Rotary system for simultaneously blowing and filling plastic containers

Abstract

A system and method to produce containers filled with liquid. A thermoplastic material preform is first subjected to thermal conditioning in the area of a heating section along a transport path. The preform is then shaped into the container inside a mold by applying pressure. The liquid with which the container is to be filled is used as the fluid for forming the container.

Claims

1. A system for simultaneously blowing and filling plastic containers from plastic preforms, comprising a rotating apparatus including: a plurality of molds each being configured to receive and enclose a preform; a plurality of stretching members configured to stretch each preform enclosed within a mold from the plurality of molds; a plurality of injectors configured to inject a liquid at a pressure into a preform enclosed within a mold from the plurality of molds so as to cause expansion of the preform within a corresponding mold; and a manifold coupled to each of the injectors to distribute the liquid under pressure to the plurality of injectors, such that the preforms are simultaneously blown and filled by the liquid, the manifold being centrally located within the system between the plurality of molds, the plurality of stretching members and the plurality of injectors and the manifold being rotatable with the rotating apparatus about a central vertical axis of the rotating apparatus; the plurality of molds being spatially arranged around the periphery of the manifold, each mold includes an upper portion provided with an aperture, and wherein each preform having a mouth that is arranged within the aperture when enclosed within the mold, the aperture being centered around a longitudinal axis that is inclined towards the vertical axis; and a pump device configured to supply liquid to the manifold at the pressure to cause expansion of the preform and simultaneous blowing and filling of the container.

2. The system of claim 1, wherein the pump device is a part of the rotating apparatus.

3. The system of claim 1, wherein the pump device is in a fixed position.

4. The system of claim 1, wherein the longitudinal axis is at an angle greater than 0 and less than 90 relative to the vertical axis.

5. The system of claim 1, wherein the manifold surrounds a central zone, the pump device being located in the central zone.

6. The system of claim 1, wherein the manifold has an annular shape.

7. The system of claim 6, wherein the manifold is a toroidal shape.

8. The system of claim 1, wherein the manifold has a cylindrical shape.

9. The system of claim 8, wherein the pump device is located above the manifold.

10. The system of claim 8, wherein the pump device is located below the manifold.

11. The system of claim 1, wherein each injector of the plurality of injectors has a proportional valve to control the volume of liquid injected into the corresponding preform.

12. The system of claim 1, wherein one rotation of the apparatus corresponds to a whole blowing and filing cycle of a preform enclosed within each of the plurality of molds.

13. The system of claim 1, wherein the system has a capacity of simultaneously blowing and filling a number of plastic containers up to 72,000 per hour.

14. A system for simultaneously blowing and filling plastic containers from plastic preforms, comprising a rotating apparatus including: a plurality of molds each being configured to receive and enclose a preform; a plurality of stretching members configured to stretch each preform enclosed within a mold from the plurality of molds; a plurality of injectors configured to inject a liquid at a pressure into a preform enclosed within a mold from the plurality of molds so as to cause expansion of the preform within a corresponding mold; and a manifold coupled to each of the injectors to distribute the liquid under pressure to the plurality of injectors, such that the preforms are simultaneously blown and filled by the liquid, the manifold being rotatable about a central vertical axis, each mold having an upper portion that is provided with an aperture and each preform having a mouth that is arranged within the aperture when enclosed within the mold, the aperture being centered around a longitudinal axis that is inclined towards the vertical axis, the plurality of molds being spatially arranged around the periphery of the manifold; and a pump device configured to supply liquid to the manifold at the pressure to cause expansion of the preform and simultaneous blowing and filling of the container.

