation comprises inflating a tube in the cavity between the shell and the tank to define a boundary for the cavity into which the insulating material is injected. The device is deflated after the foamed insulation has set in the cavity. Apparatus for carrying out such method is provided.

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: 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: An applicator is provided for coating the uncovered end portions or stubs of pipe sections after they have been welded together. A belt is maintained in tension out of contact with the pipe until the pipe stubs are welded together and coating operations are to begin. The belt is then wrapped onto the pipes forming an annular cavity about the welded stubs. Chain reinforcing mesh is also applied to the exterior of the belt for support. An expanding foam which sets into a hard coating is then injected into the cavity. Once the foam hardens and fills the cavity, the belt and reinforcement are unwrapped from the coated joint and moved away from the pipe.

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 process for manufacturing expanded polystyrene panels includes the following stages:(a) Preparation of pre-expanded panels of polystyrene by extrusion and simultaneous injection of propellent agent into an extruder fitted with an extrusion die of suitable type and in particular fitted with means allowing for good mixing of the molten polymer with the propellent agent and means allowing for uniform cooling to the best value of the temperature of the expandable plastic mass before exit from the die.(b) Conditioning of said panels at room temperature or at whatever temperature higher than room temperature, provided it is such to prevent the panels from undergoing either dimensional variation or deformation due to internal stress or true expansion.

Abstract: These novel molds are characterized in that they contain a cavity in porous material which is not monolithic, but which, on the contrary, is constituted by zones B with high capillary forces and by zones A with low capillary forces for liquids. The process of using these novel molds is useful for the manufacture of expanded plastics articles.

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: An apparatus for making a foam pad for carpets has features to improve the quality of the pad. The apparatus has a hopper section for receiving foam particles coated with heat activated bonding agent. An extruder section compresses the particles as they are moved continuously along a conveyor belt. A heat section heats the particles after being compressed. A raking device in the hopper section rakes the top of the body of particles prior to entering the extruder section. The raking device rakes in a direction opposite to the movement of the body of particles. The raking device can be raised and lowered to change the level of the particles, and thus the density. The raking device also forms the top of the body of particles with upwardly tapered corners. A plate located below the hopper and extruder sections supports the lower conveyor belt. The heat section uses steam chambers with a perforated top, which also serves to support the conveyor belt.

Abstract: An inwardly offset surface of the cover of a carton is cut in a plane transverse to the top of the cover. A protrusion on the bottom surface of a complementary recess in the latch flap extends through the hole to latch the carton with the protrusion being within the cover recess to prevent accidental opening of the carton. The mold for producing the carton cuts the hole while thermoforming by relative movement between a male key mounted in the male mold member and female key mounted in the female mold member. Both keys have flat surfaces transverse to the closing motion of the molds. These flat surfaces are biased into engagement one with the other so that the plastic is cut in a shearing action.

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: The present invention relates to an apparatus for the production of a flowable reaction mixture of at least two flowable components which mixture forms a foam or solid material, comprising:(a) storage means for said components;(b) supply lines leading from the storage means via metering pumps to a mixing head;(c) said mixing head having a mixing chamber;(d) injection openings connected to said supply lines and opening into said mixing chamber;(e) said mixing chamber having an outlet opening downstream of said injection openings;(f) said outlet opening having an elastic outlet tube whose throughflow cross section may be varied connected thereto; said apparatus further characterized in that:(g) the outlet tube has at least one means associated therewith for deflecting said outlet tube;(h) an ejection piston is associated with said outlet tube, which piston is capable of filling the outlet tube; the contour of the inside wall of said outlet tube corresponding to the external contour of said ejection piston.

Abstract: A method and apparatus are described for cutting the web remaining from a plastic sheet containing thermoformed articles into strips, loosely indexing and aligning a plurality of thermoformed articles in each strip with article punches, sequentially isolating the articles from each other so that they have complete freedom of movement in both across-machine and machine directions, exactly registering the articles with the article punches in a selected sequence, precisely trimming the articles from the plastic web, and ejecting them from the apparatus.

Abstract: A plastified mass of thermoplastic material containing an expanding agent is extruded and sliced into pieces by shaped cutting edges to produce--on expanding--elements which are shaped in a billowed manner or a double-bubble manner. The billowed elements have an inturned peripheral edge which prevents nesting and interlocking together when used in a shipping container. Similarly, the double bubble elements preclude nesting and interlocking.

Abstract: The installation comprises a rectangular, parallelepipedal, leaktight steam chamber (1) provided with a gate (2) on one of the short sides, inside which a tubular fixed mold (4) of perforated steel plate is attached at a distance from the walls of the chamber, the shape of the mold corresponding to the external shape of the panel to be obtained. A first set of fixed, parallel, perforated metal tubes (5), inside the mold (4), possesses lateral holes (9) for the passage of a second set of perforated or non-perforated metal tubes (10) firmly fixed to a movable external support (11), passing through one of the short walls of the steam chamber (1) and capable of moving perpendicular to the tubes (5) of the first set, passing through the latter. The chamber (1) is provided with inlet valves (13) for the partially expanded synthetic material, an inlet (14) for steam and an inlet (15) for a cooling fluid.

Abstract: A fishing lure having a minnow-shaped foamed plastic body and a one-piece wire located in the central longitudinal vertical plane of the body. The wire has a nose loop at the forward end of the body, a body loop at the lower mid-section of the body, and a tail loop at the rear end of the body. Treble hooks are connected with rings to the body and tail loops. A generally flat lip projects forwardly and downwardly from the nose section of the body. The body is made with a mold assembly having two plates with a plurality of body cavities and loop grooves for supporting the wire along the longitudinal central plane of each cavity. The mold assembly has a plastic material inlet passage leading to the nose section of each cavity and a vent passage open to the tail sections of each cavity. A gun is used to pressure inject plastic materials into the inlet passage which reacts in the body cavity to form the foamed plastic body.

Abstract: A smooth, plastic-lined corrugated pipe having an intermediate layer of plastic foam. The pipe is made by internally coating a corrugated pipe with a foaming mixture and pressing an expandable cylinder of plastic sheet liner against the foaming mixture until the foam solidifies. An expandable mandrel apparatus presses the plastic sheet liner into position.

Abstract: Molding apparatus 10 or 11 supports a tough, resin ball core 15 in the center of a spherical mold cavity having upper and lower mold parts 12 and 13. Core 15 is about half the diameter of the mold cavity allowing room for foamed resin exterior 16 to form over and around core 15 filling the mold cavity and completing the spherical ball. A pin support 20 formed as a single pin 21 or a pair of identical pins 31 holds core 15 in the center of the mold cavity and is withdrawn after the ball is molded. The pin support is arranged at the mold parting plane and extends through the parts to the mold exterior thus providing full support and accurate location of the core within the mold cavity. A coupling element on pin support 20 is formed as a hook 28 or other engageable element outside the mold and is used for placing the core in the mold and also for supporting the ball for curing after molding.

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: Apparatus for continuously and rapidly forming trays of highly uniform elastomeric soil plugs comprises means for continuously mixing a water-containing soil slurry with a water-reactive pre-polymer compound, means for supplying the soil slurry and the pre-polymer compound to the mixing means at respective controlled rates, and means for delivering the mixed soil slurry and pre-polymer compound to a dispensing station for dispensing into mold receptacles; the receptacles are disposed in a closed path and carried by transport means seriatim past the dispensing station. Releasable bias means biases a tray mold member against a base mold member within each receptacle so as to extrude soil-pre-polymer mixture into plug-molding cavities of the tray mold member. The bias means is released after the plugs within the tray mold member have cured.