WO2017109482A1

WO2017109482A1 - Apparatus for detecting the presence of adhesive

Info

Publication number: WO2017109482A1
Application number: PCT/GB2016/054010
Authority: WO
Inventors: Andrew Bray; Robert WHIFFEN; Julian White; Martin Horrod
Original assignee: British American Tobacco (Investments) Limited
Priority date: 2015-12-23
Filing date: 2016-12-21
Publication date: 2017-06-29
Also published as: GB201522848D0

Abstract

An apparatus for detecting the presence of adhesive (7) on a web (4) of material is disclosed. The apparatus comprises a radiation source (1) to emit beams (10) of radiation of a predetermined intensity toward the web so that a portion of the web is irradiated, a radiation detector (5) to detect the intensity of radiation scattered by the irradiated portion and, a processor (8) to compare the intensity of radiation scattered by the irradiated portion with a known intensity indicative of the presence, or absence, of adhesive on the web.

Description

Apparatus for detecting the presence of adhesive

Technical Field

The present invention relates to apparatus for detecting the presence of adhesive. In particular, it relates to apparatus for detecting the presence of adhesive on a web of tipping paper as it passes through a tobacco industry product manufacturing machine.

Background

During the manufacture of tobacco industry products such as smoking articles, adhesive is applied to a web of tipping paper before if is cut into paper strips and wrapped about individual rod shaped articles. Depending on the type of smoking article being manufactured, the adhesive may need to be applied to several discrete predetermined regions of the web. Summary

In accordance with some embodiments described herein there is provided apparatus for detecting the presence of adhesive on a web of material as it passes through a tobacco industry product manufacturing machine, comprising a radiation source to emit radiation of a predetermined intensity toward the web so that a portion of the web is irradiated, a radiation detector to detect the intensity of radiation scattered by the irradiated portion and, a processor to compare the intensity of radiation scattered by the irradiated portion with a known intensity indicative of the presence, or absence, of ad hesive on the web. Radiation from the radiation source may be transmitted along a first group of optical fibres and emitted from an end of the first group.

A second group of optical fibres may be provided to transmit the portion of scattered radiation to the detector, and wherein the portion of scattered radiation is incident on an end of the second group of optical fibres.

The ends of the first group and second group of optical fibres may be grouped together so that they both face the same side of the web. A converging lens may be disposed between the grouped ends of the optical fibres and the web to focus the radiation transmitted by the first group of optical fibres onto the web and to focus the portion of scattered radiation onto the end of the second group of optical fibres.

In accordance with some embodiments described herein there is provided apparatus for detecting the presence of adhesive on a web of material as it passes through a tobacco industry product manufacturing machine, comprising a radiation source to emit radiation having a predetermined intensity towards the web, a radiation detector configured to detect the intensity of the radiation that has passed through the web and, a processor to compare the intensity of the radiation that has passed through the web with a known intensity indicative of the presence, or absence, of adhesive on the web.

The processor may be configured to log the intensity of radiation detected by the detector over time as the web passes through the apparatus to generate a temporal data set.

The processor may be configured to store information relating to a predetermined adhesive pattern for application to a web of material and compares said information with the temporal data set. The source of radiation may comprise a linear array of radiation sources arranged perpendicular to the direction of travel of the web that directs discrete beams of radiation towards the web across its width.

The detector may be configured to independently detect the intensity of radiation that has passed through the web, and the processor is configured to compare the intensity of the radiation that has passed through the web with a known intensity indicative of the presence, or absence, of adhesive on the web for each of the radiation sources in the linear array to determine the presence of adhesive on the web at a parti cular position across the width of the web.

The detector may be a camera configured to generate an image of the web. The source of radiation may be a source of coherent radiation. The detector may be a photodiode detector. A method for detecting the presence of adhesive on a web of material as it passes through a tobacco industry product manufacturing machine, the method comprising directing radiation having a known intensity from a radiation source towards a web so that a portion of the web is irradiated, detecting the intensity of radiation scattered by the irradiated portion, comparing the intensity of radiation scattered by the irradiated portion with a known intensity indicative of the presence, or absence, of adhesive on the web.

