PREFORM DECONTAMINATION DEVICE

Abstract

The invention relates to a device (54) for decontaminating preforms (12), in particular made of thermoplastic material, comprising: - a device (22) for conveying preforms (12) equipped with members (40) for gripping each preform (12) moving longitudinally along a determined transport path (26); - a confinement tunnel (56) crossed by a section of the determined transport path (26); - at least one device (67) for projecting a flow (F) of decontaminating agent into the tunnel (56) transversely towards an opposite wall (58) of the tunnel (56) by intersecting the transport path (26) of the preforms (12) in a decontamination zone (69); characterized in that the decontamination device (54) is equipped with means (80, 84) for heating the opposite wall (58) to prevent condensation of the decontamination agent on an internal face (76) of said opposite wall (58). 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, comprising:

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

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

[0004] - at least one device for projecting a flow of decontaminating agent into the tunnel transversely towards an opposite wall of the tunnel by cutting the path of the preforms in a decontamination zone. Technical background

[0005] 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.

[0006] 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.

[0007] 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.

[0008] The container manufacturing facility is supplied with preforms which 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 sufficiently malleable for the blow molding operation.

[0009] Such large-scale container manufacturing installations are equipped with a heating station comprising a heating tunnel provided with means for heating the preforms. The preforms are generally conveyed along the tunnel at high speed without stopping by a conveying device. The tunnel has a sufficient length to allow the preforms to be heated as they pass through it.

[0010] The conveying device comprises individual preform gripping members which move 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.

[0011] Furthermore, the preforms to be heated are brought one after the other by a inlet wheel to an inlet area in the heating station. On this inlet wheel, two successive preforms are spaced apart by a first determined spacing.

[0012] Similarly, at the outlet of the heating station, the hot preforms are transferred to an outlet wheel on which two successive preforms are spaced apart by a second determined spacing. The second spacing is generally equal to the first spacing.

[0013] To carry out these conveying operations, the gripping members are generally supported by the links of a transport chain which is driven in movement along the heating path, for example by toothed wheels. Summary of the invention

[0014] The invention proposes a device for decontaminating preforms, in particular made of thermoplastic material, comprising:

[0015] - a preform conveying device equipped with gripping members on each preform moving longitudinally along a determined transport path;

[0016] - a confinement tunnel crossed by a section of the determined transport route;

[0017] - at least one device for projecting a flow of decontaminating agent into the tunnel transversely towards an opposite wall of the tunnel by cutting the transport path of the preforms in a decontamination zone;

[0018] characterized in that the decontamination device is equipped with means for heating the opposite wall to prevent condensation of the decontamination agent on an internal face of said opposite wall.

[0019] According to another characteristic of the decontamination device produced according to the teachings of the invention, the flow of decontamination agent is injected continuously by the projection device into the tunnel without interruption between the passage of two gripping members in the decontamination zone.

[0020] According to another characteristic of the decontamination device produced according to the teachings of the invention, the heating means comprise at least one electrical heating resistor.

[0021] According to another characteristic of the decontamination device produced according to the teachings of the invention, the electrical resistance is arranged in the thickness of the opposite wall.

[0022] According to another characteristic of the decontamination device produced according to the according to the invention, the electrical resistance is arranged against an external face of the opposite wall.

[0023] According to another characteristic of the decontamination device produced according to the teachings of the invention, the heating means comprise at least one heat transfer fluid circuit comprising a heat exchanger supplied with hot heat transfer fluid.

[0024] According to another characteristic of the decontamination device produced according to the teachings of the invention, the heat exchanger is arranged in the thickness of the opposite wall.

[0025] According to another characteristic of the decontamination device produced according to the teachings of the invention, the heat exchanger is arranged against an external face of the opposite wall.

[0026] According to another characteristic of the decontamination device produced according to the teachings of the invention, the opposite wall is heated to a set temperature which is greater than or equal to an evaporation temperature of the decontamination agent.

[0027] The invention also proposes a preform heating station comprising:

[0028] - a preform conveying device equipped with gripping members on each preform through a neck and moving longitudinally along a determined transport path;

[0029] - 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;

[0030] - a preform decontamination device produced according to the teachings of the invention;

[0031] characterized in that the preform conveying device of the heating station forms the conveying device of the decontamination device. Brief description of the figures

[0032] 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.

[0033] [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.

[0034] [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.

