Abstract: A method of lining a passageway comprising pulling a first flexible lining pipe sized to the passageway to be lined into the passageway, the first lining tube comprising at least one resin absorbent layer impregnated with curable synthetic resin, and by the eversion into the first lining tube of a second flexible lining tube sized to the first tube inner diameter, to the inner surface of which a second lining tube before eversion is applied an initiator for the resin impregnating the first lining tube whereby, as the second lining tube everts into and along the first tube when in the passageway, the first tube is pressed against the passageway surface by fluid pressure used to evert the second tube, and also the initiator comes into contact with the resin of the first tube and commences and effects cure of the same.

Abstract: A flexible rubber boot that transmits molding pressure to the inner surface of the structure to be molded is placed on a support fixture. The boot is held in place by a vacuum applied between the fixture and the boot. Prepregs are laid up on the boot to the desired depth and in a desired configuration. A female mold assembly, consisting of two sections, is then placed over the prepreg material and sealed to the boot. A vacuum is applied to the sealed region between the mold and boot, compressing the material against the interior of the mold that defines the outer surface of the structure. The assembly of boot, mold, and material is then placed in an autoclave. After the material has cured, the finished structure is separated from the mold and boot. The tooling is reusable and the process completed easily, allowing the efficient fabrication of structure having smooth inner and outer surfaces.

Abstract: This invention encompasses a process for making multilayer containers by conventional roll fed sheet method, with minimal scrap loss, which comprises the steps of preparing a monolayer sheet of a first thermoplastic material by conventional roll fed sheet methods, cutting or punching billets from a second thermoplastic material sheet, heating the monolayer sheet and the billets to a temperature where both the sheet and the billets become tacky, placing the billets at a position on the sheet so that the billets are in a position over forming cavities in a forming mold at the time of forming, while maintaining the billets and sheet at a temperature where the sheet and billets are tacky and weld together, and forming containers from the welded billets and sheet so that the web scrap left after forming is pure monolayer sheet.

Abstract: A method of treating a diver's suit constructed of foam core material having a cover material on both sides, including the step of hydrostatically compressing the suit to permanently compress the cells in the foam core material to provide a suit which has very little compression left and which changes little in thermal conductivity and buoyancy with depth.

Abstract: Methods for forming prestressed concrete members wherein a pressure-containing casing is disposed around the outside surface of the concrete member and is spaced therefrom so that a cavity is formed between the casing and the outside surface of the concrete member. A pressurized medium is injected into the cavity between the casing and concrete member at a pressure sufficient to apply the required prestressed compressive force to the outside surface of the concrete member. The pressurized medium changes form by hardening or solidifying after injection. Examples of solid pressurized mediums include cement-like grouts and plastic, and epoxy resin materials. When the concrete member is cast within the casing so as to be in intimate contact with the casing the cavity is then formed by peeling the concrete member and casing away from each other as the pressurized medium is injected therebetween.

Abstract: A method particularly adapted for making a complex shaped composite component that has reduced bridging defects. The method comprises disposing a composite prepreg on to a substantially flat tool. The composite prepreg has a substantially flat section and at least one prepreg member extending from and substantially perpendicular to said flat section. A layer, at least about 125% of said composite prepreg height, of a said flowable particulate silicone rubber is disposed in substantially complete contact with the composite prepreg surface. The particulate silicone rubber has a flow rate of at least 0.6 gram/second through a 1.1 cm diameter pipe 7.6 cm long under applied pressure of 10.34 MPa at room temperature. The layer of solid flowable rubber is covered with a bag to effect a gas tight seal. The bag is exposed to pressures which are transferred to said prepreg by said solid flowable polymer. The composite prepreg is exposed to temperatures to form a composite component.

Abstract: A multilayer film useful in the packaging of high acid food products at elevated temperatures comprises a core layer of ethylene vinyl alcohol copolymer, two intermediate layers each comprising a polyamide; outer blend layers of linear low density polyethylene and anti-blocking agent, and adhesive polymeric materials to adhere the outer blend layers to the respective intermediate polyamide layers.

Abstract: A process for making a rigid pipe with the aid of flexible parallel coextensive skins interiorly filled with a catalyst-curable flexible filler, where the flexible skins and filler are laid along any desired surface contour and then the interior space within the inner skin is expanded to form the pipe and catalyst is introduced through one or both of the skins which is catalyst-permeable, to produce a rigidized pipe.

