Abstract: A mold apparatus comprising: a core portion comprising a core surface, a first induction coil, and an inner core, and wherein the core portion has a core portion mass; a cavity portion comprising a second induction coil and a cavity surface, and wherein the cavity portion has a cavity portion mass; wherein the inner core comprises a non-magnetic material, the core surface comprises a magnetic material, and a density of the non-magnetic material is less than a density of the magnetic material; and wherein the core portion mass and the cavity portion mass differ by less than or equal to than 5%.

Abstract: A rotation apparatus for rotationally molded shaped objects includes a receiving apparatus for receiving at least one negative mold, a holding apparatus for holding the receiving apparatus, and a drive unit for driving rotary motion of the receiving apparatus, wherein the receiving apparatus (1) is embodied as a sphere. The holding apparatus includes at least one support and guidance element (5) for supporting and guiding the receiving apparatus. The drive unit includes a drive element (9) that is arranged in the rotation apparatus and is connected in energy-transferring fashion to the receiving apparatus (1) to cause the sphere to rotate.

Abstract: The nature of the rotational molding process is cyclic. It requires the temperature of the rotating mold and the plastic it is charged with to be elevated from room temperature to beyond its melting temperature and then cooled back to room temperature. Consequently, rotational molding cycle times are lengthy, which is often considered as the fundamental drawback of this plastic fabrication process. The motivation and objectives of this disclosure are twofold. The presently proposed invention focuses on developing an innovative extrusion-assisted rotational foam molding processing technology for the manufacture of integral-skin cellular composite moldings having adjacent, but clearly distinct, layers of non-cellular and cellular structures, consisting of identical or compatible polymeric grades.

Abstract: The present invention refers to a mold for the production of molded skins 7 and molded bodies 7 from plastic, wherein the mold is configured as a double-walled hollow body comprising a shaped front wall 1 as well as a rear wall 2, in which hollow chambers are formed. With this arrangement, it is possible to save energy and also not inconsiderable amounts of material when applying a slush-or rotation method for the production of molded skins 7 and molded bodies 7 especially those for use in interior paneling and dash boards of motor vehicles.

Abstract: A rotocast composite hybrid method for efficiently making strong but lightweight parts. The method includes filling a mold with a volume of resin through an access port and then sealing the access port by positioning a lid over the access port. The method includes mounting the mold in a rotocasting machine and then operating the rotocasting machine to rotate the mold about two orthogonal axes until a layer of the resin is applied uniformly over an inner surface of the mold to form an outer wall of a part. The method includes removing the lid and then applying a reinforcement material (e.g., sheets of woven fiberglass) to an inner surface of the outer wall of the part through the access port. The applying of the reinforcement material also involves wet layup such as by binding the reinforcement material to the inner surface by applying additional resin to the reinforcement material.

Abstract: A system for a thermal manufacturing system including a heliostat and a mold. The heliostat includes at least one reflecting surface, a steering mechanism and a controller. The steering mechanism is coupled to the at least one reflecting surface and capable of directing at least a first portion of the at least one reflecting surface toward a first one of multiple, selectable focal points. The mold is located in a second one of the selectable focal points. A manufacturing method is also disclosed.

Abstract: A machine for rotational molding of products comprises means (12, 14, 16, 17) for driven rotation of a mold around perpendicular axes (13, 15), means (22) for direct heating of the mold and means (21) for commanded opening of the mold in half molds. The machine further comprises combined means (23, 24, 25) for arresting in a predetermined position of the rotating means of the mold disengageable retaining means (26, 27) for retaining the product in a preset half mold, and evacuating means (28, 50) for evacuating the product that are suitable for being introduced between the open half molds when the rotating means is stopped in said predetermined position and which is suitable for receiving the product discharged from said preset half mold upon the release of the retaining means.

