Abstract: The wall of one end section of a plastic pipe is post thickened. As disclosed herein, this is accomplished by heating a predetermined length of the end of the pipe to its state of thermal deformability and thereafter causing the pipe to deform within and substantially fill a longitudinally extending, circumferential cavity which is thicker than the originally formed pipe wall. At the same time, a predetermined amount of heat is applied to the cavity from points along the length of and around the circumference of the inner and outer surfaces of the cavity. These points of heat extend from the back end of this cavity towards but stop short of its front end, a predetermined distance from the front end, thus defining a transition zone. This transition zone, among other things, prevents the remaining portion of the pipe from being heated and thus easily distorted during the thickening operation.

Abstract: A composition comprising .alpha.-alumina in a concentration of at least 99.95 weight percent and process for producing such .alpha.-alumina wherein alumina having an alkali metal content between 0.05 and 0.60 weight percent and Al.sub.2 O.sub.3 content of more than 95 weight percent is electrically fused with silica and additional alkali, if desired, in an electric arc furnace, the heated composition is cooled, comminuted and the so-formed glass phase is removed from an alumina containing phase by mechanical or chemical means.

Abstract: There is disclosed an all plastic hinge for hanging conventionally sized doors for buildings and the like. Means are provided to prevent the pin from rising out of the passage afforded by the hinge halves by establishing a preferred direction of pin movement in the pin inserting direction. An enlargement in the pin receiving passage is created by differentially shrinking the knuckle surrounding the passage during the process of manufacture.

Abstract: A method of molding large-sized plastics is disclosed, in which is used an apparatus comprising an extruding means and a die clamping device composed of a stationary die plate and a movable die plate, both being able to be connected to each other in order to clamp the die or separated to open the die with tie bars on the movable die plate inserted into or drawn out of the stationary die plate, and a die of thin plate make attached to the die clamping device and comprising a cavity and a core, each being partitioned into a plurality of small sections in order to control the temperature of each section separately. Thus, a molten material is extruded into the die after it is heated partially at different temperatures required, and, after it is cooled down partially at different rate required, the solidified article is taken out of the die, so that a large-sized article of good quality is obtained with low molding costs. The die is less expensive and easy to handle, and the replacement of it is also very easy.

Abstract: The method permits selective cooling of tubular plastic material as formed to provide for an exchange of internal cooling air through the central opening of the blow head. Air supply rings having outlet slots facing the tubing, as well as air guide surfaces of small axial length, are provided inside the tubing and spaced from the annular die orifice to serve to support the tubing. The interior cooling air supply rings have axially directed passages for the flow of cooling air while the exterior air supply ring or rings deliver air at higher temperatures to provide a substantial thermal differential between the tube surfaces as formed to provide a flare-top edge upon severance. Also, the method permits forming a foam-film composite of thermoplastic materials by the blown bubble co-extrusion process.

Abstract: A catheter assembly including a plastic tube having a cup-shaped bulb at one end and which is oval in cross section. The walls of the bulb are thicker than the remainder of the tube and a hub is molded about the bulb both interiorly and exteriorly thereof. The bulb is formed by placing the tube on a mandrel, which extends from a mandrel carrier, and thereafter placing the carrier on a base so that the upper end of the tube and mandrel extend through a slot and into a heating cavity defined by a housing. The upper end of the tube is subjected to radiant heat on opposite sides thereof to heat the circumference of the tube unevenly to form and define the cup-shaped bulb. The upper end of the tube is heated to a temperature close to its melting point.

Abstract: Thermoplastic resin is converted to void free billets and preforms, by techniques including: compaction of heated thermoplastic powders: compactionof heated extruded strands: rolling of heated ingots of plastic: simultaneous extrusion and combining of two or more groups of strands: coextrusion of two or more resin formulations: sequential compaction of dual powders: extrusion with differentially heated dies. The billets may be non-homogeneous in response to dielectric heating, to produce controlled temperature zones within the heated polymers, when used as billets and preforms.

Abstract: A tube of thermoplastic material is heated to plasticity, whereupon the heated tube is provided with a thickened end by subjecting the tube to an upsetting action in such a way that the thickening starts at a distance from the free end of the heated part and increases gradually from this point towards the free end of the heated part.

