PREFORM DECONTAMINATION DEVICE

Abstract

The invention relates to a device (54) for decontaminating preforms (12) comprising: - a device (22) for conveying preforms (12) by their neck (16); - a confinement tunnel (56); - at least one chamber (68) adjacent to the tunnel (56) supplied with decontamination agent; - at least one partition (60) which separates the chamber (68) and the tunnel (56), the partition (60) being pierced with orifices (72) for diffusing the decontamination agent; characterized in that it comprises closure means (74) controlled between an extreme closure position in which they selectively close diffusion orifices (72) located above a minimum height (Hmin) and an extreme open position in which the diffusion orifices (72) located below the maximum height (Hmax) are open. Figure for abstract: Figure 3

Description

Title of the invention: PREFORM DECONTAMINATION DEVICE Technical field of the invention

[0001] The invention relates to a device for decontaminating preforms, in particular made of thermoplastic material, each preform having a vertical main axis, the device being suitable for preforms of different lengths up to a maximum length, the device comprising:

[0002] - a preform conveying device equipped with gripping members on each preform by a neck running longitudinally along a determined path;

[0003] - a confinement tunnel crossed by a section of the determined route;

[0004] - at least one chamber adjacent to the tunnel supplied with decontamination agent;

[0005] - at least one vertical partition parallel to the path which separates the chamber and the tunnel, the partition being pierced with diffusion orifices for the decontamination agent in the tunnel, the diffusion orifices being distributed from orifices extending at the level of the gripping members to orifices extending at a maximum height located at the level of an upper end of a preform of maximum length carried by a gripping member. Technical background

[0006] The manufacture of thermoplastic containers, such as bottles, flasks, etc., is generally carried out from preforms, sometimes called blanks, which are introduced into a molding device with which forming means are associated, for example blowing or stretch-blow molding.

[0007] Traditionally in this technical field, the preform and the finished container have an identical neck or neck. Therefore, the same member for gripping a preform by its neck is also suitable for gripping a finished container obtained from said preform.

[0008] Before being shaped into final containers, the preforms undergo several treatments along a scroll path. The preforms can thus undergo a heating treatment, a sterilization treatment and forming.

[0009] The container manufacturing facility is supplied with preforms that are not in a condition to be directly formed. Prior to their blow molding or stretch blow molding, the preforms are therefore heated in a heating station so as to give their body a consistency that is sufficiently malleable for the blow molding operation.

[0010] Such large-scale container manufacturing facilities are equipped with a heating station comprising at least one heating zone equipped with means for heating the preforms. The preforms are generally conveyed along the heating zone at high speed without stopping by a conveying device. The heating zone has a sufficient length to allow the preforms to be heated as they pass through.

[0011] The conveying device comprises individual gripping members of preforms that travel along a loop path, one section of which conveys the preforms along the heating tunnel. The gripping members are generally formed by mandrels which are capable of driving the conveyed preform in rotation around its axis to ensure uniform heating of the preform.

[0012] It is known to decontaminate preforms before they pass through the heating zones by exposing them to a decontamination agent in the gaseous state or in the mist state. Such a decontamination agent is for example formed by hydrogen peroxide.

[0013] To do this, the preforms pass through a decontamination device comprising a containment tunnel into which the decontamination agent is projected.

[0014] Such an installation is intended to produce containers of different dimensions from preforms which may have variable lengths. In particular, it is intended to mass-produce identical containers from batches of identical preforms. When it is desired to produce different containers, the heating station is supplied with preforms from a different batch having suitable dimensions.

[0015] For each operation of changing batches of preforms, it is known to adapt certain equipment of the installation.

[0016] However, the decontamination device is designed to spray the same quantity of decontamination agent into the tunnel regardless of the size of the preforms. However, preforms of reduced dimensions require a smaller quantity of decontamination agent than preforms of larger dimensions. Thus, such a decontamination device results in overconsumption of decontamination agent when the preforms treated are small in size compared to the capacity of the heating station.

[0017] Consequently, only a fraction of the decontamination agent is actually used to decontaminate the preforms, the rest of the decontamination agent is consumed at a loss because it has no significant effect on the preforms.

[0018] This therefore results in unnecessary expenses.

[0019] In addition, the decontamination agent is often toxic to humans. It is It is therefore preferable to carefully target the objects to be decontaminated to prevent too much decontamination agent from escaping into the atmosphere. Summary of the invention

[0020] The invention proposes a device for decontaminating preforms, in particular made of thermoplastic material, each preform having a vertical main axis, the device being suitable for preforms of different lengths up to a maximum length, the device comprising:

[0021] - a preform conveying device equipped with gripping members on each preform by a neck running longitudinally along a determined transport path;

[0022] - a confinement tunnel crossed by a section of the determined transport route;

[0023] - at least one chamber adjacent to the tunnel supplied with decontamination agent;

[0024] - at least one vertical partition parallel to the transport path which separates the chamber and the tunnel, the partition being pierced with orifices for diffusing the decontamination agent into the tunnel, the diffusion orifices being distributed from orifices extending at the level of the gripping members to orifices extending to a maximum height located at the level of an upper end of a preform of maximum length carried by a gripping member;

[0025] characterized in that it comprises closure means controlled between an extreme closure position in which they selectively close diffusion orifices located above a minimum height and an extreme opening position in which the diffusion orifices located below the maximum height are open.

