Abstract: As an article of manufacture, an ovenable shaped article formed of polyethylene terephthalate having a degree of crystallinity of at least 20%, said crystallinity being substantially uniform over the whole of the shaped article, and a process and apparatus for making same.

Abstract: A headed thermoplastic tube is formed solely from a thermoplastic extruded, stretched, cylinder by positioning the cylinder over a forming mandrel with an exposed portion. The inner surface of the exposed portion is heated above the glass transition temperature of the thermoplastic material to render the inner surface molten while the outer surface provides support for the exposed portion of the cylinder. The heated exposed portion is then shaped into a conical shape, such as by heating the outer surface, and pressure applied to the conical shaped exposed portion to form a headed thermoplastic tube. The headed tubes produced have a body portion, shoulder portion and neck portion, without any seams, all of which are formed from the starting thermoplastic extruded, stretched cylinder.

Abstract: The extruded sleeve is cooled at the end of the die by a circulation of a refrigerant fluid whose temperature To satisfies the relationship: ##EQU1## G being equal to: ##EQU2## Tm and V being the mean temperature of the resin at the exit of the die and its mean extrusion velocity,Tc is a temperature characteristic of the extruded resin,.rho., Cp and .lambda. are the density, the specific heat and the thermal conductivity of the resin,H is the height of the die gap in the refrigerated zone,L is the length of the refrigerated zone.

Abstract: This invention is concerned with inflatable plastic baby baths similar in shape to a rubber tire inner tube having an impervious web across the ring. The web is preferably midway between the top and the bottom of the inflatable tube or annulus, and by inflating the article while hot during manufacture a smooth and wrinkle-free appearance can be produced. Such a plastic bath can be made virtually immovable on a smooth surface by expelling air from under the web and causing a partial vacuum. The diameter of the inflated tube is sufficiently great relative to the width of the web to prevent the web touching the supporting surface in normal use.

Abstract: A process for preparing composite films comprising at least one layer of a first plastic polymer and a substrate of a second polymer/first plastic polymer composition by intimately mixing about 15 to about 90 wt. % of first plastic polymer and about 10 to 85 wt. % of the second polymer, extruding the mixture through a film die while cooling at least one surface of the die outlet at least about 10.degree. C. below the melting point of the plastic polymer and cooling the film. In a preferred embodiment the first plastic polymer has a semi-crystalline or crystalline melting point which is at least 10.degree. C. above the softening or melting point of the second polymer.A sandwich type laminate comprising two outer skins of first plastic polymer enclosing a core comprising a blend of first plastic polymer and second polymer can be prepared by cooling both die outlet surfaces. Where a blown film die is utilized the inner and outer die layers must be cooled to accomplish this end.

Abstract: A fibrous web comprising fibers which have been differentially cooled to provide a crimped fiber conformation thereto and then thermally relaxed to a sufficient degree to at least partially decrimp the fibers and increase the loft and decrease the density of the web. Also disclosed is a process for forming a web of such type, comprising the steps of forming a web of fibers, bonding the fibers to form a bonded web, differentially cooling the fibers to provide a crimped fiber conformation thereto, and thermally relaxing the fibers to a sufficient degree to at least partially decrimp the fibers and increase the loft and decrease the density of the web, wherein the differential cooling step preferably is carried out prior to bonding of the fibers to form the bonded web and the thermal relaxing step is carried out after bonding of the fibers to form such web.

Abstract: A method for applying a high pressure liquid jet or stream to a web of polymeric film while the film is supported on a moving forming structure to produce a novel microbubbled substantially fluid-impervious web exhibiting substantially the same consumer preferred soft and silky tactile impression and reduced noise generation levels heretofore only achievable in microapertured, and hence substantially fluid pervious polymeric webs. In a particularly preferred embodiment, the microbubbled polymeric web exhibits a fine-scale pattern of discrete mushroom shaped surface aberrations, each of said surface aberrations having its amplitude oriented substantially perpendicular to the surface in which the surface aberration originates. Apparatus for producing microbubbled webs either in "planar" or "macroscopically expanded" form are also disclosed.

Abstract: In a device for the extrusion of a tube the extruded tube (2) is guided by a piston (20) placed inside said tube (2) at a distance from the extrusion head (1) the cooling of the extruded tube (2) is improved by means of nozzles (13) which spray water (5) at an angle against the inside of the tube (2) and away from the extrusion head (1), the said water sprays further kept away from the extrusion head by a fan (17) which blows air through the tube (2) away from the head (1) means (14-22) being provided for the supply and discharge of water and air respectively.

