AU2011253880A1 - An apparatus and process of monitoring adhesive - Google Patents

Abstract

- 22 The present invention relates to an apparatus and process of monitoring defects in the application of adhesive to 5 packages in a processing line. The purpose of the invention is to increase the assurance that the package is suitable for the safe storage and handling of materials such as edible powered material. The adhesive is monitored for defects that can compromise a seal formed 10 between two parts of the packages adhered together by the adhesive. The process includes exposing the adhesive to a light source, capturing images of the adhesive and analysing the images to detect the presence of defects in the adhesive. The defects may be in the form of blobs, 15 hair lines, and strands of adhesive, or similarly an absence of adhesive in areas where adhesive should be present. 2972760_1 (GHMatters) P88580.AU7/12/11 - 23 Applying an adhesive to a section of a package, such as hot melt glue being applied to closure flaps of a sack to be closed in a processing line. 10 Exposing the package including the section to which the adhesive has been applied to a light source, such as an ultra-violet lamp. The processing line may include any one or a combination of: i) 15 Ce o manufacturing operations Capturing images of the section of the packages including cutting material to to which the adhesive has been applied. For form blanks for making the example, using a Cognex digital camera packages; ii) folding the blanks 20 ,to form the packages; iii) loading contents into the packages, and iv) stacking the Analyzing the images using a computer processor packages either before or after to detect defects and faults in the adhesive applied the contents have been loaded 25 to the packages, such as blobs of excessive into the packages adhesive, string lines, strands and alike. Ejecting the package f-rm the processing line detected as having defects in the adhesive applied to the packages. 2972760_1 (GHMatters) P88580.AU7/1 2/11

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant: Amcor Limited Invention Title: AN APPARATUS AND PROCESS OF MONITORING ADHESIVE The following statement is a full description of this invention, including the best method for performing it known to me/us: -2 AN APPARATUS AND PROCESS OF MONITORING ADHESIVE FIELD OF THE PRESENT INVENTION 5 The present invention relates to an apparatus and process of monitoring adhesive applied to packages which includes monitoring for defects in the application of the adhesive applied to the packages. The adhesive may be applied for sealing different parts of the packages including parts 10 that are intended to remain closed until the package is opened, or other parts that, for example, form an openable closure. The process can be used for monitoring adhesive applied to packages such as, but by no means limited to, packages containing granular or powdered material 15 including dairy powder and milk powder. BACKGROUND OF THE PRESENT INVENTION Packages such as sacks and bags can be used for a range of 20 products and applications, including safe storage and handling of powdered products such as cement, flour and milk powder. The range of diary powdered products that may be contained by sacks and bags includes infant formula, milk powdered drinks and base ingredients for 25 nutritional products. Importantly, the sacks and bags that contain edible powdered products are required to perform at, or close to, their intended purpose on every occasion to maintain the contents contamination free and free from tampering. 30 The safe storage and handling of powdered material in sacks, bags and other packages is dependent on a large number of variables that make the packages suitable for their intended purpose. An example of one such variable 35 is that the adhesive must be applied precisely to difference parts of the package that a glued together. There is, therefore, a need to monitor the application of 29727601 (GHMatters) P88580.AU 7/12/11 - 3 adhesives applied to packages to provide assurance that the packages are fit for their intended purpose. SUMMARY OF THE PRESENT INVENTION 5 The present invention relates to a process of monitoring for defects in the application of an adhesive to packages in a processing line, the process includes the steps of: 10 a) applying the adhesive to at least one section of the packages, wherein the adhesive applied can be used to seal two parts of each package together; b) exposing the section of the packages to which the adhesive has been applied to a light source; 15 c) capturing images of the sections either during step b) and/or after step b); d) detecting the presence of defects in the adhesive applied by analysing of the images captured; and e) treating the packages determined to have at least one 20 section in which the adhesive is defective. The application of an adhesive may be without defects when, for example, the adhesive is uniform in thickness or smoothness and confined to areas that are intended to 25 receive the adhesive. As described in more detail herein, a defect in the application of the adhesive occurs when one of these conditions is not present, or if some other condition occurs, for example, during the application of the adhesive to the packages. 