Laser marking devices, apparatus and related methods

Abstract

The invention relates to a device (1) for laser marking containers (2), in particular bottles or vials of thermoplastic material, comprising at least a body (23), a shoulder (24) extending from the upper end of the body (23), a neck (21) extending from the shoulder (24) and a bottom (22) at the lower end of the body (23), the device (1) comprising at least: a plurality of laser marking stations (3), each station (3) comprising at least one laser marking optical head (30) along an optical path, a laser device (300) equipped with a laser head unit (300) and an optical system (320) for focusing a laser beam (31) to generate a mark (310) at at least one marking area (20) of each container (2) to mark that area (20); and a control device (4) connected to the marking station (3), comprising a laser processing device (40) and a power supply device (41) of the laser marking station (3). The device is characterized in that it comprises a carousel (5) having a vertical axis of rotation X driven in rotation relative to the frame (7) by at least one motor by means of a rolling device (70), the carousel (5) comprising at least: a first platform (50) supporting a plurality of holding members (54) to position the containers (2) along an axis substantially parallel to the vertical axis of rotation X of the carousel (5); and a column (53) supporting the plurality of marking stations (3) such that each optical system (320) is located opposite the container (2) held by the holding member (54). The invention also relates to a container marking method and a container (2) marking device.

Description

Technical Field

[0001] This invention relates to a marking device, a marking apparatus, and a method for laser marking containers. Background Technology

[0002] Information and decorations are known to be labeled on containers, especially plastic bottles.

[0003] Information labeled on containers may, for example, per annum or the formula of the product contained within. Decorations may, for example, indicate the trademark of the product manufacturer.

[0004] It is common knowledge that this information and decorations are labeled on paper or plastic labels. After the container forming process, that is, when the container is formed into its final shape, the label is affixed to the final container.

[0005] However, labeling containers has many drawbacks. In fact, the manufacture, printing, and affixing of labels to containers represent high costs, especially for containers manufactured in large quantities.

[0006] Furthermore, labels are easily torn off during container handling. This prevents end users from accessing certain important information, such as the expiration date.

[0007] Finally, the recycling of plastic containers is complicated by the presence of labels and adhesives. In practice, to promote recycling, it is preferable to ensure that containers, labels, or other items are collected separately according to their different materials.

[0008] However, manually removing labels from containers for specific collection purposes can be extremely tedious. Therefore, removing labels from containers is one of the factors that hinders ensuring selective collection.

[0009] Methods for marking important information on container walls have been proposed. Therefore, it is known to use special inks to print certain important information directly on the container walls.

[0010] However, this printing-based marking method is not satisfactory because, for hygiene reasons, the ink used for marking must dry almost instantly, and the ink must remain on the wall surface without seeping into the container through migration. Therefore, this ink has specific components that are very expensive to manufacture.

[0011] In addition, the use of ink complicates the recycling process for plastic containers.

[0012] To overcome these problems, a method for marking container walls by engraving has also been proposed. Engraving is typically performed using a carbon dioxide laser. This marking method is achieved by removing material from the container wall (particularly through evaporation). As a result, the wall exhibits a locally reduced thickness.

[0013] However, for economic and ecological reasons, there is a desire to reduce the thickness of container walls. This allows for the use of less plastic material in container manufacturing. However, removing material from very thin walls can make them so fragile that the container will crack under the slightest stress.

[0014] Other known laser marking devices have quality issues with uneven workpieces or substrates and / or optical components with variable focal lengths, which is the case for most containers.

[0015] In this case, the markings on the substrate are blurry, vary in height or spacing, and may be difficult to read, making the characters unsatisfactory to use. Summary of the Invention

[0016] To address these marking quality issues while maintaining compatibility with high-volume container production, this invention proposes a laser marking device that ensures optimal marking positions on containers while marking containers at a rate compatible with the productivity requirements of the industrial sector.

[0017] Advantageously, the present invention proposes a turntable with a vertical axis of rotation that allows for the synchronous rotational displacement of the container and the marking station.

[0018] The fact that the marking station and the container rotate synchronously around the same vertical axis of rotation allows the laser beam to be focused at a defined, known, and substantially constant distance. Therefore, the focal length D corresponds to the ideal focal point in the marking area, and the manufacturing tolerances of the container or its orientation do not alter the distance between the laser marking head and the marking area.

[0019] These features enable the device according to the invention to operate at industrial rates, for example, on the order of 8,000 to 100,000 marks per hour.

[0020] This invention relates first to a laser marking device for laser marking containers, particularly bottles or vials made of thermoplastic material, the containers comprising at least a body, a shoulder extending from the upper end of the body, a neck extending from the shoulder, and a bottom at the lower end of the body, the laser marking device comprising at least:

[0021] - Multiple laser marking stations, each laser marking station including at least one laser marking optical head along an optical path, the laser marking optical head being equipped with a laser head unit and an optical system for focusing a laser beam to generate a mark at at least one marking area in each container to mark said marking area, and

[0022] - A control device connected to the laser marking station, the control device including laser processing equipment and a power supply device for supplying power to the laser marking station.

[0023] The device is characterized by comprising:

[0024] - A turntable having a vertical axis of rotation X, the turntable being driven to rotate relative to a frame by at least one motor via a rolling device, the turntable comprising at least:

[0025] - A first platform, supporting multiple retaining members, for positioning the container along an axis substantially parallel to the vertical axis of rotation X of the turntable, and

[0026] - A column supporting the plurality of laser marking stations, such that each optical system is positioned opposite a container held by a retaining member.

[0027] In some embodiments, the working distance between the container axis and the optical head is constant or substantially constant.