[0035] [Fig. 3] is a cross-sectional view along section plane 3-3 of [Fig. 1] which represents the decontamination device provided with a tunnel equipped with a decontamination agent projection device and a heating wall produced according to a first embodiment of the invention.

[0036] [Fig.4] is a view similar to that of [Fig.3] in which the heating wall is produced according to a variant of the first embodiment of the invention.

[0037] [Fig. 5] is a longitudinal sectional view along section plane 5-5 of [Fig. 1] which represents the tunnel of the decontamination device equipped with ultraviolet radiation emission sources and allowing the heating means produced according to the first embodiment of the invention to be seen transparently through the heating wall.

[0038] [Fig.6] is a cross-sectional view similar to that of [Fig.3] which represents the decontamination device provided with a tunnel equipped with a device for projecting decontamination agent and a heating wall produced according to a second embodiment of the invention.

[0039] [Fig.7] is a view similar to that of [Fig.6] in which the heating wall is produced according to a variant of the second embodiment of the invention.

[0040] [Fig.8] is a longitudinal sectional view similar to that of [Fig.5] which represents the tunnel of the decontamination device equipped with ultraviolet radiation emission sources and allowing the heating means produced according to the second embodiment of the invention to be seen transparently through the heating wall. Detailed description of the invention

[0041] In the remainder of the description, similar or identical elements will be designated by the same references.

[0042] In the remainder of the description, the following orientations will be adopted without limitation:

[0043] - longitudinal "L" directed from back to front according to the direction of movement of the preforms along their transport path,

[0044] - vertical "V" directed from bottom to top along the axis of the preforms,

[0045] - transverse "T" directed from left to right.

[0046] 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.

[0047] 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.

[0048] In the remainder of the description, the terms "upstream" and "downstream" will be used in reference to the direction of movement of the preforms along their transport path.

[0049] [Fig. 1] 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.

[0050] As shown in [Fig.2], each preform 12 comprises a body 14 cy lindrique of 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 has a bottom 18 which closes its lower end and whose shape is generally hemispherical. The neck 16 has a flange 20 arranged at its junction with the body 14.

[0051] The length "A" 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 the neck 16, as indicated in [Fig.2].

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 a homogeneous heating of the body 14 of the preform 12. Such an individual support 24 is sometimes called a "spinner".

[0056] The conveying device 22 comprises a plurality of transport elements 32.

[0057] 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.

[0058] The conveying device 22 further comprises a first wheel 36 for guiding the transport chain 34 and a second wheel 38 for guiding the transport chain 34, each rotatably mounted on the frame of the heating station 10 about 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 here rotate in an anticlockwise direction, as indicated by an arrow "F1" in [Fig.l].

[0059] 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.

[0060] 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.

[0061] 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.

[0062] The linear motor thus comprises a single stator, formed by the magnetic path, and several shuttles, forming "rotors", controlled independently along said stator.

[0063] 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.

[0064] 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.

[0065] When the preform 12 is gripped by the gripping member 40, the free end rim 19 of the neck 16 of the preform 12 is received in abutment against a shoulder face 41 of the gripping member 40.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] In a variant of the invention not shown, the fixed rack is replaced by a motorized toothed belt.

[0071] 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.

[0072] 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 bend 46 from the end to 180° and by a second turn 48 downstream end at 180° to form an oblong-shaped circuit.

[0073] 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.

[0074] 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.

[0075] In the embodiment shown in [Fig.l], the turns 46, 48 of the circuit are devoid of means for heating the preforms 12.

[0076] 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.

[0077] 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.

[0078] The heating emitters 52 are, for example, lamps facing reflectors or laser sources which emit electromagnetic radiation in the infrared range.

[0079] 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".

[0080] 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.

[0081] The manufacturing installation comprises a device 54 for decontaminating preforms 12 shown in more detail in FIGS. 3 to 8. 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.

[0082] The decontamination agent is for example hydrogen peroxide or peracetic acid (PAA). The decontaminating action of these decontamination agents is gener- rarity improved by their heating. It is therefore preferable to arrange the decontamination device 54 upstream of at least one heating zone 50.

[0083] Such a decontamination device 54 comprises a preform conveying device 12 equipped with members 40 for gripping each preform 12 moving longitudinally along a determined transport path 26.

[0084] 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.

[0085] In a variant of the invention not shown, the conveying device of the decontamination device 54 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.

[0086] In the conveying device 22, two gripping members 40 are spaced longitudinally from each other at least by a determined pitch. This means that two consecutive preforms 12 transported by the conveying device 22 are separated from each other by a longitudinal space.

