APPARATUS FOR CREATING A HOLE IN A GLASS CONTAINER

Abstract

The invention provides an apparatus for creating a hole in a glass container with a medium stored therein, comprising: a laser system configured to focus laser pulses with a wavelength in the ultraviolet regime onto the glass container such as to create a hole in the glass container by laser ablation preferably without creating significant amounts of glass particles inside and outside the glass container.

Claims

1. Apparatus for creating a hole in a glass container (200) with a medium stored therein, comprising: a laser system (100) configured to focus laser pulses with a wavelength in the ultraviolet regime onto the glass container (200) such as to create a hole in the glass container (200) by laser ablation preferably with an energy of the laser pulses less than twice the laser pulse energy required at the ablation threshold of the glass container (200) to minimize the amounts of glass particles inside and outside the glass container (200).

2. The apparatus of claim 1, wherein the energy of the laser pulses is less than 30% of the laser pulse energy required at the ablation threshold of the glass container (200).

3. The apparatus of claim 1, further comprising a physical sensor, preferably an accelerometer or an acoustic wave sensor, configured to determine when the hole is created in the glass container and preferably wherein the laser system is configured to stop applying laser pulses onto the glass container upon determination by the physical sensor that the hole has been created.

4. The apparatus of claim 1, further comprising a physical sensor, preferably an accelerometer or an acoustic wave sensor, configured to observe the process parameters of the laser system and preferably the laser system is configured to adjust the process parameters according to the physical sensor feedback.

5. The apparatus of claim 3, wherein the physical sensor is located on an outside surface of the glass container or in close proximity to the glass container or on a structure that is directly connected to the glass container.

6. The apparatus of claim 1, wherein the laser system is configured to focus laser pulses with a repetition rate of f≤10 kHz, preferably f≤7 kHz, more preferably 2 kHz≤f≤5 kHz, onto the glass container and/or wherein the laser system is configured to focus laser pulses with a repetition rate of 4 kHz≤f≤5 kHz for a green, black-green, olive-green, and transparent glass container and a repetition rate of 2 kHz≤f≤5 kHz, preferably f=2 kHz, for a brown glass container.

7. The apparatus of claim 1, further comprising positioning means configured to position the laser system and the glass container relative to each other such that the laser pulses are focused onto a portion of the glass container where an air bubble is formed on the inside of the glass container, and wherein preferably the positioning means is configured to position the laser system and the glass container relative to each other such that the laser pulses are focused onto a curved portion connecting a bottleneck and a body of the glass container.

8. The apparatus of claim 1, further comprising a sealing apparatus configured to seal the hole in the glass container with a ceramic polymer composite or a ceramic glass material and preferably wherein the sealing apparatus comprises an ultraviolet light application unit configured to direct ultraviolet light to the ceramic polymer composite or a heating unit configured to heat the ceramic glass material.

9. The apparatus of claim 1, wherein the laser system is configured to guide the laser pulses in a predetermined pattern within a predetermined area over the surface of the glass container.

10. (canceled)

11. A System for withdrawal of a medium stored in a glass container, the system comprising: an apparatus of claim 1 for creating a hole in the glass container; and withdrawal means configured to manually or automatically withdraw the medium from the glass container through the hole.

12. The system of claim 11, further comprising an analysis unit configured to analyse the withdrawn medium, wherein the analysis unit preferably comprises a chemical fingerprint analysis unit and/or a biological fingerprint analysis unit.

13. The system of claim 12, wherein the fingerprint analysis unit is configured to perform chromatographic separation and high resolution mass spectrometry of the medium and/or wherein the biological fingerprint analysis unit is configured to perform DNA analysis of the medium.

14. (canceled)

15. A break-through detection apparatus for determining that a hole has been created in a glass material, preferably in a glass container, the break-through detection apparatus comprising a physical sensor, preferably an accelerometer or an acoustic wave detector, configured to determine that a hole has been created in a glass material.

