Equipment for emitting radiation to polymerise a material

Abstract

The invention relates to equipment (1) for emitting radiation intended to polymerise a polymerisable material (P), comprising: - at least one light-emitting diode of a first type (LUV-A) suitable for emitting rays with a first spectrum of radiation in the ultraviolet; - a first control unit (UC) for supplying electrical power to the light-emitting diode of the first type (LUV-A). The equipment comprises: - a light-emitting diode of a second type (LUV-C) suitable for emitting rays with a second spectrum of radiation in the ultraviolet, the first and second spectra extending over different wavelength ranges.

Description

[0001] Equipment for emitting radiation to polymerize a material.

[0002] BACKGROUND OF THE INVENTION

[0003] The present invention relates to the field of equipment for generating radiation intended to polymerize at least one polymerizable material under the effect of such radiation.

[0004] It is known to polymerize polymerizable materials by exposing them to radiation such as ultraviolet radiation (hereafter the term ultraviolet may be referred to as UV).

[0005] The polymerizable material is arranged so that its state changes under the effect of radiation and passes from a liquid or pasty state to a solid state.

[0006] Examples of such materials include polyester acrylics or urethane acrylics.

[0007] A polymerizable material is, for example, a varnishing product that hardens under the effect of UV light and is applied to electronic boards to protect them from chemical or mechanical actions.

[0008] A polymerizable material is polymerized by radiation within a specific radiation spectrum unique to that material.

[0009] Given the wide variety of polymerizable materials available on the market, prior art equipment adapted to emit radiation generally includes light-emitting diodes or medium-pressure or microwave arc lamps generating UV in a broad radiation spectrum covering several sensitivity spectra of several materials polymerizable under the effect of radiation.

[0010] In special cases, light-emitting diodes are chosen with a narrow radiation spectrum suitable for a limited range of polymerizable materials in spectra exclusively included in said narrow radiation spectrum (typically a narrow radiation spectrum may be exclusively included in a part of the UV-A spectrum).

[0011] These arc lamp type sources are also in most cases (indirectly) generators of ozone, representing a human risk and significant point sources of heat.

[0012] It is therefore necessary to choose between equipment with medium pressure or microwave arc lamps generating UV in a broad spectrum compatible with a wide variety of UV-curable materials or, on the contrary, light-emitting diodes adapted to emit in a narrow spectrum specifically adapted to the UV polymerization of some polymerizable materials.

[0013] Broad-spectrum equipment is more economical to produce but less energy-efficient because it covers radiation spectra extending well beyond the specific spectrum of the material to be polymerized.

[0014] Narrow spectrum equipment, typically equipment emitting in the UV-C spectrum, is more expensive to produce because it requires more expensive narrow spectrum diodes, but it has the advantage of being more energy efficient because the effective portion of the narrow spectrum for polymerizing the selected material is increased.

[0015] SUBJECT OF THE INVENTION

[0016] The invention is notably aimed at providing equipment for the emission of radiation intended to polymerize a polymerizable material which resolves at least partially some of the disadvantages of the aforementioned prior art.

[0017] SUMMARY OF THE INVENTION For this purpose, the invention provides equipment for emitting radiation intended to polymerize a polymerizable material, comprising:

[0018] - at least one light-emitting diode of a first type, each at least one light-emitting diode of the first type being adapted when electrically powered to emit rays on a first radiation spectrum in the ultraviolet;

[0019] - a first control unit adapted to control an electrical supply to said at least one light-emitting diode of the first type.

[0020] The equipment is essentially characterized by the following:

[0021] - at least one light-emitting diode of a second type, each at least one light-emitting diode of the second type being adapted when electrically powered to emit rays on a second radiation spectrum in the ultraviolet, the first radiation spectrum extending over a first wavelength range and the second radiation spectrum extending over a second wavelength range different from said first wavelength range.

[0022] Since the first and second spectra of the equipment according to the invention are distinct from each other (i.e., the first wavelength range of the first spectrum differs from the second wavelength range of the second spectrum), a total radiation spectrum formed from the first and second spectra can be generated, which is necessarily broader than the first spectrum alone. Alternatively, only the diodes of either the first or second type can be activated, depending on the material to be polymerized. Thus, the equipment according to the invention exhibits a variable spectral width within the limits of the range of the first and second spectra, this spectral width being chosen according to the radiation spectrum specific to the material to be polymerized.

[0023] In this way the energy efficiency of the equipment can be improved by adapting the width of the generated spectrum according to the spectrum required for the polymerization of the polymerizable material to be polymerized.