[0087] As shown in Figures 3 to 8, 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.

[0088] 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.

[0089] The decontamination device 54 also comprises at least one device 67 for projecting a flow "F" of decontaminating agent into the confinement tunnel 56 transversely towards an opposite wall 58 of the confinement tunnel 56 by intersecting the path 26 for transporting the preforms 12 in a decontamination zone 69. The flow "F" is indicated by the arrows in FIGS. 3, 4, 6 and 7.

[0090] The projection device 67 is here arranged in the partition 60 in the direction of the wall 58 which forms said opposite wall 58. The projection device 67 comprises at least one orifice 72 for diffusing the flow "F" of decontamination agent which is arranged in the partition 60 and which is supplied with decontamination agent in the gaseous state or in the mist state.

[0091] By way of non-limiting example, the projection device 67 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.

[0092] As shown in Figures 3, 4, 6 and 7, 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.

[0093] The chamber 68 is continuously 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.

[0094] The partition 60 is pierced with diffusion orifices 72 distributed over the entire height of the confinement tunnel 56. The diffusion orifices 72 allow the continuous passage of a flow "F" of 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.

[0095] The diffusion orifices 72 are here in the form of holes arranged in horizontal and / or vertical lines superimposed to form a grid.

[0096] 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 74 between the feed orifice 70 and the partition 60 to diffuse the decontamination agent homogeneously throughout the chamber 68.

[0097] Alternatively, the supply orifice 70 is directed vertically upwards.

[0098] Such a decontamination agent is generally corrosive. To prevent the containment tunnel 56 from being damaged, the various elements composing it, and in particular the wall 58 and the partition 60, are made of stainless steel.

[0099] The projection device 67 injects the decontamination agent in a continuous flow "F" into the confinement tunnel 56 without interruption between the passage of two gripping members 40 in the decontamination zone 69. As a result, between the passage of two preforms 12, a portion of the flow "F" of decontamination agent comes directly into contact with an internal face 76 of the wall 58 facing the confinement tunnel 56. If the internal face 76 of the wall 58 has too low a temperature, the decontamination agent risks condensing into droplets which will then flow in the direction of gravity. However, the decontamination agent in the liquid state is extremely corrosive, even for elements made of stainless steel. It is therefore preferable to avoid condensation of the decontamination agent to safeguard the integrity of heating station 10.

[0100] The invention proposes to arrange means for heating the opposite wall 58 to prevent condensation of the decontamination agent on an internal face 76 of said opposite wall 58.

[0101] Preferably, the heating means heat the internal face 76 of the opposite wall 58 to a set temperature "Te" greater than or equal to an evaporation temperature of the decontamination agent.

[0102] The heating means here comprise heating members which can be arranged in the thickness of the wall 58 or against an external face of the wall 58.

[0103] Such an arrangement is very advantageous because, in addition to preventing corrosion, it also makes it possible to maintain the decontamination agent in a gaseous state inside the confinement tunnel 56. A sterilizing atmosphere thus permanently prevails in the confinement tunnel 56, which contributes to the decontamination of the preforms and thus avoids overconsumption of the decontamination agent.

[0104] The decontamination device 54 optionally comprises a temperature probe 78 which is for example arranged in the thickness of the opposite wall 58, close to the internal face 76. This temperature probe 78 thus makes it possible to automatically control the heating means according to a feedback loop to maintain the internal face at the set temperature "Te".

[0105] According to a first embodiment of the invention shown in Figures 3 to 5, at least one heating member is formed by an electrical heating resistor 80.

[0106] As shown in broken lines in [Fig. 5], the electrical resistance 80 here has the shape of a coil which extends in a longitudinal vertical plane in order to heat in a substantially homogeneous manner the entire surface of the internal face 76 which is likely to receive the flow "F" of decontamination agent. The electrical resistance 80 is supplied with electricity in order to heat the internal face 76 of the opposite wall 58 to the set temperature "Te". The heat produced by the electrical resistance 80 is communicated to the opposite wall 58 by conduction and / or by radiation.

[0107] In the embodiment shown in [Fig.3], the electrical resistance 80 is here arranged in the thickness of the opposite wall 58 so as to be arranged as close as possible to the internal face 76. Thus, the internal face 76 is heated very quickly to the set temperature "Te".