Abstract: A method for the production of laminates comprises extruding a support of acrylic nitrile-butadiene-styrene (ABS) and a coating of polymethyl methacrylate (PMMA, acrylic glass) through a sheet die. The acrylic glass forming the coating has a melt flow index of at most 2.0 (MFI 230.degree. C./3.8 according to DIN 53735) and the ABS forming the support are conducted directly to the die through different channels.

Abstract: An air cushion shoe sole which is preferably blow molded of elastomeric material and has at least one cavity which in cross-section is substantially rectilinear. The cavity has a number of depressions and each cavity has an air valve for introducing a shock absorbing material, namely gas, liquid, or a combination thereof into that cavity. Each air valve has means in it for automatically bleeding off a portion of the shock absorbing material introduced into the cavity once the pressure of that material reaches a predetermined level.

Abstract: A process using molds for curing a composite skin-stiffeners assembly from fiber material impregnated with a resin. This process allows molding and co-curing of single-skin type panels with integral stiffeners, allows stiffeners of variable heights, thicknesses and widths, allows substantial freedom in the layout of stiffeners, and allows even integral cross-stiffeners. Bonding and mechanical fasteners are also dispensed with. This process is further characterized by providing a stiffener forming mold part having a corrugated face, laying composite material over the ridges defined by the corrugated face to form stiffeners of open cross-sectional shape and interspacing gaps between them in bonding contact with skin forming material, and co-curing of the skin-stiffeners assembly.

Abstract: A method and an apparatus for making blow-moulded bottle from a preform consisting of at least three layers. For making the preform a tube section heated at one end is shaped by pushing into a closed bottom mould to form a bottom and pressure is exerted in the axial direction on the center bottom region to close the still present gaps in an outer layer as soon as an inner layer has flowed together.

Abstract: Disclosed is a coated oriented plastic vessel formed by subjecting a parison, preform or sheet comprising a molecularly orientable thermoplastic resin substrate and a coating layer of a vinylidene chloride copolymer formed on at least one surface of said substrate to a draw-molding operation such as biaxial draw-blow-molding or draw-forming, wherein the coating layer of the vinylidene chloride copolymer has such a molecular orientation tht the sum of two-dimensional orientation coefficients (l+m) in the axial direction and circumferential direction is at least 0.03 as measured according to the polarized light fluorometry and the coating layer is not substantially peeled at the low-temperature burst test conducted at -5.degree. C.

Abstract: A molding process for producing a molded plastic product with a resin coating layer formed on its surface, which comprises electrostatically coating a powdery resin composition on the inner surface of a mold, filling and molding a plastic material in the mold to form a molded plastic product, and plasticizing, under compression, said powdery resin composition by the heat of the filled plastic material and/or by the heat for molding the filled plastic material, to form a resin coating layer securely bonded to the surface of the molded plastic product by anchor effect.

Abstract: Disclosed herein are a method and apparatus for converting an expended, hollow article of thermoplastic material, the article having opposite end walls, an opening in one of the end walls and an annular wall extending between the opposite end walls establishing an original configuration, into a new article of a new configuration. Specifically, the expended article is a two-liter soda bottle and the new article is a building block.

Abstract: A sealing ring having at least one jacket face serving as a slide surface is produced of fibers and sliding agent that are passed to one another, with the fibers being relatively short fibers.

Abstract: A method and apparatus for manufacturing a hollow plastic product is provided. In accordance with one aspect, into a mold half having a tubular groove portion and a projecting groove portion which projects outwardly from the tubular groove section is supplied a parison into the tubular groove portion and a clump of molding material into the projecting groove portion. When blow molding is carried out by introducing a pressurized gas into the parison, the clump becomes integrated with the parison thereby providing a hollow plastic product of unitary structure. In accordance with another aspect of the present invention, a parison extrusion nozzle is provided with at least two passages each of which is connected, preferably through a valve, to a corresponding dispensing unit for dispensing a desired molding material. A control unit is provided as connected to each of the dispensing units to control the supply of molding material so that there is obtained a parison having regions of different molding materials.

