Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/64—Heating or cooling preforms, parisons or blown articles
  • B29C49/6409—Thermal conditioning of preforms
  • B29C49/6436—Thermal conditioning of preforms characterised by temperature differential
  • B29C49/6445—Thermal conditioning of preforms characterised by temperature differential through the preform length
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/0042—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor without using a mould
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/46—Component parts, details or accessories; Auxiliary operations characterised by using particular environment or blow fluids other than air
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/78—Measuring, controlling or regulating
  • B29C49/783—Measuring, controlling or regulating blowing pressure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/46—Component parts, details or accessories; Auxiliary operations characterised by using particular environment or blow fluids other than air
  • B29C2049/4602—Blowing fluids
  • B29C2049/465—Blowing fluids being incompressible
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/07—Preforms or parisons characterised by their configuration
  • B29C2949/0715—Preforms or parisons characterised by their configuration the preform having one end closed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
  • B29C49/06—Injection blow-moulding
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/712—Containers; Packaging elements or accessories, Packages
  • B29L2031/7158—Bottles

Definitions

• the subject of the invention is improvements to the methods and installations for manufacturing plastic containers from pre-injected preforms which are thermally conditioned and then transformed into containers during an expansion carried out by injecting a fluid inside. of the preform. It applies to the manufacture, at lower cost, of containers intended more particularly, although not exclusively, to receive contents whose price is low (for example, without this being limiting, water or other refreshing liquids) relative to that of the containers.
• the preform which is in the form of a test tube formed in an injection mold, is introduced into a thermal conditioning unit, also called an oven, in which its constituent material is reheated in order to be brought to a temperature higher than its glass transition temperature, however without reaching its crystallization temperature.
• a thermal conditioning unit also called an oven
• the preform is transferred to a mold belonging to a blowing unit or, more frequently, to a mold belonging to a stretch-blowing unit.
• the mold includes a cavity with an imprint of the final container.
• the unit is a blowing unit
• the preform after having been introduced into the mold, is subjected there to an injection of fluid, generally air, at high pressure, typically of the order of 40 bars.
• the unit is a stretch blow molding unit, which is the most frequent case
• the preform after being introduced into the mold there is subjected to a stretching along its longitudinal axis, generally accompanied by an injection of pre-blowing fluid (under a pressure of ten bars) and an injection of blowing fluid.
• pre-blowing fluid under a pressure of ten bars
• blowing fluid blowing fluid
• the thermal conditioning unit is arranged so that the neck of the preform is not heated.
• the neck is a part of the preform, which corresponds to the neck of the final container. It is therefore produced in its final shape and dimensions during the injection of the preform and must not be deformed in the subsequent blowing or stretch-blowing phases.
• the neck comprises an opening (the neck proper) and a peripheral zone thereof with means (thread, rim, or the like) suitable for receiving the closure member (stopper, capsule or other) of the final container.
• it comprises, in most cases, means, typically a flange, for transporting the preform and the container after its production, and / or after its filling and / or other manipulations.
• the thermal conditioning unit is arranged to allow differentiated heating of certain areas of the preform, in order to optimize the distribution of the material in the final container.
• the preform heating profile is determined taking into account the dimensions and shape of the preform, as well as the dimensions and shape of the final container.
• document FR-A-2 703 944 in the name of the applicant discloses a process and a device for selective or preferential heating of certain areas of the preform to result in a bottle.
• the molds which constitute important elements to allow the final conformation of the containers and the repeatability of the forms are expensive. Indeed, they require delicate machining and finishing operations (polishing) of the cavities which they comprise.
• the machines known to the applicant comprise from two to forty molds, some being single-cavity, others two-cavity.
• the means for compressing the blowing fluid, in order to reach the high pressures necessary for taking shape in the cavities, are also costly elements and all the more complex the higher the flow rate which is required of them. It should be noted that some machines produce 60,000 containers per hour, which assumes that the compression means are able to deliver approximately 240,000 liters of fluid per hour (assuming that the containers, blown at 40 bars, have a volume of 1 litre).
