Heat treatment unit comprising a device for acquiring a thermal image of a preform

Abstract

The invention relates to a heat treatment unit (4) comprising: - at least two heating elements (10), each arranged to heat a heated zone (24) of a body (16) of a preform (2), - an acquisition device (36) for acquiring at least one thermal image (38) of the heated preform (2), the thermal image (38) showing at least two thermal zones (40) representative of the temperature of the heated zones (24) of the body (16) of the preform (2), - a correlation module (44) for correlating the position of the two thermal zones (40) with the height of the heating elements (10) having heated the heated zones (24) corresponding to the thermal zones (40), the height of the heating elements (10) being defined in a direction of elevation (Z) parallel to the axis (A) of the preform.

Description

Thermal processing unit including a device for acquiring a thermal image of a preform

[0001] The present invention relates to a heat treatment unit for at least one preform of a container manufacturing installation.

[0002] The invention also relates to a method of heating a preform by means of such a heat treatment unit.

[0003] It is known to heat preforms in a container production facility in order to make these preforms malleable and allow their subsequent deformation, for example by stretch blow molding, in order to produce containers from the heated preforms.

[0004] To achieve this, a series of preforms is circulated, for example, in a heat treatment unit, or furnace, where the preforms pass in front of heating elements. These heating elements are distributed along the height of the preform bodies, that is, roughly parallel to the preform axis along which the bodies extend. This allows for heating several zones of the preform bodies to controlled temperatures. Indeed, these zones must be heated to different temperatures to best control their deformation during the production of a container, according to the desired shape. Thus, the higher the temperature of a zone, the more that zone can be deformed during the container's production.The heating powers of the different heating elements thus make it possible to apply a temperature profile to a preform, this profile depending on the characteristics of the container to be made from this preform and the material of the preform.

[0005] To ensure proper heating of preforms, it is known to adjust the heating power of the heating elements based on the temperature of the preforms after heating. The heat distribution within the preform is determined by measuring a reference temperature in a specific area, and the heating power of the elements is adjusted accordingly to approximate the temperature profile to be applied to the preforms.

[0006] However, such an adjustment is not entirely satisfactory. Indeed, particularly for areas of the preform far from the area where the reference temperature was measured, the heating power setting remains based on this reference temperature, which makes the setting approximate.

[0007] One of the aims of the invention is to overcome this drawback by providing a heat treatment unit in which the temperatures of the different heated zones of the preform can be used to regulate the heating power of the corresponding heating elements.

[0008] To this end, the invention relates to a heat treatment unit for at least one preform of a container manufacturing installation, said preform comprising a body extending along a preform axis, the heat treatment unit comprising: at least two heating elements, each heating element being arranged to heat a different heated zone of the preform body along the preform axis, at least one device for acquiring at least one thermal image of the heated preform, said thermal image showing at least two thermal zones representative of the temperature of the heated zones of the preform body, a module for matching the position of said two thermal zones with the height of the heating elements that heated the heated zones corresponding to said thermal zones, the height of the heating elements being defined along an elevation direction parallel to the preform axis.

[0009] By acquiring a thermal image of the heated preform and correlating the position of each thermal zone shown in this image with the height of the heating elements that created those zones, one can easily determine the effect of these heating elements on the temperature of the heated areas of the preform, specifically by identifying which heating element heated each zone. The heating power of the heating elements can then be adjusted accordingly to obtain the desired temperature profile of the preform body.

