Abstract: A process for producing an oriented blown film of a thermoplastic resin by blown film extrusion, carried out by blowing air into an extruded bubble of the resin extruded from a ring die to expand the bubble and cooling the expanded bubble with air from a cooling air ring, wherein blown film extrusion is carried out under such conditions that the ratio of (b) the final diameter of the expanded bubble to (a) the diameter of the bubble at the crystallizing temperature of the thermoplastic resin ((b)/(a)) ranges from 1.5 to 10. The process provides an oriented blown film excellent in strength, appearance, and heat shrinkage characteristics.

Abstract: Apparatus and process for gauging and controlling extruded profiled elements, particularly extruded profiled elements made of synthetic material. The apparatus includes at least one control and correction gauge arrangeable downstream of an extrusion die along the extrusion direction and in which there is a passage shaped so as to match the profile of the extruded profiled element. The passage can be crossed by the extruded profiled element, and there are holes and/or channels for heating and cooling preset regions of the profiled element to correct the profile and/or the internal tensions of the profiled element.

Abstract: A travelling mold tunnel for the vacuum forming of profiled tube from extruded parison of molten thermoplastic material includes a plurality of parallel mold cavities with a vacuum applied to each of the mold cavities.

Abstract: A seamless tube useful in making a roofing batten is extruded from a polymeric material consisting essentially of a major amount of poly(ethylene terephthalate) and a minor amount of at least one polyolefin, flattened in a vacuum sizer so as to define two plies, and milled and drawn so as to orient the tube longitudinally. As milled and drawn, the tube is oriented so as to have a tensile strength of at least about 25,000 psi in a longitudinal direction. The plies are punched so as to have holes therethrough at spaced intervals along the tube. When used to make a roofing batten to coact with conventional fasteners, such as roofing screws, the tube exhibits superior characteristics of split resistance and pull-through resistance.

Abstract: A method producing deformed pipe liners from continuously extruded thermoplastic material by collapsing and bending deformable portions of the tube toward a back-up portion thereof and without elongation to maintain diameter and wall thickness, and apparatus to carry out said method and characterized by at least one back-up roller and at least one shaping roller folding the deformable portion along a line of symmetry and juxtaposing a fold of the tube to the back-up portion, all at raised temperature followed by reduced temperature on a rail conforming to the deformed tube configuration.

Abstract: The invention concerns a cooling plug for sizing the interior surface of thermoplastic extruded pipe. Vacuum and/or pneumatic pressure is applied at the surface of the plug. The pneumatic pressure may cause the inner wall to balloon outwardly to form bells within a mold or within an outer wall, to fit into corrugations of an outer corrugated tube, etc. The vacuum may be used to pull the inner wall back to the surface of the plug after application of pneumatic pressure.

Abstract: The invention relates to a process for the film correction of the thickness profile of a blown portion in the production of bubble film in which the flow of cooling air is varied in individual peripheral regions of the film bubble. According to the invention, at least part of the cooling air is taken via an exit slot which is divided into individual separately fed segments in the peripheral direction of the film bubble and the supply of additional cooling air via the exit slot is, for example, controlled per segment using radial blowers. In this manner it is possible accurately to regulate the cooling action and thus the film thickness in the individual peripheral regions of the film bubble.

Abstract: A compression-resistant spacer is provided between the lower track of a hauler and the calibrator mounting platform of a calibrator or sizer in a extrusion line to prevent vibration of the calibrator and minimize wall thickness variations and surface markings of extruded profiles such as window profiles.

Abstract: A process for preparing a composite product from an intake material incorporating commercial, municipal or industrial waste containing organic, plastic and fibrous material includes first granulating and sizing the material. The material is then heated in three consecutive phases, first at a temperature sufficient to achieve an internal temperature within the material of about 215.degree. to 250.degree. F., then at a temperature sufficient to achieve an internal temperature within the material of about 250.degree. to 320.degree. F. and then at a temperature sufficient to achieve an internal temperature within the material of about 320.degree. to 400.degree. F., wherein said material is continuously mixed during said heat phases. The material may then be co-extruded with a reinforcement structure and forced into vacuum profile dies to form a product or compression molded to form a product and cooled.