16. A process parameter observation apparatus for observing the progress of laser processing of a glass material, preferably a glass container, the process parameter observation apparatus comprising a physical sensor, preferably an accelerometer or an acoustic wave detector, configured to observe the progress of laser processing of a glass material.

17. Method for creating a hole in a glass container with a medium stored therein, comprising: creating a hole in the glass container by focusing laser pulses of a laser system with a wavelength in the ultraviolet regime onto the glass container preferably with an energy of the laser pulses of less than twice the laser pulse energy required at the ablation threshold of the glass container to minimize the amounts of glass particles inside and outside the glass container.

18. A method for withdrawal of a medium stored in a glass container, the method comprising: a method of claim 17 for creating a hole in the glass container; and manually or automatically withdrawing the medium from the glass container through the hole.

19. A method for break-through detection, wherein the method comprises providing a physical sensor, preferably an accelerometer or an acoustic wave detector, and determining that a hole has been created in a glass material, preferably in a glass container by using the physical sensor.

20. A method for observation of progress of laser processing of a glass material, preferably a glass container, is provided, the method comprising observing the process parameters by a physical sensor, preferably an accelerometer or an acoustic wave detector.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0119] The present invention is further described with respect to exemplary embodiments by referring to the Figures, where

[0120] FIG. 1 illustrates a laser system according to an exemplary embodiment of the present invention,

[0121] FIG. 2 shows experimental data for a green glass bottle obtained by the embodiment of FIG. 1,

[0122] FIG. 3 shows experimental data for a olive-green glass bottle obtained by the embodiment of FIG. 1,

[0123] FIG. 4 shows experimental data for a black-green glass bottle obtained by the embodiment of FIG. 1,

[0124] FIG. 5 shows experimental data for a transparent glass bottle obtained by the embodiment of FIG. 1,

[0125] FIG. 6 shows experimental data for a brown glass bottle obtained by the embodiment of FIG. 1,

[0126] FIGS. 7a and b illustrate sealing of the hole in accordance with an embodiment of the present invention,

[0127] FIGS. 8a and b a setup and respective results for detecting the thickness of a glass sample for a scanning speed of 5 mm/s in accordance with an embodiment of the present,

[0128] FIGS. 9a and b a setup and respective results for detecting the thickness of a glass sample for a scanning speed of 10 mm/s in accordance with an embodiment of the present,

[0129] FIG. 10a-c shows experimental results for break-through detection in a 40 layer ablation process in accordance with an embodiment of the present invention, and

[0130] FIG. 10d-f shows experimental results for break-through detection in a 80 layer ablation process in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0131] FIG. 1 shows a laser system 100 and a glass container 200. According to the first embodiment, the glass container 200 is a bottle 200, which contains a medium, e.g. wine. The laser system 100 will now be described in more detail with reference to FIG. 1. However, the present invention is not limited by the specific parameters of the laser system 100. In contrast, the parameters of the laser system 100 mentioned and described herein are merely exemplary. The actual parameters of a laser system 100 used for creating a hole in a glass container 200 may vary from the parameters described herein without departing from the scope of the present invention.

[0132] According to the exemplary embodiment, the laser system 100 is configured to focus laser pulses with a wavelength in the ultraviolet regime onto the glass container 200 such as to create a hole in the glass container 200 by laser ablation preferably without creating significant amounts of glass particles inside and outside the glass container 200.

[0133] According to one embodiment, the laser system 100 is operated at a wavelength of 355 nm and an average power of 0.644 W. The laser system 100 emits laser pulses with a pulse duration of 20 ns at a repetition rate between 0.5 kHz and 20 kHz. The feed rate of the laser system is 30 mm/s.

[0134] Moreover, the laser pulses are focused onto the bottle 200 by optical components with a focal length of 100 mm. The focal point diameter is set to 12 μm and the Rayleigh length is 250 μm.

[0135] According to another embodiment, the laser system is operated at an average power of 3.5 W and the laser pulses are focused onto the bottle 200 by the optical components with a focal length of 250 mm. The focal point diameter is set to 28 μm and the Rayleigh length is 700 μm.