Abstract: A method of molding a composite material comprising reinforcing fibres enclosed in a resin matrix. Layers of the resin impregnated fibres are laid-up in a suitably shaped die whereupon the laid-up layers are overlaid by a silicone rubber member which generally corresponds in shape with the die. Hydraulic pressure is exerted upon the silicone rubber member so that it urges the laid-up fibres into the configuration of the die. The whole molding apparatus is placed in an oven and its temperature is raised to that at which consolidation of the laid-up fibres occurs and the resin cures. The exerted hydraulic pressure is progressively reduced during heating as the silicone rubber member thermally expands so as to ensure that the pressure exerted by the silicone rubber member upon the laid-up fibres remains substantially constant.

Abstract: A high temperature seal, particularly suitable for use in vehicle engine exhaust systems, is formed of a composite structure including refractory sheet material and wire mesh. In a typical application, the seal is disposed between confronting ends of an engine exhaust manifold pipe and an exhaust tail pipe, and permits relative rotation of the pipes without impairment of the effectiveness of the seal, thereby preventing leakage of high temperature exhaust gases passing through the joined pipes.

Abstract: Improvements in manufacturing composite material articles. The use of male molds in forming such articles has the problem of requiring large tolerances for the outer dimensions of the articles. The use of female molds has the problem of inaccurate forming of highly contoured inner surfaces. The invention produces an accurately formed inner surface by molding material against a male mold, and outer dimensions within close tolerances by curing the material in a female mold. A male caul (34) is positioned on a male mold (30). A preplied stack (32) of composite material is supported on a blanket (36) and held in position against caul (34) with caul (34) and mold (30) in an inverted position. Stack (32) is heated. A vacuum causes blanket (36) to mold stack (32) against caul (34). Mold (30) is rotated 180.degree., and stack (32) is allowed to cool. A female mold surface (43) is placed into contact with formed stack (32). Male mold (30) is moved away, leaving caul (34 ) and formed stack (32) in female mold (42).

Abstract: A multi-layer polyester article, and particularly a beverage bottle having good oxygen and carbon dioxide permeability resistance. At least one layer of the article is made from polyisophthalate and copolymers thereof. The multi-layer articles find particular use as packaging materials, films, and molded containers such as for alcoholic beverages. Various colorants can be added to either one or more of the layers to impart a desired color to the article.

Abstract: A heat cured exhaust seal, adapted to be interposed between a pair of confronting pipes in sealing relationship therewith, is formed of wire mesh having openings between the wires thereof and a mixture of metallic fibers, non-metallic filler, a thermally stable lubricant and resin binder, which mixture surrounds the wires and substantially fills the openings in the mesh and forms the seal. The method of forming the seal includes placing a preform of wire mesh into a die cavity, forming a powder mixture of metallic fibers, non-metallic filler, a thermally stable lubricant and a resin binder, placing the powder mixture into the die cavity, pressing the wire mesh and powder mixture to the final size and shape of the seal and curing the seal at an elevated temperature.

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: Containment vessels including external aircraft fuel tanks having an internal plastic liner compatible with the substance to be stored in the vessel or tank. The plastic liner is manufactured from a cold formable thermoplastic polyurethane elastomer material that can be formed to the desired material configuration of the vessel. In a fuel tank the annular structural elements of the tank can be smoothly enveloped to provide a seamless, fluid tight liner having superior physical and chemical properties.A method of cold forming the plastic liner from a tubular element to achieve a seamless liner for a containment vessel is disclosed.

Abstract: This relates to the forming of a blow molded polyester container wherein a bottle having a conventional upper neck portion and an intermediate body is provided with a lower portion which includes an annular seaming flange which is integrally connected to the lower end of the body and wherein, with the exception of the seaming flange, the lower portion is removed and the bottle is closed by a separately formed bottom double seamed to the lower end of the body utilizing the annular seaming flange. During the interim between the removal of the bottle lower portion and the application of a separate bottom, the bottle is fully open so as to be readily commercially interiorly coated with a barrier coating. The separately formed bottom may be readily formed of metal and may be so constructed as to provide a large diameter base for supporting the bottle in upstanding position. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

Abstract: In production of a core-shell type golf club head, a thermoplastic synthetic resin core preferably of 15.degree. C. or higher glass transition point is used as a substitute for the conventional rubber air bag for stable and reliable shaping of an FRP shell even under the room temperature condition and beautiful moulding of the shell through softening and inflation of the core at heat pressing, thereby avoiding air void generation and layer separation in the FRP shell.