[0028] Advantageously, the at least one optical head of each marking station is capable of moving the focus of the laser beam relative to the at least one marking area in the horizontal and / or vertical and / or longitudinal planes.

[0029] According to one possible variation, the column includes a vertical displacement device for vertically displacing each marking station or each optical head, such that each marking station or each optical head can move vertically along the column.

[0030] In some embodiments, the first platform and / or each retaining member includes a vertical displacement device for vertically displacing the container.

[0031] In some embodiments, the turntable includes a second platform, referred to as the lower platform, located below a first platform, referred to as the upper platform, which is driven to rotate synchronously with the second platform; and for each container, the holding member includes, on the one hand, a gripping device for holding the container, preferably by means of a neck, at the upper platform, and on the other hand, a support platform at the lower platform, on which the bottom of the container is supported.

[0032] In some embodiments, the turntable includes a third platform whose rotation axis is coaxial with that of the first platform, and the third platform supports a control device.

[0033] According to another possible variation, the first platform and / or the second platform and / or the column are integrated.

[0034] In some embodiments, the control device is located on the upper part of the third platform.

[0035] According to the last possible variation, each marking station includes two optical heads placed head-to-tail in each station, such that the optical systems of the two optical heads are superimposed to simultaneously mark the marking area located at the top of the container and the area located at the bottom of the container.

[0036] Advantageously, each marking station includes a pulsed laser optical head with a wavelength between 800 and 2000 nanometers.

[0037] The present invention also relates to an apparatus comprising:

[0038] - The laser marking device as described above

[0039] - A container handling station located upstream of the marking device, which supplies containers to the device directly or indirectly at the loading point via a conveyor wheel.

[0040] - A conveyor wheel at the unloading point, used to release the marked container directly or indirectly at the downstream conveying device.

[0041] In some embodiments, the device includes a detection system for detecting marked containers.

[0042] The present invention also relates to a marking method, which includes at least the following steps:

[0043] The first step involves processing the container, preferably by filling and sealing it.

[0044] - The second step involves driving the container, preferably a filled and capped container, to rotate around a vertical axis, while the laser marking station is driven to rotate around the vertical axis synchronously with the container.

[0045] - The third step is to mark the container during rotation.

[0046] Advantageously, the marking step is performed during rotation in an angular sector of less than 360 degrees around the vertical axis.

[0047] In some embodiments, the marking step is performed during rotation on a angular sector of less than 360 degrees around the vertical axis.

[0048] In some embodiments, the marking method is:

[0049] - Following the processing steps of handling the container, preferably filling and capping the container, the process also includes a loading step of loading the container at the loading point.

[0050] - Following the marking step, there is also an unloading step of unloading the container at the unloading point, the marking step being performed between the loading point and the unloading point of the container that has been marked at at least one marking area, after which a new loop including at least these steps of the method begins.

[0051] In some embodiments, the container is moved vertically after the loading step and before or during the marking step.

[0052] In some embodiments, the marking step is performed using a near-infrared pulsed laser. Attached Figure Description

[0053] The invention will be better understood from the following description based on possible embodiments, which will be explained in an illustrative and entirely non-limiting manner with reference to the accompanying drawings, in which:

[0054] Figure 1 A perspective view of the device is shown schematically;

[0055] Figure 2 A vertical sectional view of the device is shown;

[0056] Figure 3 Detailed views of the marking stations and containers are shown;

[0057] Figure 4 A schematic view of the container holding components is shown in detail.

[0058] Figure 5 A schematic, detailed side view of the station applying a laser beam to the held container is shown.

[0059] Figure 6 An embodiment of the device comprising two scanning heads is illustrated schematically;

[0060] Figure 7 A schematic top view of the device according to the invention, particularly the platform rotation, is shown.

[0061] Figure 8 The diagram schematically illustrates a device with a detection system, and

[0062] Figure 9 An example of implementing the method according to the invention is illustrated schematically. Detailed Implementation

[0063] In the following description, elements with the same structure or similar function will be represented by the same reference numerals.

[0064] This invention first relates to Figure 1 The diagram schematically illustrates a laser marking device 1 for laser marking a container 2.

[0065] Within the scope of this invention, container 2 is a bottle or vial. It is made of plastic material. Preferably, the container is made of polyethylene terephthalate (hereinafter referred to as PET). Preferably, container 2 does not contain any additional materials, such as pigments or light-reactive chemical additives. More particularly and preferably, container 2 does not contain laser additives. The term "laser additive" refers to any pigment or additional chemical additive specifically designed to react with the type of marking laser radiation by changing color or contrast. In other words, container 2 is preferably made entirely of PET and / or recycled PET, with or without additives not specifically designed to react with marking laser radiation, such as colored pigments, visible or UV radiation blocking additives, or oxygen absorbers.

[0066] Container 2 can be rigid or semi-rigid. It is used to contain fluids, liquids, powders, or granules, particularly agricultural, food, or cosmetic types. Container 2 can have any type of symmetrical or asymmetrical shape. It can have a circular cross-section, be entirely circular or oval, or have a polygonal cross-section, particularly rectangular or square. Preferably, container 2 has a circular cross-section, particularly being entirely circular.

[0067] Container 2 has at least a body 23, a shoulder 24 extending the body 23, and a bottom 22 at the end of the body 23. The body 23 of container 2 includes peripheral walls. The walls of container 2 can be cylindrical, rectangular, or any shape. In a normal orientation, container 2 is placed with its bottom 22 facing vertically. The bottom 22 can be planar, petal-shaped, or other shapes.

[0068] Preferably, container 2 is obtained by molding a preform made of thermoplastic material. Such a preform is typically obtained by injection molding.