A method for detecting the presence of adhesive on a web of material as it passes through a tobacco industry product manufacturing machine, the method comprising directing radiation having a known intensity from a radiation source towards a web, detecting the intensity of radiation that has passed through the web, and comparing the intensity of the radiation that has passed through the web with a known intensity indicative of the presence, or absence, of adhesive on the web.

As used herein, the term "tobacco industry product" refers to any item made in, or sold by the tobacco industry, typically including a) cigarettes, cigarillos, cigars, tobacco for pipes or for roll-your-own cigarettes, (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes); b) non-smoking products incorporating tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes such as snuff, snus, hard tobacco, and heat-not-burn (HnB) products; and c) other nicotine-delivery systems such as inhalers, aerosol generation devices including e-cigarettes. This list is not intended to be exclusive, but merely illustrates a range of products which are made and sold in the tobacco industry.

Brief Description of the Drawings

Figure i shows apparatus according to a first embodiment of the invention;

Figure 2 shows apparatus according to a second embodiment of the invention;

Figure 3 shows apparatus according to a third embodiment of the invention;

Figure 4 shows apparatus according to a fourt h embodiment of the invention;

Detailed Description

Embodiments of the present invention provide apparatus for detecting adhesive on a web as it passes through a tobacco industry product manufacturing machine. During the manufacture of tobacco industry products, adhesive is applied to the web in predetermined areas and in predetermined amounts. It is therefore advantageous to monitor the presence or absence of adhesive on the web and the quantity of adhesive applied.

A tobacco industry product refers to any item made in, or sold by the tobacco industry, typically including a) cigarettes, cigarillos, cigars, tobacco for pipes or for roll-your-own cigarettes, (whether based on tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes); b) non-smoking products incorporating tobacco, tobacco derivatives, expanded tobacco, reconstituted tobacco or tobacco substitutes such as snuff, snus, hard tobacco, and heat-not-burn (HnB) products; and c) other nicotine-delivery systems such as inhalers, aerosol generation devices including e-cigarettes, lozenges and gum. This list is not intended to be exclusive, but merely illustrates a range of products which are made and sold in the tobacco industry.

An embodiment according to the invention is shown in Figure i and includes a light source i arranged to direct a beam of light radiation 2 of a predetermined intensity toward a bottom surface 3 of a web 4 of tipping paper as it travels through a smoking article manufacturing machine (not shown), and a detector 5 arranged directly opposite the source 1 and adjacent a top surface 6 of the web 4 so as to detect light transmitted from the light source 1 that has passed through the web 4. The detector 5 generates a signal depending on the intensity of light that passes through the web 4 and onto a detecting surface of the detector 5. The apparatus may be positioned directly after an adhesive applicator in the smoking article manufacturing machine.

In one embodiment, the detector 5 is a photo diode that generates a voltage depending on the amount of light incident on the detecting surface of the diode. A drop in the voltage indicates a drop in the light incident on the diode, and so is indicative of an increase in the proportion of light absorbed by the web 4. Areas of the web 4 to which ad hesive 7 has been applied will absorb more light, and so less of the light emitted by the light source 1 is transmitted through the web 4 and onto the detector 5. It follows that a drop in the voltage generated by the photo diode detector 5 is indicative of the presence of adhesive 7. Further, the thickness of the adhesive layer 7, and therefore the amount of adhesive 7, will have an effect on the amount light transmitted through the web 4. A thicker layer of adhesive 7 will transmit less light, so the amount by which the voltage drops indicates the amount of adhesive 7 present in that area of the web 4. A processor 8 is provided to receive the signal generated by the detector 5 and to determine the presence or absence of adhesive 7. To do this the processor 8 compares the intensity of light radiation that has passed through the web 4 with a known intensity indicative of the presence, or absence, or absence of adhesive on the web.