Abstract: A sliding member is provided which comprises a base body made of a firmly entangled and collapsed metal fine wire, with the voids formed between the metal fine wires constituting the metal mesh being filled compactly with a heat resistant material, the sliding surface of the base body being formed into a smooth surface with either a lubricant that fills a number of small holes formed in the heat resistant material as well as covering the surface thereof or the lubricant and the metal fine wires being exposed.

Abstract: A process of making a container of the dishtype, including, on the one hand, a bottom 40, walls 31 to 34 and 41 to 44 and edges 30a to 30d of exterior cardboard and, on the other hand, of a thermo-formed layer 2 of synthetic material. The edges 30a to 30d are constituted by the sides of a frame 30 and are in one piece. The frame 30 is integral with the walls 31 to 34, bent downward. The bottom 40 is integral with the walls 41 to 44, bent upward and complimentary to the walls 31 to 34. All walls are placed so as to be on the same level and are maintained by the layer 2.

Abstract: A nozzle assembly, for a blow-molding machine having a parison seal and an expansible chamber for biasing the nozzle seal into engagement with the lip of the parison about the parison opening.

Abstract: A high temperature seal, particularly suitable for use in vehicle engine exhaust systems, formed of a composite structure including refractory sheet material and wire mesh. In a typical application, the seal is disposed between confronting ends of an engine exhaust manifold pipe and an exhaust tail pipe, and permits relative rotation of the pipes without impairment of the effectiveness of the seal, thereby preventing leakage of high temperature exhaust gases passing through the joined pipes.

Abstract: Disclosed is a process for the production of a hollow article comprised of a biaxially oriented thermoplastic resinous material, comprising the steps of heating a sheet of thermoplastic material to a temperature above the orientation temperature of the thermoplastic material; clamping an area of the heated thermoplastic sheet between a first mold half and a second mold half, the first mold half containing a pre - form mold surface having a configuration predetermined to provide for uniform wall thickness of the hollow article to be formed, the surface being at a temperature which is not higher than the orientation temperature of the thermoplastic material, and the second mold half having a cavity which corresponds to the shape of the hollow article to be produced; forcing the heated thermoplastic sheet by pressure differential into the first mold half against the surface; maintaining the thermoplastic sheet in contact with the surface for a period of time sufficient to bring the thermoplastic sheet to its ori

Abstract: A flexible tube for use in an endoscope comprises a flexible basic tubular core structure and a homogeneous thermoplastic synthetic resin tube bonded to the outer surface of the tubular core structure to form a coating layer by positioning the synthetic resin tube tightly over the basic tubular core structure with a contact pressure therebetween and heating the synthetic resin tube to a temperature higher than a softening point of the thermoplastic synthetic resin forming the same. A flexible tube having flexibility which varies in a step-wise manner from one end of the tube to the other is obtained by integrally bonding as a whole two or more homogeneous thermoplastic synthetic resin tube sections formed of respective resin materials having different hardnesses to the outer surface of the tubular core structure to form a coating layer in an analogous manner.

Abstract: A plastic bottle has as a wall-forming component a layer of a copolymer consisting essentially of 99 to 70% by weight of vinylidene cloride and 1 to 40% by weight of at least one acrylic or methacrylic monomer and further including up to 100 parts by weight of at least one member selected from other ethylenically unsaturated monomers per 100 parts by weight of the total amount of the first two monomers, the copolymer having an oxygen permeability constant of less than 9.times.10.sup.-14 cc.multidot.cm/cm.sup.2 .multidot.sec.multidot.cmHg as measured at a temperature of 20.degree. C. and a relative humidity of 100% and a water vapor permeability constant of less than 3.times.10.sup.-3 g.multidot.cm/m.sup.2 .multidot.day as determined according to the method of JIS Z-0208.This plastic bottle is obtained by casting an aqueous latex or the like of the above-mentioned copolymer in a bottle mold and drying the cast latex. This aqueous latex may be formed as a coating layer on a preformed plastic bottle.

Abstract: A composite gasket includes two spaced rings of refractory sheet material and a ring of knitted wire mesh. The knitted wire mesh extends into the space between the refractory rings and radially outward from the outside diameter of the refractory rings.