[0069] Within the scope of this invention, container 2 has at least one marking area 20 located on its wall. The at least one marking area 20 is used to receive a mark 310 applied by laser marking.

[0070] The marking area 20 can be oriented such that the marking 310 is parallel to or orthogonal to the main direction of the container 2, or has any possible orientation relative to the wall 25 of the container 2 along its main direction.

[0071] The device 1 according to the invention includes at least a plurality of laser marking stations 3.

[0072] The laser marking station 3 includes at least one optical head 30 along an optical path, which is connected to a control device 4 for controlling the optical station 3. The control device 4 includes a laser processing device 40 and a power supply device 41 for supplying power to the laser marking station 3.

[0073] The laser processing apparatus 40 (or laser 40) includes a light emission source or pump source, and optionally includes an amplification medium to emit laser light in the form of a laser beam 31.

[0074] According to one possible variation, the optical head 30 includes a magnifying medium.

[0075] The optical head 30 is connected to the laser processing device 40 via electrical connectors and an optical fiber network, or an optical channel 600. The optical channel 600 includes at least one optical fiber, which is, for example, an optical waveguide for a laser emitted by the laser processing device 40.

[0076] According to one possible variation, the amplification medium is incorporated into the optical channel 600 in the form of a doped fiber, and the light emitted from the device 40 is injected into the laser head unit 300 in the doped fiber.

[0077] Preferably, the amplification medium is an optical fiber.

[0078] The laser marking station 3 uses the control device 4 to control the emission of the optical head 30 and the laser beam 31.

[0079] Therefore, the optical head 30 includes a laser head unit 300 and an optical system 320, the optical system being detachably mounted on the laser head unit 300. Preferably, the laser head unit 300 emits a laser beam 31 oriented in a predetermined direction.

[0080] The optical system 320 includes at least one mirror for moving the laser beam 31 in a horizontal and / or vertical plane, and optionally also includes a lens at the optical exit 321 of the optical system 320 for focusing the beam in the plane and at a location where the at least one marking region 20 is located, so as to generate a mark 310 in the at least one region 20.

[0081] The optical path refers to the path that a laser travels from its emission from, for example, a laser processing device 40 until it exits as a laser beam 31 from the optical exit 321 of an optical system 320.

[0082] In other words, the at least one marking area 20 corresponds to a processing surface in which the laser beam 31 is applied in the horizontal and / or vertical directions. Depending on the type of marking 310 to be applied, the focus of the laser beam 31 is not necessarily located directly on the wall of the container 2; that is, in the longitudinal direction relative to the at least one marking area 20 of the container 2, the focus of the laser beam 31 may be located above the wall, directly on the wall (at the outer surface of the container 2), or inside the wall (e.g., at the inner surface of the container 2, or even further away).

[0083] In some embodiments, the device 1 includes a fixed lens, which may be spherical, flat, or preferably F-θ type, so as to maintain a relatively constant focal size in the plane.

[0084] According to one possible variation, the laser head unit 300 and the optical system 320 are integrated into one unit.

[0085] In some embodiments, the control device 4 of the laser station 3 includes multiple cooling units (not shown).

[0086] Within the scope of this invention, laser marking on at least one region 20 of container 2 can be performed, in particular, by locally altering the refractive index, and / or by locally altering the transmittance, and / or by locally altering the reflectivity of the material of container 2.

[0087] Each marking station 3 includes at least one optical head 30, which emits and focuses a laser beam 31.

[0088] According to one possible variation, the at least one optical head 30 generates an optical beam 31.

[0089] In some embodiments, the optical head 30 includes a controlled device (not shown) for moving the emitted laser beam 31 in the direction of the optical axis or in a direction perpendicular to the optical axis, for example by means of a mirror movable relative to the marking area 20 of the container 2.

[0090] According to one possible variation, the optical head 30 includes a controlled device (not shown) for moving the focus of the emitted laser beam 31 in the direction of the optical axis or in a direction perpendicular to the optical axis, for example, by means of a lens movable relative to the marking area 20 of the container 2.

[0091] The control device 4 includes an electronic control unit 400 for controlling the displacement of the laser beam 31. The unit 400 can modify the markings 310 to be annotated by setting parameters as needed, which involves, for example, digital control. The parameters to be modified include, for example, the displacement coordinates of the laser beam 31, the displacement velocity of the laser beam 31, etc.

[0092] Marker 310 may include characters, patterns, barcodes, etc.

[0093] Typically, the distance D1 between the exit of the laser beam 31 and the marking area 20 of the container 2 can vary depending on the shape and / or size of the container 2.

[0094] The laser beam 31 can draw the mark 310 indiscriminately according to either a vector pattern (i.e., by continuous drawing) or a matrix pattern (i.e., by point-by-point drawing).

[0095] In some embodiments, the optical head 30 includes a pulsed laser unit 300. The pulsed laser unit 300 generates a laser beam 31, which is then diffused by the optical system 320. Preferably, the wavelength of the emitted laser is between 800 and 2000 nanometers (nm).

[0096] In other words, the optical head 30 includes a laser unit 300 that emits a pulsed laser beam 31.

[0097] In a preferred embodiment, the average optical power of the laser beam 31 is between 5 and 200 watts.

[0098] In some embodiments, depending on the type of marking sought, lasers emitting different wavelength beams 31 may also be selected, such as ytterbium, erbium, or thulium fiber lasers, or Nd-YAG or Nd:YVO4 solid-state lasers.

[0099] Depending on the different possible configurations, the laser is emitted specifically from device 40 and / or optical channel 600 or from laser unit 300.