[0024] Other features and advantages of the invention will become apparent from the following description of a particular and non-limiting embodiment of the invention.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Reference will be made to the attached drawings, including:

[0027] [Fig. 1] Figure 1 is a diagram of equipment 1 according to the invention with diodes of a first type LUV-A emitting exclusively in a first spectrum which is here exclusively in UV-A and with diodes of a second type LUV-C emitting exclusively in a second spectrum which is here exclusively in UV-C, this figure 1 also illustrating a detail of a diode support Sp carrying the diodes of the first and second types, the diode support being made up of several removable panels (in this embodiment of figure 1, each removable panel of the support Sp carries only one type of diode chosen from said first and second types of diodes);

[0028] [Fig. 2] Figure 2 is a diagram of equipment 1 according to the invention which is similar to that of Figure 1, the difference being that here, each removable panel of the support Sp carries diodes of the first and second types of diodes so that the radiation emitted by the two types of diodes is a homogeneous mixture of radiation from the first and second spectra of radiation (an advantage of this mode is a spatial homogenization of the radiation by spatial proximity of the sources of the rays in the first and second spectra);

[0029] [Fig. 3] Figure 3 is a diagram of equipment 1 according to the invention in which the equipment includes a cooling system arranged to cool portions of the equipment according to the invention in order to control the temperatures of the LUV-A, LUV-C diodes of the equipment 1, in this case the cooling system is arranged to cool portions of the support Sp independently of each other according to temperature measurements made by several temperature sensors Cth, the equipment 1 also includes a plurality of irradiation sensors Cuv arranged to measure irradiation values ​​and one or more control units UC, UC2 arranged (s) to control the power supply of the diodes according to the measured irradiation values ​​so that the irradiation of the material tends towards one or more setpoint values ​​(s),for example, a first irradiation command Cons in the first spectrum (i.e., in the first wavelength range) and a second irradiation command in the second spectrum (i.e., in the second wavelength range);

[0030] [Fig. 4] Figure 4 illustrates the regulation principle used in the equipment according to the invention to regulate the supply of diodes according to irradiation measurements made by the Cuv irradiation sensors and to regulate the cooling of the diodes via the cooling system and its Cth temperature sensors;

[0031] [Fig. 5] Figure 5 illustrates an evolution of the received cp radiation flux on a target (expressed in mW / cm2) as a function of a Pelec electrical supply power (the abscissa expresses the evolution as a percentage of the supply power, the value of 100% being reached when a diode of a given type is supplied at its maximum power), the top curve is the cp radiation flux in the first spectrum in UV-A (generated by the diodes of the first type) and the bottom curve is the cp radiation flux in the second spectrum in UV-C (generated by the diodes of the second type).

[0032] DETAILED DESCRIPTION OF THE INVENTION

[0033] As previously stated, with reference to Figures 1, 2 and 3, the invention essentially relates to equipment 1 for the emission of radiation intended to polymerize a polymerizable material P.

[0034] Equipment 1 includes:

[0035] - at least one light-emitting diode of a first type LUV-A (in this case several diodes of the first type LUV-A);

[0036] - at least one light-emitting diode of a second type LUV-C (in this case, several diodes of the second type LUV-C); and

[0037] - a first control unit UC adapted to control a power supply of each of the light-emitting diodes of the first type LUV-A and each of the light-emitting diodes of the second type LUV-C.

[0038] However, it is conceivable that the first control unit UC controls the power supply of only the first type LUV-A LEDs, while another control unit regulates the power supply of each of the second type LUV-C LEDs.

[0039] Each light-emitting diode of the first type LUV-A is adapted, when electrically powered, to emit rays exclusively on a first radiation spectrum in the ultraviolet.

[0040] Each light-emitting diode of the second type LUV-C is adapted, when electrically powered, to emit rays exclusively on a second radiation spectrum in the ultraviolet.

[0041] The first radiation spectrum extending exclusively over a first wavelength range and the second radiation spectrum extending exclusively over a second wavelength range, the second wavelength range is different from said first wavelength range.

[0042] Preferably, the first and second wavelength ranges are disjoint and far apart. Preferably, the first UV-A wavelength range extends between 340nm and 400nm, preferably between 365nm and 395nm, and the second UV-C wavelength range extends between 100nm and 280nm, preferably between 250nm and 260nm (ideally it is centered around the value of 254nm).

[0043] However, it is also possible to choose these first and second ranges so that the second range only partially overlaps the first range. In both cases, the total spectrum, consisting of at least the first and second spectra, is broader than either the first or second spectrum alone.

[0044] In the possible overlap range of the first and second ranges, the radiation flux can be selectively increased on this single overlap range by simultaneously powering the diodes of the first and second types.

[0045] Equipment 1 according to the invention makes it possible to generate a spectrum that varies between the first spectrum only, the second spectrum only, or a combination of these first and second spectra.

[0046] The spectrum generated by the equipment according to the invention is thus adaptable to the type of polymerizable material to be polymerized.