[0010] The heat treatment unit according to the invention may include one or more of the following features, taken individually or in any technically feasible combination: the heat treatment unit further includes a display device for a temperature profile of the preform body obtained from the thermal image acquired by the acquisition device; the matching module includes an interface for matching the position of at least a first thermal zone with the height of a first heating element that has heated a first heated zone corresponding to said first thermal zone;the matching module is configured to match the position of at least one second thermal zone with the height of a second heating element that has heated a second heated zone corresponding to said second thermal zone based on the matching of the first thermal zone with the height of the first heating element by means of the matching interface; the heat treatment unit comprises at least three heating elements arranged to each heat a different heated zone of the preform body along the preform axis, the matching module being configured to match each thermal zone corresponding to each heated zone of the preform body with the height of each corresponding heating element;the heat treatment unit includes a control device configured to adjust the heating power of at least one heating element as a function of the temperature of at least one heated area of ​​the preform body, said temperature being measured from the thermal zone corresponding to said heated area in the acquired thermal image of the preform body; the heat treatment unit includes a plurality of adjacent heating elements along a scroll direction substantially perpendicular to the preform axis, said heating elements extending to the same height, the preform being moved along said scroll direction in relation to said plurality of heating elements, each heated area of ​​the preform body being heated by said plurality of heating elements extending to the same height;each heating element comprises a plurality of monochromatic or pseudo-monochromatic electromagnetic radiation sources;

[0011] According to another aspect, the invention also relates to a method of heating a preform by means of a heat treatment unit as described above, comprising the following steps: heating at least two heated zones of the body of the preform by two heating elements; acquiring at least one thermal image of the heated body of the preform, said thermal image showing at least two thermal zones representative of the temperature of the heated zones of the body of the preform; matching the position of said two thermal zones with the height of the heating elements having heated the heated zones corresponding to said thermal zones.

[0012] The heating process may further include the feature that the matching step includes a matching step by an operator of at least one first thermal zone with the height of a first heating element having heated a first heated zone corresponding to said first thermal zone and an automated matching step of at least one second thermal zone with the height of a second heating element having heated a second heated zone corresponding to said second thermal zone according to the matching of the first thermal zone with the height of the first heating element.

[0013] Other aspects and advantages of the invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the accompanying drawings in which:

[0014] - This is a schematic top view of a container production installation comprising a heat treatment unit according to the invention,

[0015] - This is a schematic cross-sectional representation of a preform heated by heating elements,

[0016] - This is a schematic representation of an interface for adjusting the heating power of the heating elements, and

[0017] – laest a schematic representation of a thermal image of the body of a preform heated in a heat treatment unit according to the invention.

[0018] With reference to the, we describe a plant for producing containers 1 from a succession of preforms 2. Such a plant includes, in a known way and in the order of circulation of the preforms 2 and the containers 1 in the plant, a heat treatment unit 4, or furnace, a transfer wheel 6 and a forming station 8.

[0019] The heat treatment unit 4 is arranged to heat a succession of preforms 2 transported into the heat treatment unit 4 by a preform gripping and movement system so as to move them past heating elements 10, as will be described in more detail later. It is understood, however, that the invention also applies to a heat treatment unit 4 capable of heating at least one preform 2 individually, for example, without moving it within the heat treatment unit 4.

[0020] The forming station 8, for example, consists of a carousel carrying several molds 12 that form molding cavities in the shape of the containers 1 to be produced. The heated preforms 2 are each placed in a mold and deformed to acquire the shape of a container 1, for example, by stretch blow molding. At the exit of the forming station, the formed containers 1 are collected, for example, by means of another transfer wheel 14, to be conveyed to other stations in the installation, such as a labeling station, a filling station, and a station for applying a cap to the containers.

[0021] As previously stated, such an installation is known and will not be described in further detail here. It is understood, however, that the installation layout shown in Figure 1 is given only as an example and that the invention applies to any type of installation layout provided that it includes a heat treatment unit 4.

[0022] As more particularly illustrated in the figure, each preform 2 comprises a body 16 and a neck 18, and the heat treatment unit 4 is arranged to heat the body 16 without heating the neck 18 of each preform 2, as will be described in more detail later. The body 16 extends along a preform axis A and has, for example, the shape of a test tube extending between a bottom 20 and the neck 18, which forms an open end of the test tube. The neck 18 includes, for example, a collar 22 extending from a radial plane substantially perpendicular to the axis A of the preform projecting outwards from the body 16. Such a collar 22 forms, for example, a gripping surface for the preform 2 and the container 1 made from the preform 2. The part of the preform 2 extending from the collar 22 to the open end includes, for example, a thread for attaching a cap to the container 1 made from the preform 2.Thus, the neck 18 of the preform 2 has the same shape as the neck of the container 1 made from this preform 2. Therefore, it is necessary not to heat the neck 18 of the preform 2 in the heat treatment unit 4 in order to avoid any deformation of the neck 18.

