WO2025068369A1 - Unit for the thermal conditioning of preforms with integrated magazine - Google Patents

Abstract

The invention relates to a unit (16) for the thermal conditioning of preforms (4), the unit comprising: - an enclosure (23) in which the preforms (4) are thermally conditioned; - radiation sources (22) extending inside the enclosure (23); - a conveying means (26) extending inside the enclosure and comprising first gripping members (30) for moving the preforms along a conveying path (T), wherein at least one portion of the conveying path extends in line with the radiation sources, characterised in that it also comprises at least one magazine (57) extending inside the enclosure (23), in line with at least one portion of the conveying path (T).

Description

Thermal preform conditioning unit with integrated magazine Technical field of the invention

The present invention relates to a thermal conditioning unit of a machine for manufacturing containers, in particular thermoplastic bottles, by blowing or stretch-blow molding from preheated preforms comprising a magazine arranged inside the enclosure of the thermal conditioning unit, thus making it possible to carry out operations on this thermal conditioning unit.

The present invention relates to the thermal conditioning unit for preforms, in particular made of thermoplastic material, for the manufacture of containers comprising:

- an enclosure in which the preforms are thermally conditioned;

- radiation sources extending inside said enclosure, said radiation sources being capable of thermally conditioning the preforms;

- a conveying means extending inside the enclosure and comprising gripping members for moving the preforms along a conveying path in a horizontal plane and at least a portion of the conveying path extending in line with the radiation sources

Technical background

The state of the art is known of installations for manufacturing containers, in particular thermoplastic bottles, comprising a thermal conditioning unit and a forming unit, in particular by injecting a fluid under pressure into the preform.

Generally speaking, we seek to reduce the time during which the installation is stopped to allow the implementation of maintenance operations or operations to change personalized components linked to the format of the containers formed, such as molds, gripping components of the thermal conditioning unit, transfer clamps.

This will be the case, in particular, when starting the production of a new container. Indeed, it is then necessary to carry out various operations to change certain personalized components associated with a given preform, which itself corresponds to a container to be manufactured.

However, such a solution was not satisfactory because the total time required to carry out such operations is particularly long and therefore costly since all manufacturing generally ceases.

Furthermore, we also know the applicant's patent application WO201317411 which discloses a container manufacturing installation comprising at least:

- a thermal conditioning unit for the preforms which comprises a first vertical lateral face; and

- a unit for forming containers from thermally conditioned preforms, which has a second vertical lateral face;

This installation comprises at least one robot and at least one magazine which are arranged opposite the first vertical lateral face and the second vertical lateral face to intervene selectively through the first vertical lateral face and/or through the second vertical lateral face in order to be able to carry out operations on the thermal conditioning unit and/or the forming unit.

In other words, in this installation the layout of the robot and the store allows intervention on both units.

However, such a warehouse layout does not allow for optimized intervention times and reduced floor space. Since the warehouse must be able to serve both units, this means that it is positioned at a certain distance from the packaging unit and the forming unit. It cannot be positioned close to one unit without causing inconvenience to the other unit, or else the number of warehouses must be multiplied.

There is therefore a significant need for the thermal conditioning unit to maintain acceptable productivity times, as well as format changeover or maintenance times, while improving the compactness of the installation.

To this end, the invention proposes a unit for thermal conditioning of preforms, in particular made of thermoplastic material, for the manufacture of containers comprising:

- an enclosure in which the preforms are thermally conditioned;

- radiation sources extending inside said enclosure, said radiation sources being capable of thermally conditioning the preforms;

- a conveying means extending inside said enclosure and comprising first gripping members for moving said preforms along a closed conveying path and at least a portion of the conveying path extending in line with the radiation sources,

characterized in that it also comprises at least one store extending inside said enclosure, in line with at least part of said conveyor path, and capable of storing at least one gripping member.

This thermal conditioning unit makes it possible to reduce operating times, particularly format changes, due to the layout of the store in relation to the conveyor path of the gripping devices.

