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(11) | EP 4 209 447 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A METHOD FOR MONTORING CAP APPLICATION AND A CAP HOLDER |
| (57) A method (600) for monitoring cap application in a filling machine (300) is presented.
The filling machine (300) comprises a cap holder (100) comprising a peripheral element
(102) for encircling a cap (106), gripping elements (104) connected to the peripheral
element (102) and arranged for preventing movement of the cap (106) with respect to
the peripheral element (102) during rotation of the peripheral element (102) around
a center axis (A), a sensor arrangement (110) attached to the peripheral element (102),
and a communication module (112) linked to the peripheral element (102), communicatively
connected to the sensor arrangement (110) and arranged to transmit sensor data to
the data processing apparatus (312), said method comprising receiving (602) the sensor
data (314) captured by the sensor arrangement (110), comparing (604) the sensor data
(314) with sensor reference data (320) held in a reference database (318) communicatively
connected to the data processing apparatus (312), in case of discrepancy (606) between
the sensor data (314) and the sensor reference data (320), transmitting (608) a check
notification (322) from the data processing apparatus (312) to a control system (324).
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Technical Field
[0001] The invention relates to the field of packaging. More particularly, it is related to devices and methods for cap application.
Background Art
[0002] Today, in the food packaging industry, it is increasingly popular with packages provided with screw caps. One reason for the popularity is that this type of opening device is re-closable, which has the positive effect that the package can be stored horizontally even after being opened. Another reason for the popularity is that screw caps are easy to handle for most consumers. Even though some screw caps may be difficult to handle for people with reduced strength, it is generally easier for most people to handle screw caps compared to e.g. tear openings.
[0003] There are different techniques for applying the screw caps during production. One common approach is to screw the caps onto threaded necks of the packages using a so-called cap applicator. The general principle of such apparatus is to grab a cap, place the cap onto the neck and rotate the cap while holding the package still such that inner threads of the cap cooperate with outer threads of necks. To assure that the caps, nor the necks, are damaged during the cap application process, the cap applicator is usually fine-tuned to provide for that adequate application without damaging cap nor neck is achieved. To monitor the cap application process it is known to use camera-based systems.
[0004] Cap applicators used today are generally performing well, but an increased level of customization has proven to be a challenge in some packaging lines. For instance, caps with different colors have often different material properties. By way of example, applying a white cap onto the neck may require different settings of the cap applicator compared to applying a red cap due to different material properties for the white and red plastic material used in the two caps.
[0005] Still a challenge in the field of cap application is that there is an ever increasing will to reduce the amount of plastic material used in the caps and necks, both from a cost perspective and an environmental perspective. Using less plastic material has the effect that tolerances when applying the caps need to be kept tighter. As an effect, more reliable cap application is required as an effect of the material reduction.
[0006] Based on the examples provided above, there is a need for improved cap application process such that more reliable package production can be achieved, but also in providing for that packages with less plastic material can be used.
Summary
[0007] It is an object of the invention to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide a method enabling more reliable and flexible cap application control. Further, it is an object to provide a method for monitoring cap application in a filling machine such that data for achieving the more reliable and flexible cap application control is generated.
[0008] According to a first aspect it is provided a method for monitoring cap application in a filling machine using a data processing apparatus, wherein the filling machine comprises a cap holder comprising
- a peripheral element for encircling a cap,
- gripping elements connected to the peripheral element and arranged for preventing movement of the cap with respect to the peripheral element during rotation of the peripheral element around a center axis A,
- a sensor arrangement attached to the peripheral element, and
- a communication module linked to the peripheral element, communicatively connected to the sensor arrangement and arranged to transmit sensor data to the data processing apparatus,
said method comprising
receiving the sensor data captured by the sensor arrangement,
comparing the sensor data with sensor reference data held in a reference database communicatively connected to the data processing apparatus,
in case of discrepancy between the sensor data and the sensor reference data, transmitting a check notification from the data processing apparatus to a control system.
