Abstract: Ways for simultaneously forming and filling a container are provided. A hydraulic intensifier (60) receives a first liquid (18) and dispenses the first liquid (18) at a first pressure, where a moveable member (62) having a first surface (64) contacts the first liquid (18) and a second surface (66) contacts a second liquid (68). The second liquid (68) provides a second pressure on the second surface (66) so that the first pressure is applied to the first liquid (18) by the first surface (64). The first surface (64) has a smaller area than the second surface (66) and the first pressure is greater than the second pressure. A blow nozzle (22) transfers the first liquid (18) at the first pressure into a preform (12) within a mold cavity (16) to urge the preform (12) to expand toward an internal surface (34) of the mold cavity (16) and form a resultant container. The first liquid (18) remains within the container as an end product.

Abstract: Unitary measuring pipettes include a tubular body of biaxially oriented thermoplastic material, together with size reduction, elimination, and/or reorientation of longitudinally spaced, raised circumferential witness features, to mitigate or avoid interference between such witness features and graduated volumetric markings on an outside surface of the tubular body. Methods and apparatus for vacuum forming of unitary measuring pipettes are also provided. Gas permeable apertures or pores having a maximum width of no greater than 150 microns, in ranges of 10-100 microns, 10-50 microns, or subranges thereof, may be defined in face plates or inserts received by mold blanks, or defined in molding surface of cooperating mold bodies, and may be used to produce a tubular pipette body having reduced height witness features. Cooperating mold bodies may each be produced from multiple mold body sections with gas passages defined therein and/or therebetween.

Abstract: Process for aseptically forming containers (100) starting from parisons made of thermoplastic material, comprising the steps of: injecting sterile compressed air inside a parison arranged in a stretch-blowing forming mould (2) so as to obtain a container (100); evacuating the exhaust compressed air from the formed container (100); making at least a part of the exhaust compressed air evacuated from the formed container (100) passing through a sterile filter (SF) so as to obtain recovery sterile air; injecting the recovery sterile air in another parison arranged in another forming mould (2).

Abstract: The invention relates to a process for production of a container by blowing or blowing-stretching within a production unit comprising a mold and a nozzle which is designed to close the mold hermetically. The process comprises a sequence of forming with a blowing phase and a phase of degassing. The degassing phase comprises spacing the nozzle from the mold in order to interrupt the hermetic closure. The spacing of the is nozzle carried out (i) after the beginning of the degassing phase, when the pressure in the interior of the container has dropped and has reached an intermediate pressure which is lower than the pressure at the end of the forming sequence, and is between 14 and 3 bars or (ii) after completion of the blowing phase, and within an interval of time of between 0 and 200 ms after the stoppage of the injection of gas into the container.

Abstract: The geometry of a toroidal balloon requires that a traditional cylindrical balloon to be rotated internally into itself and the ends of the cylinder be placed in close proximity for maximal balloon rotation and to allow an entrance port for inflation of the balloon and/or attachment to an associated medical device. Described within are various techniques for the creation of such toroidal balloons.

Abstract: A blow molding method includes: performing a primary blowing on a resin preform to form an intermediate molded product; and performing a final blowing on the intermediate molded product to form a final molded product, and at least one step of performing the primary blowing and the final blowing includes a thinning step of continuously repeatedly performing, within a predetermined time, steps of: stretching an object by blowing; and contracting stretched parts of the object by exhausting blown air.

Abstract: Provided are: a pipe-shaped integrally molded article which is formed by molding a polyphenylene sulfide resin composition, and which has, at one or more portions thereof, at least one selected from different-shape sections, bent sections, and different-diameter sections, the pipe-shaped integrally molded article being characterized in that the total length L (mm) thereof is 1000 or more, and the ratio (L/D) of the total length L (mm) to the outer diameter D (mm) of the pipe-shaped integrally molded article is 20 or more: and a production method for the pipe-shaped integrally molded article. According to the present invention, it is possible to efficiently provide a pipe-shaped integrally molded article having a desired large length and including a three-dimensionally complicated shape, by using a PPS resin composition having excellent heat resistance and chemical resistance.