The known intensity is preprogramed onto the processor 8 and corresponds to an intensity of light radiation received by the detector 5 when a known intensity of light radiation is emitted onto a portion of web 4 for which the presence or absence of adhesive 7 is known. Therefore, by comparing the intensity of light radiation received by the detector 5 as the web 4 passes through the apparatus with the known intensity the processor 8 can determine whether the intensity of light radiation received by the detector 5 is indicative of the presence, or absence, of adhesive on the web 4 or on a portion of t he web 4. The processor 8 can also determine t he difference between the known intensity and the intensity received by the detector to indicate the quantity of ad hesive 7 present on the irradiated portion of the web 4. If the difference is greater than a threshold value then the processor 8 can output an alarm to alert an operator. In one embodiment, the processor 8 records the change in signal with time and can combine this information with data indicating the speed of the web 4 to determine the distance between areas of adhesive 7 on the web 4. In other words, the processor 8 logs the intensity of radiation detected by the detector 5 over time as the web 4 passes through the apparatus to generate a temporal data set. The processor 8 stores information relating to a predetermined adhesive pattern for application to the web 4 of material and compares this information with the temporal data set. Therefore, it can be determined if the spacing between areas of adhesive 7 matches the predetermined adhesive pattern. If the spacing does not match the predetermined pattern, then the processor 8 can output an alarm to alert an operator.

It will be appreciated that the adhesi ve may be patterned on a portion of the web in an even covering or, it may take the form of one or more continuous or broken lines or discrete individually spaced regions.

In another embodi ment of the inventi on, the light source 1 casts a wide beam of diffuse light 2 at the underside 3 of the web 4 and the light detector 5 comprises a camera to generate an image of region of the web illuminated by the beam of light 2. The camera can be configured to generate still images at predetermined time intervals or a continuous video signal. The processor 8 is configured to receive the image or video data from the camera and to determine from the data the presence or absence of adhesive 7 across the width and length of the web 4. Less light will be received by the camera from the regions of the web 4 covered by adhesive as less light will be transmitted by these regions, and so the processor 8 is configured to scan the image or video signal for contrasting Sight and dark regions. Therefore, the presence or absence of adhesive 7 can be determined across the width as well as the length of the web 4. The processor 8 then determines the degree of contrast between the light and dark regions to indicate the amount of adhesive 7 present. If the detected light and dark regions do not correspond with a predetermined pattern of light and dark regions indicative of correctly applied adhesive 7, the processor 8 is configured to output an alarm to alert an operator. Where the camera is configured to generate still images, the time at which each image is created will be set to correspond with an expected absence or presence of adhesive 7, so as to quickly indicate whether the adhesive 7 is properly distributed across the surface of the web 4.

Another embodiment of the invention is depicted in Figure 2, wherein like features retain the same reference numerals. In this embodiment, the light source 1 comprises a linear array of radiation sources 9 arranged perpendicular to the direction of travel 10 of the web 4 such that the beams 10 of light emitted by the array impinge across the width of the web 4. Each radiation source 9 in the array is a source of collimated radiation, for example a laser. Optionally each source 9 may further comprise a convergent lens (not shown) to focus the radiation to a point on the underside of the web 4. Therefore, the light 10 emitted by each source 9 forms a focused discreet pool of light on the underside 3 of the web 4. The light detector 5 comprises a matching array of photo-diodes provided adjacent the upper surface 6 of the web 4. Light detecting surfaces of the photo diodes are arranged in line with respective coherent beams of light 10 so that each photo diode can determine the amount of light 10 transmitted through the web 4 by their respective radiation source 9. Each photodiode generates a signal which is transmitted to the processor 8. The processor 8 can determine from the signal the position in the array of the diode which generated the signal, as well as the intensity of light received by the diode, and therefore the presence of adhesive 7 and the amount of adhesive 7 present in the region of the web 4 in line with that particular diode. By this method the distribution of adhesive 7 can be determined across the width of the web 4 as well as along the length of the web 4. If the signal generated by the detector 5 does not correspond with a predetermined signal indicative of correctly applied adhesive then the processor 8 is configured to output an alarm to alert an operator.