• blowing (or stretching and blowing) parameters so that the containers produced are correct is a complex operation.
• a method of manufacturing a plastic container of the type consisting in thermally conditioning at least certain zones of a preform of the container so that the temperature of said zones exceeds the glass transition temperature of their material component, and to inject a fluid into the preform to cause its expansion in order to conform it into a container, is characterized in that it consists in carrying out a free expansion, that is to say without the presence of a mold , at least some of said areas of the preform, and to control at least one parameter for injecting the fluid to reach the final container.
• the invention is very particularly advantageous because it can be implemented without requiring high injection pressures. Thus, tests have made it possible to produce containers with a fluid pressure of less than 10 bars. Also, the invention allows it to overcome the need for expensive compressors; moreover, it allows to implement a machine structure Alleg u ed in comparison with known machines Anlagene- they require a design suitable for high pressures used.
• a standard heating profile such as a profile for obtaining bottles on known machines
• the method of the invention makes it possible to obtain containers whose general shape is that of an elongated bubble.
• Such a general form which has limited possibilities of declination of form, is however particularly suitable, for example for the packaging of liquids, such as still water anywhere on the planet, in particular in markets where the appearance of the container is not essential.
• a limited number of injection parameters are controlled, which makes it possible to obtain containers in the form of an elongated bubble with an indeterminate although sufficiently significant volume.
• the method consists in controlling at least one fluid injection parameter so that the final internal volume of the container is within a predetermined range with respect to a reference volume.
• the method consists in controlling at least one parameter for injecting the fluid, taking into account the temperature of said zones of the preform.
• a controlled parameter is the pressure of the fluid injected inside the preform
• a controlled parameter is the flow rate of the fluid injected inside the preform.
• the pressure is variable during the injection; in an implementation, it consists in starting the injection with a pressure higher than that in. end of injection, and the initial pressure and flow of fluid are controlled to prevent the material of the preform, therefore that of the container, from freezing before obtaining the desired expansion, and the pressure at the end of injection is reduced to prevent material from bursting.
• a controlled parameter is the temperature of the fluid.
• the parameters of injection of the fluid are controlled so that the stopping of the expansion is naturally caused by freezing of the material constituting the preform when the expansion becomes significant, so that when the material is frozen the reaction forces exerted by the material oppose those exerted by the fluid; in a variant, the parameters of injection of the fluid are controlled so that the stopping of the expansion is naturally caused by freezing of the material constituting the preform when the expansion is such that the final internal volume of the container is included in a predetermined range with respect to a reference volume, so that when the material is frozen the reaction forces exerted by the material oppose those exerted by the fluid.
• the fluid consists in stopping the injection of fluid after a predetermined time; the fluid is introduced into a capacity prior to its injection and transferred into the preform in order to cause its expansion; the fluid is a gas; the container being intended to be filled with a liquid after its manufacture, it consists: firstly in causing the preform to expand using a gas, then, while maintaining a pressure residual gas inside the container when it is formed, immediately fill the container with a liquid subjected to a gas pressure at least equivalent to the residual pressure in the container.
• the fluid is a liquid; in one implementation, the container being intended to be filled with a liquid, it consists in using said liquid to cause the expansion of the preform in order to conform it into a container, during the filling phase of the container which thus constitutes its manufacturing phase; in one implementation, it consists in introducing into a capacity a volume of liquid corresponding to that desired in the container, and in predetermining injection parameters of said liquid to allow that all of the liquid contained in said capacity is introduced into the preform during its expansion in order to reach the final container.
• This characteristic is particularly advantageous, since the formation and filling of the container are carried out in a single step.
• to vary the shape of the containers from one manufacture to another it consists in modifying the heating profile of said zones of container preforms during their thermal conditioning.
• the invention is therefore not limited to obtaining containers having an elementary shape of elongated bubble, but it allows, to a certain extent, to obtain variations around this shape.