[0100] As a possible variant, the Nd-YAG laser is constructed to emit a laser beam 31 with a wavelength of 532 nm, which is emitted in the visible light range, more precisely in the green range.

[0101] According to another variation of the invention, the Nd-YAG laser of the marker station 3 is configured to emit a laser beam 31 with a wavelength (e.g., 355 nm) in the near-ultraviolet range.

[0102] Preferably, the wavelength of the emitted laser beam 31 is therefore between 1000 and 1100 nm, or between 1500 and 1600 nm, or between 1900 and 2000 nm, depending on the type of container 2 to be marked and / or on the type of mark 310 to be applied to the marking area 20 of the container 2.

[0103] It has been observed that the marked areas 20 of the "PET" material wall of container 2, when irradiated by a laser beam 31 in the near-infrared range with appropriate power and / or exposure time, undergo a phenomenon known as "foaming." Foaming involves melting the material and generating bubbles, which expand to form protrusions on the surface. These bubbles remain trapped during cooling. The strength of the material is almost unaffected. Furthermore, the resulting markings 310 are much more legible because the bubbles in the material reflect light in a diffuse manner.

[0104] Preferably, the marking station 3 uses a laser operating in pulse mode to generate short pulses (depending on the desired marking) with a duration of less than 500 ns (nanoseconds) and a peak power in the range of several kW (kilowatts) to tens of kW, and focuses the beam near the wall of container 2 at the marking area 20.

[0105] Furthermore, in a preferred embodiment, the average optical power of the laser beam 31 is between 5 and 200 watts. This embodiment is highly advantageous because it enables high-quality laser marking on the container 2.

[0106] Other types of lasers may be used within the scope of the invention, according to other variations not shown. As previously described, the laser is selected and adjusted to allow surface or depth marking on a thermoplastic wall, but not to engrave the wall.

[0107] The device 1 according to the invention is characterized in that it includes a turntable 5 having a vertical axis of rotation X, the turntable 5 being driven to rotate relative to a frame 7 by at least one motor. A schematic diagram of one embodiment of the device 1 and the turntable 5 is shown in... Figure 1 As shown in the image.

[0108] The rotation of turntable 5 relative to frame 7 is achieved by means of rolling device 70.

[0109] In some embodiments, the turntable 5 is supported by a rotating base 6 that rotates about a vertical axis of rotation X and is in the form of an oriented ring containing a rolling device 70.

[0110] The rolling device 70 can be implemented, for example, as two annular members that can rotate relative to each other, each annular member having a raceway. The directional ring also includes: a rotating device consisting of rolling elements or components (such as balls or ball bearings) inserted between the two raceways; and a fixing device for fixing the constituent elements of the directional ring to prevent them from disengaging while allowing the two annular members to rotate relative to each other.

[0111] Rotating turntable 5 around the vertical axis of rotation X can be achieved by connecting one annular element to the frame 7, with the base 6 of turntable 5 supported by another annular element. Therefore, turntable 5 can rotate relative to the frame 7. The annular element connected to the frame 7 is called the fixed ring, and the other annular element is called the rotating ring.

[0112] In some embodiments, the base 6, which is in the form of a directional ring, may include an external gear ring mounted on a rotating ring.

[0113] In one possible variation, the rotating base 6 is cup-shaped and mounted on the rotating ring, for example, through a fixing hole (blind hole or through hole, smooth hole or threaded hole). Various components of the machine (not shown) are fixed on the cup-shaped part, forming a turntable.

[0114] As an explanation, on one of the applicant's machines, for a rotational speed of thirty revolutions per minute for the turntable (and therefore the rotating ring), the rotating mass body equipped with the components of device 1 (optical head 30, control device 4, platform 50, 51, 52, column 53, etc.) can have a weight of ten tons.

[0115] The rotating ring and therefore the turntable 5 are driven to rotate by a motor, usually not directly driven, but driven by a gear and / or belt drive mechanism.

[0116] In some embodiments, the rotating base 6 is in the form of a support column.

[0117] The turntable 5 of the present invention includes at least one first platform 50 or tray. The rotation axis of at least one platform 50 is coaxial with the rotation axis of the turntable 5.

[0118] Platform 50 can be any shape, but is preferably circular.

[0119] like Figure 2 As shown, platform 50 supports multiple retaining members 54 for positioning container 2 along an axis substantially parallel to the vertical axis of rotation X of turntable 5. In other words, container 2 is held by retaining members 54 and rotated by the first platform 50 of turntable 5.

[0120] like Figure 1 or Figure 2 As shown, the turntable 5 also includes a column 53.

[0121] The column 53 supports the plurality of marking stations 3 such that each optical system 320 is positioned opposite the container 2, which itself is held by the retaining member 54. The fact that laser marking is possible during the rotation of the container 2 is that the marking stations 3 are supported by the column 53, which is capable of supporting the weight of the marking stations 3 while allowing for high rotational speeds.

[0122] Preferably, the diameter of the column 53 is smaller than the diameter of the first platform 50 to facilitate the implementation of the device 1.

[0123] like Figure 7 As schematically shown, both container 2 and optical head 30 are driven to rotate relative to frame 7 about a vertical axis of rotation X. The synchronized rotation of marking station 3 and container 2, and the vertical position of container 2 opposite the optical system 320 of optical head 30, are particularly advantageous. In effect, the working distance D2 between optical system 320 and the marking area 20 of container 2 is therefore constant or substantially constant: container 2 is stationary during marking, as is optical system 320, resulting in high-quality marking.

[0124] The marker station 3, control device 4, and container 2 are therefore driven to rotate synchronously relative to the frame 7.