[0009] An advantage with this method is that the cap application can be monitored efficiently. Having the sensor arrangement attached to the peripheral element of the cap holder, also referred to as chuck, comes with the advantage that deviations in movement of the cap holder can be detected and, as an effect acted upon. By getting indications early on and in a reliable manner that the cap application may need to be adjusted or is for any other reasons not working adequately in turn result in that the cap application may be checked and possibly adjusted to avoid filling machine stops as well as quality issues. In addition, having improved monitoring of the cap application process also provide the possibility to have tighter tolerance levels, which in turn provides for that the less plastic material may be used in the packages.
[0010] The sensor data comprises angle data measured between a cap application starting position and a cap application end position of the rotation around the center axis.
[0011] By knowing the angle data, i.e. the angle between the starting position and the end position, reliable monitoring of the cap application can be achieved. In case the angle data clearly deviates, this namely signals that the cap application process is not working properly.
[0012] The sensor data may comprise torque data measured during rotation of the cap around the center axis from the cap application starting position to the cap application end position.
[0013] In addition to the angle data or as an alternative to the angle data, the torque data provides relevant information about the cap application. In case, the torque used during cap application deviates from historical torque data and/or set torque data, this signals that the cap application may need re-adjustment.
[0014] The sensor data may comprise perpendicular angle data measured between the cap application starting position and the cap application end position of the rotation around a perpendicular axis, wherein said perpendicular axis is perpendicular to the center axis.
[0015] In case there is a rotation of the cap holder around the perpendicular axis, this is an indication that the cap application is not performing as planned and that an operator would look into why the cap applicator is not performing as expected.
[0017] Having the energy harvesting arrangement provides the advantage that battery exchange intervals may be extended, i.e. more cost efficient service. In some applications, in case no power back-up is considered necessary, the battery may be left out when having the energy harvesting arrangement. By placing the energy harvesting arrangement on the peripheral element, there will be a movement during the cap application, which provides for that there will be energy for the energy harvesting arrangement to capture.
[0018] The sensor data may further comprise data chosen from a group comprising translational movement data measured along the center axis, vibration data measured during rotation from the cap application starting position to the cap application end position, accelerometer data measured during rotation from the cap application starting position to the cap application end position, gyro data measured during rotation from the cap application starting position to the cap application end position and/or temperature data.
[0019] The cap holder further comprising a memory holding cap holder type data, and the method may further comprise
receiving the cap holder type data from the memory via the communication module,
comparing the cap holder type data with cap holder type reference data retrieved from the control system of the filling machine,
in case of discrepancy between the cap holder type data and the cap holder type reference data, transmitting an incorrect cap holder type notification to the control system.
[0020] Since different cap holders may be used for different caps, there is a risk that the wrong cap holder is used. This risk increases if several different caps are used and these caps have similar properties, since this has the effect that the different cap holders are similar. In such a situation, it may not be instantly obvious that the wrong cap holder is used, and packages may be produced that seem to be in good order, but at closer look reveal quality issues. By having a memory in the cap holder holding the cap holder type data, this risk is reduced or even completed ruled out.
[0021] The filling machine may comprise two parallel cap holders, wherein the sensor data from the two parallel cap holders may be received in parallel, and the sensor data from the two parallel cap holders may be compared in between to identify cap-holder specific discrepancies.
[0022] By having two cap holders working in parallel relative comparisons between the two can be made, which adds another possibility to identify that the cap application is not working according to plan.
[0024] Having identification data provided in the memory of the cap holder, i.e. having a code for each cap holder such that these can be identified, provides the advantage that from many cap holders over time can be aggregated and followed such that reliable models for increasing the understanding of the cap application process can be achieved, e.g. by using Al. This in turn may result in that improved sensor reference data can be achieved.