30 Suitably, steps a) to e) are carried out prior to the adhesive being used to close the packages. The processing line may also include a number of 35 manufacturing operations including cutting material to form blanks of the packages, folding the blanks to form the packages and as described by step a), applying 2972760_1 (GHMatters) P88580.AU 7/12/11 -4 adhesive to the parts of the packages that are intended to adhered to other parts of the packages. The step of treating the packages determined to have at 5 least one defect in the adhesive may include removing the respective packages from the processing line. Once removed from the processing line, the packages may be discarded. 10 In another situation, it is possible that the step of treating the packages may include removing the adhesive determined to be defective, and reapplying the adhesive. In either situation, ideally at least steps a) to d) and 15 suitably step e), can be carried out in real-time without slowing the processing line. For example, the process may be carried out at a rate of at least 1 package per second which includes, for example up to 20 packages per second, and suitably at a rate ranging from 1 to 15 packages per 20 second. Step a) includes applying the adhesive to the sections of the package, such that the sections include areas of the adhesive and areas that are free of the adhesive. 25 The adhesive may be any suitable adhesive including: pressure sensitive glue, hot melt glue, cold glue and so forth. The adhesive may be applied in any geometric configuration or pattern, including strips, lines, ovals, 30 circles, blobs and so forth. The strips and lines of adhesive may include continuous strips or lines, and discontinuous strips or lines in which gaps or spaces free of adhesive are formed along the length of the strip or line. 35 The packages to which the adhesive is applied may include envelopes, satchels, boxes, cartons, rupture packets, 2972760_1 (GHMatters) P88580.AU 7/12/11 blister packets and so forth. Examples of packages intended to contain food items including powder material, such as infant formula, powdered milk products, flower, and sugar and alike, include sacks and bags. However, 5 sacks and bags may also be used for other purposes. The packages may be made of any suitable material including polymeric material, metallic material and laminations thereof. The packages may also include 10 multiple discrete layers, including polymeric and metallic layers that are not laminated. The material or substrate of the packages may also include fibrous or paper based materials including unbleached paper materials, semi bleached materials, bleached materials and ultra-bleached 15 materials. We have found that although the paper based materials may include starch and bleaching materials which have some fluorescence properties, the fluorescence properties of the packages such as the paper based components of the packages is different to the 20 fluorescence properties of a number of the adhesives used in the manufacture of packages including paper based materials. In one example, the adhesive may have an inherent level of 25 fluorescence. In another embodiment, an additive may be added to the adhesive so as to change the reflectivity and/or emissivity of the adhesive. For example, the additive may increase the fluorescence of the adhesive. 30 An example of a suitable hot melt adhesive having different fluorescent properties to standard paper based materials and commercially available from HB Fuller include adhesives known as HL0032 and HLOO08. Another example of a suitable hot melt adhesive having different 35 fluorescent properties to paper based materials and commercially available from Henkel include an adhesive known as Technomelt 3001. 2972760_1 (GHMatters) P88580.AU 7/12/11 -6 The light source may radiate light including any light source including light from the visible and non-visible spectra. Examples of non-visible light include 5 ultraviolet and infrared light. Suitably, the light source is a "blacklight blue" light source having a wavelength from 350 rnm to 400 nm. The wavelength of the light source may, for example, peak in the range of 365 to 370 nm. 10 Suitably, the light source may be an ultraviolet light source and the adhesive has either one or a combination of the following properties: i) reflects incidental light including ultraviolet light, and/or ii) emits a 15 fluorescence, and the reflectivity or the emissivity of the adhesive is different to the reflectivity and the emissivity of the material of the packages. The fluorescence of the adhesive may be a function of both visible and non-visible light with the light source 20 emitting visible light. Step c) may include capturing images in which light radiating from the adhesive and captured in the images includes either one or a combination of reflected light or 25 emitted light. The images captured may also have images of light radiating from the material of the packages including reflected light and emitted light. Step d) may include analysing the images captured by 30 comparing radiant light of the adhesive applied to the packages to radiant light of the material of the packages. The images captured according to step c) may be analogue images, however suitably, the images are captured using a 35 digital photo receiver. Alternatively, analogue photos may be converted into digital data. Step d) may include 2972760_1 (GHMatters) P88580.AU 7/12/11 - 7 conducting image analysis of the images captured to determine defects in the adhesive applied. The image analysis may be carried out using any suitable processor. Moreover, throughout this specification the terms 5 "processor" or "processing unit" is used to refer generically