Abstract: A method and a molding station for producing containers filled with a liquid filling material from preforms made of a thermoplastic material. Thermally conditioned preforms are molded into containers and filled with the liquid filling material, which is supplied to the preforms under pressure as a pressure medium in a multi-part mold of a molding station. The mold is movable from a closed state into an open state in order to repeatedly supply a preform and subsequently remove a completely molded and filled container. Molding of the preform into the container is performed against the mold inner wall when the mold is in the closed state. Liquid is removed from the mold between temporally successive supplying processes starting with the conversion of the mold from the closed state into the open state. A working wheel including such molding stations, and a device including such a working wheel are also disclosed.

Abstract: A molding system for hydraulic blow molding of a container from a preform. The molding includes a pressurization unit that is configured to receive liquid molding medium from a source; a fill head unit coupled to the pressurization unit to receive the liquid molding medium therefrom; a mold assembly defining a mold cavity in the shape of the container. During forming of the container, a nozzle piston is moved from a retracted position to an extending position where the nozzle piston is engaged to inject the molding medium into the preform, thereby forming and filling the container. The fill head unit defines a receiving chamber for the liquid molding medium that maintains a constant volume during movement of the nozzle piston between the retracted and extended positions.

Abstract: A plastic container having a sidewall defining a chamber and having a first end and a second end and an opening at the first end into the chamber. A base of the container extends from the sidewall and closes the second end, the base having an outer perimeter portion defining a support structure, an axially inwardly extending perimeter wall spaced radially inwardly from the support structure forming an angle with a horizontal line of greater than about 80°, a centrally disposed pushup section in the shape of an axially inwardly extending truncated cone, and a toroidal-shaped channel circumscribing and connecting the perimeter wall to the pushup section. The toroidal-shaped channel has a surface that is asymmetrical about a central axis of the container when the container is under static pressure conditions.

Abstract: A method of sub-ambient pressure processing of blow-molded polymer foams and skin-over-foam sandwich panel configurations for lightweight components having improved structural properties. The method can create either skinned or un-skinned foams that offer smooth interior and exterior surfaces, zero or controlled surface porosity, skins of pre-defined thickness, and foam cells that are expanded and oriented normal to the material plane, effectively spherical or polyhedral in nature, and offering improved bending and compressive strength.

Abstract: A method for forming plastic preforms into plastic bottles, wherein the plastic preforms are transported along a predefined transport path by a transport device in a plurality of forming stations arranged on the transport device, and at least at times during the transport, bombarded with a fluid medium for their expansion, wherein the plastic preforms in a first method step are bombarded by the fluid medium at a first pressure (p1) and in a further method step, temporally following the first method step, bombarded with the fluid medium at a second pressure (p2), wherein the second pressure (p2) is higher than the first pressure (p1). At least at times during the bombardment of the plastic preforms at the first pressure (p1), a volume flow of the fluid medium entering the container is increased.

Abstract: Disclosed is a method for manufacturing a container (2) from a blank (3) made of plastic material, in a stretch-blow molding unit (7) including: a mold (11) provided with a wall (13) and a mold base (14) which is axially movable relative to the wall (13) between a low position and a raised position; a stretch rod (22) which is axially movable relative to the mold (11) between a high position and a low position; the method including: a phase of inserting the blank (3) in the mold (11); a phase of stretch-blow molding; a phase of boxing; a phase of determining the start and end of the boxing phase, respectively, by detecting the movement of the rod (22) from the low position thereof and the stopping of the rod (22) at the raised position thereof.

Abstract: A method of forming a container includes blow molding a primary form of the container inside a primary mold. The primary form has an exterior surface. The method also includes applying a fluid to the exterior surface of the primary form to shrink the primary form and to form a shrunken form of the container. Furthermore, the method includes blow molding a secondary form of the container from the shrunken form inside a secondary mold.

Abstract: A molding system for molding a container includes a first blow mold operable for blow molding a first form of the container and a second blow mold operable for blow molding a second form of the container. The system further includes a counter stretch rod and/or a base pushup operable for reducing a height of the first form of the container before blow molding the second form of the container. A corresponding method of forming a container is also disclosed.

Abstract: A method is disclosed for providing dimensional accuracy of a pour opening in or on a plastic container produced by extrusion-blow-molding. The method can include inserting a section of a plastic hose, extruded in one or more layers through an extrusion nozzle, into a mold cavity of a blow mold tool; and inflating the plastic hose by a calibrating blow pin according to a shape of the mold cavity, whereby at least one pour opening of the plastic container is determined with respect to its inside diameter and its inside contour to form a completed inflated plastic container, and wherein the calibrating blow pin is axially inserted into the plastic hose section after a head plate of the blow mold tool has been closed.