[0136] As can be seen from FIG. 1, the laser pulses are focused in a substantially perpendicular direction onto the curved portion connecting the bottleneck and the body of the bottle 200. According to FIG. 1, this is achieved by tilting the bottle 200 from its upright position by a predetermined angle, which depends on the curvature of said curved portion of the bottle 200.

[0137] Said curved portion of the bottle 200 has the advantage that an air bubble is naturally located on the inside of the bottle 200, where the hole is created when the bottle 200 is tilted accordingly. Thus, once the hole is created, the wine does not flow out of the hole.

[0138] Furthermore, an accelerometer (not shown) is provided to determine when the hole is created in the bottle. Thus, the laser system 100 can stop applying laser pulses to the bottle 200 upon detection that the hole has been created.

[0139] Instead of the accelerometer, an acoustic wave detector may also be used to determine when the hole is created in the bottle.

[0140] In general, the accelerometer is configured to measure the vibrations or the vibration pattern of the bottle 200, either directly or indirectly. When the hole has been created the vibration or vibration pattern changes and it can be determined by the accelerometer that the hole has been created.

[0141] The accelerometer may be located on an outside surface of the bottle 200 (direct measurement of the vibrations).

[0142] Alternatively, the accelerometer may be located in close proximity to the bottle 200, e.g. a holder, which is configured to hold the bottle 200 (indirect measurement of the vibrations).

[0143] That is, the accelerometer does not have to be located in contact with the bottle 200, but can also be located on any structure that is directly connected to the bottle 200, because the vibrations measured by the accelerometer may be transferred from the bottle 200 to the connected structure, and thus enabling a respective measurement.

[0144] The time of the creation of the hole is visible in the vibration spectrum as a spread in excitation frequency range and an increase in the vibration acceleration.

[0145] For example, a piezo accelerometer from Brüel & Kjaer GmbH with a sensitivity of 10 mV/ms.sup.2 and a frequency spectrum of 0.3-6,000 Hz may be used. However, any suitable accelerometer may be used instead.

[0146] For the acoustic wave detector, a microphone from Brüel & Kjaer GmbH with a frequency spectrum of 20-50,000 Hz may be used. However, any suitable acoustic wave detector may be used instead.

[0147] The physical sensor, i.e. the accelerometer or the acoustic wave detector, may further be used to observe and control the process parameters of the laser system 100. That is, during the creation of the hole, the physical sensor may provide feedback.

[0148] Thus, it is possible to detect process parameters such as the duration of laser ablation of one material layer, momentum of readjustment of the laser axis, and the characteristic vibrational behavior of the bottle 200.

[0149] It is preferable that the laser system is configured to cerate a hole with a diameter of ≤1 mm.

[0150] The hole to be created may be bigger than the actual focal point. In this case, it is advantages to guide the laser pulses in a predetermined pattern within a predetermined area (approximately the size of the hole to be created) over the surface of the bottle 200. This assists that the whole volume of material can be evaporated and thus no significant amounts of glass particles are created during the creation of the hole.

[0151] FIGS. 2-6 show the respective results obtained by the laser system 100 described above at different repetition rates for differently colored glass bottles.

[0152] In particular, the drilling depth per layer has been determined for different repetition rates by using a SmartScope Flash 200 together with the Measure-X software. The results are illustrated in FIGS. 2-6 by the curve with the error bars.

[0153] In addition, FIGS. 2-6 illustrate the creation of glass particles, i.e. glass dust and glass splinters at the inside and outside of the during the creation of the hole. The respective curves are illustrated in FIGS. 2-6 with squares and circles, respectively. The amount of glass particles created has been evaluated by visual inspection and ranked accordingly.