[0047] In one embodiment of the invention of the equipment:

[0048] - the first control unit UC is adapted to control a power supply to said at least one light-emitting diode of the second type LUV-C (in this case, the power supply to each diode of the second type); and for

[0049] - on the one hand, vary the power supply of said at least one light-emitting diode of the first type LUV-A so that the intensity of the radiation cp generated by said at least one light-emitting diode of the first type LUV-A varies between first minimum and maximum intensities of radiation in the first spectrum; and - on the other hand, vary the power supply of said at least one light-emitting diode of the second type LUV-C so that the intensity of the radiation cp generated by said at least one light-emitting diode of the second type LUV-C varies between second minimum and maximum intensities of radiation in the second spectrum.

[0050] In a particular mode, illustrated in Figure 3, the control unit UC2 varies the power supply to each of the first type diodes and each of the second type diodes.

[0051] In this case, the diodes of the first and second types are distributed in groups of several diodes of the same type and the control unit UC2 controls the power supply of each group of diodes of a given type independently of the power supply of the diodes of the other groups of diodes.

[0052] Thus, a group of diodes can be made up of diodes of a given type which are carried by the same panel of the support Sp of the diodes, which allows the power supplies of diodes of a given type to be managed by zone (diodes of a given type grouped on the same panel form a spatially grouped diode group).

[0053] With reference to Figure 5, the radiation intensity is a photon flux cp in a given relevant spectrum, in this case in the first spectrum in UV-A for diodes of the first type (top curve) or in the second spectrum in UV-C for diodes of the second type (bottom curve).

[0054] This photon flux cp is expressed here in mW / cm² 2 , which is equivalent to the amount of energy in mJ / cm2 received over a given unit of time of 1 second ) .

[0055] This unit corresponds to the luminous intensity per unit area received during the given unit of time (1 second) on a target positioned in front of a given group of diodes onto which the rays emitted by these diodes are projected.

[0056] Depending on the variation in the power supply to the first type of LUV-A light-emitting diodes, they collectively generate a photon flux cp in the first spectrum only (UV-A), the power of which is expressed in mW / cm². 2 varies between a first minimum radiation intensity in the first spectrum and a first maximum radiation intensity in the first spectrum.

[0057] In the example illustrated in Figure 5, the radiation flux cp in the first spectrum, i.e. in UV-A generated by the first type LUV-A diodes, is:

[0058] - 200 mW / cm 2 for a power supply at 10% of the maximum Pelec power admissible by these diodes of the first type LUV-A; and of

[0059] - 1200 mW / cm 2 for a power supply at 80% of the maximum Pelec power admissible by these diodes of the first type LUV-A.

[0060] Depending on the variation in the power supply to the second type of LUV-C light-emitting diodes, they collectively generate a photon flux cp in the second spectrum only (in UV-C), the power of which is expressed in mW / cm². 2varies between a first minimum radiation intensity in the second spectrum and a first maximum radiation intensity in the second spectrum. The radiation flux cp in the second spectrum, i.e., in UV-C generated by the second type LUV- diodes

[0061] This is from:

[0062] - 50 mW / cm 2 for a power supply at 10% of the maximum Pelec power admissible by these second-type LUV-C diodes; and of

[0063] - 400 mW / cm 2 for a power supply at 80% of the maximum Pelec power admissible by these diodes of the second type LUV-C.

[0064] In this particular case, the photon flux curves cp in the first and second UV-A, UV-C spectra as a function of the variation of the power supply (in %) are straight lines, the variation of these fluxes being linear as a function of the variation of the power supply value.

[0065] Depending on the characteristics specific to diodes of a given type (LUV-A, LUV-C), this variation can be linear or not, continuous or not (stepwise) and extending from a minimum intensity threshold from which the radiation begins to the maximum intensity threshold.

[0066] In a particular embodiment, the first control unit UC may be arranged to: - vary the power supply of said at least one light-emitting diode of the first type LUV-A, as a function of a first irradiation setpoint Cons in the first UV-A spectrum and at least a first irradiation value of a first optical target measured in the first UV-A spectrum; and to - vary the power supply of said at least one light-emitting diode of the second type LUV-C, as a function of a second irradiation setpoint in the second spectrum and at least a second irradiation value of said first optical target or of a second optical target measured in the second spectrum.

[0067] In this particular embodiment, the first control unit UC allows for the regulation of both irradiation in the first UV-A spectrum and irradiation in the second UV-C spectrum, these irradiation regulations being carried out independently of each other and according to irradiation measurements in each of the said first and second spectra.