[0125] The turntable 5 also includes a rotary joint 60, which supplies power to the power supply 41.

[0126] For this purpose, the rotary joint 60 includes a rotary electric current collector located at the head of the rotary joint 60 and powered by a fixed cable. In a conventional manner, the rotary electric current collector includes fixed or rotating tracks on which corresponding rotating or fixed contacts are elastically abutted, and is entirely enclosed within a housing (not shown) fixed to the base 6 and held by an anti-torque structure integral with the fixed frame 7.

[0127] Preferably, the column 53 is hollow so that the rotary joint 60 can be accommodated in its central hollow portion.

[0128] Therefore, the present invention is extremely advantageous in that it can mark the container 2 during its rotation. Thus, the container 2 can be marked at a high rate of approximately 8,000 to 100,000 times per hour.

[0129] In some embodiments, at least one optical head 30 of each marking station 3 is capable of moving a laser beam 31 in a horizontal and / or vertical plane. Preferably, the laser beam 31 is emitted along a direction orthogonal to or substantially orthogonal to the vertical rotation axis X of the turntable 5.

[0130] The vertical plane corresponds to the plane passing through the vertical rotation axis X of turntable 5, and the horizontal plane corresponds to the plane perpendicular to the rotation axis X of turntable 5.

[0131] In some embodiments, the column 53 of the turntable 5 includes a vertical displacement device for vertically displacing each marking station 3 or each laser head 30, such that each station 3 or each laser head 30 can move vertically along the column 53, for example by means of a slide rail and an actuation device (not shown) placed on the column 53. This has the advantage of being able to position the optical system 320 opposite the marking area 20 of the container 2.

[0132] In practice, the type, size, and shape of container 2 may change, thus necessitating adjustment of the relative positioning of the optical system 320 and the marking area 20. This adjustment can be performed automatically, for example, by a mechanical cam adjusted by the operator or by using an actuator via an electronic control unit 400 included in the control device 4, or manually by the operator.

[0133] According to another possible variation, the first platform 50 and / or each retaining member 54 includes a vertical displacement device for vertically displacing the container 2. This embodiment is preferred because it is simpler to implement. Similarly, the vertical position adjustment of the marking area 20 of the container 2 can be performed, for example, automatically by an electronic control unit 400, or by a cam.

[0134] Vertical positioning is preferably performed before marking container 2.

[0135] In some embodiments, the turntable 5 includes a second platform 51. The second platform 51 is referred to as the lower platform because it is located below the first platform 50 (referred to as the upper platform). The second platform 51 is driven to rotate relative to the frame 7 in sync with the first platform.

[0136] The second platform 51 supports the holding device 54 in the form of a support 541, on which the bottom 22 of the container 2 rests. The container 2 is thus securely held in place by the gripping device 540 at the top (preferably by its neck 21) and also by the bottom, more particularly by the bottom 22 of the container resting on the support 541. Figure 4 The embodiment shown is very advantageous because it ensures that container 2 remains in place during its rotation and therefore during its marking process.

[0137] In addition, the support platform 541 helps to center and vertically position the container 2.

[0138] In some embodiments, the turntable 5 includes a third platform 52 whose axis of rotation is coaxial with the axis of rotation of the first platform 50. The third platform 52 supports the control device 4 and is preferably, but not limitedly, located above the first platform 50.

[0139] Positioning the control device 4 on the upper part of the third platform 52 located above the column 53 is particularly advantageous. In practice, this allows the displacement datum of the container 2 to be smaller than that of the control device 4. Furthermore, this avoids potential leakage problems if the container 2 has already been filled before being marked.

[0140] Figure 1 An illustrative example is shown in which the turntable 5 includes three platforms 50, 51, and 52, with the control device 4 located on the upper part of the third platform 52.

[0141] Figure 2 An embodiment is also shown, wherein the turntable 5 includes a first platform 50, a second platform 51, and a third platform 52.

[0142] The first platform 50 supports a vertically movable holding device 540, while the second platform 51 supports a similarly vertically movable support 541. Preferably, only the support 541 is vertically movable. In practice, it is preferable to vertically position the container 2 by pushing the container from its bottom 22. In other words, in a preferred embodiment, only the support 541 is actuated or electrically powered to vertically move the container 2, while the holding device 540 performs so-called passive translation.

[0143] Preferably, and especially Figure 2As shown, the third platform 52 is located above the column 53 and supports the control device 4, particularly the laser processing equipment 40 and the power supply device 41. The optical channel 600 and rotary joint 60, which electrically connect the various components, can also be seen.

[0144] exist Figure 2 In the embodiment shown, each platform is connected to column 53.

[0145] Alternatively, two or three platforms 50, 51, and 52 can be connected together as a control console to be assembled onto the column 53 of the turntable 5.

[0146] Therefore, according to one possible variation, the first platform 50, the second platform 51, and / or the third platform 52 are integrated.

[0147] In some embodiments, and particularly as Figure 3 As shown, each marker station 3 includes two optical heads 30.

[0148] Two optical systems 320 can be stacked in each station along an axis parallel to the rotation axis X of the turntable 5 so as to simultaneously mark the marking area 20a located on the upper part of the container 2 and the area 20b located on the lower part of the container 2, wherein the container is in its normal orientation, i.e., the orientation when it is placed through the bottom 22.

[0149] Figure 3 One embodiment is shown in which each marker station 3 includes two optical heads 30 and two optical systems 320 arranged head-to-tail.