[0025] According to a second aspect it is provided a cap holder arranged to hold a cap during rotational application onto a package, said cap holder comprising
- a peripheral element for encircling a cap,
- gripping elements connected to the peripheral element and arranged for preventing movement of the cap with respect to the peripheral element during rotation of the peripheral element around a center axis,
- a sensor arrangement attached to the peripheral element and arranged to generate sensor data, and
- a communication module linked to the peripheral element, communicatively connected to the sensor arrangement and arranged to transmit the sensor data.
[0026] The same advantages and features as presented with respect to the first aspect are also valid for this second aspect.
[0027] The sensor arrangement and the communication module may share one and the same circuit board.
[0028] By having the sensor arrangement and the communication module, and possibly also the energy harvesting arrangement and/or the memory, on the same circuit board, i.e. same unit, these may easily be attached to the cap holder. An advantage with this is that existing filling machines can easily be upgraded.
[0029] The cap holder may comprise an energy harvesting arrangement attached to the peripheral element to power the sensor arrangement and/or the communication module.
[0030] The energy harvesting arrangement may be selected from a group comprising a moving coil arrangement, a moving magnet arrangement, a free impact mass arrangement, a levitation arrangement and a double spring mass arrangement.
[0031] According to a third aspect it is provided a filling machine comprising a cap applicator in turn comprising a cap holder according to the second aspect.
[0032] According to a fourth aspect it is provided a computer program product comprising instructions, which when the program is executed by a data processing apparatus, cause the data processing apparatus to carry out the method according to the first aspect.
[0033] Still other objectives, features, aspects and advantages of the invention will appear from the following detailed description as well as from the drawings.
Brief Description of the Drawings
[0034] Embodiments of the invention will now be described, by way of example, with reference to the accompanying schematic drawings, in which
Fig. 1 illustrates by way of example a cap holder.
Fig. 2 illustrates by way of example a cap applicator comprising two cap holders.
Fig. 3 generally illustrates a filling machine and a data processing apparatus.
Fig. 4 illustrates a circuit board by way of example.
Fig. 5 illustrates different principles for energy harvesting.
Fig. 6 is a flowchart illustrating a method for monitoring cap application.
Detailed Description
[0035] With reference to Fig. 1 a cap holder 100, sometimes referred to as chuck, is illustrated. As illustrated, the cap holder 100 may be ring-shaped such that this can be placed over a cap 106. When being placed over the cap 106, a peripheral element 102 of the cap holder 100 may encircle the cap 100. In this position, to grip the cap 106, gripping elements 104 housed within the peripheral element 102 can be used. After the gripping elements 104 have gripped the cap 106, the peripheral element 102 can rotate around a center axis A such that the cap 106 is screwed onto a neck of the package.
[0036] A circuit board 108, comprising a sensor arrangement 110, a communications module 112, optionally an energy harvesting arrangement 114 and a memory 116, can be attached to the peripheral element 102. To provide for that the circuit board 108 can withstand moisture, liquid etc. the circuit board may be encapsulated or in any other way shielded from the environment inside a filling machine. The wording "circuit board" should in this context be construed broadly and be understood to encompass any device in which the different arrangements are grouped together such that these can be handled as one unit by an operator.
[0037] An advantage with having the circuit board 108 attached to the peripheral element 102 is that the circuit board 108 can be attached to existing cap holders 100. Put differently, having the senor arrangement 110, the communications module 112, optionally the energy harvesting arrangement 114 and optionally the memory 116, comprised as one unit that can easily be attached to the peripheral element 102, this comes with the advantage that the existing base of cap applicators can easily be upgraded, which in turn provides that sensor data can easily be made available to food producers.
[0038] Fig. 2 illustrates by way of example part of a cap applicator 200 comprising two cap holders 100 made to work in parallel. One reason for having parallel cap holders in the cap applicator 200 is that the capacity can be increased.
