Abstract: An apparatus (40) for molding a thin walled plastic shell includes a mold box (42) having an inner mold surface (48). A powder box (52) includes an internal chamber and first divider wall (54) for separating the internal chamber into at least two sections (56,58). A carrier framework (60) is removably mounted on the mold box (42) and includes a peripheral seal for perfecting a seal between the mold box (42) and the powder box (52) when the same are connected thereto. A second divider wall (64) is connectable to the first divider wall (54) separating the inner mold surface into two chambers continuous with the two sections of the powder box (52). The carrier framework (60) further includes a mold surface seal (66) for perfecting a seal between the second divider wall (64) and mold surface (48).

Abstract: Process of manufacturing a cryogenic regenerator including a plurality of channels for conducting a working fluid, including the steps of providing a cylindrical forming member having a longitudinal axis and a plurality of peripheral slots displaced axially and oriented substantially parallel to the longitudinal axis of the cylindrical forming member, or having a continuous spiral peripheral slot of sufficiently small pitch such that the convolutions thereof are oriented substantially parallel to such longitudinal axis; providing epoxy which is relatively flexible upon hardening, loading the epoxy with thermally conductive material for enhancing the radial thermal conductivity of the cryogenic regenerator, and applying the epoxy to the periphery of the cylindrical forming member to fill the plurality of slots or the spiral peripheral slot with the epoxy and to form a radial layer of the epoxy of a generally first radial thickness allowing the epoxy to harden and thereafter reducing the radial thickness of the

Abstract: A pottery bowl with an integral catch tray. The process of forming the pottery bowl includes molding a bowl with a thickened sidewall adjacent to the bottom thereof. The bowl is then placed on a potter's wheel and a shaping tool is inserted into the thickened portion to form an integral catch tray. The shaping tool for forming the catch tray preferably has a rounded tip from which a stream of water is emitted.

Abstract: Improved techniques are provided for manufacturing a toroidal arc segment piston for use in a fluid pressure responsive rotary actuator, and for forming an actuator housing defining an arcuate chamber for receiving a rotary actuator piston. A moldable polymeric material is positioned within an arcuate master chamber in a piston-forming fixture, and a metal piston core is rotatably mounted to the fixture. The piston core is rotated to displace the polymeric material and form a sheath about the piston core. After curing, the piston core and sheath are rotated out of the arcuate master chamber, and are installed in a rotary actuator housing. A master piston may similarly be used to form a polymeric lining which defines the chamber for receiving the piston in the actuator housing.

Abstract: A casting containing toxic waste is made by centrifugally casting toxic waste in a pre-formed cage having heat conducting means therein. The casting is formed with suitable shielding materials selected as a function of the waste being cast. The finished casting contains passageways through which heat is removed. These passageways are oriented such that when two or more castings are stacked in abutment, the passageways of adjacent castings interconnect.

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 tool for manufacturing the two tone plastic shell includes an electroformed mold (28) having a first surface (29) for forming a front of a shell; a second surface (32) for forming the side edge portion of a shell; and a third surface segment (34) for forming a return flange on a door shell and the third surface segment has a cut-out opening (36) therein and a runout surface (40) providing for entry and removal of a seal and divider wall assembly to seal against a sealing rib (38) in the mold which separates the first, second and third segments into first and second casting surfaces. The divider rib and runout surface are sprayed with thermoplastic material to form a joint between material cast on the first and second casting surfaces and a skin return flap for sealing the cut-out opening.

Abstract: A mold assembly for molding thermoplastic particles into a solid thin shell includes a metal shell having a cavity and including an outer surface exposed to a heat source and further including an inner surface on which thermoplastic material is cast and fused to form a thin layer thermoplastic shell. The heat transfer area of the metal shell is increased by providing a plurality of heat transfer pins connected to the outer surface; each of the heat transfer pins has an extended outside surface area exposed to the heat source for heating the metal shell and each of the heat transfer pins further includes a large diameter head portion which is joined to the metal shell by a capacitive weld nugget formed solely between the large diameter head portion and the outer surface of the metal shell without disrupting the metal shell at surface portions thereof formed between the heat transfer pins.