Abstract: The present invention relates to a method for manufacturing an air mat that reduces the number of manufacturing processes by means of rotational molding, while preventing the generation of defective products, to a device for molding an air mat, and to an air mat manufactured and molded by the method and device. In a method for manufacturing an air mat formed in such a manner as to integrally couple a cushion part having a plurality of air bags arranged therein for containing air at the insides thereof with a plate-shaped lower sheet disposed on the lower surface of the cushion part, the method includes the steps of: preparing a lower mold having a plurality of air bag molding recesses having given depths arranged at given intervals thereon, for molding the cushion part of the air mat.

Abstract: The nature of the rotational molding process is cyclic. It requires the temperature of the rotating mold and the plastic it is charged with to be elevated from room temperature to beyond its melting temperature and then cooled back to room temperature. Consequently, rotational molding cycle times are lengthy, which is often considered as the fundamental drawback of this plastic fabrication process. The motivation and objectives of this disclosure are twofold. The presently proposed invention focuses on developing an innovative extrusion-assisted rotational foam molding processing technology for the manufacture of integral-skin cellular composite moldings having adjacent, but clearly distinct, layers of non-cellular and cellular structures, consisting of identical or compatible polymeric grades.

Abstract: An imprint apparatus in which a mold having a processing surface on which a predetermined imprint is formed is provided and an uncured resin material placed on a substrate is filled and cured in a space between the mold and the substrate and is subjected to imprint of the predetermined imprint formed on the processing surface of the mold. The imprint apparatus includes an attitude control mechanism for controlling attitudes of the mold and the substrate so that a first gap between a first end of the mold and the substrate and a second gap between a second end of the mold and the substrate are different from each other, and a measuring mechanism for measuring attitudes and positions of the mold and the substrate. Also provided is a mechanism for imparting a relative movement between the substrate and the mold so that the resin material approaches the first end of the mold and enters through the first gap and fills at least a part of the space between the mold and the substrate.

Abstract: An ice making device that is capable of more easily and conveniently separating ice from ice trays through a simple manipulation and a refrigerator having the same are disclosed. The ice making device includes a support frame for rotatably supporting at least one ice tray, at least one manipulation button mounted to the support frame such that the manipulation button can be moved forward and backward, and an interlocking unit for rotating the ice tray with respect to the support frame according to the movement of the manipulation button.

Abstract: The invention relates to a method for making a flexible pouch, said method being characterized in that it comprises: the step of inserting (a) at least one fluid or powdery material into a hollow mould (3) having an inner wall (3A), said inner wall (3A) defining a closed moulding surface; the step of rotating (b) the mould (3) in order to spread the material substantially against the entire inner wall (3A) of the mould (3) by centrifuging. The invention can be used for flexible containers.

Abstract: An ice making device that is capable of more easily and conveniently separating ice from ice trays through a simple manipulation and a refrigerator having the same are disclosed. The ice making device includes a support frame for rotatably supporting at least one ice tray, at least one manipulation button mounted to the support frame such that the manipulation button can be moved forward and backward, and an interlocking unit for rotating the ice tray with respect to the support frame according to the movement of the manipulation button.

Abstract: A system and method for molding the shell of a medical device or other molded article is disclosed. The system includes a multi-axis rotational molding machine in which a mold is mounted. The mold has a cavity in the shape of the article to be molded. The mold seals to hold a vacuum. In operation, silicone or other molding material is inserted into the mold, vacuum is applied to the mold, the mold is rotated about at least two axes and a molding material coats the inside walls of the mold to form the shell or other desired article. A rotationally molded medical article is also disclosed.

Abstract: A method of venting a rotational mold at a predetermined condition by actuating an actuating venting assembly pierces the shell of the molded article and introduces a passageway to relieve pressure during the molding cycle. The actuating venting assembly enables a tactical methodology for venting such molds.

Abstract: A system and method for molding the shell of a medical device or other molded article is disclosed. The system includes a multi-axis rotational molding machine in which a mold is mounted. The mold has a cavity in the shape of the article to be molded. The mold seals to hold a vacuum. In operation, silicone or other molding material is inserted into the mold, vacuum is applied to the mold, the mold is rotated about at least two axes and a molding material coats the inside walls of the mold to form the shell or other desired article. A rotationally molded medical article is also disclosed.