• a container manufacturing installation comprising a thermal conditioning unit for at least certain areas of a preform and an expansion unit with at least one device for expanding said preform, which device for expanding is associated with a source of fluid to cause the expansion of the preform by injection of said fluid, and comprises means for sealingly insulating the interior of the preform from the outside environment, and means for communicating the interior of the preform with said source of fluid for causing the expansion of the preform, is characterized in that the expansion unit is a free expansion unit of at least some of said areas of the preform, and comprises means for controlling at least one parameter for injecting the fluid in order to control the expansion of the preform with a view to arriving at the final container.
• FIG. 2 a view schematically illustrating a preform with a non-homogeneous heating profile and a corresponding container that it is possible to obtain by implementing the method of the invention
• FIG. 3 a block diagram of an annex device for conforming the bottom of the containers obtained by the implementation of the invention
• - Figure 4 a block diagram of a variant of the device of Figure 3
• Figure 5 a block diagram of a container manufacturing installation according to the invention
• FIG. 1 shows a first type of container 1 which the invention makes it possible to obtain, by carrying out a free expansion of the body 2 of a preform 3, thermally conditioned according to a relatively homogeneous heating profile, above of the glass transition temperature of the material making up the preform 3.
• the heating profile must be such that the temperature of the body 2 is around 120 ° C.
• homogeneous profile it is meant without abrupt temperature variation from one zone to another of the body of the preform.
• the container 1 of FIG. 1 has a body 4, in the general shape of an elongated bubble, which body 4 of the container T is obtained from the material constituting the body 2 of the preform 3.
• the container 1 also has a neck 5 of same as a collar 6 marking the limit between the collar
• the neck 5 and the collar 6 of the container 1 are elements which are present on the preform 3 and are not modified during the formation of the container 1.
• the neck 5 and the collar 6 of the preform 3 are not heated during thermal conditioning, or are very slightly heated.
• the thermal conditioning process implemented to obtain such a container 1 with a body 4 in the form of an elongated bubble can be perfectly conventional: it can consist, for example, of passing the preform in front of an appropriate radiation source, such as an assembly infrared radiation lamps and reflectors, by rotating it about its longitudinal axis.
• an appropriate radiation source such as an assembly infrared radiation lamps and reflectors
• the invention is not limited to the production of containers in the form of an elongated bubble.
• Figure 2 there is shown a second type of container 7 which it is possible to obtain.
• the container 7 has a biobobed body, with three parts, one upper 8, the other lower 9, and a central part 10 with an average diameter smaller than that of parts 8, 9, and separating the latter.
• This container 7 can be obtained by heating various annular zones of a preform 1 1 differently: a central annular zone 1 2 of the preform 1 1 is heated to a temperature lower than that of the other upper annular zones 1 3 and lower 14.
• the container 7 ultimately has the central part 1 0 with an average diameter smaller than that of the parts 8, 9, which central part 1 0 is formed with the material of the central annular zone 12 of the preform 1 1, and the upper 8 and lower parts 9 of the container are made respectively with the material of the upper annular zones 1 3 and lower 14 of the preform 1 1.
• the preform 1 1 and the container 7 also have a neck 1 5 and a collar 1 6.
• An implementation device making it possible to obtain such a container 7 may comprise, for differently heating various zones of the preform, a conditioning unit with radiation lamps infrared and facing reflectors, such as that which appears in FIG. 1 of the document FR-A-2 703 944 mentioned above.
• a conditioning unit with radiation lamps infrared and facing reflectors such as that which appears in FIG. 1 of the document FR-A-2 703 944 mentioned above.
• With such a unit in order to heat the central annular zone 12 less than the upper 13 and lower 14 zones of the preform, it suffices for example to apply less power to the lamps opposite the zone 12 of the preform.
• FIG. 1 3 of the same document FR-A- 2 703 944 that is to say employing reflectors with non-reflecting zones opposite the central annular zone 1 2.