Abstract: Multi-axis rotational polymeric mixture distributing apparatus includes a raw material supplying portion, a supporting portion, a raw material mixing portion, a polymeric mixture distributing portion, a polymeric mixture accepting portion and a control portion. The raw material supplying portion includes a plurality of reservoirs, each connected independently with the mixing portion. The supporting portion includes a plurality of driven frame members each with a large open central area being disposed between parallel spaced upstanding end sections and rotatably supported thereon, each being progressively smaller in size than the next larger frame member and disposed within the open central area thereof. Alternate frame members are rotatable about aligned axes with frame members therebetween rotatable about axes generally perpendicular thereto. The smallest frame member includes rotatable holding sections.

Abstract: An upper contoured die which mates with a lower contoured die is rotated relative to and against the lower die to progressively squeeze and deform a softened thermoplastic sheet. The two dies create sharp detail on both surfaces of the deformed sheet without tearing the sheet.

Abstract: A method of producing round rod formed of thermoplastic material by extrusion is described. The rod, following extrusion, is first heated and then cooled while rotating fully supported on rollers. The rollers impart a concentric outer surface shape to the extruded rods and permit uniform cooling across the entire cross section of the extruded rod.

Abstract: Apparatus for the extrusion-coating of a core, especially of an electrical conductor, with a sheathing having at least two layers or strips of different materials or differently colored materials, the apparatus having feed conduits for the plasticized materials and outflow passageways through which the core to be extrusion-coated can pass, the outflow passageways being selectively connectable to the feed conduits via a distributor device. In order to avoid the need for cleaning the conduits of the distributor device, the distributor device is formed by a sleeve (8) which is arranged rotatably between end positions in relation to an outer housing (1) having feed conduits (2, 3) for the plasticized materials. The sleeve also has a number of conduits corresponding to the number of materials to be extruded, to connect feed conduits (2, 3) alternately to the outflow cross-sections (15, 20) for the plasticized materials.

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: A process for producing improved gypsum models and molds of high duplication accuracy is provided. In the process, bundles of carbon fibers of specified length and amount having a sizing agent deposited thereon are treated to remove the sizing agent from the carbon fibers which are then separated into single fibers in water. A major part of hemihydrate gypsum (CaSO.sub.4.1/2H.sub.2 O) powder is then added to the carbon fibers dispersed in water to obtain a gypsum slurry having the carbon fibers uniformly dispersed therein. The slurry is then cast to obtain the models or molds.

Abstract: The invention relates to a method for forming twin-wall polycarbonate sheets into desired arcuate forms to be used, for example, as awnings. The method is distinguished from known forming techniques which are generally not effective in forming the polycarbonate sheets hereinafter described.The method generally includes preheating a portion of the polycarbonate sheet within a heating chamber, engaging the sheet with the mould which is pivotally mounted to the frame of an apparatus within the heating chamber, frictionally restraining the movement of the sheet with respect to the frame at a position spaced from the mould, and outside the heating chamber, and pivoting the mould so as to form the sheet.The present invention generally overcomes the difficulties in forming twin-walled polycarbonate sheets thereby allowing this material to be used in place of other conventional awning materials such as fibreglass and corrugated iron.

Abstract: A method and appaatus for curing a gasket material on a cap, the apparatus having a microwave transmitter, associated wavegide and a device for moving multiple caps through the waveguide. A plastic material is applied to the cap so as to form a gasket. The cap is then moved through the waveguide where microwave energy is absorbed by plastic material. The plastic material then heats from room temperature to a predetermined curing temperature in the waveguide. The cap is then removed and allowed to cool back to room temperature so that the gasket material will harden.

Abstract: A cooling device of the kind used in transportation vehicles, designed to maintain the transportation space of such vehicles cool over prolonged periods, includes an elongate housing of generally rectangular cross-section, having side walls and first and second end walls. The cooling device further includes a cooling pipe of elongate "U"-shape, having a curved portion and parallel arms. The ends of the cooling pipe are secured within one end wall, and the central portion of the pipe is supported in relation to the opposed wall by a supporting means.

Abstract: A method of making a foam filled polymer article includes the steps of compressing an expandable foam material (12) and containing the compressed expandable material (12) in a degradable container, such as a polyethylene bag (16). An outer polymer shell (10) is formed while degrading the container (16) therewithin, such as by rotation molding. The shell (10) is filled with the uncontained expandable foam material (12).