[0026] According to another characteristic of the decontamination device produced according to the teachings of the invention, the controlled closure means are capable of occupying at least one intermediate position in which the diffusion orifices located above a corresponding intermediate height are closed, while the diffusion orifices located below the intermediate height are open.

[0027] According to another characteristic of the decontamination device produced according to the teachings of the invention, the controlled closure means comprise a shutter sliding vertically against the partition between the uppermost opening position and the lowermost closure position, the shutter making it possible to selectively close the diffusion orifices located above a selected height.

[0028] According to another characteristic of the decontamination device produced according to the teachings of the invention, the controlled closure means comprise at least one movable transverse partition element capable of occupying an intermediate position between the extreme open position and the extreme closure position, in which divides the chamber in a manner sealed against the decontamination agent in the gaseous state into:

[0029] - an open compartment supplied with the decontamination agent and which is open on the tunnel through the diffusion orifices located below the minimum height, and

[0030] - a closed compartment which is not supplied with decontamination agent and which has the diffusion holes located above the minimum height.

[0031] According to another characteristic of the decontamination device produced according to the teachings of the invention, the partition element is a piston mounted to slide vertically in the chamber between the upper extreme opening position in which the volume of the open compartment is maximum and the lower extreme closing position in which the volume of the open compartment is minimum.

[0032] According to another characteristic of the decontamination device produced according to the teachings of the invention, the controlled closure means comprise the shutter and the partition element which are integral in movement.

[0033] According to another characteristic of the decontamination device produced according to the teachings of the invention, the chamber is supplied with decontamination agent by at least one supply orifice which is arranged in a lower part of the chamber located below the minimum height.

[0034] According to another characteristic of the decontamination device produced according to the teachings of the invention, the minimum height corresponds substantially to the height of a gripping member.

[0035] According to another characteristic of the decontamination device produced according to the teachings of the invention, the maximum height corresponds to the total height of the assembly formed by a gripping member equipped with a preform of maximum length.

[0036] According to another characteristic of the decontamination device produced according to the teachings of the invention, the sealing means are controlled by at least one motor.

[0037] According to another characteristic of the decontamination device produced according to the teachings of the invention, each gripping member is driven in rotation when crossing the tunnel so as to rotate the gripped preforms around their main axis.

[0038] According to another characteristic of the decontamination device produced according to the teachings of the invention, it comprises at least one source of emission of activation radiation which is arranged in the tunnel downstream of the partition in the direction of movement of the gripping members along the transport path.

[0039] The invention also proposes a preform heating station comprising:

[0040] - a preform conveying device equipped with gripping members on each preform through a neck and moving longitudinally along a determined transport path;

[0041] - at least one heating zone in which a section of the transport path is bordered by radiation emitters capable of heating the thermoplastic material constituting the preforms;

[0042] - a preform decontamination device produced according to the teachings of the invention;

[0043] characterized in that the preform conveying device of the heating station forms the conveying device of the decontamination device.

[0044] According to another characteristic of the heating station produced according to the teachings of the invention, the tunnel of the decontamination device is arranged upstream of the at least one heating zone according to the movement of the preforms along the transport path.

[0045] The invention also proposes a method for controlling the decontamination device, characterized in that, in a production mode, the closure means are controlled to diffuse the decontamination agent through the diffusion orifices located only below a selected height corresponding to the height of the assembly formed by the gripping members equipped with the preforms.

[0046] According to another characteristic of the method carried out according to the teachings of the invention, in a preproduction mode, the gripping members pass through the tunnel free of preforms, the closing means being controlled in their extreme lower closing position so as to decontaminate only the gripping members. Brief description of the figures

[0047] Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which reference will be made to the attached drawings.

[0048] [Fig.l] is a schematic top view which represents a preform heating station equipped with a decontamination device produced according to the teachings of the invention.

[0049] [Fig.2] is a cross-sectional view along section plane 2-2 of [Fig.l] which represents a conveying device of the station of [Fig.l] comprising a gripping member equipped with a preform.

[0050] [Fig. 3] is a cross-sectional view along section plane 3-3 of [Fig. 1] which represents the decontamination device provided with a tunnel and a decontamination agent diffusion chamber adjacent to the tunnel provided with controlled means shutter produced according to the teachings of the invention occupying an extreme upper opening position.