Abstract: Thermoplastic objects are manufactured by placing an extruded thermoplastic blank while still in a substantially molten state within a mold cavity defined on all sides by rigid walls with at least one of the walls being movable relative to the other walls. The movable wall extends substantially completely over the entire area of one side of the article to be formed and it is moved to apply pressure to the article while also simultaneously applying heat to the one side against which the wall is pressed. The other walls forming the mold cavity are cooled during the forming process.

Abstract: A process for sizing an extruded thermoplastic structure or member formed by coextrusion of a core profile of one thermoplastic material and a cover layer of another thermoplastic material provided over a portion of the periphery of the core profile which includes the steps of sizing the extruded plastic structure in the external cross sectional dimensions, cooling during the sizing step the structure and effecting a different temperature control of the cooling of the cross section of the profile depending upon the thermoplastic material being cooled. The thermoplastic material having the higher Vicat softening temperature being more gradually cooled than the one having a lower Vicat softening temperature.

Abstract: The method involves assembling an uncured belt body having a stable length tensile section adjacent an inwardly disposed mandrel made of a metal having a high coefficient of thermal expansion, heating the mandrel whereby its thermal properties are utilized to maintain the tensile member in tension, also pressurizing the belt body in a direction toward the mandrel thus sandwiching it, and while maintaining the tensile member in tension, curing the belt body from which one or more endless power transmission belts may be formed. The apparatus utilizes the mandrel in a substantially ring or cylindrical shape about which is disposed inwardly pressure supplying means, an annular cavity disposed between the mandrel and pressure means, and means for supplying heat to the mandrel to intitiate its thermal growth during curing of the belting.

Abstract: A method and apparatus for forming cured polyethylene insulation about high voltage cables by applying uncured polyethylene around a core of the cable. The polyethylene is heated, cured and then cooled to room temperature in a pressurized nitrogen gas atmosphere. In one form the molding apparatus comprises first and second mold forms which define a cavity and which include means for heating the mold halves to the polyethylene curing temperature. Means is also provided to introduce the pressurized nitrogen into the cavity and for subjecting cable portions that extend beyond the mold to pressurized nitrogen until such cable portions are sufficiently cooled to prevent their deformation under pressure, to prevent the oxidation of polyethylene and/or to prevent the formation of voids or enclosures.

Abstract: A method for forming elongated and involute thermoplastic articles is disclosed. Means are provided for controllably heating a sheet of thermoplastic material to form preselected temperature gradients throughout the sheet of thermoplastic material. Means are further provided for planarly supporting the heated sheet of thermoplastic material allowing for transverse motion of the heated sheet of thermoplastic material at the center thereof and further allowing for controlled slippage of the heated sheet of thermoplastic material toward said center thereof relative to the planar support means. Means are also provided for transversely forming a heated sheet of thermoplastic material into the shape of an elongated or involute plastic article. A plug is used to extend the heated sheet of thermoplastic material into an elongated conical shaped piece.

Abstract: The two half sections of a battery grid mold are provided with means for cooling the portions of the mold sections directly adjacent the grid cavity and for heating the larger rear portions of the mold sections. The means for cooling the mold sections comprise a plurality of coolant passageways disposed forwardly of the vertical mid-plane of each mold section.

Abstract: Method of forming a container in a collapsed or folded configuration from a thermoplastic material. A preform is made from an extruded tube of thermoplastic material in a preform mold. The preform is then transferred to a deformation mold. The preform has a skin of relatively cool material on its exterior and interior surfaces; however, the interior of the walls between the skins is still in a deformable state. In the deformation mold, the preform is collapsed or folded and held in such condition until the interior material in the walls has become set. This leaves the container so formed with a memory in the folded state. When filled, the container may be elongated beyond the folded state dimensions, but will try to return to that state as the contents are dispensed as a result of the formed-in memory.