[0150] according to Figure 6 Another possible variation shown involves marking station 3 comprising two optical systems 320a and 320b, offset at an angle α about an axis perpendicular or substantially perpendicular to the vertical axis of rotation X of turntable 5. Angle α is, for example, between 30 and 160 degrees. Each optical system 320a and 320b marks a region 20a and 20b, respectively. Optionally, regions 20a and 20b may be positioned at the same height along an axis parallel to the axis of rotation X of turntable 5.

[0151] This embodiment is particularly advantageous because it enables marking 310 to be implemented on a larger portion of the periphery of container 2.

[0152] The present invention also relates to a marking device 100 for marking a container 2, which includes the laser marking device 1 as described above.

[0153] The equipment 100 also includes a container 2 processing station 10 located upstream of the device 1. The processing station 10 supplies containers to the device 1 directly or indirectly at the output end of the conveyor wheel 8 and at the loading point 80. Such a processing station 10 can be, for example, any other container 2 processing station on a filling machine, capping machine, blow molding machine, labeling machine, or packaging production line.

[0154] Advantageously, equipment 100 allows for the continuous supply of container 2.

[0155] According to one possible embodiment, device 100 in Figure 8 The diagram is shown schematically from a top view.

[0156] Container 2 flows from processing station 10 (e.g., a filling and capping machine) on upstream conveyor 102. Then, container 2, preferably continuously, is conveyed at loading point 80 to the device 1 according to the invention via upstream conveyor wheel 8. Specifically, container 2 is held by holding member 54. Multiple laser marking stations 3 can be seen distributed around the entire perimeter of the column 53 of turntable 5.

[0157] according to Figure 8 In the variant shown, device 100 also includes an intermediate wheel 800 located between the upstream conveyor 102 and the conveyor wheel 8.

[0158] The marking station 3 faces the held container 2, allowing the laser beam 31 to be oriented toward the marking area 20 of the container 2, preferably orthogonal to or substantially orthogonal to the rotation axis X of the turntable 5. The direction of rotation is schematically indicated by a circular arrow, which, within the scope of this invention, does not limit the direction of rotation of the turntable 5. In other words, the turntable 5 can rotate in any direction about its vertical rotation axis X.

[0159] During the rotation of container 2 in sync with the rotation of marking station 3, container 2 is thus marked, i.e., mark 310 is applied to at least one marking area 20 by a laser beam 31 emitted and diffused by marking station 3.

[0160] After the marking is complete, such as Figure 8 As shown, the marked container 2 is conveyed from the unloading point 90 via the downstream conveyor wheel 9. The container 2 is placed, for example, on the downstream conveyor 101.

[0161] Preferably, the unloading of container 2 via downstream conveyor wheel 9 is also carried out continuously. In other words, by continuously supplying container 2 to device 1 from container handling station 10, device 100 allows continuous marking of container 2 until it is unloaded onto downstream conveyor device 101.

[0162] In other words, preferably, the turntable 5 of device 1 is driven to rotate continuously. This is particularly advantageous because it enables marking of container 2 at a stable rate.

[0163] like Figure 8 As shown, in some embodiments, device 100 may also include a detection system 11. Such a detection system 11 includes at least a camera and a control unit (not shown) to verify whether the mark 310 is qualified.

[0164] In the event of non-compliance, container 2 must be destroyed or at least discarded without further processing. Equipment 100 may include a discharge device 110 for discharging containers 2 marked 310 that are non-compliant.

[0165] For these detection purposes, in some embodiments, device 100 includes a central control unit 12 that allows input of information such as the type and specifications of container 2, the type of marking 310 to be applied, and the location of marking areas 20, 20a, 20b.

[0166] According to one possible variation, the central control unit 12 communicates with the electronic unit 400 of the control device 4.

[0167] In some embodiments, the central control unit 12 includes:

[0168] - Database 120, which records the control program for the marking device 1 and optionally other control programs for the container 2 processing station, is stored in a storage device or on a separate server.

[0169] - A processor connected to memory, used to execute program instructions, and

[0170] - A communication interface connected to the processor for communicating with at least the electronic unit 400 of the control device 4.

[0171] According to one possible variant, the central control unit 12 includes a computing unit that allows commands to be generated in real time based on measurements from different sensors (e.g., the height measurement sensor for container 2).

[0172] In some embodiments, the central control unit 12 transmits information to the control device 4 in the form of instructions via the rotary joint 60. The transmitted information relates, for example, to the at least one marking area 20, features of the marking 310, marking parameters, etc.

[0173] The electronic control unit 400 acts as a slave controller controlled by the central control unit 12 (referred to as the master control unit).

[0174] The electronic control unit 400 is programmed to control the device 1 to complete a marking cycle.

[0175] The central control unit 12 can also allow parameter settings for the rotation direction or rotation speed of the turntable 5.

[0176] Therefore, the main control unit can be connected to other slave controllers to optionally operate the adjustment of the rotational speed of the conveyor wheels 8 and 9, or the adjustment of the speed of the conveyor devices 101 and 102.

[0177] The central control unit 12 can also be connected to the detection system 11 to allow parameter settings for the pass / fail level of the markings 310 on the container 2. Pass / fail can be, for example, readability, marking positioning, etc.

[0178] According to one possible variation, the detection system 11 transmits information about the quality of the marker to the central control unit 12, which can then send instructions to the electronic unit 400 of the control device 4, such as instructions intended to correct the height adjustment of the marker 310 or any other parameters related to the marker.

[0179] Advantageously, the central control unit 12 includes various sensors, particularly speed sensors, which collect information that is stored in the database 120 or transmitted to the computing unit of the central control unit 12. For example, the database 120 of the central control unit 12 records speed parameters of the conveyor wheels 8 and 9 and the turntable 5, as well as information about the specifications of the container 2 to be marked (e.g., its size and / or shape).

