Abstract: Microfibers and microfibrillated articles are prepared by imparting fluid energy to a surface of a highly oriented, highly crystalline, melt-processed polymeric film. The microfibers and microfibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as reinforcement fibers for polymers or cast building materials such as concrete.

Abstract: A process of forming a nonwoven fabric is disclosed which comprises the steps of forming a precursor web of multicomponent substantially continuous filaments, exposing the precursor web to a hydraulic arrangement treatment to form apertures without causing substantial filament entanglement, and thereafter forming inter-filament bonds and an integrated web. The resulting apertured nonwoven fabrics have good hand and tactile aesthetics and have a great variety of uses including use in absorbent personal care products, garments, medical applications, and cleaning applications.

Abstract: An extrusion molding process including the steps of: i) extruding a material through an extruding die into a tubular molding, ii) driving two clamping devices to clamp the tubular molding at different elevations, causing an air-tight space to be formed within the tubular, iii) closing two symmetrical halves of a molding die on the molding between the clamping devices and simultaneously lowering one clamping device to stretch the molding downwards, causing the molding to be compressed in a die cavity between the two symmetrical halves of the molding die and molded into the desired finished product; and iv) opening the molding die from the finished product and returning the clamping devices to their former positions.

Abstract: Fibers and microfibrillated articles are provided by imparting fluid energy to at least one surface of a highly oriented, voided, melt-processed polymeric film. The fibers and microfibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as reinforcement fibers for polymers or cast building materials such as concrete.

Abstract: To make holes in ceramic green sheets that are needed to create feedthroughs, it is proposed to make the holes by using a gas that is under a higher pressure than atmospheric pressure and that is expelled in a pulsed manner from a pressure vessel and thereby acts on a principal surface of a ceramic green sheet, at at least one location at which a hole is to be made, in such a way that material is shot out of the ceramic green sheet at that location. This eliminates the disadvantages associated with the use of punches to punch holes.

Abstract: One embodiment of a microneedle array is constructed of silicon and silicon dioxide compounds using MEMS technology and standard microfabrication techniques to create hollow cylindrical individual microneedles. The resulting array of microneedles is designed to penetrate the stratum corneum and epidermis layers of skin, but not into the dermis. In a second embodiment, an array of hollow (or solid) microneedles are constructed of molded plastic, in which a micro-machining technique is used to fabricate the molds used in a plastic microforming process. Such molds contain a micropillar array and/or microhole array. The manufacturing procedures for creating plastic arrays of microneedles include: “self-molding,” micromolding, microembossing, and microinjection techniques. In the “self-molding” method, a plastic (e.g.

Abstract: Microfibers and microfibrillated articles are provided by imparting fluid energy to a surface of a highly oriented, highly crystalline, melt-processed polymeric film. The microfibers and microfibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as reinforcement fibers for polymers or cast building materials such as concrete.

Abstract: Fibers and fibrillated articles are provided by imparting fluid energy to at least one surface of a highly oriented, voided, melt-processed polymeric film. The fibers and fibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as reinforcement fibers for polymers or cast building materials such as concrete.

Abstract: A method of making a multiple neck spray bottle comprising the steps of providing a blow mold having a molding cavity configured for molding a multiple-neck spray bottle have multiple open headed neck portions with at least one threaded neck portion configured to connect with the spray head, providing at least one plastic parison inside the molding cavity, blow molding the at least one parison inside the molding cavity to form the multiple neck spray bottle, and opening the blow mold to release the formed multiple neck spray bottle from the blow mold.

Abstract: A porous structure is provided between a forming member and an underlying support structure so as to facilitate the drainage of liquid through the porous member when a web is supported on the porous member and columnar streams of liquid are directed at the web to form apertures in the web. The porous structure can include a plurality of spaced-apart, wire-like elements, a metal screen, thermoplastic netting, mesh, webbing, and the like. An improved apertured web made with the improved process employing such a porous structure has little or no lining or marking and has relatively few, if any, poorly formed apertures.

Abstract: An apertured film for use as a topsheet in absorbent products wherein the film is apertured and includes a plurality of micro-holes and a plurality of large-sized holes. A method of forming the film is disclosed, as well as an absorbent product incorporating the apertured film as a topsheet.