Abstract: The present invention is a method of rotationally molding an article having a layer made of polyamide composition. The method comprises the steps of melt blending a polyamide composition comprising the polyamide and a copolymer comprising units derived from an alpha-olefin of the formula RCH.dbd.CH.sub.2 where R is H or an alkyl having from 1 to 8 carbon atoms and from 0.2 to 25 mole percent based on the alpha-olefin-acid copolymer of an alpha, beta-ethylenically unsaturated carboxylic acid having from 3 to 8 carbon atoms. The copolymer has from 10% to 90% of the carboxylic groups neutralized by metal ions. The melt blended composition is formed into particles, including pellets and powder, suitable for rotational molding. The particles are rotationally molded to form an article.

Abstract: A method for forming a hollow body during which, for the purpose of impression of internal stresses, the body is subjected during its production to axial forces and moments. For this purpose the hollow body is supported from the inside by a mandrel constituted by disks which can move relative to one another and which, accordingly, do not obstruct axial expansion and twisting of the hollow body.

Abstract: Continuous molding apparatus includes a raw material supplying portion, a molding portion, a supporting portion, a mixing portion and a control portion. Each reservoir of the raw material supplying portion is connected independently with the mixing portion. The molding portion includes a plurality of spaced mold assemblies each with at least two separable mold sections. The supporting portion includes a plurality of the spaced mold assemblies each supported for independent rotation about more than one axis. The mixing portion includes an elongated mixing chamber disposed adjacent each mold assembly each with a plurality of deflector sections. A continuous method of molding a foamed product includes providing a plurality of raw material reservoirs and continuously moving raw material from each reservoir independently to a plurality of spaced mixing chambers each of which is located adjacent to an individual mold assembly including separable mold sections.

Abstract: A method is disclosed for the manufacture of an electrofusion coupler, for connecting adjoining lengths of thermoplastics pipes, and which coupler takes the form of a sleeve of thermoplastics material, to receive adjoining ends of adjoining pipes, the sleeve having an electrical resistance heater embedded therein and extended around the sleeve. In the method, a plastics preform is wound with a resistance heating wire, while heating the wire, to melt the surface of the preform, or applying molten plastics to the preform in the vicinity where the wire runs onto the preform, in order to ensure that the heating wire is fully embedded in the preform. A pressing roller may be run over the preform surface before the molten plastics has solidified, in order to smooth over the molten plastics. The preform 10 is subsequently placed in an injection mould and an outer encapsulating jacket is injection moulded around the preform.

Abstract: Large fittings or other structures are made by rotationally moulding a first component 18 of polyethylene and joining cylindrical pups 20, 22, 24 of polyethylene to the component by butt fusion joints 26, 28, 30. The structure within the boundary 50 is irradiated with gamma radiation followed by post-heating to remove free radicals. The extremities of the pups are shielded to prevent irradiation. Their capability to be joined to polyethylene pipes 12, 14, 16 by butt-fusion joints 32, 34, 36 is unimpaired. The irradiation introduces cross-linking to give improved properties such as impact resistance and stress crack resistance and to bring the fitting within the specification for polyethylene pipe for natural gas distribution. The joints 26, 28, 30 are made using differential heating of the ends to be joined to compensate for differences in melt flow index. Alternatively, the component 18 is slightly irradiated to lower its MFI before the pups are joined to it.

Abstract: A slush molding method including the steps of preparing a mold with a groove provided on the entire periphery of the opening portion thereof, engaging a heating medium guard frame with the groove, charging a resin material into the mold, heating the mold into the heating medium which is contained in a fluidized-bed oven and fluidized by air so as to melt the resin and cause it to adhere to the molding surface and removing the heating medium guard frame to discharge the surplus resin. An apparatus used for the slush molding method is also included.

Abstract: Disclosed is a method and apparatus for producing a flexible tube of a thermoplastic resin having poor melt flowability by melting a thermoplastic resin having poor melt flowability in a screw extruder, and melt-extruding the molten thermoplastic resin from a tube die having an L/D of 30-70 provided at a mandrel rotatable with the rotation of the screw.