15. A system for simultaneously blowing and filling plastic containers from plastic preforms, comprising a rotating apparatus including: a plurality of molds each being configured to receive and enclose a preform; a plurality of stretching members configured to stretch each preform enclosed within a mold from the plurality of molds; a plurality of injectors configured to inject a liquid at a pressure into a preform enclosed within a mold from the plurality of molds so as to cause expansion of the preform within a corresponding mold; and a manifold coupled to each of the injectors to distribute the liquid under pressure to the plurality of injectors, such that the preforms are simultaneously blown and filled by the liquid; a pump device configured to supply liquid to the manifold at the pressure to cause expansion of the preform and simultaneous blowing and filling of the container; and wherein the apparatus defines a central axis, and a longitudinal axis through an aperture of each mold to receive each preform is inclined relative to the central axis.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

(2) FIG. 1 is a schematic side view illustrating a system for simultaneously blowing and filling containers according to the invention and its main components;

(3) FIG. 2A is a very schematic overview of FIG. 1 system illustrating the whole blowing, filling and capping cycle;

(4) FIG. 2B is a schematic top view of the system of FIG. 2A representing a plurality of peripheral stations around a central manifold of the system;

(5) FIG. 3 is another arrangement of FIG. 1 system.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(6) FIG. 1 schematically represents a system 10 for simultaneously blowing and filling plastic containers, such as bottles, from plastic preforms.

(7) System 10 comprises an apparatus 12 that is capable of rotating around a central vertical axis A as indicated by the arrow.

(8) Rotating apparatus 12 includes a plurality of moulds 14a, 14b, . . . , 14n two of which only, 14a and 14b, being illustrated in FIG. 1.

(9) Each mould is a two-part mould which forms an inner cavity 16a, 16b when assembled together.

(10) A preform that is not represented in FIG. 1 is inserted into each cavity at the beginning of the blowing and filling process.

(11) The shape of the cavity corresponds to the shape of the achieved container and it will be wholly occupied by the plastic container at the end of the blowing and filling process.

(12) In the present embodiment the container is a bottle which is filled with water.

(13) However, other containers may be envisaged as well as other liquids.

(14) It is also to be noted that each mould may be alternatively composed of more than two parts depending on the manufacturing process.

(15) Apparatus 12 further includes a plurality of injection means 18a, 18b . . . , 18n two of which only, 18a and 18b, being illustrated in FIG. 1.

(16) These injection means comprise each an injection head which comes into a sealing contact (fluid tightness) with a preform which has been enclosed within a mould.

(17) The injection head includes an injection nozzle that is movable between an injection position allowing liquid to be injected into the preform and a rest position in which the injection nozzle rests against an inner surface of the injection head in a sealing engagement so as to prevent any flow of liquid from the injection head to the preform.

(18) Apparatus 12 also includes stretching means 20a, 20b, . . . , 20n, only two of them, 20a and 20b, being illustrated in FIG. 1.

(19) Each stretching means comprises a stretching rod which is in a sliding connection with the corresponding injection nozzle. Each stretching means is actuated upon command to be inserted into a preform so as to stretch it while a liquid is injected into the preform so as to cause expansion of said preform within the corresponding mould.

(20) Actuation means for actuating the rods of the stretching means have not been represented in the drawings for the sake of clarity.

(21) Apparatus 12 further includes a liquid distributing unit or manifold 22 which is centrally located in the system with respect to the plurality of moulds, injection means, and stretching means.

(22) For instance, vertical axis A is a symmetry axis to manifold 22.

(23) Manifold 22 is operable to distribute a liquid under pressure to the plurality of injection means 18a, 18b, . . . , 18n such that the preforms enclosed within the moulds are simultaneously blown and filled by said liquid together with the action of the stretching means.

(24) As represented in FIG. 1, each injection means 18a, 18b (and more generally all the injection means up to 18n) is connected to an outlet to rotating manifold 22 through a fluid line or pipe 24a and 24b respectively. The plurality of fluid lines (fluidic connections) 24a, b, . . . n are radially arranged as illustrated in FIG. 2B embodiment.

(25) For example, manifold 22 comprises one or several liquid inputs and, internally, is empty so as to make its cleaning easier. Manifold 22 further comprises several outlets that are connected to the corresponding fluid lines or pipes respectively.