Abstract: A blow molding method for molding tube containers by introducing blow air into a parison having been extruded by an extruder is disclosed, which comprises introducing blow air into the parison to shape a tube container and form a discharge outlet in part of the wall of an unnecessary portion of the tube container located lower than the cutting position of the tube container, and further continuing the introduction of blow air. The blow air may be introduced horizontally by piercing the wall of a parison having been extruded from an extruder with a nozzle for introducing blow air or vertically by introducing blow air in the axial direction of the parison. The discharge outlet is formed in part of the side wall or bottom wall of the container below a cutting position preferably as low as possible.

Abstract: The present invention pertains, in a preferred embodiment, to a fluid-pervious web comprising a first or wearer-contacting surface and a second or garment-facing surface. The web is particularly well suited for use as a topsheet on a disposable absorbent article. The first and second surfaces are separated from one another by an intermediate portion. The first surface of the web provides a structure which exhibits a surface energy less than the surface energy of the intermediate portion. In a preferred embodiment, the web exhibits a plurality of regions of comparatively low surface energy which define surface energy gradients where they interface with higher surface energy web surfaces. More particularly, the present invention pertains to a fluid-pervious web having a plurality of small-scale surface energy gradients which are oriented and located so as to effectively transport fluid away from the first or wearer-contacting surface.

Abstract: A ported tubular air duct and a method for manufacturing a side-ported tubular air duct. The air duct has a side port located substantially ninety degrees (90.degree.) to the part line of a mold in which the air duct is manufactured. The mold has two portions which are separated when the mold is opened to permit the positioning a preheated polypropylene tubular port insert member into an opening in one of the mold portions. A parison of rubber modified polypropylene is injected into the mold between the portions at approximately 410.degree. F., and the mold is closed to seal the ends of the parison. The interior of the parison is pressurized to a level in the range of approximately 90 to 100 psi to force the parison outward against the inner sides of the mold cavity and against one end of the port member. At this juncture, the parison has a thickness in the range of 0.060 to 0.090 inches.

Abstract: An extruded tubular molding is clamped at upper and lower portions thereof to form an air-tight space therebetween and thereafter compressed within two corresponding halves of a molding die and molded into the configuration of a final product. The lower portion of the molding is first clamped and lowered to stretch the molding downwardly prior to clamping the upper portion and compressing the molding in the molding die.

Abstract: A porous structure is provided between a forming member and an underlying support structure so as to facilitate the drainage of liquid through the porous member when a web is supported on the porous member and columnar streams of liquid are directed at the web to form apertures in the web. The porous structure can include a plurality of spaced-apart, wire-like elements, a metal screen, thermoplastic netting, mesh, webbing, and the like. An improved apertured web made with the improved process employing such a porous structure has little or no lining or marking and has relatively few, if any, poorly formed apertures.

Abstract: A method for making an apertured film for use as a topsheet in absorbent products wherein the film is corona treated on one side, and has received a surfactant application that is distributed to both the corona treated and non-corona treated sides of the film. A method for application of surfactant includes applying the surfactant to one side of the film and rolling the film into a roll while the surfactant is still wet in order to apply surfactant to both sides of the film.

Abstract: A cellular material, preferably a low density foam material, having an initial average normal incidence sound absorption coefficient for a selected frequency range is perforated to form a perforated cellular sound absorption material. The perforated cellular sound absorption material formed has an average normal incidence sound absorption coefficient for the selected frequency range greater than the initial average normal incidence sound absorption coefficient of the cellular sound absorption material. The depth(s), diameter(s), shape(s) and pattern of the perforations provide the cellular sound absorption material with the improved sound absorption properties that are reflected in the increased average normal incidence sound absorption coefficient of the material.

Abstract: A method of and apparatus for molding and texturizing the upper surfaces of concrete products such as patio and paving stones following the steps of densifying and molding the concrete products and releasing them on pallets to a substantially horizontally traveling, longitudinally extending conveyor, then passing the concrete products continuously on the conveyor past an overhead force spraying station at a predesignated speed and directing a predetermined volumetric, overhead spray of liquid at a predetermined spray angle and pressure to progressively loosen some of the material and texturize the upper surfaces as the products move past the spraying station, and then before they have absorbed enough liquid to deleteriously affect their strength, either in the uncured or cured state, and, while they are continuing to travel along the conveyor, directing a flow of gas at the upper surfaces at a pressure to blow off the liquid and loosened material from the surfaces.