to any device that can process instructions and may include: a microprocessor, microcontroller, digital signal processor, programmable logic device, field programmable gate array (FPGA) , application specific 10 integrated circuit (ASIC) or other computational device, a general purpose computer (e.g. a PC) or a server. In one embodiment, step d) may include pixelating the images captured, and determining the presence of 15 excessively bright pixels which represent a defect in the application of the adhesive to the packages. In other words, process may include a program operated by a processor carrying out step d), wherein image analysis includes the brightness in each pixel of the image being 20 assigned a value, and when a value of one or a group of pixels equals or exceeds a predetermined value, a defect in the adhesive applied is determined. Less bright pixels representing the adhesive applied to the packages in an even coating (ie without defects) or light reflect from 25 the material of the packages about the areas of the adhesive. The image analysis may also include detecting defects by determining boundaries of the areas in which the adhesive 30 is intended to be applied to the packages and determining the presence of adhesive outside the boundaries as a function of the brightness of the images outside the boundaries. In either situation, the adhesive in the areas will be uneven in thickness or have an uneven surface. 35 In another embodiment, step d) may include the computer 29727601 (GHMatters) P88580.AU7/12/11 -8 image analysis involving comparing a set of data, representing the images captured in step c), to a reference set of data, and determining differences therebetween to determine defects in the adhesive applied. 5 It is possible that the reference set of data may be obtained or downloaded from an external data source, for example, from data provided by a manufacture of the adhesive. 10 It will be appreciate, however, that the reference data may be dependent on a number of factors including the based material of the packages, the intensity and type of light source, and the properties of the adhesive. Accordingly, the reference set of data may be obtained 15 from by the process including a preliminary step of inspecting one of the packages and manually observing and determining that the adhesive of the selected package is free of defects. The preliminary step may also include capturing an image of one or more of the packages having 20 the adhesive applied that is free of defects, and retaining data of the image(s) captured free of defects for use as the reference set of data. The data of the images captured, for either the reference 25 data or the data of images captured, may be representative of the fluorescence of the adhesive applied to the packages. The computer image analysis may include pixel analysis. For example, the level of fluorescence of the adhesive may 30 be represented by the brightness in each pixel of the image being assigned a value, and the values of the pixels of the images captured are compared to values of the reference set(s) of data. 35 Suitably, the presence and more suitably, the defects in the adhesive applied to the packages may be a function of the fluorescence captured in the image(s). 29727601 (GHMatters) P88580.AU 7/12/11 - 9 The following defects in the adhesive may, for example, be detected as a function of the fluorescence of the adhesive: unevenness or non-uniformity of the adhesive 5 applied to the packages including, inadequate thickness or excessive thickness of adhesive applied. Step d) may include determining when adhesive is present in areas that are intended to be free of the adhesive. 10 Step d) may also include determining when the adhesive is not present in areas which are intended to have adhesive. A defect in the adhesive may also be detected according to step d) when the adhesive is applied non-uniformly in the 15 section in which the adhesive is applied. The term applied non-uniformly in this context embraces the adhesive being applied in varying thicknesses, varying widths and in areas that are not intended to receive the adhesive. For example, non-uniformity may include the 20 adhesive being applied in a thickness greater than a predetermined thickness, or at a thickness less than the predetermined thickness. The defects may also be include blobs of excessive glue 25 that may cause the glue line adjacent to the blob to stand proud and unattached from the package, strands, string lines or 'angel hairs' (very fine string lines) that have been drawn from the adhesive applied to the packages and can create regions of the glue line in which the glue has 30 been applied in insufficient amounts. According to the present invention there is also provided an apparatus that monitors for defects in the application of adhesive to packages in a processing line. The 35 apparatus includes: an applicator that applies adhesive to at least one 2972760_1 (GIHMatters) P88580.AU 7/12/11 - 10 section of the packages, wherein the adhesive applied can be used to seal two parts of each package together; 5 a light source that emits lights to the section of the packages to which the adhesive has been applied to a light source; an image capturing device that captures images of the 10 sections either whilst or after the light source has emitted light at the adhesive; a processor that detects the presence of defects in the adhesive applied by analysing the images 15 captured; and a treating station that treats the packages determined to have at least one section in which the adhesive is defective. 