Abstract: A system for forming a container from a preform includes a first mold operable to receive the preform and operable to blow mold a first form of the container from the preform. The system also includes a second mold operable to receive the first form and operable to blow mold a second form of the container from the first form. The preform, the first form, and the second form each include a substantially common transitional wall. Also, the first form can include various features that ensure that material will be distributed as desired throughout the container, to ensure high wall strength, and to ensure high crystallinity.

Abstract: A device (31) for injecting an incompressible, pressurized liquid into a container (18) made of a thermoplastic material so as to shape the container (18), includes: a pipe (30) for supplying the liquid, which is to connect a liquid source (40) to the container (18); pumping elements (42) for causing the liquid to flow in the supply pipe (30) toward the container (18) at a first pressure (P1); and compression elements (44) for temporarily raising the pressure of the liquid contained in the container (18) to a second pressure (P2) that is greater than the first pressure (P1), wherein the compression elements (44) are formed by a work chamber (48), whose volume is variable, and which is connected only to the supply pipe (30) between the pumping elements (42) and the container (18).

Abstract: A forming method, in a mold provided with a wall forming a cavity, of a container from a blank, which includes a boxing operation of pushing back the material of the blank by an insert movably mounted with respect to the wall of the mold between a retracted position in which the insert is retracted into the wall, and a deployed position in which the insert protrudes with respect to the wall, in order to form on the container, by pushing back, a hollow reserve projecting toward the interior of the container. Additionally, a local pressurization operation is performed, after formation of the hollow reserve, of injecting a pressurized fluid between the insert and the hollow reserve.

Abstract: A preform 20 for a large container, used for producing a large container which is made of a polyethylene terephthalate resin and which is formed by stretch blow molding, is formed by injecting molding to have a wall thickness of 6 mm to 9 mm and have a longitudinal axis length longer than that of the large container which is a final molded product.

Abstract: The invention relates to a method for producing an article from thermoplastic material in which a tube-shaped preform is introduced into a multi-part blow mold and is expanded and formed by applying differential pressure, wherein, before the forming of the preform, at least one insert is introduced into the preform by means of a first holding means and wherein, before the forming of the preform, the insert is taken over by at least one second holding means puncturing the wall of the preform, the second holding means being formed as a blowing pin and an expansion and re-forming of the preform taking place by applying pressure medium with the second holding means.

Abstract: A stretch blow molding system (200) is provided. The stretch blow molding system comprises a cylinder (201) including a movable stretch rod (202) and a blow-mold valve (204). The blow-mold valve (204) comprises a first fluid port (204a) in fluid communication with a first pressurized fluid source (364a). The blow-mold valve (204) also includes a second fluid port (204b) in fluid communication with a second pressurized fluid source (364b). A third fluid port (204c) of the blow-mold valve is in fluid communication with the cylinder (201) and selectively in fluid communication with the first fluid port (204a) and the second fluid port (204b).

Abstract: A plastic film preform is expanded to form a container. The preform has a longitudinal axis that extends from an open top to a closed bottom. The preform is pressurized with a first pressure sufficient to cause side walls of the preform to expand outwardly and the bottom of the preform to be drawn inwardly thereby reducing a length of the preform along the longitudinal axis. Side molds are closed around the side walls of the preform, the closed side molds being larger than the expanded side walls. A bottom mold is closed to be adjacent to the bottom of the preform after pressurizing the preform with the first pressure. The preform is pressurized with a second pressure sufficient to expand the preform to fill the closed molds. The preform is thereby significantly stretched in a direction perpendicular to the longitudinal axis and minimally stretched along the longitudinal axis.

Abstract: A blow molding method includes a primary blow molding step that molds a preform (200) in a primary blow mold (300A) that includes a primary temperature control section (330) to obtain an intermediate molded article (202), a shrinkage step that discharges blow air from the intermediate molded article to shrink the intermediate molded article, and a secondary blow molding step that blow-molds the intermediate molded article (204) that has shrunken in a secondary blow mold that includes a secondary temperature control section (430) to obtain a final molded article. The primary blow molding step cools a first intermediate molding region of the intermediate molded article that follows a neck using a first primary temperature control section, and the shrinkage step shrinks a second intermediate molding region of the intermediate molded article of which the temperature is controlled by a second primary temperature control section.