[0068] In an alternative embodiment illustrated in Figure 3, it can be ensured that:

[0069] - equipment 1 includes a second control unit UC2 which is adapted to control a power supply of said at least one light-emitting diode of the second type LUV-C, preferably of each light-emitting diode of the second type LUV-C;

[0070] - the first control unit UC being adapted to vary the power supply to said at least one light-emitting diode of the first type LUV-A so that the intensity of the radiation cp generated by said at least one light-emitting diode of the first type LUV-A varies between first minimum and maximum radiation intensities in the first spectrum; and

[0071] - the second control unit UC2 being adapted to vary the power supply of said at least one light-emitting diode of the second type LUV-C so that the intensity of the radiation cp generated by said at least one light-emitting diode of the second type LUV-C varies between second minimum and maximum intensities of radiation in the second spectrum.

[0072] In this embodiment, instead of having the same control unit UC to manage the power supply of the diodes of the first and second types LUV-A, LUV-C, we have a first control unit UC to manage the power supply of the diode(s) of the first type LUV-A and a second control unit UC2 to manage the power supply of the diode(s) of the second type LUV-C.

[0073] This particular embodiment is conducive to a responsive control speed and modularity of the equipment according to the invention, since each type of LUV-A, LUV-C diode is associated with a unique control unit specifically programmed for regulating only one type of diode. Depending on the diode type, it may require specific control parameters to maximize its lifespan while maintaining a minimum radiation quality. In this respect, dedicating a control unit to a single diode type can be advantageous for achieving control tailored to each diode type.

[0074] In this embodiment, the first control unit UC controls the exclusive supply of each of the diodes of the first type, by group of diodes of the first type.

[0075] In this embodiment, the second control unit UC2 controls the exclusive power supply to each of the second-type diodes, by group of second-type diodes. In this embodiment of Figure 3:

[0076] - the first control unit UC is arranged to vary the power supply to said at least one first light-emitting diode of the first type LUV-A, as a function of a first irradiation setpoint Cons in the first spectrum and at least one first irradiation value of a first optical target measured in the first UV-A spectrum; and

[0077] - the second control unit UC2 is arranged to vary the power supply of said at least one first light-emitting diode of the second type LUV-C, as a function of a second irradiation setpoint in the second UV-C spectrum and at least one second irradiation value of said first optical target or of a second optical target measured in the second spectrum.

[0078] Thus, the first control unit UC allows the regulation of irradiation in the first UV-A spectrum generated by at least some of the diodes of the first type, while the second control unit UC2 allows the regulation of irradiation in the second UV-C spectrum generated by at least some of the diodes of the second type, these irradiation regulations being carried out independently of each other and according to irradiation measurements in each of the said first and second spectra.

[0079] For this purpose, the equipment according to the invention comprises at least a first Cuv irradiation sensor arranged to measure said first irradiation value in the first spectrum and a second Cuv2 irradiation sensor arranged to measure said second irradiation value in the second UV-C spectrum, said first and second Cuv, Cuv2 irradiation sensors being arranged apart from each other.

[0080] Thus, each Cuv, Cuv2 irradiation sensor is specifically adapted and positioned to measure an irradiation value of a target in a single irradiation spectrum (first or second spectrum), these irradiation sensors therefore having improved measurement accuracy compared to a sensor that would measure irradiations in both spectra.

[0081] Typically, the measured irradiation value in a given spectrum is expressed, for example, in mW / cm2 and the irradiation setpoint Cons, which is used for regulation, can also be expressed in mW / cm2 (as illustrated in the example of the regulation loop in Figure 4).

[0082] A given irradiation sensor may include a target onto which the beams of the diodes are directly projected, and in this case, the irradiation sensor may be placed closer to the support of the material to be polymerized than to the diodes (direct measurement of irradiation by the sensor placed next to the material to be polymerized).

[0083] However, it is also conceivable that a given irradiation sensor measures rays emitted from diodes and reflected onto a target distant from the sensor, such a target being either positioned next to the material to be polymerized (for example on the support of this material) or being at least part of the surface of the material to be polymerized (indirect measurement of irradiation by analysis of the radiation reflected by a target distant from the sensor).

[0084] Preferably each group of diodes driven / controlled together by a given control unit UC or UC2 is associated with a corresponding irradiation sensor so that the regulation of the given group of diodes is done using measurement values ​​delivered by the corresponding irradiation sensor.

[0085] Thus, in examples 1 and 2, we have 4 groups of diodes of the first type LUV-A and 4 groups of diodes of the second type LUV-C.

[0086] Each group of diodes of the first type is assigned a single corresponding Cuv irradiation sensor (4 Cuv sensors).

[0087] Each group of diodes of the second type is assigned a unique corresponding Cuv2 irradiation sensor (4 Cuv2 sensors).