Abstract: An apparatus for making molded articles of plastic material, in particular molded films of thermoplastic flakes, by using a slush molding process, includes a mold container having at least one interior space for receiving plastic material and a mold wall which can be heated and cooled in alternating sequence. The mold container is located within a support frame which is rotatable about a rotation axis, whereby the suspension of the mold container is so configured as to allow a movement of the mold container in three degrees of freedom. The suspension includes a combined swivel and shift arrangement, which is disposed between the support frame and the mold container and supports the mold container in such a manner as to effect a rotation of the mold container about a pivot axis, which is perpendicular to the rotation axis, and a reciprocating motion in the direction of the pivot axis.

Abstract: An apparatus and related method for forming a three dimensional polymer based part including a die tool having a specified shape and size and exhibiting an exposed polymer adhering surface corresponding in configuration to a polymeric based part to be created. A bin is filled with a polymer material in particulate form and, upon positioning the die tool overhead, the die tool is inserted into the bin, such as by either lowering the tool or raising the bin. The tool is positioned within the bin such that the exposed and adhering surface is in contact with the particulate material. Heat is applied to either or both the die tool and the bin particulate and, in combination with an optional vibrating motion imparted to the bin, causes a specified volume of polymer material to adhere and to form upon the exposed surface of the die tool.

Abstract: A rotational molding oven for forming an object from a mold containing resin therein. The oven includes a cavity receiving the mold therein and a combustion chamber for providing heat inside of the cavity. A spool is rotatively positioned within the cavity, the sides of which spool substantially form the sides of the cavity, and a drive tube engages the mold and extends between first and second flanged disks of the spool. A first motor is positioned outside the cavity and rotates the spool and a second motor is positioned outside the cavity and rotates the mold within the spool. Heat in the cavity melts the resin within the mold and rotating the spool and mold by the first and second motors causes the melted resin to be evenly distributed throughout the mold. The drive tube may be selectively positioned at a peripheral edge or at a center of the spool.

Abstract: A method for the production of a double-walled plastic container, comprises the following steps:

Abstract: A multiaxis rotational molding apparatus includes a support portion, a molding portion and a control portion. The support portion includes an upstanding arcuate frame section. The molding portion includes an upstanding arcuate mold supporting assembly disposed within and spaced from the arcuate frame section. A mold assembly includes separable mold sections forming a substantially enclosed mold cavity carried within the mold supporting assembly. The control portion includes drive assemblies arranged in a preselected configuration adjacent the arcuate frame section selectively energized in coordination with adjacent drive assemblies for movement of the mold supporting assembly in a selected profile. Programmable memory stores preselected operating parameters. Monitors sense operating information form control components.

Abstract: A machine for casting radiation cured material with a mold set made of a clear, radiation cured material or other clear material, one or more radiation emitting devices preferably in the ultraviolet and visible range, a rotating mechanism to move the mold set from a horizontal or vertical load/unload position to vertical fill and cure position at the radiation devices, and one or more injection mechanisms attached to the mold set to fill the mold set and then seal at the part wall preventing cure of material in the line and resulting in a minimal gate mark. Alternatively the molds can be filled and then rotated before and during cure to create a hollow part.

Abstract: A rotational molding oven for forming an object from a mold. The oven includes a cavity for retaining the mold, a burner for heating the cavity and melting the resin and a device for rocking the mold between −45° and 45° from a horizontal plane. The rocking device is outside, extending into the cavity, maintaining the mold in the center of the cavity. The rocking device facilitates distribution of resin within the mold and improves thermal flow of heat within the cavity thereby increasing thermal efficiency and minimizing the size of the cavity. The rocking device includes a first track outside the cavity, a carriage assembly, a drive assembly connected to the carriage assembly and a guide assembly connected between the first track and carriage assembly for translating up and down the first track, causing the carriage assembly to move therewith and the mold to rock about the central axis of the cavity.

Abstract: A rotary molding system has a sintering furnace, at least one cooling chamber, and at least one transport device to receive at least one mold carrier and to transport the mold carrier between the sintering furnace and the at least one cooling chamber. The sintering furnace and the cooling chamber(s) have rotary devices to receive the mold carrier. In particular, the sintering furnace and the cooling chamber(s) are arranged serially, with the transport device designed as a mold carrier carriage moving beneath the sintering furnace and the cooling chambers.