Abstract: A high temperature seal, particularly suitable for use in vehicle engine exhaust systems, is formed of a composite structure including a refractory metallic oxide impregnated into compressed knitted wire mesh. In a typical application, the seal is disposed between confronting ends of an engine exhaust manifold pipe and an exhaust tail pipe and permits relative rotation of the pipes without impairment of the effectiveness of the seal thereby preventing leakage of high temperature exhaust gasses passing through the joined pipes.

Abstract: A process of making a hollow article from polymeric material is taught. The article is molded in two parts. The two parts are caused to remain in their respective exterior molds. If the hollow article is to be filled with a desired material, a measured amount of filler material is added to one of the formed parts. The exterior molds are brought into opposed position and sealing relationship. The space between the exterior molds is purged with a purging gas and subjected to a partial vacuum. The exterior molds are then closed and subjected to a clamping pressure to join the part halves together and remove flash from the joint. Portions at least of the exterior molds are heated and then cooled. The exterior molds are then opened, and the finished filled article is removed therefrom.

Abstract: A method of breaking loose a vulcanized hose from a rigid mandrel on which the hose has been vulcanized is described. A first end of the hose is clamped securely to prevent movement relative to the mandrel. The second end of the hose is clamped less securely so as to permit movement relative to the mandrel. Fluid pressure is thereafter introduced between the hose and the mandrel thereby causing the hose to increase in diameter and shorten in length, thus breaking the hose loose of its associated mandrel. The hose construction must be such that it will increase in diameter without rupture when subjected to sufficient internal pressure.

Abstract: Mandrel-cured, curved elastomeric hose is provided with an indexing mark that is formed prior to or during curing of the hose on the mandrel. The rigid curved mandrel has an exterior hose-bearing surface and an interior cavity. The cavity and exterior surface are connected by a small passageway or hole which is located where the index mark is to be made on the hose. A sleeve having a wall of uncured elastomeric material is mounted on the mandrel such that a portion of the sleeve covers the passageway. The mandrel having the sleeve mounted thereon is placed in an autoclave and subjected to steam pressure. The steam pressure forces elastomer material into the passageway and thereafter cures the elastomer sleeve into a hose. The pressure inside the cavity is approximately atmospheric at the introduction of the steam pressure. The cavity within the mandrel may be sealed except for the passageway or the cavity and the passageway may be vented to atmospheric pressure.

Abstract: This relates to the forming of containers and like hollow articles from sheets or webs of thermoplastic material. Two webs or sheets are simultaneously acted upon by way of a forming apparatus which includes a reciprocating clamp first cooperable with one outer platen and then the other in sequence wherein, while a first web or sheet is being formed within a plurality of mold cavities to define a plurality of hollow articles such as containers, the other sheet or web may be stripped from its respective mold set and a new sheet or a new portion of a sheet or web may be advanced into position for molding. The forming apparatus may be constructed in a manner wherein the web portions which are to be formed may be billowed away from the mold cavities as an initial step in the stretching and orientation of the thermoplastic material.

Abstract: The peripheral portion of a flat, molecularly orientable material stock of substantially uniform thickness having a temperature below the upper limit of the molecularly orientable temperatures of the plastic material is clamped, and the central portion of the plastic material stock is introduced into a die cavity while compressing the central portion with an upper plunger and a lower plunger, thereby forming a hollow preform having a sidewall portion made from the plastic material which has been forced out from between the upper plunger and the lower plunger, while the sidewall portion is kept in contact with the side surface of the upper plunger kept at about molecularly orientable temperature.

Abstract: A high temperature seal, particularly suitable for use in vehicle engine exhaust systems, is formed of refractory sheet material which is first placed within a wire mesh sleeve. The sleeve is then wound into a cylindrical preform and axially compressed to provide a unified structure in which the mesh sleeve and sheet material are firmly interlocked.

Abstract: The conventional process of manufacturing hollow bodies with multi-layer walls using extrusion and blow molding techniques is improved by first making a preform of a thermoplastic carrier layer with an adhesive layer on one or both sides and then applying the additional layer or layers to the adhesive layer(s) in a separate operation. The additional layer(s) has properties different from the carrier layer and serves as an insulation or barrier layer to shield the carrier layer from substances to be contained by or which will surround the hollow body. Among other advantages, the improved process allows recycling of waste and surplus preform material, stronger heat-seal seams in the hollow bodies, less complicated extrusion equipment and more economic use of expensive barrier layer materials.