[0154] As can be seen from FIGS. 2-6, there seems to be an optimum at around 4-5 kHz. That is, at around 4-5 kHz the least glass particles are created during the creation of the hole. For the bottles of FIGS. 2-5 this seems to be the optimum working region in this regard. For the brown bottle according to FIG. 6, the optimum working point seems to lie at around 2 kHz. However, also for the brown bottle, the creation of glass particles seems to be acceptable for the region of 4-5 kHz.

[0155] However, there are further regions where the amount of glass particles created may be acceptable. For example, at 10 kHz for the olive-green bottle and at 6 kHz for the transparent bottle.

[0156] As mentioned above, the specific parameters of the laser system 100 and in particular the repetition rates described herein are merely one example of how to find optimal parameters for a particular laser system 100. These parameters shall not be construed as limiting. It will be apparent to the skilled person that any suitable laser system 100 that can be used for laser ablation may be used to tune the respective parameters such that no significant amounts of glass particles inside and outside the bottle are created during the creation of the hole.

[0157] FIG. 7a illustrates sealing means to seal the hole in the bottle 200 with a ceramic polymer composite 201. The ceramic polymer composite 201 is inserted into the hole and ultraviolet light is directed to the ceramic polymer composite 201 to harden the ceramic polymer composite 201.

[0158] Alternatively, the hole can be sealed by using a ceramic glass material 202 as illustrated in FIG. 7b. The ceramic glass material 202 is inserted into the hole and heat is applied thereto to melt at least the top part 203 such that an airtight seal is created.

[0159] Both sealing means have the advantage that they do not deteriorate the wine stored in the bottle 200.

[0160] With reference to FIGS. 8a-9b a setup and respective results for detecting (determining) the thickness of glass in accordance with an embodiment of the present disclosure is described in the following.

[0161] FIGS. 8a and 9a shows the experimental setup and the respective results for a scanning speed of 5 mm/s and 10 mm/s, respectively. In particular, the setup consisted of an ultrashort pulse laser with a wavelength of 355 nm and a pulse width of 9.8 ps. The laser beam was coupled via optical mirrors into a dynamic optical scanning system. The F-theta focusing optic has a focal length of 56 mm. The entire optical system has a beam focus diameter of 6 μm and a Rayleigh length of 64 μm. A mechanical 3-axis CNC system allows to position the substrate (sample). The glass slides were placed and aligned with sub-micron accuracy under the scanning system, the surface of the substrate was placed in the focal plane of the beam axis as exactly as possible.

[0162] The experiments were carried out with of soda-lime glass slides of 1 mm thickness. For the test application, a line of 20 mm length and a scanning speed of 5 or 10 mm/s was drawn over the sample with an average power of 234 mW. The starting focus position was 1 mm above the glass slide (sample) and then continuously moved at a constant speed through the glass slide until a focus position 0.5 mm below the glass slide was reached. In other words, the focus position is continuously moved in the xz-direction as indicated in FIGS. 8a and 9a, wherein the sample's thickness direction corresponds to the z-direction and the sample's length and width direction corresponds to the x- and y-direction, respectively.

[0163] The acoustic signals generated during the experiments were captured by a Brüel & Kjær Type 4189 open-air microphone with a 2671 preamplifier. The microphone has a frequency range from 6.3 Hz to 20 kHz, a dynamic range from 14.6 to 146 dB and a sensitivity of 50 mV/Pa. The microphone was positioned at an application level with a distance of a few to several hundred millimeters without precision requirements. From the preamplifier, the signal was fed via BNC cables to a NEXUS 2693 as a constant power supply of 31.6 mV/Pa and further on to a multi-functional I/O device. The signals were transferred to a computer via a USB 2.0 interface at a sampling rate of 44 kS/s. A self-developed software routine combines the digitized signals into frequency band groups of different bandwidths. The reading out was performed by capturing frequency band groups, which corresponded to integer multiples of 5 kHz, to reduce the amount of data to be processed and the influence of noise.