Abstract: Plastic hoods and dividers are provided for use with row crop heads. The hoods and dividers are single walled and self-supporting. The single-walled hoods and dividers are preferably manufactured through a rotational molding process wherein a non-stick coating, such as polytetrafluoroethylene, is attached to portions of the mold.

Abstract: A process for forming a product having multiple and well defined color patterns. In a first embodiment, the rotomolding process comprises a first step of using a first powder having a first color and a second powder having a second color which is different than the color of the first powder. The rotomolding process comprises a second step of placing the first and second color powders into a pre-determined pattern within a hollow cavity mold. The rotomolding process comprises a third step of placing the closed hollow cavity mold into the oven. The rotomolding process comprises a fourth step of heating the hollow cavity mold with no rotation for a first period defined by the heating time necessary for a layer of individual colors to melt in the desired pattern upon the inside surface of the hollow cavity mold.

Abstract: A method and apparatus for making vesicles suitable for use as contrast agents in which a container containing an aqueous suspension phase and a separate gas phase is shaken using reciprocating motion. The reciprocating motion is produced by a shaker arm that moves the container in two, substantially perpendicular directions, with the motion in the first direction being along an arcuate path. The overall path of the motion occurs in a figure-8 eight pattern. The frequency of shaking is at least approximately 2800 RPM, the length of the shaker arm is at least approximately 6 cm, and the angle through which the shaker arm rotates in the first direction is at least approximately 3.degree.. The total length of travel around the figure-8 pattern is at least 0.7 cm.

Abstract: Apparatus and methods for stabilizing soils and other granular materials at the site at which they are located. The apparatus includes a platform, fixed or mobile at a contamination site, carrying a hopper for receiving contaminated material to be stabilized including additives as required, a mixer for introducing additives to the material connected to the hopper, a mechanism for transporting contaminated granular materials from an adjacent contaminated site to the mixer, at least one mold having at least one movable wall, a harmonic compactor to form a uniformly dense, solid compacted preform body, and a discharge station for handling or holding the preform. Where desired or required an air dryer, thermal curing chamber or sintering furnace may be used to dry and/or fuse the preform into a final block.

Abstract: The rotational molding apparatus includes a main support member having at least one arm extending therefrom. Each arm of the apparatus is adapted to rotate enclosed articles being formed or coated about at least one axis. In order to cool the arms during operation, each of the arms includes a cooling channel extending down the length of the arm through which a cooling fluid is circulated. Each arm further includes a fluid return in communication with the cooling channel which receives the cooling fluid at the end of the arm and recirculates it back to the main support member so that the cooling fluid does not interfere with the rotational molding process.

Abstract: A method of continuously forming an integrally molded structure in a multiaxis rotational molding operation includes the steps of rotating a multisection mold assembly about at least three axes. A first freshly formed polymerizable mixture is flowed over surfaces of an enclosed mold cavity within the multisection mold assembly. The flowing of the first mixture over the mold cavity surfaces and formation of a first resin therefrom is monitored. A second freshly formed polymerizable mixture is flowed under pressure through an orifice into the mold cavity. A liquid stream of the second mixture is formed. The liquid stream is gelled as it advances through the mold cavity to form a continuous filament with structural integrity. The filament is contacted with the first resin formed within the mold cavity. The filament is distributed over the first resin in a preselected pattern. A third freshly formed polymerizable mixture is flowed over the filament pattern formed within the mold cavity with the second mixture.

Abstract: An apparatus for making carbon discs for brake disc assemblies by feeding continuous strands of fibrous carbon material from spools into a die, the volume of the carbon material so dispensed being continuously monitored. A cutter terminates the dispensing operation and a debulking plate urges all of the fibrous carbon material so dispensed into the die alone. The material is compressed within a cylindrical annular die and, in one embodiment, is submitted to a convection curing oven where the preform is cured. Subsequently, the preform is carbonized, densified, and machined to form a final carbon disc brake. In another emobodiment, a dry preform is fabricated, obviating the need for curing and carbonizing.