Abstract: A method are disclosed for heating thermoplastic parisons to a substantially uniform temperature across their wall thickness prior to a blow molding operation. In the method, the parisons are rotated about their longitudinal axes while being conveyed adjacent a thermal conditioning means, which includes vertically spaced radiant heating elements and a gaseous cooling source. The heating elements radiate infra-red rays having a wave length to penetrate and heat the full thickness of the parison wall; whereas the gaseous cooling source directs a stream of air onto the surface of the parison facing the heating elements to prevent the parison surface from being overheated. Additionally, each of the heating elements may be individually regulated so that the parisons can be differentially heated along their axes to control the wall thickness of the final blown articles.

Abstract: The process herein is used for achieving multilevel mechanical embossing of an expanded foam having a fused or cured wear layer in register with a print on the foam. The expansion of the decorative foam and fusion of the wear layer are carried out and then the back of the foam is cooled by back wetting with or without drum cooling. The wear layer is maintained at a high temperature for embossing and is embossed with registry between the embossed pattern and the printed pattern on the foam.

Abstract: A method of incorporating a pre-cut foil sheet in a container moulded from a thermoplastic material by injection moulding techniques during the process of moulding the container. The foil sheets are fed singly from a store to a position of registry with the free end of the plunger forming part of the mould of the injection moulding apparatus, whereafter the mould is closed, the foil sheet being wrapped around the plunger upon entry thereof into the die. A moulding compound is then injected into the mould. The stream of moulding compound entering the mould is guided so that the foil sheet is either located on the inner surface of the moulded object or on the outer surface thereof.

Abstract: A thermoplastic plate, for example one of polypropylene or nylon, fabricated so it has an open-cell structure, has a radiation transparent cover sheet applied to one face thereof. The cover sheet has an energy absorbing coating (e.g. of carbon and nitrocellulose) in intimate contact with the plate. A modulated laser beam is then transmitted through said cover sheet to selectively transfer some of the energy absorbing material to the plate according to the configuration required to define the areas of relief desired in the plate. The cover sheet is then removed except for the portion of the energy absorbing coating transferred to the plate. The entire surface of the plate is then exposed to infra-red rays.

Abstract: Parisons for use in making blow molded highly molecularly oriented plastic bottles are injection molded using a cooled cavity and a relatively hot core pin to prevent the formation of residual internal stress in or near the surface of the parison. The pin is maintained at a temperature above the glass transition temperature of the resin to reduce the formation of cracks when the parison is subsequently blow molded in the orientation temperature range.

Abstract: Parisons are injection molded using a cooled cavity and a relatively hot core pin to prevent the formation of residual internal stress in or near the inner surface of the parison. The parison is promptly transferred while still hot from the injection mold to a temperature conditioning station to provide a desired temperature distribution and the temperature conditioned parison is highly molecularly biaxially oriented as it is blow molded.

Abstract: Disclosed is a method of preparing castings of bismuth, silicon and silicon alloys characterized by solidification expansion by cooling the molten material below its melting point to form a casting of the material within a suitable container. According to the disclosed method, a tapered liquid core with the smaller end downward and the larger end upward and a portion of the top of the casting, i.e., a liquid pool on top of the casting, are maintained in a molten state and in liquid communication with each other until the casting is substantially solidified, for example, by keeping the liquid pool on top molten by insulation or by heat addition or by both insulation and heat addition. Thereafter, the core and the top are allowed to solidify, providing a casting substantially free of defects.

Abstract: A molecularly oriented article having a tubular sidewall is blow-molded from a thermoplastic parison which is heat-treated prior to blowing to provide the parison sidewall with a temperature gradient wherein the temperature of the inside of the sidewall is greater than that of the outside, both of said temperatures being within the orientation temperature range of the thermoplastic. The temperature gradient results in the sidewall of the article having a different and more uniform circumferential orientation release stress distribution radially across the sidewall than would be obtained if the parison were blown isothermally.

Abstract: Hollow articles of thermoplastics, especially bottles, are made from tubular blanks by heating the ends thereof and press molding first their bottom and neck portion. Then the preformed blanks are heated around their center portion and are transferred into blow molds for inflating them to the final shape. The machine consists of a first rotary table with preheating and press molding means, a second rotary table with final heating means and a third rotary table with blow molds. The rotary tables are connected by transfer stations so that the blanks can be automatically transmitted and conveyed around all tables. The high throughput allows installation before racking plants.