[0039] In the example illustrated in fig. 2, a translation movement element 202 is provided. By using this element, the two cap holders 100 can be translationally adjusted such that a proper fit with the packages can be achieved. To provide for the rotation of the cap holders 100, a rotational movement element 204 can be used. In the example illustrated, the rotational movement elements 204 comprise belts connected to the cap holders 100 such that the cap holders 100 can be rotated around the center axes A via the belts. Other alternatives are also possible, for instance having the cap holders 100 directly connected to servo motors without using belts.
[0040] The caps may be applied after the packages have been filled with food product. This is the case for PET bottles. Another alternative is to have the caps applied before the filling of the product. This alternative can be used when having the package made of a carton-based material. In such a case, a web of packaging material may be fed into the filling machine, cut in pieces, folded into sleeves, longitudinally sealed, provided with plastic tops, i.e. shoulder and neck, in a molding station, applied with the caps, filled with food product, and bottom sealed such that the packages are closed. An advantage of applying the caps before filling is that the packages can be oriented any way when applying the caps.
[0041] To provide for that the cap application is adequately made, e.g. that no misalignment has taken place, the sensor arrangement 110 may be arranged to also measure perpendicular angle data around a perpendicular axis B, being perpendicular with respect to the center axis A. In case there is rotation occurring around the perpendicular axis B during the cap application, i.e. the cap application starting position and the cap application end position, this may prove to be an indication that the adjustment of the cap applicator 200 is to be reviewed.
[0042] Fig. 3 illustrates schematically the filling machine 300 by way of example. As described above, different types of packages are produced in different ways. Even though the filling machine 300 herein exemplified is a filling machine for producing carton packages, e.g. Tetra Top™, the principles may also be applied on other types of packages provided with screw caps.
[0043] As illustrated, the filling machine 300 can comprise a sleeve former 302, arranged to receive the web of packaging material and to form this into sleeves of packaging materials. As described above, this may involve cutting the web into pieces and longitudinally seal the pieces into the sleeves. Still an option is to feed the filling machine with blanks, i.e. ready-made sleeves folded flat, that is erected by the sleeve former 302.
[0044] After having formed the sleeves, these are provided with tops by a top former 304. As described above, forming the tops may be achieved by injection molding tops onto the sleeves such that upper ends of the sleeves are closed, but other alternatives may also exist. It is for instance, even though not commonly used, possible to have pre-made tops that are sealed onto the upper ends of the sleeves.
[0045] Once the tops are formed, caps 106 are applied onto the tops in the cap applicator 200. The cap applicator 200 may be embodied in different ways and the example illustrated in fig. 2 is one out of several possible alternatives.
[0046] Next, when the caps 106 are applied, the food product is filled into the packages via the open bottoms of the packages. After filling, the bottoms are sealed and possibly folded into bottoms of the packages. This is made in a bottom former, which may in turn be split into a number of sub-units such as bottom sealer and final former.
[0047] To assure proper cap application, sensor data 314 can be fed from the cap applicator 200, more particularly the cap holder 100, to a data processing apparatus 312. As illustrated, the data processing apparatus 312 may be a server, or a server farm, but it may also be a computer placed locally in the filling machine 300.
[0048] The sensor data 314 may be continuously fed from the cap applicator 200 to the data processing apparatus 312, but it may also be fed upon request. In the latter case, a request 316 may be transmitted from the data processing apparatus 312 to the cap applicator 200. The request 316 may be sent a regular intervals, but it may also be triggered by other events that may indicate that the cap application should be checked. For instance, such trigger may be generated by a vision-based quality system.