Abstract: A mold box is flexibly mounted to a product forming machine having upper and lower vertically displaceable beams. A feed drawer dispenses concrete material into the mold box while a vibration system vertically vibrates the mold box while dampening horizontal vibration. The vibration system is driven by a single drive shaft that actuates first and second vibrator rods while at the same rotating a counter-weight in a counter-rotating direction. A set of alignment brackets lock the mold box into a predetermined aligned relationship while being mounted in the product forming machine. The bottom side of each mold box is mounted to the product forming machine in the same relative position to reduce machine readjustments. A set of telescoping legs hold the feed drawer assembly variable distances above the mold box. A unitized pallet feeder quickly moves pallets one at a time from an "on-deck" position to a "receiving" position underneath the mold box.

Abstract: A mold box is flexibly mounted to a product forming machine having upper and lower vertically displaceable beams. A feed drawer dispenses concrete material into the mold box while a vibration system vertically vibrates the mold box while dampening horizontal vibration. The vibration system is driven by a single drive shaft that actuates first and second vibrator rods while at the same rotating a counter-weight in a counter-rotating direction. A set of alignment brackets lock the mold box into a predetermined aligned relationship while being mounted in the product forming machine. The bottom side of each mold box is mounted to the product forming machine in the same relative position to reduce machine readjustments. A set of telescoping legs hold the feed drawer assembly variable distances above the mold box. A unitized pallet feeder quickly moves pallets one at a time from an "on-deck" position to a "receiving" position underneath the mold box.

Abstract: A method of continuously forming an integrally molded structure in a multiaxis rotational molding operation includes the steps of rotating a multisection mold assembly about at least three axes. A first freshly formed polymerizable mixture is flowed over surfaces of an enclosed mold cavity within the multisection mold assembly. The flowing of the first mixture over the mold cavity surfaces and formation of a first resin therefrom is monitored. A second freshly formed polymerizable mixture is flowed under pressure through an orifice into the mold cavity. A liquid stream of the second mixture is formed. The liquid stream is gelled as it advances through the mold cavity to form a continuous filament with structural integrity. The filament is contacted with the first resin formed within the mold cavity. The filament is distributed over the first resin in a preselected pattern. A third freshly formed polymerizable mixture is flowed over the filament pattern formed within the mold cavity with the second mixture.

Abstract: A cover for an air bag unit is disclosed having a patterned tear seam therein defined by an integrally bonded, thermoplastic filler strip as the cover material and comprising a material having properties different than that of the cover material, Apparatus for forming the cover includes a thin shell mold having an inner surface that is heated to melt thermoplastic material cast thereon, A powder box adapted to contain thermoplastic material therein for distribution onto the thin shell mold carries a gasket having a shape corresponding to the tear seam shape. The powder box and gasket are adapted to be connected to the thin shell mold for forming a sealed footprint on the inner surface during distribution of the cast material against heated surface portions of the thin shell mold to form a thermoplastic cover with an opening therein that have the tear seam pattern, The opening is later filled with the lesser strength thermoplastic material to form an integrally bonded thermoplastic filler strip.

Abstract: A device for producing synthetic plastic molded sheets including a mold rotatable about at least one axis and receiving a thermoplastic synthetic resin powder which is sequentially heated and cooled by liquid heating and cooling medium admitted into a hollow chamber of the mold, and a housing formed with a housing wall provided with a plurality of bulges for compensating thermal stresses resulting from different materials of the housing wall and a wall of the chamber.

Abstract: Method and apparatus for rotationally casting a plastic tank liner having a molded-in access fitting and for ensuring a uniform thickness of plastic in the wall of the liner and on the fitting. A hollow mold having a mold cavity surface conforming to the surface of the liner is provided. An access fitting is removeably mounted on the mold so that the interior surface of the fitting may be coated with the molding plastic and so that the molded liner and the filling may be removed from the mold as a unit. The mold is rotated about orthogonal axes while the mold is heated to a resin liquifying temperature. Additional heat is supplied to the fitting at a rate proportional to the mass of the fitting so that the temperature of the inside surface of the fitting is increased at a rate substantially corresponding to the inside surface temperature of the mold.