[0051] [Fig.4] is a view similar to that of [Fig.3] in which the closure means occupy an extreme lower closure position.

[0052] [Fig.5] is a longitudinal sectional view along section plane 5-5 of [Fig.l] which represents the tunnel of the decontamination device equipped with ultraviolet radiation emission sources. Detailed description of the invention

[0053] In the remainder of the description, similar or identical elements will be designated by the same references.

[0054] In the remainder of the description, the following orientations will be adopted without limitation:

[0055] - longitudinal "L" directed from back to front according to the direction of movement of the preforms along their transport path,

[0056] - vertical "V" directed from bottom to top along the axis of the preforms,

[0057] - transverse "T" directed from left to right.

[0058] The vertical direction is used here as a geometric reference unrelated to the direction of Earth's gravity. It is directed parallel to the axis of the preforms 12.

[0059] In the remainder of the description, the terms "top", "bottom", "lower", "upper" are used for the sake of clarity with reference to the vertical orientation of the figures without this having any limiting scope.

[0060] In the remainder of the description, the terms "upstream" and "downstream" will be used with reference to the direction of movement of the preforms along their transport path.

[0061] [Fig.l] shows a station 10 for heating preforms 12 made of thermoplastic material. The heating station 10 belongs to an installation (not shown) for manufacturing containers made of thermoplastic material, in particular PET (polyethylene terephthalate), by forming, in particular stretch-blow molding, said preforms 12.

[0062] As shown in [Fig.2], each preform 12 comprises a cylindrical body 14 with a main axis "Zl" oriented vertically. An upper end of the body 14 opens through a neck 16 with the final shape of that of the container to be obtained (which generally does not undergo the slightest deformation during the manufacture of the container). The body 14 comprises a bottom 18 which closes its lower end and whose shape is generally hemispherical. The neck 16 comprises a flange 20 arranged at its junction with the body 14.

[0063] The length "Lp" of the preform 12 is determined as being the distance along the main axis "Zl" between the outer face of the bottom 18 and an upper end rim 19. of neck 16, as shown in [Fig.2].

[0064] The heating station 10 is adapted to heat preforms 12 of different lengths up to a maximum length "Amax". In general, the length "Lp" of the preforms 12 is chosen according to the dimensions of the final containers to be obtained. The preforms 12 are treated in batches of identical preforms 12.

[0065] Referring again to [Fig.l], the heating station 10 comprises a device 22 for conveying the preforms 12 in a row. The conveying device 22 comprises individual supports 24 circulating in a closed circuit in the heating station 10. Each individual support 24 is intended to transport a preform 12 in uninterrupted movement along a predetermined transport path 26 from an entry point "A" of the heating station 10 which is supplied by a row of preforms 12 to an exit point "B" in the direction of a forming station (not shown), in particular blow molding or stretch blow molding.

[0066] The preforms 12 thus move in a line through the manufacturing installation following a production flow from the entry point "A" of the heating station 10 to an exit from the manufacturing installation in the form of finished, conforming containers, after forming in the forming station. The transport path 26 forms a section of this production flow of the preforms 12.

[0067] The conveying device 22 is here supplied with cold preforms 12 by a transfer wheel 28 arranged tangentially to the entry point "A". At the end of their transport path 26, the hot preforms 12 are taken over individually by a transfer wheel 30 arranged tangentially to the exit point "B". From the exit point "B" to the entry point "A", the individual supports 24 of the conveying device 22 circulate empty.

[0068] Generally, each individual support 24 comprises means capable of driving the preform 12 in rotation around its main axis during its movement along at least part of the transport path 26 to allow homogeneous heating of the body 14 of the preform 12. Such an individual support 24 is sometimes called a "spinner".

[0069] The conveying device 22 comprises a plurality of transport elements 32.

[0070] According to a first embodiment of the conveying device 22 shown in [Fig.l], the transport elements 32 form the links of a closed transport chain 34. The transport chain 34 is flexible. For this purpose, the transport elements 32 are mounted articulated to each other around vertical axes. The transport chain 34 is mounted movable relative to a frame fixed relative to the floor of the heating station 10.

[0071] The conveying device 22 further comprises a first wheel 36 for guiding the transport chain 34 and a second wheel 38 for guiding the chain 34 transport chains each rotatably mounted on the frame of the heating station 10 around a respective vertical axis "Z2, Z3". The transport chain 34 is meshed around the two guide wheels 36, 38. At least one of the two guide wheels, called the driving wheel, is rotated by a motor to set the transport chain 34 in motion in order to move the transport elements 32 along the closed circuit. The guide wheels 36, 38 rotate here in a counterclockwise direction, as indicated by an arrow "F1" in [Fig. 1].