[0088] The regulation of the diodes in a given diode group is illustrated in Figure 4. The irradiation setpoint Cons chosen for a given group of diodes of the first type is compared to a current irradiation value in the first spectrum, which is delivered by the irradiation sensor Cuv corresponding to this group of diodes of the first type. Based on the difference, here called the "error," the control unit UC (i.e., the regulator) generates a power supply command for the diodes in this group. This command is denoted here as "UV Power"; it is the electrical power supplied to this group of diodes, here named the "UV LED System." This group of diodes delivers radiation in the first spectrum with an "actual intensity" which is expressed here in mW / cm².

[0089] It is this actual flux intensity in the first spectrum that is received by the material to be polymerized. The same regulation principle is applied simultaneously to independently control each group of diodes of the second type. The irradiation value in the second spectrum delivered by a given group of diodes of the second type is measured by a Cuv2 irradiation sensor that is sensitive exclusively in this second spectrum; this sensor is dedicated to the group of diodes of the second type thus regulated.

[0090] An irradiation setpoint in the second spectrum Cons2 is assigned to this given group of diodes and the control of this given group of diodes of the second type is then carried out according to an irradiation measurement and an irradiation setpoint which are specific to each given group.

[0091] Thus, the first power supply control unit UC is arranged to vary the supply to each at least one diode of the first type LUV-A independently of the supply to each at least one diode of the second type LUV-C.

[0092] Equipment 1 according to the invention also includes an SR cooling system arranged to cool at least one LUV-A type LED and at least one LUV-C type LED.

[0093] In this case, as can be understood from the example in Figure 3, the SR cooling system comprises a cooling unit UF, at least one first temperature sensor Cth located in a space where said diodes of the first and second types LUV-A, LUV-C are located, at least one first solenoid valve M fluidically coupled to a heat exchanger Eth of the cooling unit UF and at least one first thermal regulator Rth.

[0094] As can be seen from Figures 3 and 4, this thermal regulator Rth is arranged to control, based on at least one temperature value measured by said at least one first temperature sensor Cth and at least one first temperature setpoint Consth, the passage of said at least one first solenoid valve M between:

[0095] - an open position in which the first solenoid valve M allows the circulation of fluid refrigerated by the refrigeration unit UF to a first zone of said space; and

[0096] - a closed position in which the first solenoid valve M prohibits the circulation of the refrigerated fluid towards the first zone of said space.

[0097] The SR cooling system also includes:

[0098] - a second temperature sensor Cth2 located in said space but at a distance from the first temperature sensor Cth;

[0099] - a second solenoid valve M fluidly coupled to the heat exchanger Eth of the refrigeration production unit.

[0100] The first thermal controller Rth (or, where applicable, another thermal controller separate from the first thermal controller Rth) is arranged to control, based on at least one temperature value measured by said second temperature sensor Cth and at least one second temperature setpoint, the passage of said second solenoid valve M between:

[0101] - an open position in which the second solenoid valve M allows the refrigerated fluid to circulate to a second zone of said space (the first and second zones being distinct from each other); and

[0102] - a closed position in which the second solenoid valve M prevents the circulation of the refrigerated fluid towards the second zone of said space.

[0103] The cooling system according to the invention thus makes it possible to control, zone by zone, the temperature in the space where the different LUV-A, LUV-C diodes are located.

[0104] Because the diodes of the equipment are distributed between the different zones of space, it is possible to control the temperature of the diode(s) located in a given zone independently of the temperature of other diodes located in other given zones of space.

[0105] The refrigerated fluid circulating through the Eth exchanger is, for example, a liquid, and each given area of ​​the space where the diodes are arranged is, for example, equipped with its own heat exchanger in which the refrigerated fluid can circulate before returning to the Eth exchanger.

[0106] The cooling system is arranged here to allow circulation of the chilled liquid in a closed loop(s) passing through heat exchangers.

[0107] Each solenoid valve M controls the flow of refrigerated fluid to its corresponding heat exchanger, which is located within the area to be refrigerated. This creates a sealed, closed circuit extending from the heat exchanger of the refrigeration unit (UF) to the heat exchangers situated in the various zones of the space housing the diodes. These latter heat exchangers are connected in parallel between a refrigerated fluid supply line and a refrigerated fluid return line. Each of the valves M is positioned between the refrigerated fluid supply line and the heat exchanger located within the zone of the space containing the diodes.

[0108] Thanks to the equipment 1 according to this embodiment of the invention, it is possible to regulate the operating temperature of each diode located in a given area at the same time as its power supply and the radiation thus generated can be regulated.

[0109] Since the ability of a diode to emit in the correct radiation range, as well as its lifespan and power consumption, can vary, for a given power supply level, depending on its operating temperature, the invention also makes it possible to improve the regulation accuracy of each diode as well as its lifespan.

[0110] In a preferred embodiment, the first thermal regulator Rth may include a first computer arranged to control each of the solenoid valves M of the equipment 1 in order to control / control the evolution of the temperatures of each of the zones of the space where the light-emitting diodes of the first and second types LUV-A, LUV-C are located.