Abstract: A manually operable and steerable curb extrusion device for extruding curb, barrier, wall, gutter or the like from concrete, cement or some other moldable building material. The curb extrusion device has a segmented vibrating hopper into which building materials are placed to fall onto two tapered counter rotating vibrating augers which compact and force the building material through an extrusion mold where it is shaped before extrusion.

Abstract: A method of continuously forming an integrally molded structure in a multiaxis rotational molding operation including the steps of rotating a multimold section mold assembly about at least three axes. A first freshly formed polymerizable mixture is flowed over surfaces of an enclosed mold cavity within the multisection assembly. Flowing of the first mixture over the cavity surfaces and formation of a first resin therefrom is monitored through optical fibers extending through the mold sections. Second and third freshly formed polymerizable mixtures are flowed over resin formed within the mold cavity. Flowing of the second and third mixtures and formation of resins therefrom are monitored through optical fibers extending through the mold sections. The rotation of the multisection mold assembly is continued throughout the modling operation. Each axis rotation of the multisection mold assembly is monitored individually.

Abstract: A dough rounder machine for kneading and forming dough and similar plastic masses into uniformly shaped form in which the dough is placed in an annular die driven by eccentric drive means over a stationary horizontal tray table whereby to move the die in a generally circular orbit over the table. Dough placed in the die is overcovered by a weighted cover which orbits with the die and is gravity actuated to exert vertical force on the dough. Engagement of the dough with the table, orbiting die and cover serves to knead and roll the dough into a substantially spherical mass, the texture and density of which is regulatable by the cover weight and movement of the die over a limited time interval.

Abstract: This invention relates to a one-step formed all-plastic boat, the entire hull of which is comprised of plastic material that contains in addition small amounts of an additive and a filler. The hull has a cavity, divisional cavities, open and closed compartments, but no welded parts. The process of manufacturing the all-plastic boat comprises feeding physically modified resinous material into a closed container type boat mold, subjecting the mold to a complex motion of circular and semicircular rotations of 360.degree.-180.degree. and rockings of selected positional angles; applying an operational heat treatment at 200.degree.-450.degree. C. to the mold while the mold undergoes the complex movements; and after heat treatment, cooling the mold and then releasing the entire all-plastic boat.

Abstract: An apparatus for the production of molded shells and bodies of plastic material by a rotational molding procedure within an electroplate mold includes a double-walled hollow body which is heated up and cooled down by a heating and cooling medium. A box which contains plastic material can be fitted on to the mold. The mold and the box are jointly pivotable so that the plastic material can pass into the mold and fuse at the wall of the mold. At its rear wall, which is remote from the internal contour which produces the molding action, the double-walled hollow body has a multiplicity of intake and discharge openings for the heating and cooling medium so that heating and cooling can be effected specifically and quickly. The total discharge cross-section is greater than the total feed cross-section whereby the hollow body remains substantially pressure-less.

Abstract: Hazardous radioactive waste is compacted and cast into safely handled monolithic castings having a radiation barrier wall completely enclosing the radioactive waste by centrifugal casting processes in which the barrier wall may be either a pre-formed shell transported to the jobsite or it may be formed by biaxial centrifugal casting and curing of the barrier wall in a mold. When a pre-formed shell is used, means are provided for thickening the radiation barrier if necessary by biaxial casting of additional barrier material inside of the shell. Castable radioactive material is cast inside the barrier wall before removal of the casting mold from the finished cast monolith. The cast monolith is supported for rotation as the mold is removed therefrom so that additional impact resisting and radiation barrier material can also easily be applied to the exterior surface monolith if radiation leakage exceeds tolerance levels.