This thermal conditioning unit also makes it possible to reduce the footprint compared to known arrangements.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the closed conveyor path comprising at least: a so-called outward section, a so-called return section and two turns connecting the outward section and the return section, the radiation sources extending in line with at least one outward and/or return section.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the store is arranged at least one of the turns of said conveyor path.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the enclosure comprises at least one vertical partition adjacent to said conveyor path.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the enclosure comprises a first vertical partition of longitudinal orientation adjacent to the forward section of said conveying path, extending by a second vertical partition of transverse orientation adjacent to said bend of the conveying path, extending by a third vertical partition of longitudinal orientation which is generally parallel to said first partition and adjacent to the return section of said conveying path.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the magazine is mounted to move between a so-called "active" position in which said magazine extends outside said enclosure to carry out the changing of said gripping members and a so-called "retracted" position in which said magazine extends inside said enclosure to carry out maintenance operations and/or format changes.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, at least one of the partitions of the enclosure comprises a retractable panel to allow said magazine to move from its active position to its retracted position and vice versa.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the thermal conditioning unit comprises at least one magazine capable of storing second gripping members in line with at least one robot.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the magazine comprises a vertical plate adjacent to the bend of the conveyor path, and the plate comprising bores in which the gripping members are housed.

According to another characteristic of the thermal conditioning unit produced according to the teachings of the invention, the magazine comprises a barrel on the periphery of which bores are made to house the gripping members.

This thermal conditioning unit also makes it possible to reduce the installation and setup time of the thermal conditioning unit at the customer's premises. In fact, this conditioning unit containing the store is transported to the customer in a single block, whereas this was not the case in the prior art arrangements seen previously.

This thermal conditioning unit also allows for a reduction in the footprint on the ground because all the structural elements used to carry out the operations are located within the enclosure of the thermal conditioning unit.

Brief description of the figures

Other characteristics and advantages of the invention will appear during the reading of the detailed description which follows for the understanding of which one will refer to the appended drawings which we describe briefly below.

is a schematic general view of a container production installation seen from above and more particularly of a packaging unit and a robot according to the invention;

is a detail view of a preform;

is a sectional view of the thermal conditioning unit according to section AA of the ;

is a perspective view showing the layout of the store in the retracted position within the enclosure of the thermal conditioning unit;

is a perspective view showing the layout of the store in active position within the enclosure of the thermal conditioning unit

Detailed description of the invention

In the remainder of the description, elements having an identical structure or similar functions will be designated by the same reference.

The longitudinal, vertical and transverse orientations will be adopted without limitation with reference to the trihedron (L, V, T) shown in the figures.

By convention, the longitudinal and transverse directions are determined in a fixed manner relative to the molding devices so that the open or closed position occupied has no effect on said orientations.

The terms "front" and "rear" will also be used, without limitation, in reference to the longitudinal orientation, as well as "upper" and "lower" in reference to the vertical orientation and finally "left" or "right" and "inner" or "outer" in reference to the transverse orientation.

We have represented schematically in the , an installation 1 for the mass production of containers 2 made of thermoplastic material from preforms 4.

In the remainder of the description, the preforms 4 and the containers 2 move in the production facility along a production path from upstream to downstream. The preforms 4 are moved in line along a production path by conveyor means which will be detailed later.

In a non-limiting manner, the containers here are bottles. The thermoplastic material is for example formed by polyethylene terephthalate, hereinafter referred to by its acronym "PET".

Such a preform 4, with reference to the , has a main axis "X" shown vertically in the figure. It has a cylindrical body 6 with a tubular wall 7 closed at one of its axial ends by a bottom 8, and which is open at its other end by a neck 10, also tubular. The neck 10 is delimited downwards by a collar 12 and upwards by an upper end edge called a drinking rim 14.

The neck 10 generally has its final shape while the body 6 of the preform is intended to undergo a relatively significant deformation to form the final container 2 during a forming step.

As shown in the , the container manufacturing installation 1 comprises at least one thermal conditioning unit 16, one forming unit 18.