• a heating method as described above makes it possible to obtain containers in the form of a bilobed bubble in which each section perpendicular to the longitudinal axis of the container is substantially circular.
• the number of lobes could be greater than two, by adapting the heating profiles.
• controllable parameters are the fluid pressure, its flow rate, its temperature and the total volume of injected fluid.
• the total volume of injected fluid can be controlled differently, depending on whether this fluid is a liquid or a gas: for example, when the fluid is a liquid, it is possible to fill a capacity with a volume of fluid 40 corresponding to the volume of the container to be obtained, and then to empty the capacity in the preform to cause its expansion; it is also possible to inject liquid directly into the preform while measuring the quantity injected, for example using a flow meter, then to stop the injection after a time such that the volume injected corresponds to the desired volume; when the liquid is a gas, knowledge of the pressure, flow rate and injection time makes it possible to calculate the volume of the container.
• the material constituting the preform tends to cool and to freeze so that the material becomes less and less malleable. It is therefore necessary to adapt the parameters so that the material is not frozen before a sufficient volume is reached.
• the method of the invention makes it possible to obtain containers in the form of an elongated bubble or containers with lobes, that is to say, more generally, containers with rounded shapes.
• the seating area 1 7 of a container 1 8 is centered around the longitudinal axis 1 9 of the container 1 8. It is produced by causing a support, against an element 20, of the zone 21 of the end of the container, that is to say the zone which is centered around said longitudinal axis 1 9 and which has an outward convexity (visible on the left-hand side of FIG. 3) before the formation of the seating area. Under the effect of the pressure exerted when the element 20 is pressed, the end zone 21 turns over, as visible on the right part of FIG. 3, so that a zone appears at this location. 22 with a concavity facing outwards, the periphery of this area 22 constituting the seating area 1 7.
• the support is obtained by causing a relative approximation between the container 1 8 and the element 20, which is illustrated by the double arrow 23.
• the element 20 has a flat bearing surface.
• the realization of a zone 1 7 sitting on a container 1 8 is obtained by using a member 24 which has a bearing surface with a protrusion 25, to favor the reversal of the zone of the container where the bearing surface 1 7 is to be made.
• the protuberance 25 is of frustoconical shape.
• the member 20 or 24 for producing the seating areas can be associated with the container filling machine. However, in this case, to avoid loss of liquid during the formation of said zones, it is desirable to take into account the reduction in the internal volume of the container which occurs during the inversion of the support zone.
• the container previously filled to a standard level 26 compared to conventional filling techniques, is maintained during the formation of the support zone under the filling head 27, which is arranged so that, during the formation of the support zone, the liquid which is in excess due to the reduction in internal volume can start again (arrow 28) through the filling head.
• This implementation is particularly advantageous since it is independent both of the initial volume (when it is still in the form of a bubble) and of the final volume (after formation of the seating area) of the container.
• the container is initially filled with a lower volume of liquid, as account is taken of the reduction in internal volume; in a variant, an oversized free volume is left, and a leveling is carried out after the formation of the seating area.
• a leveling is carried out after the formation of the seating area.
• FIG. 5 The block diagram of an installation for implementing the invention appears in FIG. 5.
• the installation is conventional, that is to say that it includes a unit 29 for thermal conditioning of the preforms 30, associated with a unit 31 for the expansion of the preforms.
• the thermal conditioning unit 29 is constituted in a known manner. It includes heating elements with lamps 32 and reflectors 33, for example formed in accordance with FIG. 1 of document FR-A-2 703 944, and / or one or other of its variants of FIGS. 4 to 1 1, and / or to that of FIG. 1 3. Furthermore, preferably, the thermal conditioning unit 29 includes means for protecting the neck of the preforms 30 (not visible in the figure) to prevent the necks from heating up.