[0072] For example, the two guide wheels 36, 38 are motorized or mechanically linked in rotation so as to simultaneously drive the transport chain 34 to avoid excessive variations in tension in the transport chain 34.

[0073] In a variant not shown of the conveying device 22, the transport elements 32 are formed by independent shuttles. The conveying device 22 then comprises at least one linear motor for controlling the movement of each shuttle independently of each other along the closed circuit. Such a conveying device 22 for a heating station 10 is for example described in document FR-A1-3.035.651.

[0074] The linear motor comprises a stator comprising a series of windings which are distributed along the closed circuit. Each winding is individually controlled to locally induce a magnetic field independently of the other windings which acts on the shuttles to cause their movement. For this purpose, the shuttles carry a magnetic element capable of interacting with the magnetic field emitted by the stator windings. The windings are for example controlled by an electronic control unit (not shown) which is programmed appropriately.

[0075] The linear motor thus comprises a single stator, formed by the magnetic path, and several shuttles, forming "rotors", controlled independently along said stator.

[0076] Whatever the embodiment of the conveying device 22, each transport element 32 carries at least one individual support 24. Each individual support 24 comprises a gripping member 40 which is intended to cooperate with the neck 16 of the preform 12 to transport it.

[0077] In a known manner, the gripping member 40 is here formed by a mandrel. Such a mandrel is for example provided with elastic means (not shown), such as an O-ring, advantageously made of an elastic material (such as an elastomer), which constrains metal sectors against an internal face of the neck 16 of a preform 12, so as to ensure that the preform 12 is held by friction against the internal wall of the neck 16, when the mandrel is inserted into the neck 16 of the preform 12.

[0078] When the preform 12 is gripped by the gripping member 40, the rim 19 free end of the neck 16 of the preform 12 is received in abutment against a shoulder face 41 of the gripping member 40.

[0079] The gripping member 40 here extends vertically from a base 43, located below the shoulder face 41, to a free upper end 45 located above the shoulder face 41. The part located vertically between the shoulder face 41 and the upper end 45 is here intended to be inserted inside the neck 16.

[0080] In a variant of the invention not shown, the gripping member 40 is intended to grip the neck 16 of the preform 12 from the outside. This variant is well known to those skilled in the art and will therefore not be described in more detail below.

[0081] Furthermore, each individual support 24 is capable of rotating the preform 12 around its axis during its movement along the transport path 26 to enable heating all around said preform 12. For this purpose, each individual support 24 is mounted for rotation around a vertical axis in the associated transport element 32. Said axis is coaxial with the main axis "Zl" of the preform 12 transported by said individual support 24.

[0082] According to a first example not shown, the individual support 24 is driven in rotation by a pinion secured to the gripping member 40 which cooperates with a fixed rack of the heating station 10.

[0083] In a variant of the invention not shown, the fixed rack is replaced by a motorized toothed belt.

[0084] According to another example not shown, the individual support 24 is driven in rotation by means of an electric motor on board the transport element 32.

[0085] As a non-limiting example shown in [Fig. 1], the closed circuit comprises at least two rectilinear sections 42, 44 which are separated from each other by bends 46, 48. More particularly, the closed circuit here comprises two parallel rectilinear sections 42, 44 which are linked by a first upstream end bend 46 at 180° and by a second downstream end bend 48 at 180° to form an oblong-shaped circuit.

[0086] The individual supports 24 are intended to transport preforms 12 when they travel along the rectilinear sections 42, 44. Thus, the rectilinear sections 42, 44 are part of the transport path 26. The entry point "A" and the exit point "B" are both located on the same bend, here the upstream bend 46.

[0087] The heating station 10 also comprises at least one heating zone 50 crossed by the transport path 26 to allow the preforms 12 to be heated during their movement. The heating station 10 here comprises two heating zones 50 which are arranged on each rectilinear section 42, 44 of the circuit.

[0088] In the embodiment shown in the figures, turns 46, 48 of the circuit are without means of heating the preforms 12.

[0089] Each heating zone 50 is intended to heat the bodies 14 of the preforms 12 beyond their glass transition temperature to allow their forming by the forming station while they are hot.

[0090] For each heating zone 50, a series of adjacent emitters 52 is arranged along the transport path 26, for example two rows of emitters 52 on either side of the transport path 26.

[0091] The heating emitters 52 are, for example, lamps facing reflectors or laser sources which emit electromagnetic radiation in the infrared range.

[0092] According to a non-limiting example of embodiment, the preforms 12 are heated with the neck 16 at the bottom and they are turned over with the neck 16 at the top between the last heating zone 50 and the exit point "B".