[0111] Since this temperature control is done zone by zone, it is possible to assign a predetermined temperature setpoint specific to each given zone or to a set of zones.

[0112] Each given temperature setpoint can optionally be stored in a database in such a way that the temperature setpoint to be applied is chosen from the database according to criteria such as the type of diode to be cooled, the supply power or the supply duration.

[0113] By defining the setpoint evolution rules in the database, it is possible to choose a maximum temperature change rate for each diode or group of diodes in order to limit thermal shock or overheating. This implementation again protects the diodes and prevents drift in the radiation spectra.

[0114] The efficiency of polymerization is improved (better quality / optimization of polymerization time / precision of control of polymerization kinetics).

[0115] It should be noted that it could also be envisaged that the equipment includes a Cbr chamber to position the material P to be polymerized, the support B of this material being a conveyor, as illustrated in figures 1 and 2.

[0116] The limited polymerization time afforded by equipment 1 according to the invention can be used to reduce the storage areas for the material being polymerized. In this respect, equipment 1 according to the invention can also save floor space in a factory, since it allows the space reserved for products / materials undergoing polymerization to be reduced to the bare minimum.

[0117] In a particular embodiment, shown schematically in figures 1 and 2, the first thermal regulator Rth could include a plurality of calculators Call, Caln each arranged to control one or more of the solenoid valves M that correspond to it.

[0118] Each given computer Call, Caln of the thermal regulator Rth could here be arranged to control and command the temperature variation in one or more of said zones of space which correspond to that given computer, the temperature of one of said given zones of space being controlled by one of said computers of the plurality of computers.

[0119] This method of implementation is advantageous because it allows temperature regulation, zone by zone, with a calculator dedicated to one or some of the zones of the space only.

[0120] Typically each plate supporting a group of diodes can be associated with a heat exchanger, one of the said solenoid valves M and one of the Caln calculators of the thermal regulator, this Caln calculator being thus dedicated to the regulation of a single solenoid valve M and consequently to the regulation of a single zone.

[0121] This method of implementation simplifies the calculations required for temperature regulation, since they can be carried out at the level of each computer dedicated to one or more zones instead of being carried out in a single computer of the cooling system.

[0122] This allows us to gain in thermal regulation speed. In all embodiments of the invention where there is a thermal regulator Rth controlling at least one solenoid valve M, each computer of the thermal regulator Rth is arranged to control the solenoid valve(s) corresponding to it in such a way as to make the actual temperature in °C in one or more given zones tend towards a given temperature setpoint which is specific to said or said given zones (for example a setpoint denoted Consth).

[0123] Of course, the thermal regulator Rth could, as in the example of Figure 3, be a software layer executed by the computer of the control unit UC. According to another aspect of the invention, the control unit UC could be configured to generate an alarm signal indicating a deviation between a measured temperature and at least a predetermined alert temperature level.

[0124] Such an alarm signal is useful, for example, to warn the operator of equipment 1 that he must intervene and carry out a maintenance operation on the equipment.

[0125] An alert can be triggered if overheating is detected (the temperature measured by the Cth sensor is greater than or equal to the alert temperature).

[0126] An alert can also be provided when the measured temperature is too low, in order to guarantee that each diode operates within a predefined ideal temperature range.

[0127] The equipment may, for example, include an audible and / or visual alarm device arranged to emit a sound and / or a visual signal upon receipt of said alert signal.

[0128] This warning signal may also be accompanied by a command to cut off the power supply to at least one of the said light-emitting diodes.

[0129] When a diode is electrically powered with a known supply signal, it is known that it must generate an irradiation flux as well as heat related to its operation.

[0130] Detecting diode operation outside the nominal temperature range can signal either premature diode wear or a thermal regulation defect that could be detrimental to the diode's proper operation and polymerization quality.

[0131] The operator can thus regularly maintain the equipment according to the invention by monitoring the evolution of the different temperature and radiation intensity measurements in each of the spectra and in each of the areas of the equipment.

[0132] Equipment 1 can also include a recorder to store, zone by zone, the successive values ​​measured by the sensors, the successive setpoints applied, and the successively applied electrical supply values. This allows for traceability of the conditions to which the material to be polymerized is subjected. Different ways of positioning the diodes on the Sp support will now be presented.

[0133] As can be understood from the modes in Figures 1 to 3, the equipment includes an Sp diode support made up of several panels removable from each other.

[0134] The Sp support is here schematically represented by a perimeter comprising 8 zones, each corresponding to one of the removable panels.

[0135] Each removable panel carries several of the first type LUV-A diodes and / or several of the second type LUV-C diodes as well as possibly at least one of said Cth temperature sensors.