Abstract: A method and apparatus for producing mesh film include an extrusion die for extruding a tube of a heat-plastified, resinous, mesh film material. A first cooling arrangement, centrally located within the extruded tube, cools the internal surface of the tube. The first cooling arrangement has an outer diameter substantially equal to the inner diameter of the extruded tube. A plurality of cooling nozzles are disposed radially outward from the first cooling arrangement for directing a plurality of streams of a cooling gas toward the exterior surface of the extruded tube. An annular gas bearing is spaced axially from the first cooling arrangement such that the extruded tube passes therethrough after leaving the first cooling arrangement, thereby permitting the diameter of the extruded tube to be increased subsequently by means of a trapped air bubble therewithin.

Abstract: A method of forming bottomed cylindrical bodies, which can be used conveniently as preforms for the production of containers by stretch blow-molding, etc., from a cylindrical body of thermoplastic resin. The method includes a softening step of heat-softening an axially intermediate part of the cylindrical body, a necking step of necking the axially intermediate part of the cylindrical body radially inwardly, said necking step being carried out subsequently to, or simultaneously with, the softening step, a cutting step of cutting the axially intermediate part of the cylindrical body necked radially inwardly in the necking step, thereby to divide the cylindrical body into two members, and a fusing step of heat-melting the cut end portion of each of the two members and fusing the cut end portion.

Abstract: A polymeric film having preferential one-sided cling is prepared from a relatively crystalline polymer such as a copolymer of ethylene and an .alpha.-olefin having at least 3 carbon atoms, e.g., 1-octene (linear low density polyethylene); a relatively amorphous polymer such as low density polyethylene and a tackifying polymer such as a low molecular weight polybutene by extruding a film of the blend at melt temperatures and subsequently cooling the two sides of the extruded film at different rates.In addition to preferential one-sided cling, a film of a low density polyethylene, linear low density polyethylene and a low molecular weight polybutene which exhibits excellent film strengths and high resistance to tear, particularly in the cross direction, is prepared.

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 forming a tube including a base, a pair of legs secured to the ends of the base, and a holder base attached to the base. A tube holder for holding the tube is connected to the holder base. The tube holder has a structure defining a pair of diametrically opposed openings. A pair of soldering irons is oppositely secured with respect to each other in proximity to the top of the pair of legs. Each soldering iron has a hot end that generally registers with one of the opposed openings such as to be in close proximity to the tube being held by the tube holder in order to soften the material of the tube in the area contiguous to the openings. Power is conducted and supplied to each of the soldering irons. Vacuum is drawn on top of the tube to suck or pull inward the tube in the spots being softened from the heat of the pair of soldering irons.

Abstract: This disclosure relates to a method for preheating and preforming a green tire prior to final vulcanization of the tire. The method includes the steps of supporting the beads of a green tire between a pair of relatively cool discs to form a tightly closed space, moving the discs toward each other until the tire has a shape substantially the same as the final tire shape, supplying the space with a thermal medium, and heating the medium and the tire to a temperature substantially lower than that at which the vulcanization starts but high enough to preform the tire. A coolant is passed through the parts of the discs which engage the tire beads to prevent overheating of the beads.

Abstract: A method and apparatus for the formation of a continuous web of a tubular thermoplastic film from an extrudate of a thermoplastic polymeric material or resin, wherein the thermoplastic film has a profiled wall contour extending in the direction of the longitudinal axis of the film. The apparatus for forming a profiled tubular thermoplastic film, and the method which is implemented through the intermediary of the apparatus, provides for an annular cooling ring extending about the extrusion die orifice and which incorporates a central aperture through which the extruded plastic material is conveyed while still in a molten or heat-plastified state, and is adapted to direct a uniformly distributed flow of a cooling medium, such as air, against the circumferential surface of the extruded tubular plastic film material.

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 method of moulding a shaped article from a curable composition in which the composition is cured in a mould comprising at least two mould parts defining a cavity characterized in that prior to introducing the curable composition into the mould cavity, the pressure inside the cavity is increased above atmospheric pressure, preferably to at least 0.3 bar above atmospheric pressure, the dispersion is injected into the mould against this pressure and is subsequently cured. The method is useful for overcoming problems of color banding on the surface of the moulding which originate in the filling process and are particularly evident when high mould temperatures are used.

Abstract: In an extruder for making blown tubular film, an extrusion nozzle is divided into equally long segments provided with temperature setting elements. The film thickness is measured over the circumference of the film and film sectors of equal cross-sectional area are allocated to the nozzle segments out of which they were extruded. To produce thick film portions, the associated nozzle segments are cooled accordingly and to produce thin portions the associated nozzle segments are heated accordingly.