[0093] The preforms 12 enter the heating station 10, mounted on the conveying device 22 on which they carry out their U-shaped transport path 26 passing through the heating zones 50. They are heated as they pass by the emitters 52, which, if necessary, are placed on one side or on either side of the preforms 12 relative to their direction of travel. The hot preforms 12 are extracted from the heating station 10 after their passage through the heating zone 50 and transferred to molds of the forming station by the output transfer wheel 30.

[0094] The manufacturing installation comprises a device 54 for decontaminating preforms 12 shown in more detail in FIGS. 3, 4 and 5. This is a device 54 for decontaminating the exterior of the preforms 12 operating by spraying a decontamination agent in the gaseous state or in the mist state. The decontamination agent is, for example, hydrogen peroxide or peracetic acid (PAA). The decontaminating action of these decontamination agents is generally improved by heating them. It is therefore preferable to arrange the decontamination device 54 upstream of at least one heating zone 50.

[0095] Such a decontamination device 54 comprises a preform conveying device 12 equipped with members 40 for gripping each preform 12 by their neck 16 and moving longitudinally along a determined transport path 26. The preforms 12 move so that their main vertical axis "Zl" is orthogonal to the transport path 26.

[0096] In the embodiment shown in the figures, the device 22 for conveying preforms 12 of the heating station 10 forms the conveyor of the decontamination device.

[0097] In a variant of the invention not shown, the conveying device of the device 54 decontamination is separate from that of the heating station 10. In this case, the decontamination device 54 is for example arranged upstream of the entry point "A" of the heating station 10.

[0098] As shown in [Fig.3], the decontamination device 54 also comprises a confinement tunnel 56 crossed by a section of the transport path 26 of the preforms 12. This is a rectilinear section.

[0099] The confinement tunnel 56 is delimited transversely by a first vertical wall 58 and by a vertical partition 60. Said wall 58 and the partition 60 are parallel to the transport path 26. It is also delimited vertically upwards by a horizontal ceiling 62. Optionally, the confinement tunnel 56 is also delimited downwards by a floor not shown. The confinement tunnel 56 is open at its two longitudinal ends by an inlet 64 and by an outlet 66 for the passage of the gripping members 40 provided with a preform 12.

[0100] The confinement tunnel 56 has a height capable of receiving preforms 12 of maximum length "Amax".

[0101] The decontamination device 54 further comprises at least one chamber 68 adjacent to the confinement tunnel 56. The chamber 68 is separated from the confinement tunnel 56 by the vertical partition 60. The chamber 68 extends vertically at least from the base 43 of the gripping member 40 to the ceiling 62 of the confinement tunnel 56.

[0102] The chamber 68 is also delimited transversely by a wall 69 parallel to the vertical partition 60. The wall 69 and the partition 60 thus determine a transverse width of the chamber 68.

[0103] The chamber 68 is also delimited downwards by a bottom wall 71 which is here arranged substantially at the level of the base 43 of the gripping members 40. The chamber 68 is here open vertically upwards by a passage 73.

[0104] Finally, the chamber 68 is delimited longitudinally by lateral walls 75 shown in [Fig.5].

[0105] As shown in [Fig.3], the chamber 68 extends along the confinement tunnel 56 over a longitudinal distance necessary for the gripping member 40 to make at least one turn on itself.

[0106] The chamber 68 is supplied with decontamination agent in the gaseous state. The chamber 68 is here supplied via at least one supply orifice 70. The supply orifice 70 is preferably arranged at the same level as the gripping member 40.

[0107] The partition 60 is pierced with diffusion orifices 72 distributed at least from lower end orifices 72A, extending at the level of the gripping members 40, to upper end orifices 72B extending at a height maximum "Hmax", here near the ceiling 62.

[0108] The lower end orifices 72A are arranged at the same level as the shoulder face 41 or below this level. Here they are arranged at the level of the base 43 of the gripping members 40 which is located below the level of the shoulder face 41.

[0109] The upper end orifices 72B are arranged at least at the level of the bottom 18 of a preform 12 of maximum length "Amax" when it is gripped by the gripping member 40.

[0110] Intermediate diffusion orifices 72 are regularly distributed at several intermediate heights between the lower end orifices 72A and the upper end orifices 72B. The diffusion orifices 72 allow the continuous passage of the decontamination agent present in the chamber 68 towards the confinement tunnel 56 in a transverse direction. For this purpose, the decontamination agent is supplied with an overpressure in the chamber 68 relative to the pressure prevailing in the confinement tunnel 56.

[0111] The diffusion orifices 72 are here in the form of holes arranged in superimposed horizontal lines to form a grid.

[0112] In a variant of the invention not shown, the diffusion orifices 72 may have other shapes, for example the shape of horizontal and / or vertical slots.