Abstract: A method and apparatus for manufacture of duckbill valves in which the opposed lips of the valve are split by applying a high fluid pressure inside the valve. This pressure causes the valve to balloon and burst. Preferably, the valve is supported over all of its outer surface except the end to be split by a die. The system is particularly suited to duckbill valves made of thermoplastic elastomer.

Abstract: A method of forming apertured webs is provided comprising the steps of: (a) forming a foraminous member comprising gross foramina and fine foramina wherein the gross foramina define a patterned design superimposed on the fine foramina by means of applying and curing a photosensitive resin onto a foraminous element comprising fine foramina in order to form elevated portions on the fine foramina defining the gross foramina, (b) providing a layer of fibers on said foraminous member; and (c) applying fluid streams to said layer of fibers such that the fibers are randomly entangled in regions interconnected by fibers extending between adjacent entangled regions in a pattern determined by the pattern of the gross foramina of the foraminous member to form an apertured web.

Abstract: This invention relates to a process for forming a single-layer, durably wettable polymeric web having a plurality of apertures. This process comprises melting a mixture of at least one thermoplastic polymer and at least one migratable surfactant and extruding the mixture to form a single-layer, substantially continuous polymeric film. The film is then apertured using high pressure fluid flows. Aperture formation is conducted when the single-layer polymeric film has a contact angle of at least about 30.degree., to minimize wash-off of the surfactant impregnated in the polymer web. The invention also relates to durably-wettable apertured webs.

Abstract: A parison 4 of hot thermoplastics material is delivered into a mould 1 comprising two mould halves 2, 3 which are closed towards one another. A stress force is applied to the wall of the parison 4 either by a projection 5 extending from one of the mould halves 3 and/or by blowing air at a low pressure against the parison 4 through a blow pin 10. The parison 4 is then penetrated by the blow pin and high pressure air is blown through the blow pin 10 to inflate the parison 4 against the mould halves 2, 3. The blow pin 10 is withdrawn and a formed article such as a case is released from the mould after a preset time.

Abstract: An apparatus for producing an apertured plastic film having a tricot-like texture. The apparatus includes a film forming member comprising a rotatable hollow drum having a pattern of apertures and a topographical outer surface formed by a cluster of peaks and valleys surrounding each aperture. A plastic film is placed on the apices of the peaks and fluid streams are projected against the film while the drum is rotated. The fluid forces the film against the topographical outer surface of the drum causing the film to become apertured and to have a tricot-like texture corresponding to the pattern of apertures and peaks and valleys.

Abstract: This invention relates to a process for forming a single-layer, durably wettable polymeric web having a plurality of apertures. This process comprises melting a mixture of at least one thermoplastic polymer and at least one migratable surfactant and extruding the mixture to form a single-layer, substantially continuous polymeric film. The film is then apertured using high pressure fluid flows. Aperture formation is conducted when the single-layer polymeric film has a contact angle of at least about 30.degree., to minimize wash-off of the surfactant impregnated in the polymer web. The invention also relates to durably-wettable apertured webs.

Abstract: An apertured film for use as a topsheet in absorbent products wherein the film is apertured and includes a plurality of micro-holes and a plurality of large-sized holes. A method of forming the film is disclosed, as well as an absorbent product incorporating the apertured film as a topsheet. The method includes the step of supporting the starting film on a backing member which has recessed zones into which the film may be deformed. In the preferred embodiment, fluid in the form of columnar streams is directed from at least two sets of orifices against the upper surface of the starting film. The orifices of the first set have a diameter greater than 10 mils, and the orifices of the second set have a diameter less than or equal to 10 mils. The fluid is discharged from the smaller orifices at a pressure of at least 500 psig, and the fluid is discharged from the larger orifices at a pressure less than 500 psig.

Abstract: A blow molding method by horizontal blow molding of piercing the wall of a parison having been extruded by an extruder with a blow nozzle is disclosed, which comprises moving forward the blow nozzle to pierce the parison, introducing blow air at least in the direction toward the bottom, i.e., opposite to the bottle neck and, after shaping of a hollow container by the blow air, forming an opening in the parison at a position in the vicinity of or above the blow nozzle-pierced portion to discharge the blow air having circulated inside the hollow container.