The radiation emitted by the source of coherent radiation 9 is preferably in the infra- red spectrum. By emitting radiation in the infra-red spectrum, the transmitted radiation is readily absorbed by the adhesive. Therefore any change in the signal that results from the presence of adhesive 7 is easily detectable. In addition, a reference channel can be used. The reference channel comprises an additional source of radiation that emits radiation of a different wavelength. In the above described embodiment, the reference channel can be a second linear array of radiation sources arranged upstream of the first array mentioned above. The wavelength of radiation emitted by the reference channel is less readily absorbed by the adhesive 7, for example the wavelength range of the reference channel can be between ΐμιη and 1. 1 an, while the wavelength emitted by the first array can be between i.4,um and ι.5μηι or greater than i.Ss.um. The wavelengths emitted by the first array are more readily absorbed by water which is a large constituent part of the adhesive 7. The reference channel further comprises a second set of detectors that correspond with the second array of radiation sources. The signal generated by the additional detectors provides a reference against which any change in the signal transmitted by the first defectors 5 (mentioned above) can be compared to determine if the change is the result of the presence of adhesive 7 or some other variation such as a contaminant on the web 4.

In yet another embodiment, depicted in Figure 3 in which like features retain the same reference numerals, a Micro-Opto-Electro-Mechanical Systems (MOEMS) mirror 11 is provided to scan a coherent beam of light 12 across the underside 3 of the web 4. The MOEMS mirror 11 comprises a flat reflective 13 surface mounted in an outer housing (not shown for simplicity). Coherent light emitted by a laser 14 impinges on the reflective surface 13 through an opening in the housing and is reflected onto the underside 3 of the web 4. The reflective surface 13 is pivotably mounted in such a way that the angle it forms with the incident beam of light can be changed. A small electric actuator mechanically coupled to a rear side of the reflective surface 13 causes it to pivot periodically between two positions to cause the reflected beam 12 of coherent light to sweep across the underside 3 of the web 4 between outer edges 15 of the web 4. The light detector 5 comprises a linear array of photo diodes arranged perpendicular to the direction of travel 10 of the web 4 and adjacent the upper surface 6. The detector 5 is arranged so that the photodiodes are positioned directly along the path 16 described by the reflected beam 12 as it sweeps across the underside 3 of the web 4. Therefore, as the reflected beam 12 moves between outer edges 15 of the web 4, a portion of said beam 12 will be transmitted through the web 4 and across consecutive photodiodes in the sensor array. Each photodiode generates a signal which is transmitted to the processor 8. The processor 8 can determine from the signal the position in the array of the diode which generated the signal, as well as the intensity of light received by the diode, and therefore the presence of adhesive 7 and the amount of adhesive 7 present in the region of the web 4 in line with that particular diode. By this method the distribution of adhesive 7 can be determined across the width of the web 4 as well as along the length of the web 4. If the signal generated by the sensor 5 does not correspond with a predetermined signal indicative of correctly applied adhesive 7 then the processor 8 is configured to output an alarm to alert an operator. As in the above described embodiment, the wavelength of radiation emitted by the laser 14 is preferably in the range lum to 1.35 urn, and more preferably greater than ι.8.5μηι, to ensure a high degree of sensitivity of the transmitted radiation to the presence of adhesive.

According to the invention the light source 1 and detector 5 can be disposed in a chamber (not shown) to protect them from dust and other contaminants that might be present. It is envisaged that the chamber is positioned over the web so that the web passes through an opening in one end of the chamber, to travel between the detector and the light source and out through a second opening. Additionally, a fan can be provided in fluid communication with the chamber to maintain a positive pressure in the chamber and so prevent dust from entering the chamber. The fan draws in filtered air so that the fan does not introduce contaminants. This will assist in keeping the light emitting and detecting surfaces clean.