Abstract: The invention realizes easy manufacturing of a flat container molded by blow molding, in which the wall thickness of a container wall is made uniform, and which provides improved mechanical strength, heat resistance, etc. and has a good appearance. The flat container obtained by the blow molding of a polyester resin is characterized in that the container has a flatness ratio of not less than 1.3, and in that its body has a wall thickness ratio of a maximum wall thickness to a minimum wall thickness of not more than 1.6, a difference in elongation between a maximally stretched portion and a minimally stretched portion of not more than 150% in a tensile test at 95° C., a crystallinity of not less than 30%, and a difference in TMA non-load change between a maximally stretched portion and a minimally stretched portion of not more than 500 ?m at 75° C. and 100° C.

Abstract: A method and a device for recycling compressed gas where the compressed gas used in a compressed gas consumer, particularly a container blow-molding machine, is fed back into a compressed gas generator. In order to increase the recycling volume, the compressed gas from the compressed gas consumer is collected separately and fed back to at least a first and a second pressure range of the pressure generator separately according to pressure stages.

Abstract: Use of optimized piston member for generating peak liquid pressure. A one-step hydraulic blow molding system and method for forming a preform and a liquid filled container from the preform. The machine and method include a sealing mechanism that forms a seal primarily utilizing compressive forces in an axial direction to prevent the leakage of liquid blow medium. The sealing mechanism includes an axial end face of a forming head and an upper axial surface of a neck ring.

Abstract: A method of fluid forming a container comprising positioning a plastic preform into a mold cavity, wherein the mold cavity defines a first configuration and a first volume. The method further includes injecting a fluid within the plastic preform at a first fluid pressure urging the plastic preform into an expanded shape. The method includes actuating the mold cavity into a second configuration and a second volume, whereby the second volume is smaller than the first volume, thereby resulting in a second fluid pressure within the plastic preform being greater than the first fluid pressure.

Abstract: In at least some implementations, a blow molding process provides that portions of the parison are engaged by one or more clamping devices disposed on or adjacent to the blow mold parts, and that the blow mold is opened whereby the parison is torn apart between the clamping devices, into two or more pieces of the parison. In other implementations, the clamping devices may be moved relative to the blow mold to tear the parison, or the parison may be torn by a combined movement of the blow mold parts and clamping devices.

Abstract: In effecting the stretching by using a stretch rod in a method of producing a biaxially stretched polyester bottle, the air is blown into the preform at such a flow rate that the preform does not come in contact with the stretch rod but the end thereof and does not come in contact with the surfaces of the mold, either. There can be produced a biaxially stretched polyester bottle having an average thickness of about 0.05 to about 0.2 mm or having a further decreased thickness using a resin in decreased amounts and having a decreased weight without developing burst or whitening caused by over-stretching, without forming ring-like thick portion yet maintaining a good yield and efficiency.

Abstract: A one piece plastics material container has mouth, a wall portion adjoining the mouth in a longitudinal direction (L) and a base portion in the form of a standing face. The base portion has an injection point—situated on the inside in a radial direction (R) with respect to the longitudinal direction (L)—on the outer wall of the plastics material container, a central area which surrounds the injection point, and a transition portion which extends from the central area to the wall portion. The transition portion has in at least one radial direction (R) and preferably in each radial direction (R) a curvature with a finite radius of curvature in at least one portion. The base portion has a plurality of reinforcement ribs which starting from the central area extend in the direction of the wall portion.

Abstract: A process for producing containers includes the steps of providing a container having a shaping region, the shaping region comprising a thermoplastic material; applying an ink to the shaping region; discretely heating the shaping region to a shaping temperature; and discretely shaping the shaping region to take a desired three dimensional shape. A system for producing containers having three dimensional decorations, and containers having three dimensional decorations, are also disclosed.

Abstract: Method of manufacturing a container from a blank of plastic material, within a mold provided with a wall defining a cavity with the impression of the container, and a mold bottom that is movable with respect to the wall between a retracted position and a deployed position in which it extends protruding into the interior of the cavity in order to form a hollow recess in the container. The method includes inserting the blank into the mold; a pre-blowing operation including injecting a fluid under pressure into the blank, at a pre-blowing pressure; a blowing operation including injecting a fluid under pressure into the blank at a blowing pressure that is greater than the pre-blowing pressure; and a boxing operation, initiated prior to the blowing operation, and including moving the movable mold bottom from its retracted position to its deployed position.