Abstract: The perforated sheet, in particular for sanitary articles, and made of a substance that is impervious to liquid, includes a multiplicity of craters each having a base in the plane of the outside face, an apex, and a sidewall that slopes between the base and the apex. The peripheral shape of the base includes at least one zone of discontinuity such that on going round the periphery of each crater, its sidewall presents non-uniform inclination with angles of inclination relative to the perpendicular to the plane of the outside face of the sheet that vary between positive values and negative values, said angle being negative at least in the zone of discontinuity. The peripheral shape of the base is preferably the result of partially overlapping a plurality of curved geometrical shapes, in particular circles and ellipses, and the zone of discontinuity corresponds to the junction between superposed shapes.

Abstract: A cylindrical screen for perforating a thermoplastic film or sheets has an outer surface and an inner surface. A plurality of outer apertures extend from the outer surface and terminate at a corresponding inner aperture on the inner surface of the screen. The apertures in the outer surface can have the same or a different geometrical shape as the apertures in the inner surface. The apertures form a passageway through the screen. The passageways are disposed at least one angle from about 5.degree. to about 60.degree. with respect to a plane that is disposed substantially perpendicular to the outer surface of the screen to prevent a direct line of sight through the screen.

Abstract: In a method of manufacturing material suitable for use as a top sheet in an absorbent disposable article, such as a sanitary napkin, an incontinence guard or a diaper, a laminate (1) comprised of a plastic film (2) and a layer of non-woven material (3) on at least one side of the plastic film is applied to a perforated supportive device (6) with one layer of non-woven material facing towards the supportive device. The plastic film is heated to a temperature above its softening temperature and there is generated between the two mutually opposing sides of the laminate a pressure difference of such magnitude that the plastic film will rupture within the regions of the holes in the supportive device so as to form openings (10) which lead to the associated non-woven material. A soft and smooth, liquid-permeable top sheet material is achieved.

Abstract: The present invention provides a process for forming a three-dimensional, macroscopically-expanded, fluid pervious web having an improved functional surface comprised of a sheet of polymeric material having a first surface and a second surface. A plurality of discrete deposits of a water resistant resinous material having a pre-determined open time are deposited on the first surface of the sheet. The deposits of resinous material are drawn upwardly from the first surface of the sheet to form corresponding fibrils during the open time. After resinous material has cured, the sheet is fed onto a forming structure having opposed surfaces such that the sheet is in contact with the forming structure. The forming structure exhibits a multiplicity of apertures which place the opposed surfaces of the forming structure in fluid communication with one another.

Abstract: A fluid pervious topsheet suitable for use on an absorbent article is disclosed. The topsheet includes an apertured, three-dimensional, macroscopically expanded, fluid pervious web having a textured wearer-contacting surface. The composite web permits liquids to penetrate while providing an improved, less plastic-like feel and visual aesthetics. The process of the present invention, in one embodiment, comprises extruding a polymeric film onto a forming structure, applying a pneumatic pressure to the film to cause the film to be urged into substantial conformance with the forming structure, and depositing a particulate material on said film while the film is in a semi-molten state.

Abstract: A method for making air bag covers includes enclosing leather or other covering material in a mold, advancing a projection on a mold portion against a covering material to form a tear seam, and injecting moldable material behind the covering material to form a backing layer bonded to the material while forming an aligned groove in the backing layer. Embossing a desired pattern in the leather or covering material with a design in the mold cavity is also disclosed. A method for molding leather covered, resinous articles using a preformed, preshrunk leather piece, which articles optionally have designs, indicia or enhanced leather graining embossed during molding, is also disclosed.

Abstract: A method of manufacturing an integral one-piece needle, the method comprising feeding a polymeric resin into a mould cavity and injecting a fluid under pressure into at least a portion of the cavity to eject therefrom the central region of the polymeric resin. This creates an annulus of polymeric resin having an orifice therethrough, the annulus of polymeric resin forming the cannula of the needle, the mounting hub being provided by the remaining portion of the cavity.