[0023] The heat treatment unit 4 is arranged to heat the body 16 of each preform 2 in order to raise the temperature of the body 16 above the glass transition temperature of the material forming the body 16 so that the body 16 acquires a malleable character allowing its deformation to form a container 1.

[0024] For this purpose and as shown in Fig. 2, the plurality of preforms 2 is arranged to circulate in relation to at least two heating elements 10 arranged to emit thermal radiation towards the body of the preforms 2 passing in relation to each other. More specifically, the heating elements 10 are arranged one above the other along an elevation direction Z of the heat treatment unit 4, substantially parallel to the axis A of the preform when a preform 2 is placed in the heat treatment unit 4. Thus, the heating elements 10 are arranged so as to expose the entire body 16 of the preforms 2 to radiation, more particularly from the bottom 20 to the collar 22 of the preforms 2. Each heating element 10 is more particularly arranged to heat an area, called the heated area 24, of the body 16 of a preform 2, the heated area 24 extending over a part of the height of the body of the preform 2, measured along the axis A of the preform.In other words, the body 16 of each preform 2 comprises at least two heated zones 24 arranged one above the other along the axis A of the preform, each heated zone 24 extending opposite a corresponding heating element 10 so as to be exposed to the heat emitted by that corresponding heating element 10 when the preform 2 circulates in the heat treatment unit 4.

[0025] Each heating element 10 comprises, for example, a plurality of monochromatic or pseudo-monochromatic electromagnetic radiation sources. More specifically, each heating element 10 is, for example, a laser emitter, and the radiation sources are laser chips arranged to emit laser radiation in the infrared range along an emission direction E substantially perpendicular to the elevation direction Z and corresponding to the direction separating the heating elements 10 from the body 16 of the preforms 2 circulating in the heat treatment unit 4. The radiation sources are, for example, arranged side by side on a support so as to form at least one row of radiation sources extending along the longitudinal direction.According to one embodiment, the radiation sources form at least one upper row and at least one lower row arranged one above the other in the direction of elevation.

[0026] Such heating elements are described, for example, in document FR 3 124 030, and those skilled in the art may refer to this document for further details, particularly concerning the structure of each radiation source, the arrangement of the radiation sources on a support, the connection of the radiation sources to each other, and the cooling of the heating elements. It is understood that the invention is not limited to heating elements formed by laser emitters and also applies to other types of heating elements, such as halogen-type incandescent tubular lamps.

[0027] It should be noted, however, that the invention is particularly well-suited to laser emitters because such laser emitters emit radiation with very low dispersion, that is, radiation primarily oriented along the emission direction E, unlike halogen heating elements which have a particularly large radiation emission cone. Thus, laser emitters allow heating of a very localized heated area 24 of the preform body 16, whereas a halogen heating element will heat a larger area, and the radiation emitted by this heating element and / or the reflection of this radiation in the heat treatment unit 4 may interfere with the radiation emitted by another heating element and thus heat an area other than the one for which it is intended, thereby reducing the efficiency of the heating process that will be described later.

[0028] With such laser emitters, each heated zone 24 has, for example, a height of approximately between 4 mm and 5 mm, for example approximately equal to 4.7 mm. According to one embodiment, a preform 2 has between eighteen and thirty-six heated zones 24, the heat treatment unit 4 comprising at least as many heating elements 10 arranged in a column extending along the elevation direction Z, each heating element 10 of the column being arranged to heat one of the corresponding heated zones 24 depending on the height of the body 16 of the preforms 2.

[0029] It should be noted that the heating elements 10 do not necessarily all have the same height, so the heated zones 24 may also have varying heights. In this case, the height and position of each heating element 10 are known for implementing the matching process that will be described later.