Abstract: The invention concerns an apparatus and process particularly for molding profile thermoplastic tubing and process. The apparatus includes the travelling mold type for molding profile tubing, e.g. corrugated or ribbed, including double walled tubing of various types. A sizing plug for the internal diameter of the pipe is provided with suction applying device which applies suction of diminishing strength in the upstream direction of the plug to the inside diameter of the pipe to provide a smooth inside wall of the pipe and allowing faster pipe formation. Suitably, the plug is a cooling plug and provision may be made for communicating the suction to cooling liquid to draw it to the surface of the plug to provide lubrication for a faster pipe forming process.

Abstract: A process for forming plastic tubing which involves extruding a molten plastic composition through a die which produces an extended length of plastic tubing, passing the hot tubing through a vacuum sizing tube wherein the wall of the tubing is sized by being drawn to the wall of the sizing tube by a vacuum, and cooling the sized tubing so that the tubing will be self-supporting at normal ambient temperatures, wherein the plastic composition contains a phosphorus-containing additive in an amount sufficient to cause an improvement in the smoothness of the interior of said tubing.

Abstract: In the extrusion of plastic pipe wherein the pipe is in a self supporting but semi-molten state on exiting a die orifice, the inner surface of the extrudate is cooled by a device which applies a suction for establishing flow of a cooling fluid which contacts the inner surface of the extrudate. In a further embodiment the flow of cooling fluid established for cooling the extrudate additionally cools a cavity within a mandrel of the die orifice.

Abstract: Method in manufacturing a heat insulated tube includes a tube (17) for conducting fluid and a sheath (12) enclosing said tube, a heat insulating material (15) being disposed between the fluid tube and the sheath. The sheath is being extruded in an angle extruder die (10) while the fluid tube and the heat insulating material enclosing said tube are being fed axially through the angle extruder die as the sheath is being extruded around the heat insulating material. Then the sheath (12) extruded from the angle extruder die is kept spaced from the heat insulating material (15) enclosing the fluid tube (17), over an initial length of the axial movement thereof up to chains of chill molds (13) for imparting to the sheath a corrugated shape by forming the sheath against the chains of chill molds under the influence of negative pressure. The invention also relates to a device in extruders having an angle extruder die (10) for the manufacture of the heat insulated tube.

Abstract: The invention provides a new air ring of single or dual orifice type for use as a primary or secondary ring to cool a blown extruded tube of molten plastic material, and also to stabilize the moving tube. The air from the ring is kept in contact with the tube outer surface as much as possible by a chamber surrounding the tube. Maximum cooling requires maximum air velocity and in prior art apparatus this may then cause generation of vibrations of the bubble, resulting in non-uniform film, or even disruption of the bubble. The air volume and velocity must therefore be restricted to ensure that this does not happen. In the new air rings the side wall of the chamber diverges outwards in the direction of bubble movement with an end wall closing the downstream of the chamber and forming a short narrow orifice. The chamber is provided with a plurality of thin annular partition members which extend radially inwards so that their inner edges are close to the bubble wall to provide respective short, narrow gaps.

Abstract: A seamless parison extruded from an extruder via an annular die, passes through a calibrator and coaxially surrounds a probe pipe, which is made to extend through the annular die beyond the calibrator. On the probe pipe there is mounted a sealing element. Ahead of the sealing element, a pressure equal to atmospheric pressure prevails inside the tube and, after the sealing element, a higher pressure than atmospheric pressure prevails. The pressurization is achieved in that a second belt take-off folds together the tube, so that the compressed air fed in through the probe pipe causes a higher tube internal pressure, since the sealing element bears in a sealing manner against the inside of the tube. As a result, a substantial pressure separation is effected at the point of the sealing element.