According to another embodiment of the invention as shown in Figure 4 and in which like features retain the same reference numerals, there is provided an apparatus for detecting the presence of adhesive on a web 4 of material as it passes through a tobacco industry product manufacturing machine. The apparatus comprises a radiation source 1 to emit radiation of a predetermined intensity toward the web 4 so that a portion of the web 4 is irradiated by the source 1. Radiation absorbed by the irradiated portion is then scattered and a radiation detector 5 is provided to detect the intensity of radiation scattered by the irradiated portion. As shown in Figure 4, a ferrule 17 is provided into which ends of optical fibres are inserted. The optical fibres extend from the ferrule 17 and are split into two groups, A first group 18 is optically connected to the radiation source 1 and a second group 19 is optically connected to the detector 5.

Radiation is transmitted along the first group 18 from the radiation source 1 to an opposing end 20 disposed in the ferrule 17. The ferrule 17 groups the optical fibres into a bundle in which the fibres are arranged parallel to each other. This collimates the radiation emitted from the end 20 of the first group 18 so that a single defined beam irradiates the web 4. The end 20 of the first group 18 is exposed to the web 4 through an opening 21 in the ferrule 17 which is arranged directly facing the web 4. Therefore the collimated beam of radiation irradiating the web 4 is directed towards it at an angle perpendicular to the web 4. A converging lens 22 is disposed in the opening 21 of the ferrule 17 to focus radiation onto the irradiated portion of the web 4. The lens 22 also serves to focus a sample of the radiation scattered by the irradiated portion onto an end 23 of the second group 19 of fibres so that said sample of scattered radiation is transmitted along the second group 19 to the detector 5. The detector 5 then generates a signal based on the intensity of the sample of scattered radiation.

A processor 8 is provided to receive the signal and determine from the signal whether adhesive 7 is present on the irradiated portion of the web 4. The processor 8 compares the intensity of radiation scattered by the irradiated portion with a known intensity indicative of the presence, or absence, of adhesive on the web.

The known intensity is preprogramed onto the processor 8 and corresponds to an intensity of light radiation received by the detector 5 when a known intensity of light radiation is emitted onto a portion of web 4 for which the presence or absence of adhesive 7 is known. Therefore, by comparing the intensity of light radiation received by the detector 5 as the web 4 passes through the apparatus with the known intensity the processor 8 can determine whether the intensity of light radiation received by the detector 5 is indicative of the presence, or absence, of adhesive on the web 4. The processor 8 can also determine the difference between the known intensity and the intensity received by the detector to indicate the quantity of adhesive 7 present on the irradiated portion of the web 4. If the difference is greater than a threshold value then the processor 8 can output an alarm to alert an operator.

In one embodiment, the processor 8 records the change in signal with time and can combine this information with data indicating the speed of the web 4 to determine the distance between areas of adhesive 7 on the web 4. In other words, the processor 8 logs the intensity of radiation detected by the detector 5 over time as the web 4 passes through the apparatus to generate a temporal data set. The processor 8 stores information relating to a predetermined adhesive pattern for application to the web 4 of material and compares this information with the temporal data set. Therefore, it can be determined if the spacing between areas of adhesive 7 matches the predetermined adhesive pattern. If the spacing does not match the predetermined pattern, then the processor 8 can output an alarm to alert an operator. In any of the embodiments of the invention, the tobacco industry product

manufacturing machine may comprise a feedback loop. The processor 8 can then send a signal via the feedback loop in order to stop the machine after a predetermined number of consecutive rejects are detected. This may be in addition or as an alternative to outputting an alarm to an operator.

In a preferred embodiment, the radiation emitted by the radiation source 1 is in the infra-red range and the source is a laser. It is intended that the chosen wavelength of radiation is one that is more readily absorbed by the adhesive than by the web 4. The wavelength of the emitted radiation is preferably in the range ΐμηι to i.35um, and more preferably greater than i.Sstim, to ensure a high degree of sensitivity of the transmitted radiation to the presence of adhesive 7.