Abstract: Apparatus for selectively rotationally molding an industrial drum in either a closed-head configuration or an open-head configuration within a mold constructed for selective modification to accomplish molding of the drum in either selected configuration by inserting or deleting a separator between a first mold cavity for forming the body of the drum and a further mold cavity for forming the head of the drum, the further mold cavity being selected from alternate second and third mold cavities, such that both the body and the head are rotationally molded simultaneously within the mold during molding of either configuration of the industrial drum.

Abstract: A plastic mold (A, B) for rotational molding are disclosed. The plastic mold, used in lieu of a conventional metal mold, is constructed from a fiber (52) reinforced thermoset plastic resin (50) having a heat distortion point above the melt point of the thermoplastic polymeric material from which an article is molded. Metal (64, 70, 74) or other dissimilar material may be used to provide different coefficients of heat transfer at preselected portions of mold (A, B). The entire mold may include a thermal coefficient modifier to increase the heat transfer rate of the mold uniformly over the entire mold in addition to the preselected portions.

Abstract: A device for manufacturing concrete parts, particularly concrete pipes, and based on the principle of sinking mold whereby a molding bottom ring together with a jacket are continuously lowered relative to a stationary mold core while concrete mixture is poured from above and distributed into the emerging molding space by a radial pressing device mounted on the top end of the mold core. Simultaneously with the lowering of the mold jacket and the molding bottom ring a supply device for delivering the concrete material is also lowered such as to keep a constant distance from the open top end of the mold jacekt. The radial pressing device is designed to compact the incoming concrete material in radial direction without imparting any torque thereto. In this manner any stress in the finished part, particularly between the concrete and reinforcing wire mesh is effectively avoided.

Abstract: Rotational molding apparatus for molding a kayak and the like in a mold (12). The apparatus includes an oven (A) having an oven chamber (40). A frame (B) pivotally supports oven (A) above a ground floor (10). Mold (12) rotates about a roll axis (123) on a carriage (C) while in oven chamber (40). Oven (A) pivots about a pivot axis (72) in counter-pivotal movement. Oven pivot axis (72) is spaced a distance "d" from roll axis (123) of mold (12). This causes a pendular motion to be imparted to the mold (12). Mold (12) thus swings to and fro in an arc as oven (A) pivots. Mold (12) rotates about its roll axis (123) at the same time. A well-controlled, even distribution of plastic material in the mold occurs by this combination of motions. A desired pattern of heat distribution is applied along the length of mold (12) by a series of hot air openings (50a-50d) and a like number of openings on an opposing side of a hot air plenum (49).

Abstract: A hollow forming machine capable of rotating moulds in both horizontal and vertical directions wherein a motor is used to drive sleeves to rotate in both vertical and horizontal directions, and through the engagement of outer gears of the sleeves and the drive gear shaft, a horizontal mandrel is driven to rotate in the same direction as the sleeves, and through the engagement of two bevel gears, the rotation of the horizontal rotation of a vertical mandrel to drive a mould seat to rotate in both horizontal and vertical directions. An air pipe is disposed in hollow pipes of the horizontal and vertical mandrels to communicate an air extractor and the mould for performing air extracting and air blowing so that the molded product has fine quality and uniform wall thickness without bubbles on the surface.

Abstract: A method and apparatus for attaching an insert in an opening in a molded thermoplastic body. The insert includes a thermoplastic mounting portion which is fused with the thermoplastic material of the body. The insert is maintained in a spaed position from the opening during the heating portion of the molding cycle and positioned within the opening while the thermoplastic material is still sufficiently hot to fuse with the thermoplastic mounting portion of the insert.

Abstract: An apparatus for reflow smoothing a molded article made by first heating a face of a mold at a first station, then applying a fusible synthetic resin to the heated face and thereby melting the resin into a continuous coating covering the heated mold face at a second station spaced angularly from the first station, and cooling the coating and mold at the second station until the coating hardens. To reflow smooth the article, the surface of the cooled coating is then smoothed by confining the mold and hardened coating in a substantially closed chamber at the second station and reheating the confined coating until its surface flows. Thereafter the coating is cooled again at a third station angularly spaced from and downstream of the second station until it hardens and the hardened covering is stripped from the mold at a fourth station angularly spaced downstream of the third station and upstream of the first station.