The thermal conditioning unit 16, also called an oven, allows a succession of preforms to be heated to a reference temperature. The reference temperature is chosen so that the body of each preform at the outlet of the thermal conditioning unit 16 is in a malleable state allowing deformation of the body 6 of the heated preform in order to form the container 2 in the forming unit. The reference temperature is between the glass transition temperature and the crystallization temperature of the plastic material of the preform. In the case of PET, the reference temperature is, for example, close to 110°. The value of the reference temperature may vary depending on the product with which the container will be filled or depending on the container filling technique. Thus, the reference temperature is different for hot filling or for a carbonated product, for example.

According to the embodiment shown in the , the thermal conditioning unit 16 is a scroll oven, in which the preforms 4 are transported to be exposed to a plurality of heating radiation sources 22.

For this purpose, the thermal conditioning unit 16 comprises a means for conveying the preforms circulating along a conveying path T in an enclosure 23 between an inlet 25 and an outlet 27 and lying in a horizontal plane B.

As shown in the , the conveying means comprises a succession of gripping members 30 mounted on a transport chain 28, capable of gripping a preform in particular by fitting its neck.

The conveying means further comprises a first guide wheel 36 of the transport chain 28 and a second guide wheel 38 of the transport chain 28 are each rotatably mounted on a frame (not shown) of the thermal conditioning unit around a respective vertical axis "Z2, Z3". The transport chain 28 is meshed around the two guide wheels 36, 38 thus forming a closed loop. At least one of the two guide wheels, called the driving wheel, is rotated by a motor to set the transport chain 28 in motion in order to move the gripping members along the conveying path. The guide wheels 36, 38 here rotate in an anticlockwise direction, as indicated by an arrow in the .

In another embodiment not shown, the conveying means comprises for example a succession of gripping members, each being capable of supporting a preform, mounted on a linear motor type shuttle circulating on a closed magnetic loop along the conveying path. The movement of each of these shuttles being controlled independently of each other by a control unit (not shown).

At least part of the gripping member 30 is complementary to the preforms 4 and in particular to the geometric characteristics of the neck, in particular to grip them by fitting.

The preforms circulate along the conveyor path T forming a closed circuit.

As shown in the , the conveyance route T comprises at least one so-called outward section 39, one so-called return section 41 and two turns 43, 45 connecting the outward section and the return section.

Thus, the preform conveying path T has the shape of a “U”.

The enclosure 23 comprises at least one vertical partition adjacent to the conveying path T.

Here, the enclosure 23 comprises a first vertical partition 47 of longitudinal orientation adjacent to the outward section 39 of said conveyance path T, extending by a second vertical partition 49 of transverse orientation adjacent to said turn 43 of the conveyance path, extending by a third vertical partition 51 of longitudinal orientation which is generally parallel to said first partition 47 and adjacent to the return section 41 of said conveyance path T.

These partitions are fixed to a frame which will be described later.

The enclosure includes the radiation sources 22 which are capable of thermally conditioning the preforms 4.

The radiation sources 22 form a heating cavity which comprises two side walls 53 facing each other and at least one of these walls being the one which supports several radiation sources 22, arranged one above the other and one next to the other opposite the preforms.

In other words, the thermal conditioning unit 16 comprises a plurality of radiation sources 22 distributed throughout the conveying path T and at a height corresponding substantially to the height of the preforms so that the entire height of the body of each preform is exposed to the radiation emitted by the radiation sources 22 on the path T of the preform in the thermal conditioning unit 16. By rotating the preforms 4 around their main axis X, the conveying means 26 makes it possible to uniformly expose the entire body 6 of the preforms to the radiation sources 22. In this particular embodiment, the radiation sources 22 are distributed on only one side of this path, and a reflective wall 55 is arranged on the other side of the heating path to reflect the heat towards the preforms.

In another embodiment not shown, the radiation sources 22 can be distributed on either side of the heating path without departing from the scope of the invention.