(26) A flow valve 26a and 28b is respectively mounted on the corresponding fluid line so as to control the flow of liquid between manifold 22 and injection means 28a and b respectively.

(27) This flow valve is for instance a proportional valve.

(28) Such a valve allows the flow of liquid to be accurately controlled and therefore, the liquid filling curve (when filling the container together with its blowing) to be adjusted so as to correspond to a given curve.

(29) Optionally, a corresponding flow meter 28a, 28b, . . . , 28n is respectively associated with the corresponding valve 26a, 26b, . . . 26n so as to measure a flow rate or volume of flowing liquid between manifold 22 and the corresponding injection means.

(30) The whole connection between each injection means and the manifold rotates together with these components.

(31) Liquid to be distributed and injected is supplied from a source of liquid S which feeds said liquid to a pump device 30.

(32) Pump device 30 therefore supplies pressurized liquid to rotating manifold 22.

(33) In the present embodiment, pump device 30 is also part of the rotating apparatus 12.

(34) More particularly, pump device 30 is operatively connected to manifold 22 in a conventional manner.

(35) It is to be noted that a flow valve 32 is mounted in parallel to pump device 30 as a safety valve.

(36) This valve acts as a discharge valve in order to protect the pump device, for instance when the pressure is building up or if there is no fluid flow to supply when no bottle is being manufactured).

(37) Pump device 30 may be centrally located, e.g. in a position that is aligned with vertical axis A.

(38) Such an arrangement makes it possible to provide whole system 10 with a more compact design. This arrangement is also easier to conceive since the pump device is centered around the rotating axis of the system.

(39) However, other arrangements of the system may be envisaged, in particular with a pump device laterally offset with respect rotating axis A.

(40) As represented in FIG. 1, pump device 30 is located above manifold 22.

(41) However, in a alternative arrangement, pump device may be located under manifold 22.

(42) In the present embodiment manifold 22 is cylindrical in shape.

(43) However, other shapes may be alternatively envisaged for distributing liquid to the injection means of the system.

(44) It is to be noted that the different rotating parts of the system may be supported by a common rotating plate.

(45) It will be appreciated that each mould enclosing a preform and its corresponding injection means and stretching means forms a station and all these stations are spatially arranged around the manifold as schematically represented in FIG. 2B.

(46) FIG. 2A is a schematic partial view of the system 10 according to the invention and showing the different operations performed at each station during a whole manufacturing cycle of a container.

(47) This cycle includes blowing, filling and capping phases.

(48) During the whole manufacturing cycle each station is subject to the above-described phases.

(49) As represented in FIG. 2A, manifold 22 of system 10 is very schematically represented in the central position and different stages of the manufacturing cycle are schematically represented at the periphery of manifold 22 and indicated by references 40, 42, 44 and 46.

(50) Stage indicated by reference 40 represents a preform 48 positioned or enclosed within a mould 50 according to a known manner. Plastic preform 48 has been firstly manufactured through a known moulding process and then heated before been positioned within mould 50.

(51) The preform usually assumes the shape of a cylindrical tube closed at its bottom end 48a and open at its opposite upper end 48b.

(52) Once preform 48 has been positioned within mould 50 only the open end 48b of the preform is visible from above the mould.

(53) Stage 40 of the process takes place at a station that is represented by position P1.

(54) Position P1 is disposed on a circle C which schematically represents the peripheral line or circumference on which the different stations of the system are spatially arranged around the periphery of manifold 22.

(55) Stage 42 illustrates a stage or step of the process which makes use of a stretch rod 52. Stretch rod 52 is actuated to be downwardly engaged into open end 48b of the preform so as to come into contact with the closed bottom end 48a thereof.

(56) As represented at stage 42, stretch rod 52 is then further actuated to push the closed end 48a downwardly and stretch the preform accordingly in a controlled manner.

(57) At stage 42 the stretching process is in progress.

(58) After the stretching phase has been initiated liquid is injected into the preform through its open end 48b, while the stretch rod is still being actuated.