Abstract: A process for making a substantially even thickness fascia part. The fascia part is prepared by placement of a plastic powdered material into an enclosed mold, heating and agitating the mold for distributing the plastic powder on the mold surfaces to provide a substantially even thickness fascia part on the molding surface. The mold includes first mold surfaces for defining critical portions of the mold which correspond to the desired portions of the mold for forming the finished shape of the part by melting of the plastic powder to a uniform film along the surface. The mold also includes second mold surfaces defining non-critical portions of the mold where it is undesirable for plastic filming to occur.

Abstract: A top air nozzle for blowing water off a washed moving vehicle in a car wash includes a unit nozzle housing of molded plastic material having an arcuate top wall, laterally diverging side walls, a pair of laterally spaced mount blocks, an upright rear wall, an upper front wall portion inclined downwardly and outwardly of the rear wall and terminating in a lower front wall portion inclined downwardly and inwardly toward the rear wall. The walls and wall portions define an air chamber of laterally increasing width from its top with the rear wall, lower front wall portion and side walls defining a laterally elongated throated air outlet. A plurality of spaced threaded insert fasteners arranged in a circle are molded, interlocked and enclosed within one of the upper front wall portion and rear wall. A plurality of spaced fasteners are arranged in a row, are molded, interlocked and enclosed within each mount block.

Abstract: Apparatus for manufacturing thin-walled hollow shells for parts such as automobile door panels, control and instrument panels and the like includes a charge box or powder box for supplying dry thermoplastic material to separate casting surfaces on a heated mold selectively connected to the charge box during a casting process. A selectively pressurizable inflatable seal gasket is connected to the charge box for sealing a division surface on the heated mold which surface separates the casting surfaces of the mold. The inflatable seal gasket includes a base portion fixed to the charge box; an inflatable core with expandable walls to bridge the distance between the charge box and the division surface and a seal bead that sealingly engages the division surface when the seal gasket is inflated to keep the division surface clean for a subsequent application of material to form a connector bond between previously cast two tone colored segments.

Abstract: A method of making a solid core locatable between a wheel rim and a tire fitted to the rim, includes introducing a foamable composition into a mould cavity having a substantially inflexible mould surface. The cavity is suitably shaped so that a core locatable between a wheel rim and a tire fitted to the rim can be moulded therein. The composition is allowed to foam, thereby to fill the mould cavity. Air and excess composition is allowed to vent from the cavity via an elongate vent slit extending along a major portion of the cavity. The foamed core thus moulded in the cavity is removed from the cavity on the composition having set at least partially.

Abstract: A method for the manufacture of a physical blend of pigment and a polymer powder whereby polymer powder having a particle size in the range of 250 to 750 microns is fed to a high intensity mixer and then powdered pigment is fed to the mixer at a rate of not more than 0.5 parts of pigment per 100 parts of polymer per minute. The pigment has a particle size that is substantially smaller than that of the polymer powder. The resultant admixture is mixed for a further period of time and then discharged from the mixer. The method is particularly applicable to powdered polyethylene intended for use in a rotational moulding process e.g. for the manufacture of containers and other hollow articles.

Abstract: A rotational molding process for slush casting mold with plastisol includes providing a conveyor having a plurality of spaced reversing arm assemblies, each arm assembly having opposite ends carrying molds thereon; providing first and second conveyor paths for the molds on the opposite ends of each arm assembly and locating one of the first and second conveyor paths inside the outer perimeter of the other of the first and second conveyor paths; preheating a mold on one of the arm assemblies on the first conveyor path and filling the preheated mold with an excessive charge of plastisol to form a gel layer thereon while on the first conveyor path and thereafter dumping plastisol from the preheated mold for return to a supply source of plastisol; and simultaneously curing a gel layer on another of the arm assemblies by directing the mold through the second conveyor path as the preheated mold on the other end of the arm assembly is being filled and dumped whereby the movement of an arm assembly produces simultane

Abstract: Low-level radioactive wastes and the like are identified by composition and segregated based on specific contaminants identified. The separated wastes are subsequently encapsulated in a centrifugal process prior to disposal. The wastes advantageously are subjected to heat prior to classification in order to remove any volatiles and hydrocarbons present.