[0113] To enable the preforms 12 and / or the gripping members 40 to be decontaminated effectively while using just the quantity of decontamination agent required for this operation, the invention proposes to equip the decontamination device 54 with controlled means 74 for closing off the diffusion orifices 72. The closing means 74 are controlled between an extreme closing position in which they selectively close off diffusion orifices 72 located above a minimum height "Hmin" and an extreme opening position in which the diffusion orifices 72 located below the maximum height "Hmax" are open.

[0114] The minimum height "Hmin" corresponds at least to the height of the part of each gripping member 40 intended to be inserted into the neck 16. The minimum height is thus at least between the shoulder face 41 and a free upper end 45 of the gripping member 40. Preferably, the minimum height does not extend above the free upper end 45 of the gripping member 40.

[0115] The minimum height "Hmin" here extends between the base 43 of the gripping member 40 and the free upper end 45 of the gripping member 40. It extends for example up to the height of the collar 20 of a neck 16 gripped by the gripping member 40.

[0116] The maximum height "Hmax" corresponds to the total height of the assembly formed by a gripping member 40 equipped with a preform 12 of maximum length "Amax". In other words, the maximum height "Hmax" is measured between the base 43 of the gripping member 40 and the bottom 18 of the preform 12 of maximum length "Amax".

[0117] When a preform 12 has a length "Lp" less than the maximum length "Amax", as illustrated in [Fig. 3], the closing of the diffusion orifices 72 located above the intermediate height measured between the base 43 of the gripping member 40 and the bottom 18 of said preform 12 which equips the gripping member 40 is thus controlled. Thus, the decontamination agent is not injected unnecessarily towards the parts of the confinement tunnel 56, here the upper part, which are not crossed by the preforms 12.

[0118] The controlled closure means 74 comprise at least one flap 78 sliding vertically against the partition 60. The flap 78 here has the shape of a solid longitudinal vertical plate delimited downwards by a lower edge 79. The flap 78 is here arranged inside the chamber 68. The flap 78 is capable of selectively closing the diffusion orifices 72 located above the lower edge 79, while the diffusion orifices 72 arranged below the lower edge 79 remain open. For example, the flap 78 has a solid part delimited downwards by the lower edge 79.

[0119] The flap 78 is sufficiently wide, in the longitudinal direction, to cover all the diffusion orifices 72 located above its lower edge 79. The flap 78 here has the same longitudinal dimension as the chamber 68.

[0120] The flap 78 is mounted to slide vertically in the chamber 68 between the uppermost opening position, shown in solid lines in [Fig. 3], in which a lower edge 79 of the flap 78 is arranged substantially at the level of the maximum height "Hmax", and the lowermost closing position, shown in [Fig. 4], in which the lower edge 79 of the flap 78 is arranged substantially at the level of the minimum height "Hmin" so that the flap closes all the diffusion orifices 72 arranged above its lower edge 79.

[0121] The flap 78 can be controlled in an intermediate position, as illustrated in broken lines in [Fig. 3], in which its lower end edge 79 is arranged at a selected height intermediate between the minimum height "Hmin" and the maximum height "Hmax". The flap 78 makes it possible to effectively close the diffusion orifices 72 located above the selected height.

[0122] The decontamination device 54 further comprises a transverse partition element 76 movable between the extreme open position in which the chamber 68 has a maximum volume and an extreme closed position in which it divides the chamber 68 in a manner sealed to the decontamination agent in the gaseous state into:

[0123] - an open compartment 68A supplied with the decontamination agent in gaseous state and which is open onto the confinement tunnel 56 via the orifices located below the minimum height "Hmin", and

[0124] - a closed compartment 68B which is not supplied with decontamination agent at the gaseous state and which includes the diffusion orifices 72 located above the minimum height "Hmin".

[0125] The partition element 76 is capable of occupying intermediate positions between the extreme open position and the extreme closed position so that the open compartment 68A supplied with the decontamination agent in the gaseous state is open to the confinement tunnel 56 via the orifices located below a selected intermediate height.

[0126] Since the preforms 12 are here carried with the neck 16 downwards, the open compartment 68A is arranged below the closed compartment 68B.

[0127] The partition element 76 is formed by a piston mounted to slide vertically in the chamber 68 between the uppermost open position, shown in [Fig. 3], in which the volume of the open compartment 68A corresponds to the volume of the chamber 68 and the lowermost closed position, shown in [Fig. 4], in which the volume of the open compartment 68A is less than the volume of the chamber 68. In the uppermost open position, the piston is arranged substantially at the level of the maximum height "Hmax". In the lowermost position, the piston is arranged substantially at the level of the minimum height "Hmin".

[0128] This makes it possible to avoid having to fill the entire chamber 68 with decontamination agent in the gaseous state when the preform 12 to be treated has a length "Lp" less than the maximum length "Amax".