[0180] In some embodiments, the central control unit 12 also transmits instructions to the electronic unit 400 to transmit instructions to the holding member 54 and / or the marker station 3, thereby setting parameters for the positioning of the container 2 opposite the optical system 320. The central control unit 12 thus allows for the automatic management of the vertical displacement of the container 2 and / or the marker station 3, particularly according to the specifications of the container 2.

[0181] In some embodiments, the central control unit 12 allows setting parameters for the markings 310 to be applied to regions 20, 20a, 20b of the container 2.

[0182] Operators can input various parameters at a dedicated interface on the central control unit 12 or optionally remotely.

[0183] For this purpose, the central control unit 12 may include the control screen of the device 100, which has a dedicated human-machine interface that allows input of information, such as the specifications of the container 2, the selection of the label 310, etc.

[0184] The present invention also relates to a method for marking a container 2, which includes at least the following steps:

[0185] - The first step, E1, involves processing the container 2.

[0186] - The second step, E2, involves driving container 2 to rotate around a vertical axis, with laser marking station 3 being driven synchronously with container 2 to rotate around this vertical axis.

[0187] - The third step, E3, involves marking the container 2 during rotation.

[0188] In some embodiments, the method is implemented using the apparatus 1 of the present invention as described above.

[0189] Therefore, the device 1 according to the present invention can implement the marking method of the present invention.

[0190] Preferably, the first processing step E1 is the filling and capping step of container 2. In fact, it has been observed that laser marking using laser beam 31 is of better quality (especially in terms of readability) when container 2 is being filled.

[0191] In practice, it is generally difficult to use laser systems to mark plastic materials, especially PET containers 2, because laser marking tends to degrade container 2 due to the high power required to mark container 2 at high rates. This, for example, means creating holes in the walls of container 2.

[0192] Advantageously, in some embodiments, the method therefore includes marking the container 2 after it has been filled (preferably filled with liquid). This allows the liquid to rapidly diffuse the heat from the transferred laser beam 31 and prevents degradation of the container 2 wall. Thus, the internal integrity of the container 2 in contact with the liquid is maintained, while high power can be used to generate strong contrast for a high marking rate, and the marking is confined to the outer surface of the container 2 wall.

[0193] Preferably, container 2 is therefore filled and capped before being driven to rotate for marking.

[0194] Figure 9 The steps of a method according to one embodiment are illustrated schematically, wherein container 2 is filled and capped in step E1.

[0195] Then, according to one possible variation, the filled and capped container 2 is conveyed to the retaining member 54, such as... Figure 9 As shown, for example, by means of a gripping device 540 and a support 541 that grip by the neck.

[0196] After being captured, container 2 is then driven to rotate synchronously with marker station 3. Preferably, the rotation driving step is performed continuously without interruption: container 2 enters the trajectory of device 1, is then captured, and is driven to rotate.

[0197] During step E3, and while the container is rotating, container 2 is marked.

[0198] Finally, after step E3, container 2 is unloaded. Preferably, container 2 is unloaded during the rotation of turntable 5, and turntable 5 does not stop for this unloading step.

[0199] In some embodiments, the marking step E3 is performed during rotation in a angular sector of less than 360 degrees around the vertical axis. In other words, each container 2 makes approximately only one revolution, or more precisely, less than a full circle.

[0200] In some embodiments, such as Figure 8 As shown schematically:

[0201] - Following container 2 processing step E1, the method includes loading step E1', which loads the container at loading point 80.

[0202] - After the marking step E3, the method includes an unloading step E4 to unload the container 2 at the unloading point 90, where each marking station 3 and each container 2 move about a vertical axis of rotation between the loading point 80 of the container 2 and the unloading point 90 of the container 2 that has been marked at the marking area 20, and then a new cycle including at least the steps E1 to E4 begins.

[0203] Advantageously, container 2 is moved vertically after loading step E1' and / or before step E3. According to a possible variation, laser marking station 3 is moved vertically during or after loading step E1'.

[0204] Therefore, in some embodiments, the container 2 is moved vertically after loading to adjust the positioning of the at least one marking area 20 opposite the marking station 3, particularly opposite the optical exit 321 of the optical system 320. The container 2 is thus moved from an initial vertical position (or height) to the marking vertical position.

[0205] Preferably, the vertical displacement step of container 2 is performed during step E2, that is, during the rotation of container 2.

[0206] In practice, preferably, step E2, which involves rotation about axis X, is performed synchronously with all other steps of the method. Therefore, rotation step E2 is performed simultaneously with each of steps E1', E3, and E4, and the rotation is carried out continuously. In other words, advantageously, there is no interruption in the displacement of container 2.

[0207] Then, once the marking step E3 is completed, container 2 is moved vertically again to return from the marked vertical position to the initial position so that container 2 can be unloaded.

[0208] Container 2 and / or marking station 3 may also be moved during their rotation, during rotation drive step E2 and / or during marking step E3.

[0209] In some embodiments, the marking step E3 is performed using a near-infrared pulsed laser.

[0210] In some embodiments, the marking method includes an additional step of detecting the marked container 2 after the marking step E3.

[0211] The marking method can be implemented in the device 100 as described above.

[0212] Therefore, the present invention aims to provide a particularly efficient container 2 marking device 1, which not only achieves high-quality marking but also performs it at a high rate. Thus, there is no need to stop the movement of the container 2 to be marked, which directly and advantageously affects the operating speed of the industrial production line.