[0030] In one embodiment, the heat treatment unit comprises several columns of heating elements 10 arranged side by side along the direction of circulation of the preforms 2 in the heat treatment unit 4, such that the preforms pass in front of a succession of heating elements 10 as they circulate in the heat treatment unit 4. In other words, a heated area 24 of the body 16 of a preform 2 is heated by a plurality of heating elements 10 extending to the same height along the elevation direction Z as the preform 2 circulates in the heat treatment unit 4. In another embodiment, the preform 2 is further rotated about its preform axis A while it circulates in the heat treatment unit 4, so that the entire circumference of the body 16 is exposed to radiation from the heating elements 10.Thus, each heated zone 24 extends over the entire circumference of a portion of the body 16 of each preform 2. However, as will be described later, in the case of an asymmetric deformation of the body 16 of the preform 2 in a heated zone 24, the temperature of this heated zone 24 is not uniform over the entire circumference of the preform.

[0031] The heating power of each heating element 10 is adjustable by means of a control device 26 of the heat treatment unit 4. The control device 26 thus allows the heating intensity of each heated zone of the preform 2 to be adjusted in order to manage the temperature profile applied to it. Indeed, as is known, the heated zones 24 of the same preform 2 are not necessarily heated to a uniform temperature. The temperature of a heated zone 24 depends, in particular, on the shape of the container 1 to be produced from the preform 2. More specifically, the more a given zone of a preform 2 must be deformed, or stretched, to form the container 1, the higher the temperature to which it must be heated.

[0032] As shown in Figure 1, the control device 26 allows the heating power of a particular heating element 10, as represented by the histogram on the left of Figure 1, to be adjusted according to the temperature to which the heated zone 24 corresponding to that particular heating element 10 must be heated, as shown in the graph on the right of Figure 2. In this figure showing an example of a display of the setting applied by the control device 26 to the heating elements, there are twenty-four heating elements 10, numbered from 1 to 24, and the bars 30 of the histogram each represent the heating power of one of these heating elements 10 as a function of the heated zone 24 of the preform 2 opposite these heating elements 10. In Figure 1, the body of the preform 2 comprises twenty-two heated zones 24.On the graph on the right, each point 32 represents the desired temperature, called the target heating temperature, for the corresponding heated zone 24. In the example shown, we can see that the heating power of heating elements 6 to 10 is significantly lower than the heating power of the other heating elements, which allows for a constriction extending approximately halfway up the body of a container 1.

[0033] It should be noted that the target heating temperature is considered to have been achieved if the heating temperature falls within an acceptable range around the target heating temperature, as represented by the two dashed curves 34 shown around points 32 on the right-hand side of the graph. In other words, the target heating temperature lies between a lower acceptable heating temperature, below the target heating temperature, and a higher acceptable heating temperature, above the target heating temperature. The heating power of the heating elements 10 is thus adjusted so that a heated zone 24 has a temperature between the lower acceptable heating temperature and the upper acceptable heating temperature.

[0034] When the heat treatment unit 4 comprises several columns of heating elements 10, the heating power of the heating elements 10 in the same row—that is, the heating elements 10 extending to the same height along the Z-axis—is constant. Thus, when the control device 26 controls the heating power of a particular heating element 10, this heating power is applied to all the heating elements 10 located at the same height as that particular heating element. However, if the vessel 1 to be formed has at least one portion where the cross-section is not circular, the heating power of the heating elements 10 located at the height of this portion can be modulated to allow for asymmetrical deformation of the preform 2 in this portion.

[0035] The heating process according to the invention involves passing the preforms through the heat treatment unit 4 in relation to the heating elements 10, the heating power of which is regulated by the control device 26 according to the target heating temperature for the corresponding heated zones 24.

[0036] According to the invention, the heating power of the heating elements 10 is adjusted in particular according to the temperature of at least one heated zone 24 of the body 16 of the preform from the acquisition of a temperature profile of the body of the heated preform 2.