Abstract: Disclosed is a normally solid, high molecular weight, gel-free, amorphous to predominantly crystalline, propylene polymer characterized by high melt strength due to strain hardening which is believed to be caused by free-end long chain branches of the molecular chains forming the polymer.Also disclosed is a process for making the polymer by high energy radiation of a normally solid, high molecular weight, linear, propylene polymer in a reduced active oxygen environment, maintaining the irradiated material in such environment for a specific period of time, and then deactivating free radicals in the material.Further disclosed is the use of the strain hardening polymer in extensional flow operations such as, for example, extrusion coating, film production, and thermoforming.

Abstract: Apertured plastic films comprise a stretchable thermoplastic polymeric material having a plurality of micro-holes defined by a network of fiber-like elements. The films are produced by directing fluids, especially water, against the upper surface of a starting film in the form of columnar streams in a contact zone, while the film is supported on a backing element. The films of the invention are useful as covering materials for absorbent products such as diapers, wound dressings and sanitary napkins.

Abstract: A cylindrical screen for perforating a thermoplastic film or sheets. The screen is formed from a relatively thin sheet that is secured together to form a cylindrical shape. A plurality of apertures are positioned in the sheet and the apertures in the sheets forms a passageway through the screen. The passageways are disposed at an angle from about 5.degree. to about 60.degree. with respect to a plane that is disposed substantially perpendicular to the surface of the screen.

Abstract: A coextruded, multilayer polymeric film having a core layer including a surfactant and at least one outer layer is placed on a forming structure. The forming structure moves in a direction parallel to the direction of travel of the multilayer film and carries the multilayer film in that direction. A fluid pressure differential is applied across the thickness of the multilayer film along the direction of movement of the forming structure. The fluid pressure differential is sufficiently great to cause the multilayer film to conform with the forming structure forming a formed polymeric web. The formed polymeric web is exposed to a temperature which is sufficiently great enough to allow the surfactant in the core layer to migrate to the outer layer to form a surfactant treated formed polymeric web.

Abstract: A continuous, multi-phase process for microaperturing and microembossing a substantially continuous web of substantially planar polymeric film to conform with the image of multiple forming structures, each having a patterned forming surface with a multiplicity of fine-scale apertures and an opposed surface. Each forming structure is open from the apertures in the forming surface to its opposed surface. The web of film has an indefinite length, a first surface, a second surface and a thickness. The thickness is the distance between the first surface and the second surface. The process includes at least two sequential forming phases, one of which involves aperturing of the web of film to coincide with fine-scale apertures in the first forming structure and another of which involves conformance of the web of film to the profile of the fine-scale apertures in the second forming structure.

Abstract: A method for forming a product having a substrate and an overmold material secured thereto, with the substrate having a shape substantially as set forth in a predetermined design, and further with the product being formed in a molding machine that erodes portions of the substrate during a step of injecting the overmold material into a molding cavity of the molding machine. The method includes the step of providing the substantially design-shaped substrate having a compensation member secured thereto. The method further includes the step of placing the substantially design-shaped substrate having the compensation member secured thereto into the molding cavity so that the compensation member is positioned in a path of flow of the overmold material during the step of injecting the overmold material into the molding cavity.

Abstract: A travelling mold tunnel for forming double walled corrugated tube has a first portion for forming corrugated tube and a second belled portion for forming a cuff portion suitable for coupling with another tube. At the upstream end of the belled portion, radial small diameter passages are provided so that a pressure differential may be set up between the inside and the outside of a first parison within the belled portion. Thus, vacuum may be applied through the radial passages to allow an inner parison to laminate with the first parison over its inner surface in the belled portion. The first parison is drawn into the passages in protruding balloons. These may be ruptured. Alternatively, positive pressure may be used. In this case, the balloons may be ruptured inwardly.

Abstract: Tooling for facing a wall includes a plurality of cavities which are formed by four blades, each of the cavities corresponding to various brick sizes. Six lines of interconnected cavities are attached to a cross beam. Adjacent cavities and lines are spaced from another by a predetermined dimension. Unset settable building material is mixed with appropriate coloring and waterproofing agent and is applied to a wall to form an outer layer. The surface thereof is sponged to produce a brick like surface relief. The tooling is pressed into the outer layer to impress a pattern resembling brickwork. Unset material is sucked from the joint line space between adjacent cavities and the layer is allowed to set. Then, mortar is added to the joint line. Once the mortar has set, the final outer layer has a true brick finish that resembles a real brick wall. The unset settable material can be applied to damaged or wood walls so that a true brick finish can be given to a wall in a quick, simple and cost effective manner.