By selecting a wavelength that is readily absorbed by the adhesive 7 than the web 4, less scattering occurs where adhesive 7 is present. Therefore a decrease in the intensity of the scattered radiation indicates the presence of adhesive 7. Further, information about the relative intensity of the scattered radiation indicates the quantity of adhesive 7 present. Whilst the present invention is primarily intended for use in detecting the presence of adhesive on a web of tipping paper as it passes through a tobacco industry product manufacturing machine, it may also be used in other industries in which adhesive is applied to a moving web of material.

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed invention may be practiced and provide for superior apparatus for the manufacture of rod shaped articles. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future.

Claims

Claims l. Apparatus for detecting the presence of adhesive on a web of material, comprising a radiation source to emit radiation of a predetermined intensity toward the web so t hat a portion of the web is irradiated , a radiation detector to detect the intensity of radiation scattered by the irradiated portion and, a processor to compare the intensity of radiation scattered by the irradiated portion with a known intensity indicative of the presence, or absence, of adhesive on the web.

2, Apparatus according to claim i, wherein radiation from the radiation source is transmitted along a first group of optical fi bres and emitted from an end of the first group.

3. Apparatus according to claim 2, wherein a second group of optical fibres is provided to transmit the portion of scattered radiation to the detector, and wherein the portion of scattered radiation is incident on an end of the second group of optical fibres.

4. Apparatus according to claim 3, wherein the ends of the first group and second group of optical fibres are grouped together so that they both face the same side of the web.

5. Apparatus according to claim 4, wherein a converging lens is disposed between the grouped ends of the optical fibres and the web to focus the radiation transmitted by the first group of optical fibres onto the web and to focus the portion of scattered radiation onto the end of the second group of optical fibres.

6. Apparatus for detecting the presence of adhesive on a web of material, comprising a radiation source to emit radiation having a predetermined intensity towards the web, a radiation detector configured to detect the intensity of the radiation that has passed through the web and, a processor to compare the intensity of the radiation that has passed through the web with a known intensity indicative of the presence, or absence, of adhesive on the web.

7. Apparatus according to either claim 1 or claim 6, wherein the processor is configured to log the intensity of radiation detected by the detector over time as the web passes through the apparatus to generate a temporal data set.

8. Apparatus according to claim 7, wherein the processor stores information relating to a predetermined adhesive pattern for application to a web of material and compares said information with the temporal data set.

9. Apparatus according to claim 8 when dependent on claim 6, wherein the source of radiation comprises a linear array of radiation sources arranged perpendicular to the direction of travel of the web that directs discrete beams of radiation towards the web across its width.

10. Apparatus according to claim 9, wherein the detector is configured to independently detect the intensity of radiation that has passed through the web, and the processor is configured to compare the intensity of the radiation that has passed through the web with a known intensity indicative of the presence, or absence, of adhesive on the web for each of the radiation sources in the linear array to determine the presence of adhesive on the web at a particular position across the width of the web.

11. Apparatus according to any preceding claim, wherein the detector is a camera configured to generate an image of the web.

12. Apparatus according to any preceding claim, wherein the source of radiation is a source of coherent radiation.

13. Apparatus according to any preceding claim, wherein the detector is a photodiode detector.

14. A tobacco industry product manufacturing machine comprising the apparatus according to any of claims 1 to 13.

15. A method for detecting the presence of adhesive on a web of material, the method comprising directing radiation having a known intensify from a radiation source towards a web so that a portion of the web is irradiated, detecting the intensity of radiation scattered by the irradiated portion, comparing the intensity of radiation scattered by the irradiated portion with a known intensity indicative of the presence, or absence, of adhesive on the web.

16. A method for detecting the presence of adhesive on a web of material, the method comprising directing radiation having a known intensity from a radiation source towards a web, detecting the intensity of radiation that has passed through the web, and comparing the intensity of the radiation that has passed through the web with a known intensity indicative of the presence, or absence, of adhesive on the web.