Claims

1. A laser marking device (1) for laser marking a container (2), the container being, in particular, a bottle or vial made of thermoplastic material, the container comprising at least a body (23), a shoulder (24) extending the body (23) from the upper end of the body, a neck (21) extending the shoulder (24), and a bottom (22) at the lower end of the body (23), the laser marking device (1) comprising at least: - Multiple laser marking stations (3), each laser marking station (3) includes at least one laser marking optical head (30) along an optical path, the laser marking optical head being equipped with a laser head unit (300) and an optical system (320) for focusing a laser beam (31) to generate a mark (310) at at least one marking area (20) in each container (2) to mark the marking area (20). - A control device (4) connected to the laser marking station (3), the control device including a laser processing device (40) and a power supply device (41) for supplying power to the laser marking station (3). The laser marking device is characterized in that it includes a turntable (5) having a vertical axis of rotation X, the turntable being driven to rotate relative to the frame (7) by at least one motor via a rolling device (70), the turntable (5) comprising at least: - A first platform (50) supports a plurality of retaining members (54) for positioning the container (2) along an axis substantially parallel to the vertical axis of rotation X of the turntable (5). - A column (53) supports the plurality of laser marking stations (3) such that each optical system (320) is positioned opposite a container (2) held by a retaining member (54), such that the laser marking station (3), the control device (4) and the container (2) are driven to rotate synchronously relative to the frame (7), and the container (2) is marked during its rotation.

2. The laser marking device (1) according to claim 1, characterized in that, The working distance (D2) between the axis of the container and the at least one laser marking optical head (30) is constant or substantially constant.

3. The laser marking device (1) according to claim 1 or 2, characterized in that, The at least one laser marking optical head (30) of each laser marking station (3) is capable of moving the focus of the laser beam (31) relative to the at least one marking area (20) in the horizontal and / or vertical and / or longitudinal plane.

4. The laser marking device (1) according to any one of the preceding claims, characterized in that, The column (53) includes a vertical displacement device for vertically displacing each laser marking station (3) or each laser marking optical head (30), such that each laser marking station (3) or each laser marking optical head (30) can move vertically along the column (53).

5. The laser marking device (1) according to any one of the preceding claims, characterized in that, The first platform (50) and / or each holding member (54) includes a vertical displacement device for vertical displacement of the container (2).

6. The laser marking device (1) according to any one of the preceding claims, characterized in that, The turntable (5) includes a second platform (51) called the lower platform, which is located below a first platform (50) called the upper platform, which is driven to rotate synchronously with the second platform (51); and for each container (2), the holding member (54) includes, on the one hand, a gripping device (540) for holding the container (2), preferably by means of a neck (21), at the upper platform, and on the other hand, a support (541) at the lower platform, on which the bottom (22) of the container (2) is supported.

7. The laser marking apparatus (1) according to any one of the preceding claims, characterized in that, The turntable (5) includes a third platform (52), the rotation axis of the third platform is coaxial with the rotation axis of the first platform (50), and the third platform (52) supports the control device (4).

8. The laser marking apparatus (1) according to any one of the preceding claims, characterized in that, The first platform (50) and / or the second platform (51) and / or the column (53) are integrated.

9. The laser marking device (1) according to any one of the preceding claims, characterized in that, The control device (4) is located on the upper part of the third platform (52).

10. The laser marking apparatus (1) according to any one of the preceding claims, characterized in that, Each laser marking station (3) includes two laser marking optical heads (30), which are placed head to tail in each laser marking station (3) such that the optical systems (320) of the two laser marking optical heads (30) are superimposed so as to simultaneously mark the marking area (20a) located on the upper part of the container (2) and the marking area (20b) located on the lower part of the container (2).

11. The laser marking device (1) according to any one of the preceding claims, characterized in that, Each laser marking station (3) includes a pulsed laser optical head (30) with a wavelength between 800 and 2000 nanometers.

12. An apparatus (100) comprising: - The laser marking device (1) according to claims 1 to 12. - A container processing station (10) located upstream of the laser marking device (1) supplies containers directly or indirectly to the laser marking device (1) at a loading point (80) via a conveyor wheel (8). - A conveyor wheel (9) at the unloading point (90) is used to release the marked container (2) directly or indirectly at the downstream conveying device (101).

13. The device (100) according to claim 12, characterized in that, The device includes a detection system (11) for detecting the marked container (2).

14. A method for marking a container (2), comprising at least the following steps: - The first processing step (E1) involves processing the container (2), preferably by filling and sealing the container (2). - The second step (E2) involves driving the container (2), preferably a filled and capped container, to rotate around a vertical axis. The laser marking station (3) is driven synchronously with the container (2) to rotate around the vertical axis. - The third marking step (E3) involves marking the container (2) during rotation.

15. The container marking method according to claim 14, characterized in that, The third marking step (E3) is performed during rotation on an angular sector of less than 360 degrees around the vertical axis.

16. The container (2) marking method according to claim 15 or 16, characterized in that, The container marking method: - After the first processing step (E1) of processing the container (2), preferably filling and sealing the container, there is also a loading step (E1') of loading the container (2) at the loading point. - Following the third marking step (E3), there is also an unloading step (E4) to unload the container (2) at the unloading point, the third marking step (E3) being performed between the loading point of the container (2) and the unloading point of the container (2) which has been marked at at least one marking area (20), after which a new cycle including at least the steps (E1) to (E4) begins.

17. The container marking method according to any one of claims 15 to 17, characterized in that, The container (2) is moved vertically after the loading step (E1') and before or during the third marking step (E3).

18. The container marking method according to any one of claims 15 to 18, characterized in that, The third marking step (E3) is implemented using a near-infrared pulsed laser.

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