It should also be noted that the radiation sources 22 are arranged, where appropriate, so as not to subject the neck 10 to the heating radiation emitted by the radiation sources. Indeed, as indicated previously, only the body 6 of the preform 4 is heated to produce the container. Consequently, the neck 10 must not be deformed during forming and must not be heated. To avoid heating the neck 10, the oven may comprise a ventilation device, not shown in the figures, positioned in line with the necks 10 to evacuate the heat likely to be absorbed by said necks 10.

Each radiation source 22 is formed by an incandescent lamp emitting infrared radiation.

In another embodiment, each radiation source 22 is at least one laser diode emitting infrared radiation capable of thermally conditioning the preforms.

In other words, each radiation source 22 is at least one laser source (for example laser diodes) emitting in the infrared and arranged by juxtaposition and/or superposition of several sources to form one or more matrices as described in the applicant's European patent EP1824659.

In another embodiment, each radiation source 22 is a microwave generator.

It is obvious that the radiation sources 22 may consist of any radiation source well known to those skilled in the art, or a combination of these radiation sources without departing from the scope of the invention.

The enclosure 23 of the thermal conditioning unit also comprises at least one robot 19 extending inside the enclosure 23, along at least part of said conveying path T, and capable of carrying out operations on the conveying means and/or on the radiation sources.

The robot 19 comprises a base 20 and a robotic arm 21, equipped at one of its ends with a gripping tool capable of gripping and moving at least one gripping member 30, from the conveying means to a store.

The robot 19 comprises an articulated arm 21 which is mobile in the enclosure 23 following a trihedron (X, Y, Z).

The arm 21 comprising at least three articulation axes following the trihedron (X, Y, Z).

As shown in the , all or part of the robot 19 extends inside the conveying path T.

In other words, all or part of the robot 19 extends between the so-called outward section 39, the so-called return section 41 and the turn 43 connecting the two sections.

More particularly, the base 20 of the robot extends inside the conveying T path.

All or part of the articulated arm 21 extends inside the conveying path T.

The thermal conditioning unit 16 also comprises at least one storage means 57 of the magazine type capable of storing the gripping members 30 and/or second gripping members 59.

Here, the thermal conditioning unit 16 comprises a storage means 57 of the magazine type capable of storing the second gripping members 59.

The storage means 57 extends inside the enclosure 23 of the thermal conditioning unit to the right of the robot 19.

The location of this robot in relation to the store makes it possible to limit the travel of the articulated arm 21 and thus reduce the time required to carry out a format change.

Then, once the preform 4 has been thermally conditioned in the thermal conditioning unit 16, it is transferred to the forming unit 18 to be formed there.

The unit 18 for forming containers 2 from preforms 4 consists of a forming wheel 42 rotating a plurality of blowing stations 44 from an inlet to an outlet, at which a succession of containers are formed from the preforms, then are extracted, as shown in the . The axis of rotation of the forming wheel is, for example, substantially parallel to the main axis X of the preforms as they are transported by the forming wheel.

Each blowing station 44 comprises a mold 46 provided with walls forming a molding cavity having the shape of the container to be formed and arranged to receive a preform so that the body of the preform extends into the molding cavity.

There represents a sectional view of the according to section AA whose thermal conditioning unit 16 consists of the enclosure 23 which includes inside, the radiation sources 22, the conveying means 26, the robot 19, and the store 57. In other words, this enclosure 23 surrounds the radiation sources 22, the conveying means 26, the robot 19, and the store 57 to protect them, isolate them from the external environment and conversely, protect the external environment from elements which may come from inside the enclosure such as radiation from the radiation source.

In the context of the production of containers containing sensitive products (milk, orange juice, etc.), the enclosure 23 defines a more or less airtight volume. This volume can be equipped with a means of blowing filtered air to establish an overpressure inside this volume and to control the quality of the air in order to avoid any contamination of the enclosure.

The enclosure 23 of the thermal conditioning unit 18 consists of a frame 60 capable of receiving at least one vertical partition and possibly at least one horizontal partition for the floor and/or the ceiling.