(59) This liquid injection causes expansion of the preform together with the movement of the stretch rod until coming into contact with the inner walls of the cavity of the mould, thereby achieving the final shape of the container.

(60) Injection of liquid is schematically represented at next stage 44 by arrow 54.

(61) A position denoted P2 illustrates the position occupied by a station in which the blowing and filling process is achieved. At position P2, the container in each station has been blown and filled with liquid.

(62) The blowing and filling process takes place between position P1 and position P2 along the peripheral line C.

(63) The different stations which are arranged between position P1 and P2 undergo the blowing and filling process which has been described above.

(64) The different stations of the system which are distributed along peripheral line C between position P2 and P3 (second working zone; the first working zone being situated between P1 and P2) are submitted to a capping process.

(65) A cap distributing unit or cap distributor 56 is laterally offset with respect to the plurality of stations disposed along peripheral line C and is more particularly tangent to peripheral line C.

(66) Cap distributor 56 includes a plurality of caps 58 which are disposed at the periphery thereof and spaced from each other.

(67) More particularly, cap distributor 56 takes the shape of a rotating device comprising a circular support 60 viewed from the above this support a substantially cylindrical shape in 3D).

(68) Cap distributor 56 further comprises a plurality of housings which are regularly spatially arranged around the periphery of support 62 in a manner which may be different from that illustrated in FIG. 2A.

(69) As schematically represented in FIG. 2A, cap distributor 56 further comprises a central element 64 which accommodates the plurality of caps 58 thanks to a plurality of recesses or housings 66 disposed at its periphery.

(70) More particularly, the peripheral zone of central element 64 may be scalloped so as to be formed by a succession of protuberances and cavities in which the caps are housed.

(71) Central element 64 is fixed on support 62.

(72) In this embodiment, the whole cap distributor rotates around its central axis 68.

(73) However, in an alternative embodiment, only the central element 64 may be rotatable whereas support 62 remains in a fixed position.

(74) Thus, the successive caps 58 are successively distributed to the different stations passing by cap distributor during rotation of system 10.

(75) Although not represented in FIG. 2A, means for supplying caps to cap distributor 56 are provided in this embodiment in order to load cap distributor 56 with new caps.

(76) The caps 58 which have been distributed to each station passing by cap distributor 56 are then positioned above and around the necks of the containers respectively and capped thereon in a conventional manner. For the sake of clarity conventional capping means are not represented in the drawings.

(77) For instance, the caps are screwed around the threaded neck of each container.

(78) This capping process takes place between the position P3 on peripheral line C that is located vis--vis cap distributor 56 and position P4.

(79) At position P4, cap 58 has been fixed on the dispensing opening of container 70 (here, the container is a bottle). This position corresponds to a stage 46 of the process.

(80) Positions P1 and P4 straddle a third working zone in which the moulds of the different stations enclosing a capped and filled container are opened so that the container can be removed before welcoming a new preform at position P1 (stage 40).

(81) It is to be noted that when the apparatus rotates liquid is supplied to manifold 22 through pump device 30 and to the different fluid lines or pipes connected thereto. The different valves 26 may isolate the part of the lines connected to the injection means from the manifold upon command. Thus, a central processing unit (not represented) that controls the whole manufacturing cycle (in particular, the simultaneous blowing and filling process) may send control commands to shut off the valves 96 which are not timely concerned with liquid filling and open those which have been previously closed and are now involved in the filling process.

(82) FIG. 2B is a very schematic top view of a system 80 according to a further embodiment of the invention.

(83) System 80 comprises a plurality of stations 90 which each include a mould 92 enclosing a preform or a container according to the stage of the manufacturing process (blowing, filling and capping).

(84) Each station further includes stretching means for stretching the preform enclosed within the mould. Such stretching means are not represented in FIG. 2B for the sake of clarity.

(85) Each station includes injection means referred to as 94 that is connected through a fluid line 96 incorporating a flow valve 98 to a rotating central manifold 100.