Abstract: An apparatus for cooling a tubular polymer film material which is being extruded, and more particularly, an apparatus for extruding tubular thermoplastic films including two tandem spaced air rings for controlling the cooling rate and production speeds of the thermoplastic films during extrusion thereof. Moreover, there is also disclosed a method for the cooling of an extruded tubular thermoplastic film material through the utilization of a tandem air ring cooling structure.

Abstract: Apparatus for extruding a pliable, thin-walled tube comprising an extrusion and shaping die assembly comprising an annular die body, a mandrel supported within the annular die body, a mandrel extension mounted on the mandrel adjacent the die outlet, the mandrel extension having a diameter less than the diameter of the mandrel, a sizing disk supported by the mandrel extension, and a source capable of supplying molten polymeric material to the die assembly under pressure to force the material through an annular extrusion flow channel around the mandrel and out the die outlet thereby forming a moving tube of the material, the mandrel extension extending outwardly from the die in the direction in which the tube is extruded, the annular die body having at least one fluid passageway to channel fluid introduced under pressure into the annular die body axially through the mandrel and outwardly from the axis of the mandrel extension to form an air pillow adapted to cool and support the tube around and spaced from the

Abstract: The invention provides a new air ring of single or dual orifice type for use as a primary or secondary ring to cool a blown extruded tube of molten plastic material, and also to stabilize the moving tube. The air from the ring is kept in contact with the tube outer surface as much as possible by a ring "chimney" surrounding the tube. Maximum cooling requires maximum air velocity and in prior art apparatus this may cause generation of vibrations of the bubble, resulting in non-uniform film, or even disruption of the bubble. The air volume and velocity must therefore be resricted to ensure that this does not happen. In the new air rings the side wall of the chimney diverges outwards in the direction of bubble movement to form a chamber, an end wall closing the downstream end of the chamber turning suddenly radially inwards toward the bubble to form a short narrow orifice.

Abstract: The invention refers to a method and apparatus for manufacturing a single-wall pipe, tube or like conduit (9,44) having smooth inner surfaces and a mechanical-strength enhancing pattern of walls, flanges or ridges on the outer surface thereof, the conduit being made of plastics or like extrudable material.

Abstract: A plastic multilayer multiple-wall panel, manufactured by the coextrusion of a plurality of adhesively bonded layers of thermoplastically extrudable synthetic resins by means of a multicomponent extrusion die, and comprising a supporting core layer of polycarbonate resin with a plurality of continuous hollow chambers, a UV absorption layer, boned on one or both sides of said core layer and made of a synthetic resin containing at least 2 weight percent of a UV absorber that is volatile at elevated temperatures, and a cover layer, on that side of the UV absorption layer which faces away from the core layer, of a synthetic resin which contains less than 2 weight percent of volatile UV absorber.

Abstract: Apparatus for preparing seamless, creaseless, pliable, thin-walled tubes comprising means to extrude a moving continuous tube of polymeric film material from a die, means to radially stretch the continuous tube as it emerges from the die, means to longitudinally stretch the tube, and means to sever the tube while the tube is in motion to form tube segments while maintaining the tube substantially free of creases. This apparatus may be employed in a process to prepare seamless, creaseless, pliable, thin-walled tubes.

Abstract: A method for the production of thermoplastic tubes comprising: (1) extruding the thermoplastic tube of which the interior surface in a molten state by a heating unit disposed within the area of a mandrel near the nozzle of an extrusion mold, and (2) sliding the interior surface of the tube on an additional mandrel supported to the front end of the mandrel through a heat-insulating material in axial alignment with the hollow mandrel in a manner to bring the interior surface of the tube into contact with the smooth surface of the additional mandrel and simultaneously cooling the interior surface of the tube with a cooling medium.

Abstract: An apparatus for producing a sheet having many hollow bodies from thermoplastic material such as polyethylene, used for cushioning and insulation, is disclosed. Film extruded from a T die, after being cooled, is heated by an induction heating roller with a jacket and inner cooling means.The induction heating roller with a jacket and inner cooling means has, along with the jacket within a rollershell, an induction coil for heating, and a hermetically sealed heat transfer medium between the jacket and the induction coil. The characteristic feature of the present invention is a cooling means provided to cool the heat transfer medium, with advantages of rapid temperature rise and fall, and uniform temperature distribution on the circumference and longitudinal axis of the roller.Using this apparatus, a sheet having many hollow bodies, with high transparency and high product yield without defects such as partial inferior fusing, can be produced.