This frame consists of metal beams forming a supporting structure or frame on which are fixed the vertical partitions 47, 49, 51 and/or a horizontal partition 62 of the ceiling and/or a horizontal partition 64 of the floor.

The partitions are fixed removably to the frame using fixing means such as screws or they are fixed permanently using fixing means such as welding or any other fixing means known to those skilled in the art.

As shown in the , the enclosure comprises the first vertical partition 47 of longitudinal orientation adjacent to the outward section 39 of the conveying path T, extending by the second vertical partition 49 of transverse orientation adjacent to the turn 43 of the conveying path T, extending by the third vertical partition 51 of longitudinal orientation which is generally parallel to the first partition 47 and adjacent to the return section 41 of the conveying path T, a fourth vertical partition, which may be the partition of the forming unit (not shown), of transverse orientation adjacent to the turn of the conveying path common to the forming unit in which at least one opening is made to transfer the hot preforms to the forming unit. These first, second, third and fourth partitions are fixed to the beams of the frame 60 by any known fixing means.

This enclosure 23 defines a volume having the shape of a rectangular parallelepiped.

Alternatively, the enclosure may define a volume in the shape of a cylinder.

The enclosure 23 also includes the radiation sources 22 as mentioned previously in the description and shown in dotted lines on the .

As illustrated on the , the enclosure 23 also comprises the conveying means 26 extending along the conveying path T, in a horizontal plane B, which is substantially parallel to the horizontal partition 62 of the ceiling and/or the horizontal partition 64 of the floor and/or a horizontal plane defined by the ground on which the thermal conditioning unit 16 rests.

The conveying means 26 comprises a succession of gripping members 30 transporting the preforms 4 to be heated neck-up from the inlet to the outlet of the thermal conditioning unit 16.

As a non-limiting example, reference will be made to the applicant's French patent whose publication number is WO2007025909 which describes a gripping member 30 for preforms mentioned above.

Alternatively, the preforms are heated neck down, then are turned neck up at the inlet and outlet of the thermal conditioning unit to carry out the preform transfers.

As a non-limiting example, reference will be made to the applicant's French patent, the publication number of which is EP2626177B1, which describes a preform gripping member equipped with a rapid disassembly device.

The enclosure 23 also includes the robot 19 consisting of the base 20 and the articulated arm 21 which is equipped at its free end with a gripping tool capable of gripping the gripping members 30 or the radiation sources 22.

In this embodiment, the base 20 can be fixed or mobile. When the base is mobile in rotation, it is mobile relative to an axis V. Here, the axis V and the axis Z3 of the second wheel 38 are merged.

As shown in the , a lower part 72 of the base 20 is secured to the enclosure 23.

The lower part 72 of the base 20 of the robot 19 is fixed on the horizontal partition 64 of the floor or a horizontal part of the frame 60 of the thermal conditioning unit.

In a variant not shown, the robot can be fixed directly to the ground on which the thermal conditioning unit rests. In other words, the robot is arranged in the enclosure 23, under the horizontal plane B defined by the conveying path T. Thus, the articulated arm 21 moves in a zone called “below” 23A of the enclosure 23.

In a variant not shown, the base of the robot is fixed to the horizontal partition 62 and/or a part of the frame 60 forming the ceiling of the thermal conditioning unit. In other words, the robot can be arranged in the enclosure called “above” the horizontal plane B defined by the conveyor path. Thus, the articulated arm moves in a zone called “above” 23B of the enclosure 23.

In another variant, the base 20 can be fixed on the horizontal plane B and extending inside the conveyor path forming a loop and the articulated arm 21 can move in the lower zone 23A and/or in the upper zone 23B of the enclosure.

As shown in the , the arm 21 is coupled at one of its ends to the base 20 and at the other free end to a gripping tool for carrying out the operations of changing the gripping members 30 or the radiation sources 22.