[0108] In the variant shown in [Fig.4], the electrical resistance 80 is arranged against an external face 82 of the opposite wall 58. In this case, the electrical resistance 80 must heat the entire thickness of the wall 58 in order to be able to heat the internal face 76.

[0109] According to a second embodiment of the invention shown in Figures 6 to 8, the heating members comprise at least one heat transfer fluid circuit 84 comprising a heat exchanger 86 supplied with hot heat transfer fluid.

[0110] As illustrated in broken lines in [Fig.8], the heat exchanger 86 here presents itself as a pipe shaped like a coil which extends in a longitudinal vertical plane in order to heat in a substantially homogeneous manner the entire surface of the internal face 76 which is capable of receiving the flow "F" of decontamination agent.

[0111] The hot heat transfer fluid circulating in the heat exchanger 86 thus transmits heat to the opposite wall 58 by thermal conduction. Then, the heat transfer fluid thus cooled leaves the heat exchanger 86 to be able to be heated again by a heating member 88 before being reinjected into the heat exchanger 86, for example by a pump 90.

[0112] In the embodiment shown in [Fig.6], the heat exchanger 86 is arranged in the thickness of the opposite wall 58 so as to be as close as possible to the internal face 76. Thus, the internal face 76 is heated very quickly to the set temperature "Te".

[0113] In the variant shown in [Fig.7], the heat exchanger 86 is arranged against the external face 82 of the opposite wall 58. In this case, the heat transfer fluid must heat the entire thickness of the wall 58 in order to be able to heat the internal face 76.

[0114] As illustrated in Figures 5 and 8, the decontamination device 54 advantageously comprises at least one source 92 for emitting activation radiation which is arranged in the confinement tunnel 56 downstream of the decontamination zone 69 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 decontamination zone 69 and a second downstream zone 94 for exposure to activation radiation.

[0115] 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. The UV radiation also acts on the decontamination agent suspended in the air to participate in the creation of a sterilizing atmosphere in the confinement tunnel 56.

[0116] The decontamination device 54 here comprises a plurality of sources 92 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.

[0117] The invention advantageously makes it possible to avoid condensation of the decontamination agent by maintaining it in its gaseous state inside the confinement tunnel 56. This advantageously makes it possible to use all of the decontamination agent projected by the projection device to maintain a sterile atmosphere in the confinement tunnel 56.

[0118] This also makes it possible to prevent corrosion of various elements of the decontamination device 54 by contact with condensed decontamination agent.

Claims

Claims

1. Device (54) for decontaminating preforms (12), in particular made of thermoplastic material, comprising: - a device (22) for conveying preforms (12) equipped with members (40) for gripping each preform (12) moving longitudinally along a determined transport path (26); - a confinement tunnel (56) crossed by a section of the determined transport path (26); - at least one device (67) for projecting a flow (F) of decontaminating agent into the tunnel (56) transversely towards an opposite wall (58) of the tunnel (56) by intersecting the transport path (26) of the preforms (12) in a decontamination zone (69); characterized in that the decontamination device (54) is equipped with means (80, 84) for heating the opposite wall (58) to prevent condensation of the decontamination agent on an internal face (76) of said opposite wall (58).

2. Decontamination device (54) according to the preceding claim, characterized in that the flow (F) of decontamination agent is injected continuously by the projection device (67) into the tunnel (56) without interruption between the passage of two gripping members (40) in the decontamination zone (69).

3. Decontamination device (54) according to any one of the preceding claims, characterized in that the heating means comprise at least one electrical heating resistor (80).

4. Decontamination device (54) according to the preceding claim, characterized in that the electrical resistance (80) is arranged in the thickness of the opposite wall (58).

5. Decontamination device (54) according to claim 3, characterized in that the electrical resistance (80) is arranged against an external face (82) of the opposite wall (58).

6. Decontamination device (54) according to any one of the preceding claims, characterized in that the heating means comprise at least one heat transfer fluid circuit (84) comprising a heat exchanger (86) supplied with hot heat transfer fluid.

7. Decontamination device (54) according to the preceding claim, characterized in that the heat exchanger (86) is arranged in the thickness of the opposite wall (58).

8. Decontamination device (54) according to claim 3, characterized in that the heat exchanger (86) is arranged against an external face (82) of the opposite wall (58).

9. Decontamination device (54) according to any one of the preceding claims, characterized in that the opposite wall (58) is heated to a set temperature (Te) which is greater than or equal to an evaporation temperature of the decontamination agent.

10. 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).

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