Abstract: A technique for producing one or more shaped bodies of semiconductor material using the steps of depositing a layer of the semiconductor material from the gas phase onto the outer surface of a heated, hollow carrier body, or onto the mutually remote surfaces of two carrier bodies spaced from one another, and thereafter removing the carrier body or bodies from the layer or layers so formed. Each carrier body is heated indirectly by a heater body located within said hollow carrier body, or between said spaced carrier bodies, and heated to a temperature above the deposition temperature of the semiconductor material.

Abstract: A brassiere cup of a resilient fibrous material intermixed with a resin formed by cooperating male and female die parts with the male die having a pad formed over the apex. The die parts are heated to a temprature above the softening temperature of the resin while said pad is maintained at a temperature below the softening temperature of the resin whereby the cup upon removal from the mold will have a thin peripheral portion and the material at the apex will expand to provide an apex of greater thickness.

Abstract: This invention cools the blowing mold and the plastic article blown therein to shorten the time that a core rod must remain at a blowing station of a blow molding machine for making plastic articles. The cooling is performed by conditioned air that is dried to lower its dew point. An air curtain is used to prevent other air from contacting with and depositing moisture on the mold. In order to take advantage of the shorter time at the blowing station, an auxiliary injection device is used to also shorten the time required for the injection operation; and auxiliary cooling is supplied to the core rod at the stripper station.

Abstract: A method and a device for making objects from plastics, wherein a plastic present in the moulding cavity is made to set while pressure is maintained, said moulding pressure being made to act on the plastic being moulded by means of the inflation of one or more fully or partly flexible and expansible moulding tools.The invention relates to a method of making objects from plastics by means of compression moulding, a plastic present in the cavity of a mould being made to set while a moulding pressure is maintained, and also to a device for performing this method.Plastics can be moulded in any given manner while in the plastic condition. For example, the plastic can be introduced into a hollow mould for this purpose. While the plastic material, particularly thermoplastic material is setting, sunk spots may form on the surfaces and pockets may arise inside the plastic as a result of shrinkage, especially when the object being moulded has relatively thick walls.

Abstract: A thermoplastic plate, for example, one of polypropylene or nylon, fabricated so it has an open-cell structure, has a radiation transparent cover sheet applied to one face thereof. The cover sheet has an energy absorbing coating (e.g. of carbon and nitrocellulose) in intimate contact with the plate. A modulated laser beam is then transmitted through said cover sheet to selectively transfer some of the energy absorbing material to the plate according to the configuration required to define the areas of relief desired in the plate. The cover sheet is then removed except for the portion of the energy absorbing coating transferred to the plate. The entire surface of the plate is then exposed to infra-red rays.

Abstract: A method of making blown plastic articles of non-circular cross-section, having convex exterior portions, such as a bottle of rectangular or oval shape, or having localized protuberances. The article is blown from a pre-form of inverted shape, i.e., the convex article portions are formed from concave pre-form portions. Also, the concave, pre-form portions are of increased thickness to compensate for their greater subsequent expansion during blowing.During final blowing, the non-convex portions of the article are first formed against the mold cavity-thereby stabilizing the partly blown pre-form in the blow mold cavity-and the concave pre-form portions are then blown to their final convex shape to complete the article.

Abstract: Described herein are articles which are heat recoverable in involute fashion to an overlapping, generally cylindrical configuration and which are useful as wrap-around sleeves for wires, cables, cable splices and the like. Also described are articles initially heat recoverable to an elongate S-shaped configuration, which latter can be wrapped about an elongate substrate, the edge portions thereof interlocked, and heat recovered to form a protective closure. The articles of the invention comprise a molecularly oriented unitary polymeric layer which has been differentially annealed while restrained against dimensional change and cross-linked to provide an anisotropic gradient from a first to a second primary face of the layer through the thickness thereof. Subsequently, when the article is heated to recovery temperature, regions of high anisotropy adjacent one primary face of the layer shrink.

Abstract: An open end parison preform is heated to molding temperature preparatory to transfer to a molding station. The thus heated parison is grasped by a pair of opposed picker fingers and transferred into position over a neck forming plug. The relative temperature of the opposed picker fingers is controlled which effects the alignment of the bottom end of the parison over the plug.