The articulated arm 21 is composed of several sections 66. These sections 66 are articulated relative to each other by articulation axes 68 to move in the lower zone 23A or in the upper zone 23B depending on the position of the base 20.

The gripping tool is capable of detaching and gripping a first gripping member 30 which was secured to the conveying means 26. Then, the articulated arm 21 moves the first gripping member 30 to place it in the magazine. Then, the gripping tool is capable of detaching and gripping a second gripping member 59 which was secured to the magazine before being moved and fixed on the conveying means 26.

There are two types of operations performed on the gripping organ 30:

Maintenance operations consisting of changing at least one gripping member 30, i.e. replacing the gripping member with another gripping member having the same technical characteristics (dimension, stiffness of the joints for holding the preform).

The format change operations consist of changing all the first gripping members 30 secured to the conveying means 26 by the second gripping members 59 stored in the magazine 57.

As shown in the , the enclosure 23 also comprises the store 57 capable of storing the gripping members 30 to carry out maintenance operations or capable of storing the second gripping members 59 to carry out operations for changing the format of the produced container.

There represents a partial perspective view of the thermal conditioning unit showing several positions of the articulated arm in the area below 23A of the enclosure 23, as well as the magazine in a retracted position, i.e. in a position where the magazine is inside the enclosure 23.

This figure shows the thermal conditioning unit comprising the conveying means 26, the frame 60, the enclosure 23, the robot 19 and the store 57.

To lighten this figure, the succession of gripping organs and an upper part of the frame 60 have not been shown.

The conveying means 26 was described previously when describing the .

In this figure, the conveying means 26 is shown schematically and is intended to show its size and its positioning in the thermal conditioning unit, in particular in relation to the robot 19 and the store 57.

The conveying means 26 forms a closed loop.

The lower part of the closed loop of the conveyor means defines the horizontal plane B.

The frame visible in this figure comprises beams 70, forming part of the floor, on which the structural elements of the thermal conditioning unit will rest, in particular the robot, the store and part of the partitions not shown.

Enclosure 23 and especially the area below 23A is defined by a volume located between the horizontal plane B and the beams forming the floor.

For this embodiment, this volume of the lower zone 23A constitutes the volume in which the robot will be positioned to carry out the different operations.

The same reasoning can be applied to define the volume of the upper area 23B, that is, between the horizontal plane B and the beams forming the ceiling (not shown in this figure).

In this figure, the robot is arranged in the area below 23A.

The robot 19 consists of the support 20 and the robotic arm 21.

The support 20 also consists of two parts, a lower part 72 and an upper part 74.

The lower part 72 of the support is secured to the frame 60, by any fixing means well known to those skilled in the art.

The support 20 is arranged in the lower zone 23A and more particularly, under one of the two turns 43, 45 of the transport path T, under the axis of the wheel of the conveying means.

The support 20 extends inside the conveying path T.

The upper part 74 of the support is secured to the robotic arm 21.

The articulated arm 21 comprises several sections 66 connected to each other by rotation axes 68.

There shows the arm 21 articulated in several positions, notably in a position for depositing the gripping member 30 in the magazine 57 or for gripping the gripping member in the magazine 57.

As shown in the , 4, and 5, the magazine 57 consists of a vertical plate 76 adjacent to the turn 43 of the conveyor path T.

Plate 76 consists of a multitude of smaller plates.

The vertical plate 76 comprises locations 78 in which the gripping members 30 are housed. Here, the locations 78 take the form of bores.

Here, the gripping members are held in these different bores by holding means such as magnets or by any other holding means known to those skilled in the art, clamps, O-rings for example.

When all the second gripping members are present in the magazine, the latter comprises at least one additional free location 78. When a first gripping member 30 is dismantled from the conveying means 26, the latter is stored in the additional free location 78, then a second gripping member 59 is taken from the magazine 57 to be mounted in place of the first gripping member which has just been dismantled from the conveying means 26.

Store 57 retracts outside the enclosure so that an operator can change the gripping devices in hidden time, that is, while the thermal conditioning unit continues to produce.