Abstract: Apparatus and a process for manufacturing plastic shells having decorative features thereon includes a method for casting thermoplastic material against a heated mold by use of a combination mask and container unit (hereinafter referred to as the combination unit) that is joined to a known heated mold to deposit a first semi-cured deposit on the mold from supplies of material in the combination mask and container; the mask is configured to have a plurality of wire reinforced foot portions with sealing edges configured to be aligned with the sharp edges of recesses in the mold surface defining the decorative feature; when the combination unit is inverted it casts material only on the recesses to form a semi-fused deposit of a first color. The combination unit is separated from the mold which is then processed to a higher fusion temperature and a base layer of contrasting thermoplastic material is cast thereon to be bonded to the recess material prior to cooling and stripping the mold.

Abstract: An apparatus for forming a multi-colored integral vinyl skin shell including a heated mold and dual powder box arrangement wherein the mold is formed to include alternately positioned tear surfaces and recessed surfaces. The powder box has a plurality of spaced dams or dividers formed therein such that the dams cooperate with the respective recessed surfaces of the mold to provide clearance therewith that permit different colored powders in the compartments between the dams to cover the previously cleared tear surfaces and to flow past the selectively formed free ends of the dams to become integrally secured to the adjacent edge portions of the shell segments remaining in the areas of the recessed surfaces of the mold, forming the multi-colored, integral plastic shell.

Abstract: A panel having high strength relative to its weight is made of rigid material and is formed with a plurality of open cells, each open at one side, and with a plurality of closed cells, each closed on all sides. Each of the open cells is surrounded on all its sides by a plurality of the closed cells, and each of the closed cells is surrounded on all its sides by a plurality of the open cells.

Abstract: A access-hole frame for the construction of a spherical tank made of nonmetal moldable material, the frame having a cylindrical neck, an outwardly extending flange at the top side of the neck, and a collar configured as a segmented sphere to be integrated with the spherical wall of the tank. Bolt holes are drilled around the flange for bolts that hold an access-hole cover to the access-hole frame. A three-piece die provided for making the access-hole frame includes a bottom die piece and two top pieces that are bolted together to form an integral top die piece that fits over the bottom die piece. The access-hole frame is formed in accordance with a manufacturing process by placing the three-piece die in stages upon a rotatable table and spraying the nonmetal moldable material onto the rotating bottom and top die pieces.

Abstract: A blower comprises a unit blower housing of molded plastic material having a circular outer wall and laterally spaced front and rear walls, defining an impeller chamber and a tangential outlet upon a first axis adapted to receive a flexible hose. The outlet defines with an end portion of the outer wall a reverse curved cut off edge extending between the side walls. An opening in the front wall is arranged upon a second axis at right angles to the first axis and receives an air inlet secured to the housing by a plurality of threaded inserts molded into the housing. An electric motor upon a support has a drive shaft extending through the rear wall. The rear wall is mounted upon and secured to the motor and an impeller is positioned within the housing and axially mounted upon the motor shaft and has an air intake receiving the air inlet cone.

Abstract: A process which comprises (i) the generation of release surfaces by application to predetermined areas of a solid surface of a solution, suspension or dispersion of a release agent and a supercritical fluid that vaporizes from the release agent, (ii) the deposition of a mass onto the release surface containing the release agent, and (iii) the separation of the mass or a product derived from the mass from such surface covered by the release agent. Novel apparatus for carrying out the process are described.

Abstract: A tubular compact (14) obtained by compacting a powder is applied with one circumferential surface (16) at a minimum distance required for said application, from an abutment surface (15) corresponding to said one circumferential surface (16). The space between said one circumferential surface (16) and the abutment surface (15) is evacuated, such that the compact (14), while undergoing a certain deformation to bridge said space, is sucked against the abutment surface (15) so as to be firmly retained against it.

Abstract: A system for producing a screw feeder for use in a plastic injection-molding machine, according to which system a molten material is extruded through an injection opening of a rotating die, the injection opening of the die including a groove obliquely with respect to the axis thereof, thereby forming a screw feeder having a shank and a spiral integral lengthwise therewith.

Abstract: A method for manufacture of a sealing ring with a flanged sealing lip having hydrodynamically acting return transport properties in which a sealing lip is first generated by extrusion of a plastically deformable material through a ring nozzle having rotating inner and outer surfaces which are rotated relative to each other to impart a helical motion to the extruded material; the hydrodynamically acting return transport properties being a microscopically fine pleating of the surface of the extruded hollow cylinder. The extruded cylinder is then solidified and cut to a predetermined length. The cylinder is then widened in the radial direction at its front end by an assembly tool which shapes the cylinder into a trumpet-shaped sealing ring with a flanged sealing lip.