Abstract: A method for controlling the extrudate emerging from an extruder is provided by sealing a portion of the extrusion die opening with a deckle bar into which is incorporated means for affecting the temperature at the surface of the deckle bar. The embodiments of this invention provide deckle bars into which are incorporated means for heating, cooling and heating and cooling in combination.

Abstract: A method for producing hollow articles comprises extruding a thermoplastic material, initially in a molten state, through a lubricated die having a mandrel for constraining the material into a tubular shape, cooling the outer surface of the material during its passage through the die so that said material emerges therefrom as a tubular extrudate having its inner surface molten and its outer surface at a temperature below its freezing temperature, squeezing the extrudate at suitable intervals to fuse the molten inner surface together and thereby seal discrete lengths, and inflating the sealed lengths to conform to a surrounding mould to produce a shaped article.

Abstract: Glass fiber reinforcing members with at least one end anchorage point are formed from glass fiber rovings impregnated with resin and shaped into a ribbon. The ribbon is surrounded before curing at discrete intervals with castings which, after curing, provide areas which can be formed into anchorage areas.

Abstract: Box-like units having at least one open side for use, for example, in the construction of prefabricated buildings are cast from a composition of gypsum and water optionally including other material such as Portland or Aluminous cement. The mixture is cast between an external mould defining the external faces of the unit and an internal core defining the internal faces of the unit and the core is formed from, or covered with, material which causes its faces which come into contact with the mixture to have a higher co-efficient of heat reflection than that of the faces of the external mould which come into contact with the mixture. The mixture is allowed to set and the external mould is removed, after which the mixture is allowed to harden further and during this hardening becomes heated by the exothermic reaction between the gypsum and the water to cause the hardened mixture to expand away from the core. This allows the core to be subsequently removed without it being necessary to make the core collapsible.

Abstract: A method or process of forming an arch or curve or other geometric figure or a memory retention of said arch, curve, or other geometric figure, in either extruded moldable polymer or moldable polymer, either filled or unfilled.

Abstract: The process comprises heating a hollow thermoplastic parison to orientation temperature ranges by selectively applying radiant heat to at least three portions of the parison. The thus irradiated parison is passed to a molding zone, and therein subjected to a pressure differential sufficient to expand the parison into conformity with a molding zone cavity.

Abstract: Processes for coating concrete bricks with exposed surfaces having sharply delineated portions of contrasting color and/or texture by periodically and regularly forming atomized particles of a viscous cementitious slurry and directing same on to portions of surfaces of each of a plurality of green concrete bricks in groups located stationary in regular fashion for a brief period and thereafter firing the thus coated uncured brick. The processes include steps for rapidly and/or sequentially varying the colors applied to the different groups of bricks during successive cycles of coating the successively treated different groups of such brick.

Abstract: Seamless hollow molding rubber articles are produced by concurrently molding two article halves with mateable edges which extend toward each other. Portions of the mold plates and core are maintained continuously at the full vulcanizing heat until the halves of the articles have been vulcanized to about 60 percent of the optimum vulcanization of the material, except for thin strata defining the mateable edges. By cooling at the portions which form these strata, these portions are maintained at a lesser temperature to cause the reaction in these strata to progress slightly beyond the scorching or blowing stage to dimensional and volumetric stability. At this stage, the mateable faces of the edges are substantially free from the usual "skin" effect which effect would render them non-fusible. The mold is then opened, the core is removed, and the mold is reclosed.

Abstract: A method of blow molding plastic articles in two blowing stages. A freely extruded pendant tubular parison is first blown into a pre-form, then the pre-form, while at the temperature most conductive to orientation, is blown to its final configuration. By performing certain operations on the pre-form prior to the final blowing step, improved products can be made. For example, by pinching shut a portion of the pre-form, handled containers can be made on a free extrusion blow molding machine. By stretching the pre-form prior to final blowing, containers of increased top-load or stacking capabilities can be made. .Iadd.This application is a re-issue of U.S. Pat. 3,781,395, issued Dec. 25, 1973, matured from U.S. Pat. application Ser. No. 110,685, filed January 28, 1971. .Iaddend.