[0129] In the embodiment shown in Figures 3 and 4, the partition element 76 and the flap 78 are mounted integral in displacement. The partition element 76 is formed by a lower face of the flap 78 which extends at the level of the lower edge 79. The flap 78 then has a transverse thickness substantially equal to the transverse width of the chamber 68. The flap 78 is slidably mounted in the passage 73 formed in the top of the chamber 68.

[0130] The shutter 78 is controlled in sliding by an electric motor 80.

[0131] Alternatively, the shutter 78 is controlled to slide manually, for example by means of a crank.

[0132] In a variant of the invention not shown, the flap 78 has a transverse thickness less than that of the chamber 68. In this case, the closure means are devoid of a partition element. It is therefore necessary to provide an additional quantity of decontamination agent to fill the entire chamber 68 during operation of the decontamination device 54. In this case, the chamber is closed upwards by a ceiling wall in which a slot is provided. passage of the shutter.

[0133] In a variant of the invention not shown, the decontamination device does not have a flap. Only the partition element 76 is used to prevent the decontamination agent from reaching the diffusion orifices 72 located above the selected height. In this case, the chamber is closed upwards by a ceiling wall in which a hole is provided for the passage of a piston tail.

[0134] Furthermore, the supply orifice 70 is arranged in a lower part of the chamber 68 located below the minimum height "Hmin" so that the chamber 68 can be supplied even when the flap 78 and / or the partition element 76 occupies its lowermost position.

[0135] The feed orifice 70 is here directed transversely towards the confinement tunnel 56. To prevent the decontamination agent from being directed preferentially towards the gripping member 40 to the detriment of the preform 12, provision is made to interpose a vertical deflection plate 82 between the feed orifice 70 and the partition 60 to diffuse the decontamination agent homogeneously throughout the chamber 68.

[0136] Alternatively, the supply orifice 70 is directed vertically upwards.

[0137] As illustrated in [Fig. 5], the decontamination device 54 advantageously comprises at least one source 84 for emitting radiation for activating the decontamination agent which is arranged in the confinement tunnel 56 downstream of the partition 60 pierced in the direction of movement of the gripping members 40 along the transport path 26. The confinement tunnel 56 is thus divided in the direction of the transport path 26 into a first upstream zone 86 for projecting decontamination agent and a second downstream zone 88 for exposure to activation radiation.

[0138] Activation radiation is defined here as radiation that is capable of decomposing the decontamination agent into active compounds, such as oxidants. This is, for example, ultraviolet radiation, infrared radiation, or microwave radiation. In the example shown in the figures, this is more particularly ultraviolet radiation. Activation radiation, in particular ultraviolet radiation, makes it possible to act on the decontamination agent to decompose it into highly active components to improve the decontamination of the preforms 12 and / or the gripping members 40.

[0139] The decontamination device 54 here comprises a plurality of sources 84 for emitting ultraviolet radiation which make it possible to irradiate the entire height of the confinement tunnel 56 over a longitudinal distance allowing the gripping members 40 to make at least one turn on themselves. These are tube lamps. They are arranged horizontally but can also be arranged vertically.

[0140] They are arranged directly downstream of the pierced partition 60 to act as quickly as possible.

[0141] The decontamination device 54 can be used in a production mode when the gripping members 40 transport preforms 12. In this case, the closing means 74 are controlled as a function of the length "Lp" of the preforms 12 currently being processed by the installation. They are more particularly controlled to close the diffusion orifices 72 located above a selected height which is equal to the height between the base 43 of the gripping member 40 and the bottom of the preform 12 which equips the gripping member 40, as shown in broken lines in [Fig. 3]. When the preform 12 has a maximum length "Amax", no diffusion orifice 72 is closed.

[0142] Thus, the quantity of decontamination agent used is adapted according to the length "Lp" of the preforms to be decontaminated.

[0143] It is also possible to use the decontamination device 54 in a pre-production mode, in which the gripping members 40 pass through the confinement tunnel 56 without preforms 12. It is in fact preferable to decontaminate the gripping members 40 before their use in order to avoid contaminating the internal wall of the necks 16. In this case, the closure means 74 are controlled at their minimum height "Hmin" so as to decontaminate only the gripping members 40, as illustrated in [Fig.4].

[0144] The invention thus makes it possible to use just the necessary quantity of decontamination agent. This makes it possible to save money but also to avoid the health hazards linked to the use of an excessive quantity of decontamination agent.