• the thermal conditioning unit 29 also includes a device 34 for driving the preforms, such as an endless chain provided with individual members 35 suitable for transporting and each driving a preform supported by its neck between the lamps and the reflectors. The individual members 35 of the device 34 are moreover arranged so that, when they travel, the preforms 30 are rotated on themselves to allow correct reheating of the periphery of their body.
• the expansion unit 31 comprises a fluid injection system, with at least one head 36 for injecting the fluid, which is connected by a conduit 37 to an assembly 38 for supplying the fluid and controlling its injection. . More detailed block diagrams of various variants of the injection system are shown in Figures 6 to 11.
• the expansion unit 31 comprises several injection heads 36 which are arranged, for example, on a rotating structure (carousel) materialized by the arrow 39, and which are each connected by a respective conduit 37 to the assembly 38 for supplying the fluid and for controlling its injection.
• This arrangement makes it possible to reach high production rates for containers
• the head or each head 36 for injection is arranged to be associated with a preform during the step of -.onformation container, 'that is to say during the injection of fluid, and isolating, so sealed, the interior of the preform of the external atmosphere during this step, so as to prevent the fluid supplied by the respective conduit 37 in the preform via the head from escaping towards the outside during of his injection.
• means for controlling the temperature of the preforms such as sensors (not shown) are arranged in the installation in order to provide real information at this temperature to the assembly 38 for supplying the fluid and controlling its injection, so that, if necessary, this temperature can be taken into account by said assembly 38, in order to control the injection.
• the preforms 30 are successively introduced (arrow 40) into the thermal conditioning unit 29, where they are individually gripped by a member 35 and they are driven, in the direction of arrows 4, 42 at through reheating elements 32, 33. At the end of their journey in the conditioning unit 29, they are unloaded individually, then taken up and transferred (arrow 43) by a transfer device, not shown, to the unit 31 expansion.
• each preform 30 is placed, in a sealed manner, opposite a head 36 of the expansion unit, and fluid is injected under predetermined conditions inside, in order to form the containers 44 which are then discharged (arrow 45) from the installation.
• FIG. 5 The expansion of the preforms has been schematically represented in this FIG. 5: there is a progressive increase in the diameter of the object (initially preform 30, then container 44) associated with the injection heads 36.
• FIGS. 6 and 7 two variants of a fluid injection system are illustrated with an assembly 38 for supplying the fluid under pressure and for controlling its injection. These two variants, which have a minimal difference between them, each allow the use of gas or liquid as expansion fluid; they also allow a control of all or part of the parameters (flow rate and / or pressure and / or quantity and / or time and / or temperature of the fluid relative to that of the preform).
• the fluid injection system illustrated in these Figures 6 and 7 comprises three injection heads 361, 362, 363 associated with the assembly 38 for supplying the fluid and controlling its injection. It is understood that the number of heads could be different.
• Each head 361, 362, 363 is associated with a respective valve 461, 462, 463 with remote opening and closing control (such as an electric or pneumatic control).
• the remote control of the valves is carried out from a unit 47 for managing the operation of the injection system.
• this unit 47 is shown as an integral part of the assembly 38 for supplying the fluid and controlling its injection.
• Each valve can be all-or-nothing (single flow) or proportional (variable flow) control.
• Each valve 461, 462, 463 is also interposed between its respective associated head 361, 362, 363 and a conduit 48 for supplying pressurized fluid.
• the three assemblies each consisting of a valve and the respective associated head are therefore mounted in parallel on the conduit 48, so that, when a valve is open, in response to the appropriate command from the management unit 47, of the fluid can travel in the direction of the respective associated head.
• a head 361 is free, while a preform 30 is disposed under the head 362, ready to be transformed into a container, and a container 44 formed is under the head 363, ready to be removed.
• the difference between the variants of FIGS. 6 and 7 resides in the fact that, in the system of FIG. 6, the pressurization of the fluid is carried out outside the assembly 38 (therefore for example next to or at some distance from the expansion unit 31 of FIG. 5) and the conduit 48 for supplying pressurized fluid is a conduit entering the assembly 38, while, in the system of FIG. 7, the pressurization of the fluid is carried out inside the assembly 38 (therefore for example inside the expansion unit 31 of FIG. 5) and the duct 48 for supplying pressurized fluid is a duct internal to the '' together 38.