There shows the magazine 57 in the active position, i.e. the magazine extends outside the enclosure 23.

As illustrated on the , the retraction of the store is carried out, here, following a translation movement.

In a variant not shown, the magazine is retracted using another movement, for example a rotational movement.

To maintain the magazine in its active position, the magazine comprises a blocker 82, that is to say, an actuator such as a cylinder capable of blocking the magazine in the active position or in the retracted position.

To move from one position to another, the vertical plate constituting the magazine is secured in the upper part and in the lower part to slides 80 which themselves are secured to the frame 60 and/or to one of the horizontal partitions 62, 64.

In a variant not shown, the magazine comprises a barrel on the periphery of which locations 78 are made to house the gripping members.

These locations 78 may be bores or grooves capable of receiving the gripping members 30.

In this embodiment, the rotation of the barrel is combined with the movement of the articulated arm to optimize the filling of the magazine without operator intervention.

In the context of this invention, the magazine takes the form of a plate or a barrel; many other means of making magazines are known to those skilled in the art.

Claims (11)

Thermal conditioning unit (16) for preforms (4) in particular made of thermoplastic material for the manufacture of containers (2) comprising:
- an enclosure (23) in which the preforms (4) are thermally conditioned;
- radiation sources (22) extending inside said enclosure (23), said radiation sources being capable of thermally conditioning the preforms;
- a conveying means (26) extending inside said enclosure and comprising first gripping members (30) for moving said preforms along a closed conveying path (T) and at least a portion of the conveying path extending in line with the radiation sources,
characterized in that it also comprises at least one store (57) extending inside said enclosure (23), in line with at least part of said conveying path (T), and capable of storing at least one gripping member (30). Thermal conditioning unit (16) according to the preceding claim, characterized in that said closed conveying path (T) comprises at least: a so-called outward section (39), a so-called return section (41) and two turns (43, 45) connecting the outward section (39) and the return section (41), the radiation sources (22) extending in line with at least one outward and/or return section. Thermal conditioning unit according to any one of the preceding claims, characterized in that said store (57) is arranged at right angles to at least one of the turns (43, 45) of said conveying path (T). Thermal conditioning unit according to any one of the preceding claims, characterized in that said enclosure (23) comprises at least one vertical partition adjacent to said conveying path (T). Thermal conditioning unit according to any one of the preceding claims, characterized in that said enclosure comprises a first vertical partition (47) of longitudinal orientation adjacent to the outward section (39) of said conveying path (T), extending by a second vertical partition (49) of transverse orientation adjacent to said bend (43) of the conveying path, extending by a third vertical partition (51) of longitudinal orientation which is generally parallel to said first partition (47) and adjacent to the return section (41) of said conveying path (T). Thermal conditioning unit according to any one of the preceding claims, characterized in that said magazine (57) is mounted to move between a so-called “active” position in which said magazine extends outside said enclosure (23) to carry out the changing of said gripping members (30) and a so-called “retracted” position in which said magazine (57) extends inside said enclosure (23) to carry out maintenance operations and/or format changes. Thermal conditioning unit according to claim 6 characterized in that at least one of the partitions (47, 49, 51) of the enclosure comprises a retractable panel to allow said magazine (57) to pass from its active position to its retracted position and vice versa. Thermal conditioning unit according to any one of the preceding claims, characterized in that it comprises at least one magazine (57) capable of storing second gripping members (59) in line with at least one robot (19). Thermal conditioning unit according to any one of the preceding claims, characterized in that said magazine (57) comprises a vertical plate (76) adjacent to said bend (43) of the conveying path (T), and said plate (76) comprising locations (78) in which the gripping members are housed. Thermal conditioning unit according to any one of the preceding claims, characterized in that said magazine comprises a barrel on the periphery of which locations (78) are made to house the gripping members. Thermal conditioning unit according to any one of the preceding claims, characterized in that the locations (78) have the shape of at least one bore and/or at least one groove.