[0037] For this purpose, the heat treatment unit 4 includes at least one acquisition device 36 for acquiring at least one thermal image 38 of at least one preform 2 heated by the heating elements 10. Such an acquisition device 36 is, for example, a thermal camera capable of obtaining an image in the infrared range of a preform 2 after it has been heated by at least two heating elements 10. Thus, the acquisition device 36 is, for example, positioned at the outlet of the heat treatment unit 4 upstream of the transfer wheel 6 so that an image of each preform 2 exiting the heat treatment unit 4 can be acquired by the acquisition device 36. It should be noted that the thermal image 38 is not necessarily a visible image but can be formed from a set of data representative of the temperature profile of the body of the preform 2.

[0038] As shown in Figure 1, the acquired thermal image 38 thus shows at least two thermal zones 40 representative of the temperature of the heated zones 24 of the preform body 2. In other words, the zones 24 heated by the heating elements 10 appear on the thermal image 38 as thermal zones 40, and the temperature of these heated zones 24 can be measured by analyzing the thermal image 38, particularly as a function of the color and / or light intensity and / or contrast with the rest of the thermal image of the thermal zones 40. Thus, as schematically shown in Figure 1, in which the image of several preforms 2 appears, the thermal zones 40 appear as lighter or brighter areas than the rest of the image of the preforms 2.

[0039] The thermal images 38 acquired by the acquisition device 36 are processed by a processing device 42 arranged in particular to determine the temperature of the heated zones 24 from the analysis of the thermal zones 40 and this information, as well as the thermal images 38 acquired, are transmitted to the control device 26.

[0040] A matching module 44, associated with the control device 26, is further configured to match the position of the thermal zones 40 on the thermal image 38 with the height measured along the elevation direction Z of the heating elements 10 that heated the heated zones 24 corresponding to these thermal zones 40. In other words, the matching module 44 is arranged to associate the position of a given thermal zone 40 in the thermal image 38 of a preform 2 with the height of the heating element 10 that heated the heated zone 24 that generated this given thermal zone 40.Indeed, in order to effectively exploit the information obtained by means of the acquisition device 36 as will be described in more detail later, it is necessary first to know the source of the information contained in the thermal image 38, that is to say, it is necessary to identify the heating element(s) 10 which generated each thermal zone 40 of the thermal image 38.

[0041] According to one embodiment, the matching module 44 includes an interface 46 enabling an operator to match the position of a first thermal zone 40 with the height of a first heating element 10 that has heated a first heated zone 24 corresponding to the first thermal zone 40. More specifically, the interface 46 includes, for example, a display device for a temperature profile obtained from the acquired thermal image 38, as represented by the points 32 on the right of the diagram. By viewing this profile, an operator can select at least one particular thermal zone 40, referred to as the first thermal zone, and determine the height of the heating element 10, referred to as the first heating element, that heated the heated zone 24, referred to as the first heated zone, which generated the first thermal zone 40 in the image. The operator then enters this information using the interface 46.The interface 46 takes the form of a touch-sensitive human-machine interface, from which an operator can act directly on the thermal profile obtained from the thermal image 38 displayed on the display device to select a thermal zone 40 and on the adjustment interface shown on the, to identify which heating element 10, among the heating elements 10 numbered 1 to 24, made it possible to obtain the selected thermal zone 40.

[0042] According to one embodiment, this matching by an operator using the interface is carried out on at least two non-adjacent thermal zones 40.

[0043] From this information, the matching module 44 is configured to automatically match the position of at least one second thermal zone 40 with the height of a second heating element 10 which has heated a second heated zone 24 corresponding to the second thermal zone 40 according to the matching of the first thermal zone 40 with the height of the first heating element 10.Indeed, by knowing the correspondence between the height of the first heating element 10 and the position of the first thermal zone 40, the matching module 44 can perform the matching between the height of the second heating element 10 and the position of the second thermal zone 40, for example by using the thermal image 38 to measure the distance between the first thermal zone 40 and the second thermal zone 40 in order to deduce the difference in height between the first heating element 10 and the second heating element 10. Alternatively, the matching is done on several distinct thermal images, a first image showing at least one thermal zone and another image showing at least another thermal zone.