Abstract: In a blow moulding machine for the production of plastics material containers, during a blow mould procedure, the container to be expanded is supplied with blow moulding air from a first gas preparation device on the one hand or from a second gas preparation device on the other hand. During this procedure a cooling of the base of the container is additionally carried out.

Abstract: A forming method, in a mold fitted with a wall forming a cavity, of a container from an intermediate container including at least one lateral protrusion projecting toward the exterior of the container. The method includes a boxing operation of pushing the lateral protrusion by an insert movably mounted with respect to the mold between a retracted position in which the insert is retracted into a recess formed in the wall and a deployed position in which the insert protrudes with respect to the wall, in order to form, by overturning, a hollow reserve projecting toward the interior of the container. Also included is an operation to pressurize the intermediate container, including, prior to the boxing operation, injecting a fluid under pressure into the intermediate container; and a local pressurization operation, prior to the boxing operation, of injecting a fluid under pressure into the volume defined in said recess between the lateral protrusion and the insert.

Abstract: A method for the shaping of plastics material pre-forms into plastics material containers, wherein the plastics material pre-forms are introduced into a blow mould and are expanded to form the plastic bottles by being acted upon with a gaseous medium in the blow mould, includes the steps of: preliminary blow moulding by acting upon the plastics material pre-forms with a first pressure; intermediate blow moulding of the plastics material pre-forms at a second pressure which is higher than the first pressure; and final blow moulding of the plastics material pre-forms at a third pressure which is higher than the second pressure, wherein at least the second pressure is varied during a working operation.

Abstract: A hollow article is provided comprising a first wall, and a second wall, where the first and second walls are positioned in opposing relationship thus defining a space therebetween. A first set of structural members are provided that extend internally from one of the first and second walls, the first set of structural members spanning the space and having an end surface that is integrally bonded with an inside surface of the opposing wall. A second set of structural members is also provided that extend internally from one of the first and second walls, the second set of structural members spanning the space and having an end surface integrally bonded with an inside surface of the opposing wall. The first and second sets of structural members are provided in different orientations.

Abstract: A method of molding a large returnable container includes a heat treatment step for subjecting a thick preform formed of a polyester resin or a primary blow-molded article to intermediate blow molding with heating to obtain an intermediate molded article, and a final blow molding step that includes subjecting the intermediate molded article that has shrunk to final blow molding with heating to obtain a large returnable container. The heat treatment step includes disposing the preform or the primary blow-molded article in a heat treatment mold, and pressurizing the preform or the primary blow-molded article so that a shoulder and a body obtained by blow molding close contact to a cavity surface of the heat treatment mold, and are subjected to a heat treatment, the shoulder being heated at a low temperature as compared with the body.

Abstract: A process for blow-molding a container, the container having a handle, whereby the process includes the steps of: (i) introducing a preform into a mold cavity and stretching the preform with a stretch rod; (ii) increasing the pressure within the preform so that the preform expands within the mold cavity in a first blowing step, the pressure in the first blowing step is from 1 to 10 bar; (iii) inwardly moving jaws within the mold cavity so that the expanding preform is partially gripped between the jaws in the handle region; (iv) subsequently increasing the pressure within the preform wherein the maximum pressure in the second blowing step is greater than 10 bar, so that the preform expands to the limits of the mold cavity in a second blowing step to form a container; and wherein the inward movement of the jaws is completed within the first blowing step.

Abstract: A method for blow molding containers in blow molds of a device operated with the recovery of air from the blow molds, where operation is accomplished consecutively in a preblow stage with a low pressure and at least two further blow stages with respective higher pressures, and where subsequently, in a recovery phase with several pressure stages, air is fed from the respective blow mold, air from the blow mold is first fed into the volumes allocated to the preblow stage, with priority over a feeding at least into the volume allocated to the pressure stage following the preblow stage. Further, a blow control and a control means for the pressure in the volume, where the blow control has a program section for primarily feeding air first into the volume, and possibly for limiting the pressure in the volume to a multiple of the pressure.

Abstract: Process for manufacturing a fuel tank equipped with an internal accessory and having a plastic wall produced from a parison, said process comprising, in order, the following steps: a) the accessory and the molten parison are introduced into a mold so that the accessory is surrounded by the parison, said mold comprising cavities equipped with at least one moving part; b) a pressurized gas is introduced inside the parison to carry out a pre-blow molding of said parison; c) the pre-blow-molded parison is pressed locally against the accessory using the moving part in order to firmly attach the two without piercing the parison; d) the mold is closed and the final blow molding of the parison is carried out by flattening it against the mold cavities using the pressurized gas; and e) the tank is removed from the mold.