Abstract: The production of tension-proof, liquid impermeable, flexible bands which are preferably utilized for presses to dewater fiber material webs and are subjected therein to substantial tensile stresses between a press-shoe and a press-roll as the same glide across the press-shoe which is effected by means of penetration of a flowable mixture of a prepolymer with a cross linking agent onto the reinforcing band, preferably formed of fabric and receiving the tension forces in a direction longitudinally of the press band. Penetration most effectively occurs through covering the fabric band by pouring thereover of the flowable mixture as the band is in stretched condition and is moved.

Abstract: The present invention relates to a composition comprising crosslinkable polyethylene homopolymer, copolymer or mixture thereof. The composition includes a peroxide crosslinking agent, a crosslinking co-agent, and a metal compound having a cation selected from Group IIA and IIB of the Periodic Table of Elements. The composition is particularly useful for polymers which are formed using Ziegler-type catalysts and have complete terminal saturation. The present invention also includes a composition which has been found particularly suitable for use in critical molding processes such as rotational molding. This composition comprises a polyethylene homopolymer, copolymer, or mixture thereof. The present invention includes a method of rotational molding.

Abstract: Jiggering for ceramic ware is effected while providing a jiggering surface of a jiggering profile tool with a gas to produce a thin gas film between the jiggering surface and plastic clay. The gas film is formed by a gas fed from the outside of the jiggering surface and the jiggering profile tool is heated to 50.degree.-60.degree. C. High-temperature heating of the tool is dispensed with.

Abstract: A process for the continuous preparation of an oriented film of a polymer material comprising shearing at least one film of a solution and/or gel of the polymer material between at least one set of two solid surfaces which are in motion relative to one another. At least one of which surfaces is endless, so as to cause by the shearing, solidification of the polymer material from the solution or gel to a degree sufficient that a coherent, oriented film of the polymer material is formed on one of the surfaces. The film is sufficiently coherent so as to be capable of being removed from the surface on which it is formed in a continuous manner.

Abstract: A method of making O-rings by depositing a filament of a liquid hot-melt material onto a rotating spindle, or directly upon the shank of a rotating fastener.

Abstract: A three-piece tank assembly including a tank, a support base, and a support liner. The tank has a conical bottom with a discharge conduit at its apex; a longitudinally corrugated antisplash filling trough integrally formed with a sidewall of the tank; and an integrally formed cover including a bunghole for providing access to the filling trough. The discharge conduit may include a flow valve and check valve. The base includes a sidewall for nesting engagement with the tank sidewall, a flat ground-engaging surface and transverse longitudinal slots for receiving the forks of a forklift. The support liner has an upstanding wall and a conical top wall for supporting the conical bottom of the tank and nesting within the support base. Mating projections and grooves in the tank and support base prevent relative movement of the three elements of the tank assembly. Each of the three elements is rotationally molded of cross-linked, high density polyethylene.

Abstract: An improved rotational molding method for making a laminated plastic structure of the type in which successive charges of particulate plastics are released in a mold cavity rotating in an oven to coalesce successively along the mold cavity wall after which the mold is removed from the oven for cooling. By removing the rotating mold from the oven prior to completion of the formation of the inside layer, cooling of the outside of the mold will be concurrent with coalescence of the inside layer. This shortens the time of the molding cycle and reduces warping problems.

Abstract: A method for uniformly coating a moving substrate by eliminating nonuniformities in the voscosity of the coating solution along the line where the solution is applied to the substrate. A viscosity-varying region is provided either inside or outside of a coating solution pocket in an extruder assembly. In one embodiment, the voscosity-varying region is provided by making the length of a slit through which the coating solution flows onto the support less than that of the pocket. In another embodiment, the viscosity-varying region takes the form of small-diameter tube through which the coating solution is supplied to one end of the pocket. In a third embodiment, a roller is disposed in the pocket and the diameter of the roller and the pocket are tapered towards the center. In a still further embodiment, the solution is supplied through a distributor.