[0136] In the examples in Figures 1 and 3, each removable panel carries only one type of diode, which simplifies the production of said panels.

[0137] In the example in Figure 2, each removable panel carries both types of diodes, which is favorable to spatial homogenization of the radiation received by the polymerizable material.

[0138] The advantage of fixing the diodes on a removable panel is to facilitate the replacement of the groups of diodes, which is favorable to the scalability of the equipment both in terms of how the diodes are distributed and in terms of the choice of radiation spectra.

[0139] Having a Cth temperature sensor mounted on a removable panel allows the temperature to be detected at the panel level, directly near the diodes. The panel is preferably made of a material with good thermal conductivity so that the measured temperature is representative of that of the diodes mounted on the panel.

[0140] The good thermal conductivity of the panel is also favorable to good heat exchange with the refrigerated fluid.

[0141] It is also possible to ensure that the Cuv irradiation sensor(s) are respectively carried by the panels and are oriented towards a target carried by a support B carrying the material P to be polymerized.

[0142] In this way the Cuv irradiation sensor is necessarily fixedly positioned opposite the diodes carried by the panel and it can measure the actual irradiation on the target located opposite this panel (the target can be the material to be polymerized P).

[0143] This results in a measurement quality that accurately reflects the radiation actually received by the target. The measurement quality is thus improved.

[0144] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0145] In summary, the equipment according to the invention allows UV polymerization of the material (for example, a varnish) after its application with precise radiation dosage for each chosen wavelength range, both in intensity and cycle time.

[0146] This improves the quality of polymerization and reduces the time required for polymerization, which is favorable to a reduction in the floor area devoted to polymerization of products.

[0147] Thanks to the absence of solvents in the material / varnish used and lower power consumption (efficiency of the projected spectrum), the equipment according to the invention also contributes to a reduction in environmental impact. The need for solvent treatment is thus greatly minimized.

[0148] The equipment according to the invention makes it possible to combine several ranges of UV-C (254 nm) and UV-A (395nm and 365nm) wavelengths on the same equipment to increase the range of polymerizable materials (varnishes) with the equipment.

[0149] Equipment 1 incorporates the following functions:

[0150] - Independent temperature monitoring and regulation in different zones to ensure a long lifespan of the diodes;

[0151] - Heat produced by the diodes is dissipated using the SR cooling system (diode performance is preserved and diode lifespan is improved);

[0152] - Independent monitoring and regulation of radiation intensity by spatial zone and wavelength range (since the actual light power differs from the electrical power consumed, the Cuv sensor system ensures, at every instant, for each measured wavelength range, the actual radiation intensity received by the material); - Independent control and operation, zone by zone of the equipment, allowing for adaptation of polymerization conditions for each given zone (better management of the energy required for polymerization). Although the equipment presented here is configured to generate radiation in two spectra, using two types of diodes, it would be possible to increase the number of radiation spectra by increasing the number of diode types.Similarly, the number of irradiation sensor types could be increased to measure radiation across a wider range of wavelengths, with each sensor dedicated to a specific measurement within a narrow wavelength range. This would improve the accuracy of the control system over a greater number of frequency ranges.

Claims

DEMANDS 1. Equipment (1) for the emission of radiation intended to polymerize a polymerizable material (P), comprising: - at least one light-emitting diode of a first type (LUV-A), each at least one light-emitting diode of the first type (LUV-A) being adapted when electrically powered to emit rays on a first radiation spectrum in the ultraviolet; - a first control unit (CU) adapted to control a power supply to said at least one light-emitting diode of the first type (LUV-A), characterized in that the equipment comprises: - at least one light-emitting diode of a second type (LUV-C), each at least one light-emitting diode of the second type (LUV-C) being adapted when electrically powered to emit rays on a second radiation spectrum in the ultraviolet, the first radiation spectrum extending over a first wavelength range and the second radiation spectrum extending over a second wavelength range different from said first wavelength range.

2. Equipment according to claim 1, wherein - the first control unit (CU) is adapted to control a power supply to said at least one light-emitting diode of the second type (LUV-C); and for - on the one hand, vary the power supply to said at least one light-emitting diode of the first type (LUV-A) so that the intensity of the radiation (cp) generated by said at least one light-emitting diode of the first type (LUV-A) varies between first minimum and maximum intensities of radiation in the first spectrum; and - on the other hand, vary the power supply of said at least one light-emitting diode of the second type (LUV-C) so that the intensity of the radiation (cp) generated by said at least one light-emitting diode of the second type (LUV-C) varies between second minimum and maximum intensities of radiation in the second spectrum.