[0049] To assess the sensor data 314, sensor reference data 320 may be retrieved from a database 318. This database 318 may be filling machine-specific, but it may also be shared among a number of filling machines. An advantage of sharing between many filling machines is that more reliable models, either statistical models or Al models, can be established. This especially holds true in case a large variety of parameters are taken into account, such as translational movement data, accelerometer data, gyro data, temperature data, torque data, plastic material type data (providing information of the material used for the cap and/or the neck), etc. In addition, by measuring over time, the models can be further improved, and as an effect the sensor reference data 320, generated by the models, can be further improved. An advantage of measuring over time is also that historical data may be used as a basis for making predictions, e.g. predictive maintenance. In other words, in case a comparison of the sensor data 314 and the reference sensor data 320 do not match, i.e. the sensor data 314 indicates that something in the cap application is not working according to plan, this may suggest that the cap application is currently working, but may be at risk to not work within a future period of time.
[0050] In case there is a discrepancy between the sensor data 314 and the sensor reference data 320, i.e. there is a mismatch between the current values and the expected values, a check notification 322 may be issued and transmitted to a control system 324 of the filling machine 300. This may in turn trigger that a notification message is sent to an operator or that a service event is scheduled. Even though the control system 324 is illustrated as part of the filling machine 300, the control system may also be stand-alone or form part of other equipment.
[0051] Fig. 4 illustrates by way of example the circuit board 108. In this particular example, a battery is provided in a left end of the board 108 to assure power supply even though the energy harvesting arrangement 114 is not generating electrical energy. In a right end, a microphone is provided. By having the microphone, the sensor data 314 may further comprise audio data.
[0052] To further ease installation of the circuit board 108 onto the peripheral element 102, the communication between the circuit board 108 and the data processing apparatus 312 may be wireless, at least in part such that wires at risk of hindering the cap holder 100 to rotate can be avoided.
[0053] By having the energy harvesting arrangement 114, less battery changes are needed, which in turn reduce the need for frequent service intervals for the circuit board 108. As illustrated in fig. 4, to assure reliable operation, the circuit board 108 may be provided with the battery as a complement to the energy harvesting arrangement 114.
[0054] Using the energy harvesting arrangement 114 in this context is beneficial since the peripheral element 102 of the cap holder 100 will move during operation of the filling machine 300. Put differently, a positive effect of placing the circuit board 108 provided with the energy harvesting arrangement 114 on the peripheral element 102 is that movement will be provided such that the energy harvesting arrangement 114 can generate electricity for the circuit board. In addition to generating electricity, the energy harvesting arrangement 114 may function as a wake-up arrangement and a close-down arrangement, i.e. the circuit board may be set in idle mode or low power mode by using input from the energy harvesting arrangement 114.
[0055] As illustrated in fig. 5, the energy harvesting arrangement 114 may be using different principles for harvesting energy, e.g. a moving coil arrangement (A), a moving magnet arrangement (B), a free impact mass arrangement (C), a levitation arrangement (D) and a double spring mass arrangement (E).
[0056] Fig. 6 is a flowchart illustrating a method 600 for monitoring the cap application in the filling machine 300. In a first step 602, the sensor data 314 can be received. In a second step 604, the sensor data 314 can be compared with the sensor reference data 320. In case of discrepancy 606 between the two, in a third step 608, the check notification 322 can be transmitted.
[0057] Optionally, to reduce service need and to improve energy efficiency, in a fourth step 610, energy can be harvested using the energy harvesting arrangement 114.
[0058] Optionally, to avoid that a wrong type of cap holder, also known as chuck, is used, in a fifth step 612, cap holder type data can be received from the memory 116. In a sixth step 614, the cap holder type data can be compared with cap holder type reference data. In case of discrepancy 616, in a seventh step 618, an incorrect cap holder type notification can be transmitted.
1. A method (600) for monitoring cap application in a filling machine (300) using a data
processing apparatus (312), wherein the filling machine (300) comprises a cap holder
(100) comprising
- a peripheral element (102) for encircling a cap (106),
- gripping elements (104) connected to the peripheral element (102) and arranged for preventing movement of the cap (106) with respect to the peripheral element (102) during rotation of the peripheral element (102) around a center axis (A),
- a sensor arrangement (110) attached to the peripheral element (102), and
- a communication module (112) linked to the peripheral element (102), communicatively connected to the sensor arrangement (110) and arranged to transmit sensor data to the data processing apparatus (312),
said method comprising
receiving (602) the sensor data (314) captured by the sensor arrangement (110),
comparing (604) the sensor data (314) with sensor reference data (320) held in a reference database (318) communicatively connected to the data processing apparatus (312),
in case of discrepancy (606) between the sensor data (314) and the sensor reference data (320), transmitting (608) a check notification (322) from the data processing apparatus (312) to a control system (324).