Abstract: Disclosed herein is a cooling/guiding method and a cooling/guiding apparatus that will be used when a film of a thermoplastic synthetic resin or the like is to be produced by the inflation method or the T-die method.According to the invention, a thermoplastic synthetic resin film is continuously passed through a section constituted by a single or a plurality of air-introducing members having air intake ports, the air surrounding said film is vacuumed by said air-introducing members so that the pressure differential imparted to the film is balanced, and the film is guided into a predetermined path under the condition where the film is separated away from the air-introducing members.Therefore, the apparatus cools and guides the film without coming into contact thereto, and without cooling the film irregularly and without marring the film, making it possible to markedly increase the film-forming speed and quality of the film.

Abstract: Apparatus including an extruder, a die member and a vacuum device connected in series. The vacuum device includes a chamber and a device at at least the outlet thereof to air-tightly seal the chamber around the extruded mass of foamed thermoplastic resin. The air-shielding or sealing device is an annular tube which is inflatable radially inwardly having a flexible inner face which seals around the extruded mass. A durable, abrasion-resistant, flexible protective sheet can be interposed between the mass and the tube.

Abstract: A method of making a tendon suitable for use in the post-tensioning of concrete as well as for other applications is disclosed. The method comprises the steps of coating a wire or a multiple-wire strand with a thin coat of a corrosion inhibitor. In the preferred embodiment, the thin coat may be more easily applied by coating the wire or multiple-wire strand with a thick coating of corrosion inhibitor and then removing the surplus amount of the corrosion inhibitor from the outer periphery of the strand, including the interstices, to leave the desired thin coat. A seamless plastic jacket is then formed around the wire or the multiple-wire strand while simultaneously creating a differential pressure across the wall of the seamless plastic jacket to provide a loosely fitting seamless plastic jacket.

Abstract: Wire which has been coated with a polymeric material is useful in a wide variety of applications. One such application is as a winding for electrical equipment such as motors, transformers, magnetic coils, relays and the like. Generally, coated wires of this type have been prepared by coating the wire with multiple layers of a solution of the coating material. It has been determined that metal wires can be satisfactorily coated with a specific type of thermoplastic composition in a single layer without using solvents. This process utilizes a tubing type cross-head die with the thermoplastic composition comprising a mixture of 80% to 99% by weight polyethylene terephthalate and from 1% to 20% by weight of polyethylene, polypropylene, or a mixture thereof.

Abstract: A vat under vacuum bears in its sidewall a sizing sleeve, the cylindrical downstream portion of which includes annular channels interconnected by distribution channels. Injection ducts leave the bottoms of the annular channels and open out in the inside surface of the sleeve. The interior of the sleeve communicates with the interior of the vat via rows of radial suction ducts. During operation, the injection ducts are supplied with water under pressure which forms a film between the outside of the tubing and the inside surface of the sleeve even when the tubing is pressed against that inside surface owing to the partial vacuum prevailing within the vat.

Abstract: Polyamide plastic fuel lines which are dimensionally stable and resistant to fuels, alcoholic fuels and alcohols as fuels are prepared from aliphatic high molecular weight polyamides. The fuel lines are prepared by extruding a hot melt of the polyamide, sizing through a die having a diameter in excess of the given diameter of the fuel line, cooling the fuel line in a cooling bath, removing the fuel line from the bath and sizing the fuel line adiabatically through a disk having a diameter less than the given diameter.

Abstract: A process for the calibration of a profiled article of thermoplastic synthetic resin wherein a vacuum is applied to the external surface of the profiled article while the article is drawn through a calibrating tool and wherein the profile surface of the profiled article is cooled indirectly by a liquid coolant flowing through ducts within the calibrating tool involves applying a vacuum via a plurality of slots within the calibrating tool which are placed adjoining the profile surface and feeding coolant through the ducts of the calibrating tool in such a manner that the coolant is discharged by means of the vacuum via the profile surface which is under the vacuum.