[0164] The glass thickness was determined by extracting the time when the signal amplitude of a predetermined threshold was exceeded. If the signal amplitude subsequently did fall below the threshold value again, the time is also read out. The time between the two points in time and the scan speed was used to calculate the glass thickness, taking into consideration the total shift of the focus position. The final result of the thickness is shown in the graph of FIGS. 8a and 9a, whereas the respective signals measured over time are shown in FIGS. 8b and 9b. In particular, FIGS. 8b and 9b show the measured amplitude signals over time for different frequency band groups, namely for 5 kHz, 10 kHz, 15 kHz and 20 kHz.

[0165] Next, with reference to FIGS. 10a-f experimental results for break through detection in a 40 and 80 layer ablation process, respectively, in accordance with an embodiment of the present disclosure is described in the following together with details about the respective setup. In particular, FIGS. 10a-c show experimental results for break through detection in a 40 layer ablation process for frequency band groups of 5 kHz, 10 kHz and 15 kHz. Moreover, FIGS. 10d-f show experimental results for break through detection in a 80 layer ablation process for frequency band groups of 5 kHz, 10 kHz and 15 kHz.

[0166] The experimental setup consisted of an ultrashort pulse Coherent AVIA LX 355 laser. The laser beam was coupled via optical mirrors into a highly dynamic optical scanning system. The scanning system deflects the laser beam in a controlled manner in the xy-plane and shifts the focus position in the beam z-axis relative to the application plane in predetermined steps. The scanning system is followed by an F-theta focusing optic with a focal length of 250 mm. The entire optical system has a beam focus diameter of 30 μm and a Rayleigh length of 1.67 mm. The experimental setup comprises a mechanical 3-axis CNC system with a work surface to position the substrate with micrometer accuracy under the scanning system in the focal plane of the beam axis as exactly as possible.

[0167] The experiments were carried out with soda-lime glass slides with a thickness of 1 mm. The test application consisted of the layer-by-layer removal of a cylindrical bore with a diameter of 1.5 mm. Controlled by the scanner software, the circular cross-section of the hole was ablated with lines at a distance of 30 μm. After the scanning system had finished ablating the first circular cross-section, the focus position was adjusted in the direction of the beam axis and the circular cross-section was ablated again, this process was repeated until a breakthrough was achieved.

[0168] The acoustic signals generated during the experiments were captured by a Brüel & Kjær Type 4189 open-air microphone with 2671 preamplifier. The microphone has a frequency range from 6.3 Hz to 20 kHz, a dynamic range from 14.6 to 146 dB and a sensitivity of 50 mV/Pa. The microphone was oriented towards the application field at a distance of a few to several hundred millimeters without precision requirements. That is, the microphone was directed towards the sample that was subjected to the laser beam. From the preamplifier, the signals were fed via BNC cables to a NEXUS 2693 as a constant power supply of 31.6 mV/Pa and further on to a multi-functional I/O device and to a computer via a USB 2.0 interface at a sampling rate of 40 kS/s. A self-developed software routine combined the digitized signals into frequency band groups of different bandwidths. By reading out the frequency band groups, which correspond to integer multiples of 5 kHz, the amount of data to be processed and the influence of noise was reduced. The signal amplitudes above a certain threshold value were extracted from the individual frequency band groups. A polynomial fit was formed for each frequency band group and in combination with falling edges the time of the shot through (break-through) was detected. The correct calculated shot through time may be validated with an external light microscope.

[0169] As the present invention may be embodied in several forms without departing from the scope or essential characteristics thereof, it should be understood that the above-described embodiments are not limited by any of the details of the foregoing descriptions, unless otherwise specified, but rather should be construed broadly within the scope as defined in the appended claims, and therefore all changes and modifications that fall within the present invention are therefore intended to be embraced by the appended claims.

[0170] Furthermore, in the claims the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single unit may fulfil the functions of several features recited in the claims. The terms “essentially”, “about”, “approximately” and the like in connection with an attribute or a value particularly also define exactly the attribute or exactly the value, respectively. Any reference signs in the claims should not be construed as limiting the scope.