2. The method according to claim 1, wherein the sensor data (314) comprises angle data
measured between a cap application starting position and a cap application end position
of the rotation around the center axis (A).
3. The method according to any one of the preceding claims, wherein the sensor data (314)
comprises torque data measured during rotation of the cap around the center axis (A)
from the cap application starting position to the cap application end position.
4. The method according to any one of the preceding claims, wherein the sensor data (314)
comprises perpendicular angle data measured between the cap application starting position
and the cap application end position of the rotation around a perpendicular axis (B),
wherein said perpendicular axis (B) is perpendicular to the center axis (A).
5. The method according to any one of the preceding claims, further comprising
harvesting (610) energy using an energy harvesting arrangement (114).
harvesting (610) energy using an energy harvesting arrangement (114).
6. The method according to any one of the preceding claims, wherein the sensor data (314)
further comprises data chosen from a group comprising translational movement data
measured along the center axis (A), vibration data measured during rotation from the
cap application starting position to the cap application end position, accelerometer
data measured during rotation from the cap application starting position to the cap
application end position, gyro data measured during rotation from the cap application
starting position to the cap application end position and/or temperature data.
7. The method according to any one of the preceding claims, wherein the cap holder further
comprising a memory (116) holding cap holder type data, said method further comprising
receiving (612) the cap holder type data from the memory (116) via the communication module (112),
comparing (614) the cap holder type data with cap holder type reference data retrieved from the control system (324) of the filling machine (300),
in case of discrepancy (616) between the cap holder type data and the cap holder type reference data, transmitting (618) an incorrect cap holder type notification to the control system (324).
8. The method according to any one of the preceding claims, wherein the filling machine
comprises two parallel cap holders (100), wherein the sensor data (314) from the two
parallel cap holders (100) is received in parallel, and the sensor data (314) from
the two parallel cap holders (100) are compared in between to identify cap-holder
specific discrepancies.
9. The method according to claim 7, wherein the memory (116) comprises identification
data.
10. A cap holder (100) arranged to hold a cap (106) during rotational application onto
a package, said cap holder comprising
- a peripheral element (102) for encircling a cap (106),
- gripping elements (104) connected to the peripheral element (102) and arranged for preventing movement of the cap (106) with respect to the peripheral element (102) during rotation of the peripheral element (102) around a center axis (A),
- a sensor arrangement (110) attached to the peripheral element (102) and arranged to generate sensor data (), and
- a communication module (112) linked to the peripheral element (102), communicatively connected to the sensor arrangement (110) and arranged to transmit the sensor data ().
11. The cap holder (100) according to claim 10, wherein the sensor arrangement (110) and
the communication module (112) share one and the same circuit board.
12. The cap holder (100) according to claim 10 or 11, further comprising an energy harvesting
arrangement (114) attached to the peripheral element (102) to power the sensor arrangement
(110) and/or the communication module (112).
13. The cap holder (100) according to claim 12, wherein the energy harvesting arrangement
(114) is selected from a group comprising a moving coil arrangement, a moving magnet
arrangement, a free impact mass arrangement, a levitation arrangement and a double
spring mass arrangement.
14. A filling machine (300) comprising a cap applicator (306) in turn comprising a cap
holder (100) according to any one of the claims 10 to 13.
15. A computer program product comprising instructions, which when the program is executed
by a data processing apparatus (312), cause the data processing apparatus (312) to
carry out the method of any one of the claims 1 to 9.