Abstract: A method of producing a biaxially oriented sheet or film, wherein molten resin is simultaneously, biaxially oriented in a direction of extruding the molten resin and in a direction perpendicular thereto, and an apparatus therefor, are disclosed. In the method of producing a biaxially oriented sheet or film, the molten resin is extruded into a tubular form in the horizontal direction, once cooled, thereafter, in heating the tubular resin prior to the biaxial orientation, the tubular resin is uniformly heated with the heating applied on the vertically lower side and the heating applied on the vertically upper side of the tubular resin being controlled separately of each other so as to prevent the ununiformity of the heating of the tubular resin in the circumferential direction thereof due to the elevation in heat caused by a thermal convection phenomenon, and then, the tubular resin is biaxially oriented.

Abstract: A process for the calibration of a profiled article of thermoplastic synthetic resin wherein a vacuum is applied to the external surface of the profiled article while the article is drawn through a calibrating tool and wherein the profile surface of the profiled article is cooled indirectly by a liquid coolant flowing through ducts within the calibrating tool involves applying a vacuum via a plurality of slots within the calibrating tool which are place adjoining the profile surface and feeding coolant through the ducts of the calibrating tool in such a manner that the coolant is discharged by means of the vacuum via the profile surface which is under the vacuum.

Abstract: A process for the manufacture of a flat-shaped hollow body through the use of a forming die, wherein mold segment halves move continuously along a forming die and which, upon entering the forming die, are moved in an operating direction facing each other in pairs in a closed mold in tight proximity to each other. The mold is injected with warm thermoplastic hose stock which is shaped under vacuum action in the mold. In order to produce flat-shaped hollow bodies on a continuous basis the hose stock is subjected to vacuum action over at least a portion of its cross section even before mold segment halves are brought together and is pressed together accompanied by the formation of welds and the creation of hollow spaces over a portion of its cross section.

Abstract: Disclosed is a method of making corrugated reinforced thermoplastic pipe having interior and exterior tubes with corrugations therebetween, comprising extruding through a pipe forming die, the interior and exterior tubes of a pipe at one linear rate while extruding a third skin or ribbon at a faster linear rate whereby the third skin buckles between the interior and exterior tubes to create corrugations in the space between the two tubes.

Abstract: The present invention relates to a method and apparatus for the manufacture of oriented plastic film, in particular polyester film, by the inflation in two steps of an extruded seamless tube of plastic material. The present invention also relates to the laminate manufactured in accordance with the method.

Abstract: A sweep ell production apparatus (10) receives extruded plastic pipe (98) from an extruder (96). The plastic pipe (98) is passed through a curved sizing sleeve (100) which imparts a curvature to the plastic pipe (98) while at the same time sizing the pipe wall thicknesses and exterior diameter. After the pipe (98) passes through the sizing sleeve (100) a clamp (84) is secured about the periphery of the pipe (98). The clamp (84) is driven by means of a motor (34) which causes the clamp (84) to travel along an arc (112) which corresponds with the radius of curvature of the sizing sleeve (100). As the clamp (84) draws pipe (98) along the arc (112) of travel, the pipe (98) is set to have the desired radius of curvature. After a selected arc length of pipe (98) is produced, the pipe section is cut to produce the desired sweep ell.

Abstract: An apparatus for making biaxially stretched tubular films of thermoplastic synthetic resin which permits operation in a stabilized manner and economically by using the hot air used in stretching a bubble again in heating a raw film. In said apparatus, a suction ring is provided in the section where a heated raw film is inflated by the gas filled therein under pressure, and the diameter of the resulting stretched bubble reaches its maximum diameter. The suction ring sucks the air used for heating the stretching part simultaneously with the air used for cooling it after stretching to attain a thermal interception effect between the stretching part and the cooling part after stretching. Air flow around the stretching bubble is made uniform.