(86) Rotating manifold 100 distributes liquid to each of the above-described station.

(87) Different stations are spatially arranged around the periphery of manifold 100.

(88) Manifold 100 is annular in shape and surrounds a central zone in which a pump device 102 is located. A source of fluid that feeds liquid to pump device 102 is not represented in this drawing.

(89) In the present embodiment, pump device 102 also rotates together with manifold 100 and has suitable fluidic connection therewith.

(90) As represented in FIG. 2B, pump device 102 has several radially extending arms, e.g. three denoted 102a, 102b and 102c which are connected on one end to the pump device and on the other end to an inlet to manifold 100. It is to be noted that several fluid inputs are used instead of a single one in order not to favour a distribution path to a given blowing and filling station.

(91) Liquid is being sent under pressure by pump device 102 to manifold 100 as indicated by the radial arrows. It is more particularly fed to the empty inner space within manifold 100, through a regular spatial arrangement of the inlets and then distributed to the different fluid lines 96 connected to each station. Flow valves 98 act as flow valves 26a, b, . . . n in FIG. 1 and control the flow of liquid from manifold 100 to each injection means according to the stage of the process. For example, valves 98 are commanded to open when the filling stage is being performed.

(92) Only a few stations 90 have been represented in FIG. 2B at different stages of the whole blowing, filling and capping process.

(93) The angular position of each stage represented in FIG. 2A is the same in FIG. 2B.

(94) After position P4, next station illustrates the opening of mould 90 for successively removing and ejecting the blown, filled and capped container and introducing therein a new preform.

(95) System 80 also comprises a cap distributor as in FIG. 2A but which has not been represented here for the sake of clarity.

(96) It is to be noted that this cap distributor does not rotate together with the rotating parts of system 80 but only rotates around its own axis.

(97) However, in a variant embodiment, cap distributor may be part of the rotating apparatus in the system.

(98) FIG. 3 illustrates another embodiment of a system 120 according to the invention.

(99) System 120 comprises the same components as those illustrated in FIG. 1. Although for each piece of equipment references a and b have been used (e.g. 14a and b, 26a and b, etc), it is to be understood that the system also includes references a to n.

(100) For the sake of easiness all the different components of system 120 bear the same references as those of system 10 in FIG. 1.

(101) The different features and advantages set out as regards system 10 are the same for system 120 in FIG. 3 and therefore will not be repeated.

(102) The difference between system 120 and system 10 resides in that the plurality of stations are inclined relative to central vertical axis A around which the whole system rotates, whereas in FIG. 1 the different stations extend each along an axis that is parallel to axis A.

(103) More particularly, in FIG. 3 each mould 14a, 14b extends in a longitudinal direction that is in alignment with longitudinal axis a, b respectively.

(104) All the other stations not represented in this drawing have the same orientation.

(105) Mould 14a, 14b has an aperture 15a, 15b that is provided in the upper portion of the mould.

(106) A preform with a mouth that is not represented in FIG. 3 is to be inserted inside the mould and more particularly through aperture 15a, 15b so that the preform mouth protrudes from the mould.

(107) Aperture 15a, 15b is respectively centered around longitudinal axis a, b that is inclined towards central vertical axis A.

(108) More particularly, longitudinal axis a, b is at an angle relative to the vertical axis that lies between 0 and 90 and that is, for instance, 45.

(109) This inclination towards central vertical axis A makes it possible to avoid splashing of the liquid all around the container during the rotation of the whole system thanks to centrifugal forces exerted on the liquid in motion.

(110) It is to be noted that the angle of inclination has to be appropriately selected according to the speed of rotation of the system and its diameter. Put it another way, the angle depends on the tangential speed of rotation of the stations.

(111) A system according to the present invention has a capacity of simultaneously blowing and filling a number of plastic containers up to 72,000 per hour.

(112) It is to be noted that the capping process is also included in this high throughput.