Abstract: A carbon-organic resin composite which has been initially shaped as by molding and in which the resin binder has been at least partially precured is transformed into an all-carbon composite and substantially densified by a continuous process in which the composite is continuously heated at different temperatures and subjected to increased pressure. Initially, the composite is heated at a first rate to a temperature on the order of 1000.degree. F., the first rate and the increased pressure applied to the composite being selected to substantially decompose the resin rapidly but without delamination or other damage to the composite. Heating is then continued at a second rate until the composite undergoes substantial softening and becomes plastic, typically at a temperature in excess of 3500.degree. F. Thereafter the composite is maintained at a high temperature, typically in excess of 5000.degree. F.

Abstract: Inner tubes for pneumatic tires including a toric cushion made from an elastomer material having cells independent of each other.A process for manufacturing such inner tubes with a mold for preforming and vulcanizing semi-toric elements, the mold includes fingers for molding recessed cavities and an incorporated heating network, the preformed semi-toric elements having undergone a first vulcanization are then joined together and subjected to a second vulcanization in an appropriate apparatus.

Abstract: A method and apparatus for pressure forming plastic pipe bells utilizing external air pressure is disclosed. The apparatus includes a horizontally oriented, shaped mandrel, which may or may not have expanding segments for forming an internal groove in the pipe bell, mounted within a pressure chamber. A natural rubber circular gasket is positioned at the front end of the pressure chamber and the end of the pipe is pushed through the rubber gasket and over the mandrel. A pair of cooperating upper and lower front plates are oppositely vertically reciprocal relative to the bell end of the pipe and act to retain the gasket when pressure is built up within the pressure chamber. Suitable air and water spray inlet and outlet connections are provided.

Abstract: A stretched plastic casing is tensioned by means of a fluid medium after having been introduced into two clamping rollers, and conveyed to a bending member in front of or at the location of which it is subjected to a thermal treatment such, that it is bent out of its original path, while being thermally deformed, and is subsequently conveyed in the same direction of curvature, in a bent form, so as to be cooled down.

Abstract: Provision is made for evenly controlling the cooling of the inner die pin of an extrusion die assembly so that the hot plastic coming in contact therewith is frosted. A conduit extends through the inner die pin to a point near the tip of the inner die pin. A cap is mounted on the end of the conduit and spaced from the front face thereof to provide an annular discharge opening. At least the tip portion of the inner die pin is formed of a material of good heat conductivity, such as brass, and the cooling air is directed through the discharge opening relatively evenly over the inner portion of the inner die pin to effect uniform inside frosting of a plastic tube formed in the apparatus. The inside of the plastic tube is open to the atmosphere.

Abstract: A process and apparatus for producing a ribbed pattern on extruded film by differential cooling of the film during its stretching process. The film is extruded through a tubular film die, stretching as it leaves the die. Cooling mechanisms rotate about the tube as it is being extruded to define a large plurality of narrow strips on the melt as it is being extruded. The film is fixed in space to maintain a close proximity to the cooling mechanisms in order to achieve sharply defined ribs. A cross-ribbed pattern can be obtained by counter-rotating the cooling mechanisms. Increased tear strength is imparted to the film without increasing the amount of resin necessary to make the film. Such tube can be formed into high strength film products such as trash bags and the like.

Abstract: This invention relates to a method of making a tube of thermoplastic material, comprising longitudinal channels of circular cross-section and having such wall stresses that, after axially cutting the tube, the edge parts along the cut edge overlap each other for less than 8% of the outer circumference of the tube.

Abstract: A process and apparatus for producing a ribbed pattern on extruded film by differential cooling of the film during its stretching process. The film is extruded through a tubular film die, stretching as it leaves the die. Cooling mechanisms rotate about the tube as it is being extruded to define a large plurality of narrow strips on the melt as it is being extruded. The film is fixed in space to maintain a close proximity to the cooling mechanisms in order to achieve sharply defined ribs. A cross-ribbed pattern can be obtained by counter-rotating the cooling mechanisms. Increased tear strength is imparted to the film without increasing the amount of resin necessary to make the film. Such tube can be formed into high strength film products such as trash bags and the like.

Abstract: A process and apparatus for heat setting side walls of biaxially oriented thermoplastic resin containers to reduce shrinkage of the container and container treated by the process. Heating is by infrared radiation while shielding portions of the container. The apparatus comprises container handling systems to provide a fully automated system capable of being incorporated in present container production lines.

Abstract: An improved process of producing a predetermined textured surface on a polypropylene film is disclosed including the steps of extruding the polypropylene into a stalk, cooling the stalk to crystallize the polypropylene, passing the stalk through a heating zone and biaxially stretching the stalk into a thin film. The stalk emanating from the extruder has a section primarily temperature controlled and correlated to the stalk velocity to cause extensive, continuous and uniform spherulite formation with a predominantly type III polypropylene crystal structure on the outer surface of the stalk, which upon subsequent inflation of the stalk causes the desired texture to occur.