Abstract: What is disclosed is an improvement in a system for producing a vacuum in which both liquid and gas streams are involved. Specifically, in one aspect the improvement is in a vacuum system for extruding plastic pipe having conventional extrusion apparatus, vacuum tank, mold and vacuum and liquid pumps with a chilled water flow system, the improvement being characterized by an outer housing connected intermediate the effluent water conduit and the liquid pump with a vacuum port connected with a vacuum pump; and an internal sleeve interiorly of the outer housing defining an annular space about the sleeve and directing the combined stream directly into the entrance to the liquid pump so that by inertia the liquid is sucked into the liquid pump whereas the gas is diverted by the vacuum pump to maintain the pressure without flooding the vacuum pump.

Abstract: A sweep ell production apparatus (10) receives extruded plastic pipe (98) from an extruder (96). The plastic pipe (98) is passed through a curved sizing sleeve (100) which imparts a curvature to the plastic pipe (98) while at the same time sizing the pipe wall thicknesses and exterior diameter. After the pipe (98) passes through the sizing sleeve (100) a clamp (84) is secured about the periphery of the pipe (98). The clamp (84) is driven by means of a motor (34) which causes the clamp (84) to travel along an arc (112) which corresponds with the radius of curvature of the sizing sleeve (100). As the clamp (84) draws pipe (98) along the arc (112) of travel, the pipe (98) is set to have the desired radius of curvature. After a selected arc length of pipe (98) is produced, the pipe section is cut to produce the desired sweep ell.

Abstract: A method for manufacturing retortable cans is taught which includes the step of cable extruding a tube of plastic. Subsequently, a substantially gas-tight material is laminated to the outside of the tube and a plastic layer is laminated to the layer of substantially gas-tight material. Preferably, the gas-tight material comprises a metallic foil.

Abstract: Polytetrafluoroethylene resin tubes having small pore size and high porosity are produced by a process which includes stretching the tubes by drawing using a metal die and a metal plug. By using the die and plug, the stress necessary for stretching is converted to a compressive force in the thickness direction of the tube. This compressive force is an essential factor in producing the microporous structure of the tubes. In addition, when stretching is performed by drawing, a ratio of thickness to inside diameter of the tube of 0.07 or less can be easily achieved.

Abstract: A porous polytetrafluoroethylene tubing, useful as artificial internal organs or industrial filtering materials for, for example reverse osmosis, ultrafilteration, etc., having a microporous fibrous structure in which the fibrous structure is composed of fibers and nodes connected with each other and the microporous fibrous structure differs between the outer surface portions of the tubing and the inner surface portions of the tubing, and a process for producing the porous resin tubing comprising heating a tubing made of an unsintered polytetrafluoroethylene under conditions in which the tube is stretched at least in the longitudinal direction of the tubing and such that the outer surface of the tubing is heated above about 327.degree. C. and the inner surface of the tubing is heated to a temperature below the temperature of the outer surface.

Abstract: What is disclosed is a method and apparatus for forming a radially expanded and stretched tube of synthetic resin having a plurality of longitudinal-support members, corrugated in the longitudinal tube direction, joined to and extending between two opposing tube walls, by extruding the tube such that that areas of the opposing walls extending between two adjacent support members comprise alternating thick and thin wall portions in the longitudinal direction and every thin portion has a laterally-adjacent thick wall portion, whereby on subsequent stretching and expansion, the thick and thin wall portions stretch disproportionately and deform the support members attached thereto unequally to effect their corrugation in the longitudinal direction.

Abstract: In the manufacture of fiber-reinforced cellulose casing wherein a paper tube is passed downwardly over a mandrel, impregnated with viscose and subjected to the action of a coagulating liquid to regenerate cellulose, a gas stream is flowed upwardly within the tube as the tube is passed over the mandrel, the gas stream pressure being sufficient to maintain the cylindrical dimensions of the tube but insufficient to cause a measurable change in the dimensions of the tube walls whereby contact of the internal surface of the impregnated tube with the mandrel is reduced or substantially eliminated.