3. Equipment according to any one of claims 1 to 2, wherein the first control unit (CU) is arranged to: - vary the power supply to said at least one light-emitting diode of the first type (LUV-A), as a function of a first irradiation setpoint (cons) in the first spectrum and at least a first irradiation value of a first optical target measured in the first spectrum; and for - vary the power supply of said at least one second type light-emitting diode (LUV-C), as a function of a second irradiation setpoint in the second spectrum and at least a second irradiation value of said first optical target or of a second optical target measured in the second spectrum.

4. Equipment according to claim 1, wherein - The equipment includes a second control unit which is adapted to control a power supply of said at least one light-emitting diode of the second type (LUV-C); - the first control unit (CU) being adapted to vary the power supply to said at least one light-emitting diode of the first type (LUV-A) so that the intensity of the radiation (cp) generated by said at least one light-emitting diode of the first type (LUV-A) varies between first minimum and maximum radiation intensities in the first spectrum; and - the second control unit (UC2) being adapted to vary the power supply of said at least one light-emitting diode of the second type (LUV-C) so that the intensity of the radiation (cp) generated by said at least one light-emitting diode of the second type (LUV-C) varies between second minimum and maximum intensities of radiation in the second spectrum.

5. Equipment according to claim 4, wherein: - the first control unit (CU) is arranged to vary the power supply to said at least one first light-emitting diode of the first type (LUV-A), as a function of a first irradiation setpoint in the first spectrum and at least one first irradiation value of a first optical target measured in the first spectrum; and in which - the second control unit (UC2) is arranged to vary the power supply to said at least one first light-emitting diode of the second type (LUV-C), according to a second irradiation setpoint in the second spectrum and at least one second irradiation value of said first optical target or of a second optical target measured in the second spectrum.

6. Equipment according to claim 3 or claim 5, comprising a first irradiation sensor (Cuv) arranged to measure said first irradiation value in the first spectrum and comprising a second irradiation sensor (Cuv2) arranged to measure said second irradiation value in the second spectrum, said first and second irradiation sensors (Cuv, Cuv2) being arranged apart from each other.

7. Equipment according to any one of claims 1 to 5, wherein the first and second wavelength ranges are disjoint.

8. Equipment according to any one of claims 1 to 7, wherein the first wavelength range (UV-A) extends from 340nm to 400nm, preferably from 365nm to 395nm and the second wavelength range (UV-C) extends from 100nm to 280nm, preferably from 250nm to 260nm.

9. Equipment according to any one of claims 1 to 3, wherein the first control unit (CU) of the power supply is arranged to vary the supply to each at least one diode of the first type (LUV-A) independently of the supply to each at least one diode of the second type (LUV-C).

10. Equipment according to any one of claims 1 at 9, also comprising a cooling system (SR) arranged to cool each at least one light-emitting diode of the first type (LUV-A) and each at least one light-emitting diode of the second type (LUV-C).

11. Equipment according to claim 10, wherein the cooling system (SR) comprises a cooling unit (UF), at least one first temperature sensor (Cth) located in a space where said diodes of the first and second types (LUV-A, LUV-C) are located, at least one first solenoid valve (M) fluidly coupled to a heat exchanger of the cooling unit, and at least one first thermal controller (Rth) arranged to control, as a function of at least one temperature value measured by said at least one first temperature sensor (Cth) and at least one first temperature setpoint (Consth), the passage of said at least one first solenoid valve (M) between: - an open position in which the first solenoid valve (M) allows the circulation of refrigerated fluid from the refrigeration unit to a first zone of said space; and - a closed position in which the first solenoid valve (M) prohibits the circulation of the refrigerated fluid towards the first zone of said space.

12. Equipment according to claim 11, wherein the cooling system (SR) comprises a second temperature sensor (Cth) located in said space but at a distance from the first temperature sensor (Cth), a second solenoid valve (M) fluidly coupled to the heat exchanger thermal (Eth) of the refrigeration unit (UF) and said at least one first thermal controller (Rth) being arranged to control, as a function of at least one temperature value measured by said second temperature sensor (Cth) and at least one second temperature setpoint, the passage of said second solenoid valve (M) between: - an open position in which the second solenoid valve (M) allows the refrigerated fluid to circulate to a second zone of said space; and - a closed position in which the second solenoid valve (M) prohibits the circulation of the refrigerated fluid towards the second zone of said space.

13. Equipment according to any one of claims 11 or 12, wherein the control unit (CU) is arranged to generate an alarm signal informing of a deviation between a measured temperature and at least a predetermined alert temperature level.

14. Equipment according to claim 13, comprising an audible and / or visual alarm device arranged to emit a sound and / or a visual signal upon receipt of said alarm signal.

15. Equipment according to any one of claims 11 to 14, comprising a diode support (Sp) consisting of several removable panels, each removable panel carrying several diodes of the first type (LUV-A) and / or several diodes of the second type (LUV-C) as well as at least one of said temperature sensors (Cth).

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