Abstract: This invention is concerned with inflatable plastic baby baths similar in shape to a rubber tire inner tube having an impervious web across the ring. The web is preferably midway between the top and the bottom of the inflatable tube or annulus, and by inflating the article while hot during manufacture a smooth and wrinkle-free appearance can be produced. Such a plastic bath can be made virtually immovable on a smooth surface by expelling air from under the web and causing a partial vacuum. The diameter of the inflated tube is sufficiently great relative to the width of the web to prevent the web touching the supporting surface in normal use.

Abstract: There is disclosed a new process for preparing coupled and coextruded multilayer articles (consisting of two or more layers) made of thermoplastic materials, and closed-surface bodies comprising the same.

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: Polymer sheets or films are provided with tear paths that are substantially indistinguishable from the remainder of the polymer sheet or film in outward appearance and in chemical properties. Throughout the tear path, molecular chains of the polymer are oriented generally along a predetermined axis, while the molecular chains of the remainder of the polymer sheet or film are oriented generally differently from said predetermined axis. Such tear paths are typically formed by means of a device that extracts heat from the polymer as it is extruded or otherwise molded, the extraction rate being faster than the rate at which the remainder of the molded polymer is cooled in order to encourage maintenance of the substantially monoaxial orientation of the polymer chains along the tear path when the entire polymer is subsequently blown up or otherwise reoriented.

Abstract: The uniformity of the gauge profile of thermoplastic sheet material is improved by means of a method comprising the detection of areas of non-uniform thickness in the sheet after drawing it away from the extrusion die and the redirection of a controlled portion of the cooling fluid by means of adjustable deflector blades which extend into the flowing stream of cooling fluid and alter the angle at which the cooling fluid contacts and quenches the molten extrudate, thereby allowing additional stretching of thick areas or earlier solidification of thin areas, as appropriate to the problem at hand.

Abstract: A polypropylene film which is useful for electrical devices is produced by biaxially stretching an unstretched polypropylene molded article having, on at least one side, a surface layer having .beta.-form crystals, of mean diameter over 7 .mu.m, under such conditions that the stretching temperature at the stretch initiation point is in the range of 145.degree. to 176.degree. C., and the stretch ratio in one direction is less than a factor of 8. The resulting stretched polypropylene film is characterized by excellent mechanical properties, a very dense inner structure, and high air-tightness. The surface of the film has an efficiently roughened, fine, uneven structure containing crater-like patterns or an isotropic network structure and an anisotropic network structure, which is aligned in the extrusion direction.

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 method of forming articles from thermoplastics sheet by free-blowing, without use of moulds, in which the sheet is pre-heated to elastic state, free-blown by establishing a differential fluid pressure between opposite faces of the sheet and maintained at optimum temperature during the period of free-blowing by heating or cooling by heat-exchange between the sheet and fluid flowing over at least one face. Apparatus for performing the method comprises a tank diversible into two halves adapted to hold the sheet edgewise in between, the differential fluid pressures being established between the volumes in the two halves and fluid flow over the face of the sheet being established in one half.

Abstract: A method for forming a heated end of a plastic pipe into a bell having a sealing groove therein arranged to receive a seal so that it may be sealingly joined with a plain end of a second pipe inserted therein. The apparatus comprises a mandrel base rigidly secured to a mandrel core having annular grooves formed thereabout communicating with a vacuum source through a passage formed in the core and base. A mandrel shell comprising four separable segments is secured on the core. The mandrel shell has a plurality of apertures formed therein communicating with the annular groove on the core such that a vacuum may be drawn through the apertures. A heated plastic pipe is forced over the mandrel shell until it engages a tapered shoulder formed on the mandrel base, thus forming a seal between the end of the pipe and the base. A vacuum is drawn on the cavity formed between the plastic pipe and the mandrel shell thus drawing the plastic pipe to the shell, forming an annular internal groove in the pipe.

Abstract: Cooling a tubular extrudate for conversion to tubular film by passing the extrudate through a bath of cooling liquid so that the external surface of the extrudate contacts in sequence countercurrent streams of cooling liquid in a quiescent zone, a restricted throttle zone and a spiral flow zone.

Abstract: A method for curing resin in the fabrication of a composite material is described comprising enclosing the composite material within a flexible vacuum enclosure, and substantially simultaneously pressing the material within the enclosure between first and second platens of a press to preselected pressure, evacuating the enclosure, selectively heating one of the platens according to a preselected scheme to preselected cure temperature to cure the resin within the material, and cooling the other platen to maintain a preselected temperature differential between the platens across the thickness of the material, whereby cure of the resin is effected in the material first near the heated platen and progresses through the thickness of the material toward the cooler platen as the material is heated to the cure temperature.