• the pressurization is carried out using a pressurizing device 49 suitable for the fluid used (compressor, booster pump, pump, etc.), which device 49 is preferably connected to the management unit 47 : thus, it is possible to act on the pressure and / or the flow leaving this device 49.
• a pressurizing device 49 suitable for the fluid used compressor, booster pump, pump, etc.
• the device 49 for pressurization external to the assembly 38, is supplied by a conduit 50 also external, and discharges the fluid towards the conduit 48.
• the device 49 for pressurizing is internal to the assembly 38; it delivers the fluid to the conduit 48 and is supplied by a conduit 50 entering the assembly 38.
• FIGS. 6 and 7 make it possible to use, as fluid for causing the expansion, the liquid intended to serve as final content for the container.
• the use of a fluid is very particularly possible in the case of hot filling of containers (temperature close to the glass transition temperature of the preform material), since the temperature of the liquid prevents too rapid freezing of matter.
• FIG. 8 presents an arrangement which makes it possible to cause the expansion of the preforms with a gas and to fill the containers immediately after expansion, without waiting for the material to freeze, so that the cycle of formation and filling of a container can be optimized.
• This arrangement comprises means for causing the preform to expand using a gas, means for maintaining a residual pressure of gas inside the container when the latter is formed, and means for immediately filling the container using a liquid subjected to a gas pressure at least equivalent to the residual pressure in the container.
• maintaining a residual pressure in the container prevents shrinkage of the material; subjecting the liquid to a gas pressure at least equivalent (therefore greater than or equal) to the residual pressure in the container allows filling by gravity, since the internal pressure of the container does not prevent the arrival of the liquid.
• the arrangement of FIG. 8 uses the principle and the arrangements implemented in the fillers for carbonated or carbonated drinks, by taking advantage of the gasification or carbonation phase of the container, prior to its filling, to cause expansion.
• the injection system of FIG. 8, illustrated in the example for the distribution of fluid in the direction of two heads 364, 365, comprises an assembly 38 for supplying the fluid under pressure and for controlling its injection.
• a tank 51 in which there is liquid 52, surmounted by a free space 53 with gas under pressure.
• the gas can be compressed air or any other gas, in particular a gas useful for conditioning the liquid (carbon dioxide in the case where the liquid is a carbonated drink for example).
• the free space 53 of the top of the tank 51 is placed in communication with a device 490 suitable for carrying out the pressurization and / or maintenance of the gas pressure inside this free space 53.
• the device 490 can for example be a compressor or a device for supplying the gas useful for conditioning the liquid.
• the liquid 52 is brought into the tank 51 by a conduit 54 provided with a non-return mechanism 55, to prevent the gas under pressure in the tank from escaping.
• this free space 53 is moreover placed in communication with the heads 364, 365, by means of respective conduits 564, 565, in each of which is interposed a valve 464, 465 with remote opening and closing control.
• the remote control of the valves is carried out from a unit 47 for managing the operation of the injection system.
• Each valve can be all-or-nothing (single flow) or proportional (variable flow) control.
• the bottom of the tank 51 is placed in communication with the heads 364, 365, thanks to. respective conduits 574, 575 in each of which is inserted another valve
• valves can also be single or variable flow.
• the opening and closing control, both of the valves 464, 465 for supplying gas into the heads and those 584, 585 for supplying the liquid are provided by a unit 47 for managing the operation of the injection system; the management unit is also connected to the device 490 suitable for carrying out the pressurization and / or maintenance of the gas pressure inside the free space 53 of the tank 51.
• the operation of the device is as follows.
• the valves 464, 465 for supplying gas to the heads and those 584, 585 for supplying the liquid are placed in the closed position by the management unit 47 the operation of the injection system.