Abstract: A coextrusion die for the extrusion of plastics materials in the shape of a tubular film comprising supply means for separately supplying at least two plastics materials to said die, a distribution channel system connected to each supply means, each distribution channel system comprising at least two arched channels provided in different axial planes, the ends of each arched channel being connected to the middle portion of the following arched channel and the distribution channel systems being located at different distances from the center axis of the die, collecting chambers communicating with said distribution channel systems and an annular extrusion slot communicating with the collecting chambers.

Abstract: A thin-wall deep drawn container having a molding depth vs. aperture caliber ratio of 2.0 or more, having a mean wall thickness of 0.1-0.6 mm at the sidewall and bottom of the hollow part and having a flange part of 1.4 mm or less in thickness at the aperture end can be produced from a thick sheet of a thermoplastic resin, preferably a crystalline plastic, having a thickness of 2 mm or more by plug-assist pressure forming.

Abstract: A cable for cryogenic use includes an inner conductor and a solid polymeric insulator loosely positioned about said inner conductor above 0.degree. C. A collapsible spacer can be positioned between the inner conductor and the polymeric insulator to further space the insulator away from the conductor and thereby accommodate greater shrinkage of the insulator. In fabricating the cable, the cable is sealed and pressure is applied to the cable to expand the insulation. The cable is placed inside a rigid cylinder having an inside diameter larger than the outside diameter of the cable. The cylinder is heated to facilitate expansion of the insulation, and the cylinder is subsequently cooled while maintaining pressure to the cable.

Abstract: Disclosed is a laminated plastic container in the form of a bottle, the wall of which comprises a substrate formed of a melt-moldable plastic material, a coating layer formed on at least one surface of the substrate, said coating layer being composed of a copolymer consisting essentially of 99 to 70% by weight of vinylidene chloride and 1 to 30% by weight of at least one acrylic or methacrylic monomer and further including up to 100 parts by weight of at least one member selected from other ethylenically unsaturated monomers per 100 parts by weight of the total amount of said two monomers, said copolymer having an oxygen permeation coefficient of less than 9.times.10.sup.-14 cc.multidot.cm/cm.sup.2 .multidot.sec.multidot.cmHg as measured at a temperature of 20.degree. C. and a relative humidity of 100% and a water vapor permeability coefficient of less than 3.times.10.sup.-3 g.multidot.cm/m.sup.2 .multidot.

Abstract: An apparatus and method for forming components having one or more inner cavities wherein material forming the component is laid up about a number of eutectic salt mandrels corresponding to the inner cavities. The mandrels are melted and the laid up material compressed during the formation of the component by hydraulic pressure transmitted through the molten mandrels.

Abstract: Method and apparatus for forming multi-layer expanded film. A base film extruded by a die is coated, immediately downstream of the die mouth, by a further layer of fluid propelled from a manifold through a metering orifice. The combination of manifold and metering orifice is necessary to permit accurate control of the flow rate of the fluid and hence of the thickness of the coating, and the mouth of the die and the metering orifice must be very close so that the base film is as resistant as possible to deflection by the impact of the coating fluid, and so that contact takes place before any substantially expansion has taken place. The downstream end of the resulting multi-layer tubular film is then held closed in known fashion and the closed tube is expanded by air under pressure admitted by an opening in the die.

Abstract: A method for providing a container with one or more layers of barrier material during the production of the container from a thermoplastic. A preform (10) is stretched in its axial direction, generally an amount corresponding to the total axial stretching required for conversion of the preform to a container, after which the stretched preform (11, 13) is provided with one or more barrier layers (12, 14), and the preform is then heated and converted to a container. In one embodiment, the axially stretched preform (15) is produced by assembling axially stretched part-preforms (13a,b) covered with one or more barrier layers. The combined preform is then converted to a container.

Abstract: A method for forming a deep drawn paperboard container coated with a layer of grease and water impermeable polymeric material. A paperboard blank is disposed between and acted upon by a heated mandrel and a heated mold to form a container. The surface of the blank engageable by the mandrel bears the polymeric coating, and means are operative relatively to move the mandrel and mold toward one another, to engage, the blank, and, just prior to fully engaging the blank to set the same, to introduce a film of air between the heated mandrel and the polymer coated surface to ensure against sticking of the coating to the mandrel.