Abstract: The present invention relates to a method of improving balloon refoldability by molding a preformed balloon into a larger, predetermined shape at a lower temperature and higher pressure than that with which the balloon was originally formed.

Abstract: The present invention relates to a process for blowing an article with at least one recess.

Abstract: Disclosed are a method and a device for blow molding containers (2). A parison (1) is stretched by means of a stretching rod (11) within a blow mold (4) and molded into the container by applying blow pressure following thermal conditioning. The pressurized gas is introduced into the container (2) via at least two different flow paths (55, 56). Advantageously, one of the flow paths (56) ends near the orifice area (21) while a second flow path (55) ends near a container bottom (51). At least some of the pressurized gas is introduced into the container (2) through the stretching rod (11).

Abstract: A process for blow-molding a container, the container having a handle, whereby the process includes the steps of: (i) introducing a preform into a mold cavity and stretching the preform with a stretch rod; (ii) increasing the pressure within the preform so that the preform expands within the mold cavity in a first blowing step, the pressure in the first blowing step is from 1 to 10 bar; (iii) inwardly moving jaws within the mold cavity so that the expanding preform is partially gripped between the jaws in the handle region; (iv) subsequently increasing the pressure within the preform wherein the maximum pressure in the second blowing step is greater than 10 bar, so that the preform expands to the limits of the mold cavity in a second blowing step to form a container; and wherein the inward movement of the jaws is completed within the first blowing step.

Abstract: A blow molding having capacity of at least 250 ml, having a shell which is composed of impact-resistant polystyrene and which is produced via injection stretch blow molding where an average aspect ratio of rubber particles derived from longitudinal section and an average aspect ratio of rubber particles derived from cross section measured in transmission electron micrographs is greater than 4 respectively, and a biaxial orientation of the rubber particles, given by the ratio of the aspect ratio derived from cross section to the aspect ratio derived from longitudinal section is smaller than 3.

Abstract: A process for blow-molding a container, the container comprising a handle, whereby the process comprises the steps of: (i) introducing a preform (2) into a mold cavity and stretching the preform (2) with a stretch rod; (ii) increasing the pressure within the preform (2) so that the preform (2) expands within the mold cavity in a first blowing step, the pressure in the first blowing step is from 1 to 10 bar; (iii) inwardly moving jaws (3, 4) within the mold cavity so that the expanding preform (2) is partially gripped between the jaws in the handle region; (iv) subsequently increasing the pressure within the preform (2) wherein the maximum pressure in the second blowing step is greater than 10 bar, so that the preform (2) expands to the limits of the mold cavity in a second blowing step to form a container; and wherein the inward movement of the jaws (3, 4) is completed within the first blowing step.

Abstract: A catheter balloon molding system designed to facilitate multi-expansion step balloon forming processes using a segmented mold form. A multi-mating segment of the mold form, defining one end portion of the balloon, is retained throughout the multiple steps and the parison is kept in place in the multi-mating segment between expansion steps while the mold form is reconfigured for the next expansion step.

Abstract: A container can have a body with an integrally formed base attached to the body. The base includes a concave annular wall extending from the container sidewall to a standing surface, and an inner wall extending from the standing surface to a substantially flat inner annular wall. The inner annular wall is recessed in the base and is substantially perpendicular to the container sidewall. The inner annular wall includes a centrally located dimple. The dimple includes a plurality of spaced apart and radially extending indented ribs. One or more of the ribs extend radially into a brace that tapers to meet the inner annular wall.

Abstract: A method and an apparatus for the economical production of containers from thermoplastic material with a blow moulding machine (3) are disclosed. For shaping the containers at least one first pressure channel (21) is provided, supplying a first pressure. Likewise at least one second pressure channel (22) is provided, supplying a second pressure, wherein the first pressure is lower than the second pressure. The air in the first pressure compartment (21) is used for the pre-blowing or for other blowing steps of the containers. The air in the second pressure compartment (22) is used for the final blowing of the containers. The final blown containers are vented into the first pressure compartment (21). A control unit is provided which maintains an essentially constant pressure in the first pressure compartment during the pre-blowing and the venting into the first pressure compartment. A pressure level of the external pressure reservoir (20) can be adjusted accordingly.