• the valve 464 corresponding for the gas supply is opened by the management unit 47, gt the expansion of the preform is caused.
• the corresponding valve 584 for supplying the liquid is open, so that the liquid arrives by gravity into the container. In known manner, the filling must be accompanied by an evacuation of the gas contained in the container.
• the evacuation occurs without the pressure in the container falling too much;
• the pressure in the container should not decrease too much during the evacuation accompanying the filling.
• the evacuation does not disturb the arrival of liquid, and is carried out by a circuit separate from that of liquid arrival.
• the evacuation is carried out directly towards the tank, by the air intake circuit itself, so that the overall pressure of the fluid circuit incorporating the tank and the container does not change not during filling, and only fluid transfers (gas, then liquid) are carried out at constant pressure, which also makes it possible to maintain a suitable gas pressure in the container, if necessary.
• the valve 464 for the gas inlet is not closed by the management unit 47, and the two valves are only closed again. after completion of filling.
• the evacuation is carried out directly towards the tank, however by a dedicated circuit, which may include gas filtration means.
• I t is however conceivable to start filling by evacuating the gas towards the tank and to finish it by evacuating the gas towards the outside (return to atmospheric pressure), to further reduce the duration of the filling cycle: in fact, the filling liquid, when it is brought to a temperature below the glass transition temperature of the material constituting the container, contributes to freeze the material when it enters the container. Therefore, after the filling has started and the material has become frozen, it becomes possible to reduce the pressure in the container to the level of the external pressure. This is however only possible with flat liquids (water or other) which do not require the maintenance of a gas pressure after filling. It is easily understood that, with the arrangements described with reference to FIGS.
• the management unit 47 in order to more or less precisely control the final volume of a container, the management unit 47 must more or less precisely control the following injection parameters of the fluid (gas or liquid) used to cause the expansion, also taking into account the temperature of the preform at the time when it is brought under a head (or even the temperature of the preform at the outlet of the unit 29 packaging visible in Figure 5): fluid temperature and / or injection pressure and / or flow rate and / or injection time.
• the device management unit 47 of FIGS. 6 to 8 may incorporate devices (not shown) which allow this unit to manage all or part of the various mentioned parameters (flow rate, pressure, temperature of the preforms and / or of the fluid, duration) implemented during the injection.
• the device of FIG. 9 is used, which makes it possible to reduce the number of parameters to be checked, and which is moreover usable for carrying out containers of different volumes.
• This device comprises a cylinder 59 - piston 60 assembly, which determines a chamber constituting a capacity 61 of variable volume, in function of the position of the piston 60 in the cylinder 59.
• the capacity is connected by a conduit 62 to a source of fluid, not shown
• a second conduit 63 connects the capacity to a head 366 for injecting fluid.
• a valve 466 with remote opening and closing control is interposed between the head 366 and the capacity.
• a non-return valve 64 is disposed on the conduit 62 between the source of fluid and the capacity.
• the operation of the device is as follows: the piston 60 is placed in a determined position in the cylinder 59, so that the capacity 61 has an initial volume; then fluid (liquid or gas) is introduced (arrow 620) into the capacity 61 through the conduit 62, so as to fill it; the valve 466 is open and the piston 60 is pushed by its actuating rod 65, so as to reduce the volume of the capacity and to inject the fluid towards the head 366.
• the non-return valve 64 opposes the return of the fluid towards the source.
• the final volume of the container will depend not only on the volume initial capacity, but also the initial pressure and temperatures of the fluid and the material of the preform. These various parameters must therefore be taken into account when trying to predetermine the final volume of the containers.
• FIG. 1 0 is illustrated a first alternative embodiment of the device of Figure 9, a fluid injection system with an assembly 38 for supplying the fluid under pressure and for controlling its injection.