Abstract: An apparatus for forming curing envelopes which apparatus enables the use of a conventional inner tube mold for making a curing envelope preform in the form of an envelope tube which may have a portion thereof easily removed to provide a curing envelope suitable for use in a tire retreading process. A curing envelope is made by placing an annular tube of uncured envelope material in a curing mold having a center core and a mold insert installed therein. The insert includes a pair of coaxial annular rings projecting radially outwardly from the center core and connecting straps for maintaining the axial spacing between the rings. The mold is closed and heat and internal pressure are applied to the envelope tube for curing the envelope tube and urging the tube against the interior cavity surface with the annular rings penetrating into the inner wall of the tube for forming therein corresponding annular grooves.

Abstract: The present invention generally relates to a device which can form a lid for a cup. This apparatus is for thermoforming a plastic sheet of material into a plurality of production sheets. Each sheet has a partible port section, which has integrity against passage of fluid, yet which is partible under mechanical pressure so as to open and allow the passage of fluids. The lid structure with a breakaway port is formed by an apparatus including an oven for heating the production piece, mold assembly that has a mold formed as a female cavity with a plurality of grooves formed around the cavity surface and a pressure box assembly that has an open position and a closed position. The breakaway port in the lid structure is formed as a female cavity with accordion-like grooves therearound which expand to engage the outside of the straw. This eliminates escape of the fluid through the breakaway port when the straw is inserted.

Abstract: A gas assisted injection molding method and apparatus wherein articles are produced by injecting molten resin into a mold cavity and then injecting a quantity of pressurized gas into the resin to fill out the mold cavity and form a hollow in the resin. Following the injection of the gas into the resin to form the hollow, gas is injected into the resin in the mold cavity at a second location. The gas injected at the second location may either form a separate hollow within the resin or may form a passage extending through the resin for communication with the hollow formed by the gas injected at the first location. The first location is preferably the resin injection location and the second location is preferably a location communicating directly with the mold cavity. Gas is vented from the article either at the first location, the second location, or both locations.

Abstract: A method and apparatus for treatment of relatively moving substrate materials and the novel products produced thereby created by precise application of high temperature pressurized streams of fluid against the surface of the materials to melt and remove material which imparts a recessed channel to the materials that facilitates separation of the materials. The apparatus includes an elongate manifold for receiving heated pressurized fluid, such as air, disposed across the width of the relatively moving material and having a single slit the full width of the substrate for directing the fluid into the surface of the material. The substrate material is treated with an acrylic resin to eliminate jagged or frayed edges either prior to or after the melting and removal process by means of the high temperature pressurized fluid streams.

Abstract: A pre-cast terrazzo panel having detailed, multicolor designs therein constituted by background and inlay designs of different colors includes inlay and background colors which are integral with no surface difference between the inlay and the background.

Abstract: A soft, silky, cloth-like polymeric web exhibiting either patterns of microapertured or microbubbled surface aberrations, said webs further including a contrasting visually discernible pattern which imparts an embossed appearance to at least one surface thereof. Such polymeric webs may be either fluid-pervious or fluid-impervious, as desired, depending upon the particular end use. In a particularly preferred embodiment, the visually discernible pattern comprises a regularly repeating pattern which imparts an improved aesthetic appearance to the webs. Method and apparatus for producing such polymeric webs are also disclosed.

Abstract: A method of manufacturing a porous static pressure gas bearing includes the steps of impregnating a porous material to be adjusted in injection flow rate with resin and closing vent openings, and applying a solvent for dissolving the resin to the porous material through a pattern having a predetermined opening distribution.

Abstract: A method for manufacturing a filter cartridge by polymerization of a polyethylene hydrocarbon with granular elements are set forth. The method involves the preparation of a mixture comprising the hydrocarbon and the granular elements, then introduction of the mixture into a mold which is formed by a first porous wall and a second porous wall, these walls being connected to a jacket, the introduction of the mold in an oven so as to raise the temperature of the mixture and by a thermal polymerization reaction to transform the hydrocarbon into a material binding the granular elements of the mixture, the assembly of the material and granular elements then forming a cartridge, and injection of a chemically inert gaseous composition into the mold through one of the walls to impart fluid permeability to the cartridge.