Claims

Claims

1. Device (54) for decontaminating preforms (12), in particular made of thermoplastic material, each preform (12) having a vertical main axis (Zl), the device (54) being suitable for preforms (12) of different lengths (Lp) up to a maximum length (Amax), the device (54) comprising: - a device (22) for conveying preforms (12) equipped with members (40) for gripping each preform (12) by a neck (16) running longitudinally along a determined transport path (26); - a confinement tunnel (56) crossed by a section of the determined transport path (26); - at least one chamber (68) adjacent to the tunnel (56) supplied with decontamination agent;- at least one vertical partition (60) parallel to the transport path (26) which separates the chamber (68) and the tunnel (56), the partition (60) being pierced with orifices (72) for diffusing the decontamination agent into the tunnel (56), the diffusion orifices (72) being distributed from orifices (72A) extending at the level of the gripping members (40) to orifices (72B) extending to a maximum height (Hmax) located at the level of an upper end of a preform (12) of maximum length (Amax) carried by a gripping member (40); characterized in that it comprises closure means (74) controlled between an extreme closure position in which they selectively close diffusion orifices (72) located above a minimum height (Hmin) and an extreme opening position in which the diffusion orifices (72) located below the maximum height (Hmax) are open.;

2. Decontamination device (54) according to the preceding claim, characterized in that the controlled closure means (74) are capable of occupying at least one intermediate position in which the diffusion orifices (72) located above a corresponding intermediate height are closed, while the diffusion orifices (72) located below the intermediate height are open.

3. Decontamination device (54) according to any one of the preceding claims, characterized in that the controlled closure means (74) comprise a flap (78) sliding vertically against the partition (60) between the upper extreme opening position and the extreme lower closing position, the shutter (78) making it possible to selectively close the diffusion orifices (72) located above a selected height.

4. Decontamination device (54) according to any one of the preceding claims, characterized in that the controlled closure means (74) comprise at least one movable transverse partition element (76) capable of occupying an intermediate position between the extreme open position and the extreme closure position, in which it divides the chamber (68) in a manner sealed to the decontamination agent in the gaseous state into: - an open compartment (68A) supplied with the decontamination agent and which is open to the tunnel (56) via the diffusion orifices (72) located below the minimum height (Hmin), and - a closed compartment (68B) which is not supplied with decontamination agent and which comprises the diffusion orifices (72) located above the minimum height (Hmin).

5. Decontamination device (54) according to the preceding claim, characterized in that the partition element (76) is a piston mounted to slide vertically in the chamber (68) between the upper extreme opening position in which the volume of the open compartment (68A) is maximum and the lower extreme closing position in which the volume of the open compartment (68A) is minimum.

6. Decontamination device (54) according to the preceding claim taken in combination with claim 2, characterized in that the controlled closure means (74) comprise the flap (78) and the partition element (76) which are integral in movement.

7. Decontamination device (54) according to any one of the preceding claims, characterized in that the chamber (68) is supplied with decontamination agent by at least one supply orifice (70) which is arranged in a lower part of the chamber (68) located below the minimum height (Hmin).

8. Decontamination device (54) according to any one of the preceding claims, characterized in that the minimum height (Hmin) corresponds substantially to the height of a gripping member (40).

9. Decontamination device (54) according to any one of the preceding claims, characterized in that the maximum height (Hmax) corresponds to the total height of the assembly formed by a gripping member (40) equipped with a preform (12) of length maximum (Amax).

10. Device (54) according to any one of the preceding claims, characterized in that the closure means (74) are controlled by at least one motor (80).

11. Decontamination device (54) according to any one of the preceding claims, characterized in that each gripping member (40) is rotated when passing through the tunnel (56) so as to rotate the gripped preforms (12) around their main axis (Zl).

12. Decontamination device (54) according to any one of the preceding claims, characterized in that it comprises at least one source (84) for emitting activation radiation which is arranged in the tunnel (56) downstream of the partition (60) in the direction of movement of the gripping members (40) along the transport path (26).

13. Station (10) for heating preforms (12) comprising: - a device (22) for conveying preforms (12) equipped with members (40) for gripping each preform (12) by a neck (16) and running longitudinally along a determined transport path (26); - at least one heating zone (50) in which a section of the transport path (26) is bordered by radiation emitters (52) capable of heating the thermoplastic material constituting the preforms (12); - a device (54) for decontaminating the preforms (12) produced according to any one of the preceding claims; characterized in that the device (22) for conveying preforms (12) of the heating station (10) forms the conveying device (22) of the decontamination device (54).

14. Heating station (10) according to the preceding claim, characterized in that the tunnel (56) of the decontamination device (54) is arranged upstream of the at least one heating zone (50) according to the movement of the preforms (12) along the transport path (26).

15. Method for controlling the decontamination device (54) according to claims 1 to 12, characterized in that, in one production mode, the closure means (74) are controlled to diffuse the decontamination agent through the diffusion orifices (72) located only below a selected height corresponding to the height of the assembly formed by the gripping members (40) equipped with the preforms (12).

16. Control method according to the preceding claim, characterized in that, in a preproduction mode, the gripping members (40) pass through the tunnel (56) free of preforms (12), the closure means (74) being controlled in their lower extreme closure position so as to decontaminate only the gripping members (40).

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