• the system shown here for feeding two heads 367, 368, comprises on the one hand a conduit 66 for supplying the fluid to the assembly 38, two devices conforming to that of FIG. 9, which are connected in parallel to the conduit 66, and a management unit 47, for controlling the system.
• each device conforming to that of FIG. 9 comprises a non-return valve 647, 648 between the conduit 66 and its respective capacity 617, 618, and a valve 467, 468 with remote opening and closing control interposed between the head 367, 368 and the capacity 61 7, 61 8 respectively.
• the management unit 47 makes it possible to control the valves 467, 468 and the motor members of the rods 657, 658 for actuating the pistons associated with each capacity, in order to obtain suitable flow rates and / or pressures, taking account of the case if necessary, the temperature of the fluid and the temperature of the preforms, using appropriate sensors, not shown.
• the device of Figure 1 0 allows to use either gas or liquid as injection fluid.
• Figure 1 1 is illustrated an improved variant of the invention, which implements the device of Figure 9 on a system similar to that of Figure 8, so that the same elements have the same references.
• valve 644, 645 with remote opening and closing control is positioned upstream of the respective capacity, therefore between the free space 53 of the top of the tank 51 and the respective capacity, which valve 644,
• the remote control of all of the valves is connected to a unit 47 for managing the operation of the injection system; so are even the driving members of the rods 654, 655 for actuating the pistons associated with each capacity.
• this capacity 61 4, 61 5 is initially filled with an initial volume of gas under pressure, corresponding to that of the gas contained in the free space 53 of the top of the tank 51 , and the movement of the piston to transfer the gas to the respective associated head 364, 365 increases the pressure.
• valves 584, 585 for supplying liquid and 464, 465 for supplying air are put in the closed position by the management unit 47;
• the piston is positioned in the chamber to determine a capacity 61 4 of predetermined volume (taking into account the temperatures of the fluid, and / or the material, and the desired final volume); and gas contained in the free space 53 of the top of the tank 51, enters the capacity 614, through the valve 644 which is open;
• this valve 644 is closed; the valve 464 interposed between the capacity 614 and the corresponding head 364 is opened, and the piston is pushed (actuator 654) so as to reduce the volume of the capacity and entrain the fluid in the container, to cause its expansion.
• the filling cycle corresponds to that of FIG. 8.
• the filling must be accompanied by an evacuation of the gas contained in the container without the pressure in the container falling too much and without it disturbing the arrival of liquid.
• the evacuation can be carried out directly towards the tank, by the air intake circuit itself, so that the overall pressure of the fluid circuit incorporating the tank and the container does not change not during filling.
• the valve 584 for supplying liquid not only the valve 464 for the gas inlet is not closed by the management unit 47, but the valve 644 upstream of the capacity is again open, to allow the gas to leave towards the free space 53 from the top of the tank 51.
• the filling valve 584 is closed, as is the valve 464 located between the capacity 614 and the head 364; the piston is again positioned in the chamber to determine a capacity 61 4 of predetermined volume, which capacity is filled with gas coming from the free space 53 from the top of the tank 51, and the cycle begins again.

Landscapes

• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
• Basic Packing Technique (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=32406527

Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (46)

Family Cites Families (7)

• 2002
  • 2002-12-23 FR FR0216692A patent/FR2848906B1/fr not_active Expired - Fee Related
• 2003
  • 2003-12-17 KR KR1020057011774A patent/KR20050088465A/ko not_active Application Discontinuation
  • 2003-12-17 AU AU2003300640A patent/AU2003300640A1/en not_active Abandoned
  • 2003-12-17 CN CNA2003801093569A patent/CN1744982A/zh active Pending
  • 2003-12-17 EP EP03815416A patent/EP1587664A1/de not_active Withdrawn
  • 2003-12-17 WO PCT/FR2003/003758 patent/WO2004065105A1/fr active Application Filing
  • 2003-12-17 US US10/540,141 patent/US20060097417A1/en not_active Abandoned
  • 2003-12-17 JP JP2004567014A patent/JP2006511380A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events