[0044] According to one embodiment, the matching by the matching module is also performed automatically for the first thermal zone, that is, without an operator using interface 46 to perform this initial matching. This can be done, for example, by creating a thermal image 38 in which a single thermal zone 40 appears and knowing which single heating element 10 was used to heat the heated area 24 corresponding to this thermal zone 40.

[0045] When the heat treatment unit includes more than two heating elements, i.e., at least three heating elements arranged to each heat a different heated zone 24 of the preform body 16 along the preform axis A, the matching module 44 is configured to match each thermal zone corresponding to each heated zone of the preform with the height of each corresponding heating element. Thus, the matching module 44 makes it possible to associate each thermal zone 40 of the thermal image 38 with the heating element 10 that heated the heated zone 24 producing that thermal zone 40.

[0046] Thus, thanks to the matching module 44, the control device 26 makes it possible to determine the heating temperature of each heated zone 24 of the preform 2 as a function of the heating power of each corresponding heating element 10. This result is displayed, for example, on the adjustment interface shown in Figure 3, in which the heating power of each heated zone 24 is compared to the heating temperature represented by points 32.

[0047] Thus, if a heating temperature falls outside the acceptable temperature range represented by curves 34 on the diagram, the control device 26 can adjust the heating output of the corresponding heating element to correct this temperature. In other words, the control device 26 establishes a control loop for the heating output of the heating elements based on the temperature of the heated zones 24 at the outlet of the heat treatment unit 4, as measured by the data acquisition device 36.

[0048] It should be noted that regulation is not necessarily performed for each heating element 10 individually. Indeed, one or more extended heated zones can be formed by grouping several adjacent heated zones 24 along the preform axis A, as represented by rectangles on the diagram. Regulation can then be applied to the extended heated zone(s), simultaneously with regulation for heated zones 24 outside of an extended heated zone, by simultaneously modifying, in the same direction (increasing or decreasing the heating power), the heating powers of the heating elements 10 corresponding to each extended heated zone based on the measured temperature of one of the heated zones 24 of the extended heated zone(s) and a target heating temperature of the extended heated zone(s).For example, the heated zones 24 of an extended heated zone are designed to be similarly deformed to form a container 1.

[0049] The thermal image 38 can be used to establish and, for example, display a heating temperature profile of the preform body, as shown on the right. Such a display also allows an operator to easily and immediately observe the effect of changing the heating power of one or more heating elements 10 on the heating of the preform body 16.

[0050] In addition, if the heating temperature profile of one or more preforms measured by the acquisition device 36 and the processing device 42 does not conform to the desired temperature profile, the container production installation can be arranged to remove the non-conforming preforms 2 before they are transmitted to the forming station 8, thus limiting the risks of forming containers that do not have the desired characteristics.

[0051] The acquisition device 36 can also be used to detect the absence of a preform 2 in the sequence of heated preforms 2, for example, if this preform 2 was incorrectly grasped by the preform gripping and handling system 2 or if the preform 2 fell from this system during its movement in the heat treatment unit 4. Indeed, such an absence can easily be detected by observing the absence of thermal zones 40 in the acquired thermal image 38 where this preform should have passed in front of the acquisition device 36, or by observing temperatures measured from this thermal image 38 that are significantly lower than the expected temperatures. Detecting such an absence makes it possible, for example, to activate the blowing process in an empty mold corresponding to the mold that should have received the missing preform 2.

[0052] Thus, thanks to the acquisition device 36 and the control device 26, in particular the matching module 44, the setting and operation of the heat treatment unit 4 can be controlled in a simple and efficient manner.

[0053] The control device 26 and the processing device 42 of the acquisition device 36 are electronic circuits designed to manipulate and / or transform data represented by electronic or physical quantities in registers of the computer and / or memories into other similar data corresponding to physical data in register memories or other types of display devices, transmission devices or storage devices.

[0054] As specific examples, the control device 26 and the processing device 42 are implemented as a programmable logic component, such as an FPGA (Field Programmable Gate Array), or as an integrated circuit, such as an ASIC (Application Specific Integrated Circuit).

[0055] Alternatively, when the process is implemented as one or more software programs, that is, as a computer program, also called a computer program product, it is also capable of being stored on a computer-readable medium, not shown here. A computer-readable medium is, for example, a medium capable of storing electronic instructions and being connected to a bus of a computer system. Examples of such a readable medium include an optical disc, a magneto-optical disc, ROM, RAM, any type of non-volatile memory (e.g., FLASH or NVRAM), or a magnetic card. A computer program containing software instructions is then stored on this readable medium.

Claims

Heat treatment unit (4) for at least one preform (2) of a container manufacturing installation (1), said preform (2) comprising a body (16) extending along a preform axis (A), the heat treatment unit (4) comprising: at least two heating elements (10), each heating element (10) being arranged to heat a different heated zone (24) of the body (16) of the preform (2) along the preform axis (A), at least one acquisition device (36) for at least one thermal image (38) of the heated preform (2), said thermal image (38) showing at least two thermal zones (40) representative of the temperature of the heated zones (24) of the body (16) of the preform (2), a matching module (44) for the position of said two thermal zones (40) with the height of the heating elements (10) that heated the heated zones (24) corresponding to said thermal zones (40),the height of the heating elements (10) being defined along an elevation direction (Z) parallel to the axis (A) of the preform. Heat treatment unit according to claim 1, further comprising a display device for a temperature profile of the body (16) of the preform (2) obtained from the thermal image (38) acquired by the acquisition device (36). Heat treatment unit according to claim 1 or 2, wherein the matching module (44) includes a matching interface (46) of the position of at least a first thermal zone (40) with the height of a first heating element (10) having heated a first heated zone (24) corresponding to said first thermal zone (40). Heat treatment unit according to claim 3, wherein the matching module (44) is configured to match the position of at least one second thermal zone (40) with the height of a second heating element (10) having heated a second heated zone (24) corresponding to said second thermal zone (40) as a function of matching the first thermal zone (40) with the height of the first heating element (10) by means of the matching interface (46). Heat treatment unit according to any one of claims 1 to 4, comprising at least three heating elements (10) arranged to each heat a different heated zone (24) of the body (16) of the preform (2) along the axis (A) of the preform, the matching module (44) being configured to match each thermal zone (40) corresponding to each heated zone (24) of the body (16) of the preform (2) with the height of each corresponding heating element (10). Heat treatment unit according to any one of claims 1 to 5, comprising a control device (26) configured to adjust the heating power of at least one heating element (10) as a function of the temperature of at least one heated zone (24) of the body (16) of the preform (2), said temperature being measured from the thermal zone (40) corresponding to said heated zone (24) in the thermal image (38) acquired of the body (16) of the preform (2). Heat treatment unit according to any one of claims 1 to 6, comprising a plurality of adjacent heating elements (10) along a scroll direction substantially perpendicular to the axis (A) of preform, said heating elements (10) extending to the same height, the preform (2) being moved along said scroll direction in relation to said plurality of heating elements (10), each heated zone (24) of the body (16) of the preform (2) being heated by said plurality of heating elements (10) extending to the same height. Heat treatment unit according to any one of claims 1 to 7, wherein each heating element (10) comprises a plurality of monochromatic or pseudo-monochromatic electromagnetic radiation sources. A method for heating a preform using a heat treatment unit according to any one of claims 1 to 8, comprising the following steps: heating at least two heated zones (24) of the body (16) of the preform (2) by two heating elements (10); acquiring at least one thermal image (38) of the heated body (16) of the preform (2), said thermal image (38) showing at least two thermal zones (40) representative of the temperature of the heated zones (24) of the body (16) of the preform (2), matching the position of said two thermal zones (40) with the height of the heating elements (10) having heated the heated zones (24) corresponding to said thermal zones (40). Heating method according to claim 9, wherein the matching step comprises a matching step by an operator of at least a first thermal zone (40) with the height of a first heating element (10) having heated a first heated zone (24) corresponding to said first thermal zone (40) and an automated matching step of at least a second thermal zone (40) with the height of a second heating element (10) having heated a second heated zone (24) corresponding to said second thermal zone (40) according to the matching of the first thermal zone (40) with the height of the first heating element (10).

Images