20 The treating station may include a device that removes the packages detected as having a defect from the processing line. 25 The apparatus of the present invention may also include any one or a combination of the features of the process described herein. BRIEF DESCRIPTION OF THE DRAWING 30 A preferred embodiment of the present invention will not be described with reference to the accompanying drawings, of which: Figure 1 is a block diagram illustrating the steps of a process of monitoring for defects or faults in the 35 application of an adhesive to packages in a processing line; Figure 2 is a schematic illustration of a sack having 2972760_1 (GHMatters) P88580.AU 7/12/11 - 11 flaps extending from the side wall of the sack to which the adhesive is applied in strips; and Figures 3a, 3b, 3c and 3d are schematic illustrations of part of adhesive strips having defects, wherein Figure 5 3a illustrates an a blob of adhesive, Figure 3b illustrates gaps in the adhesive and glue hairs extending from the glue line, Figure 3c illustrates gaps in the adhesive and strands of glue extending from the glue line, and Figure 3d illustrates excessive glue bulging upwardly 10 from the glue line. DETAILED DESCRIPTION A preferred embodiment will now be described with 15 reference to a process of monitoring for defects in an adhesive applied to a package in the form of a sack or bag. The term sack embraces a multi-walled bag, however, in some instances the term sack can also embrace a single walled bag. Accordingly, the terms bag and sack, or 20 variations thereof, have been used interchangeably. The package may be used in a range of applications and is particularly suited to sacks for containing edible powdered material. The sack is suitably a multi-wall sack 25 and may include, for example, one or more internal bags such as a moisture impermeable polymeric bag in which the contents are contained, an intermediate paper bag which contains the polymeric bag, and one or more outer paper bag that contains the intermediate bag. The intermediate 30 bag and the outer bag may be made of paper based materials containing fibre such as cellulosic fibre at provide abrasion resistance and puncture resistance. The intermediate and outer bags may be manufactured by 35 cutting and folding a sheet of polymeric material and paper based material into a tubular form having a longitudinal glued seam. In the case of the polymeric 2972760_1 (GHMatters) P88580.AU 71211 - 12 inner bag, the bag may be an extruded tube that can then be welded at opposite ends. The bottom end of the intermediate and outer bags may then be thoroughly sealed by gluing and bonding together overlapping flaps. The top 5 end of the intermediate and outer bags may be closed by adhering flaps extending from the side wall of the intermediate and outer bags over the side wall into a closed sealed position. 10 Closing the side wall flaps of the inner, intermediate or outer bags of the sack include applying an adhesive to the flap, and folding the flaps so that the adhesive on the flaps adheres to an side wall of the bag and holds the flaps in a closed position. Prior to the flaps being 15 folded and adhered to the side wall of the bag, the process includes applying an adhesive to at least one section of the flaps of the intermediate and outer bags that overlap with one or more side walls of the sack when folded into a closed position. The adhesive applied to 20 the flaps of the intermediate and outer bags may be adhered to side walls of the respective intermediate and outer bags, or alternatively to the side wall of the outer side wall only. 25 To ensure that the sack is capable of safely storing and handling powdered material in a manner that minimises the possibility of contamination or tampering, the process includes monitoring the adhesive applied to the flaps at the top of the sack to detect defects that could 30 compromise the performance of the sack. Maintaining quality of the adhesive applied to the package is important to prevent the ingress of contaminants into the sack such as insects, bugs, rodents and other pests. 35 Hot melt adhesives commercially available from HB Fuller, such as HL0032 and HLOO08, and commercially available from Henkel, such as Technomelt 3001, are suitable adhesives 29727601 (GHMatters) P88580.AU 7/12/11 - 13 for securing the flaps at the top end of the sack to the side walls of the sack. Importantly, we have found that such adhesives have inherent fluorescence properties that can be captured in images and analysed to detect defects 5 or faults in the adhesive including defects in the manner in which the adhesive has been applied to the package. The process includes use of a light source to expose the adhesive to ultra-violet light, however, the light source may be any light source including visible and non-visible 10 light. Moreover, the visible fluorence of the adhesive may be a function of at least one or both the visible and non visible light of the light source. An example of a light source is a so called blacklight 15 blue light source which emits light having a wavelength between 350 and 400 rm, and peaking from 365 to 370 nm. With reference to Figure 1, while the adhesive is exposed to the light source, or shortly thereafter, a digital 20 camera is used to capture light radiating from the adhesive. The light radiating from the adhesive may include reflected light and emitted light including fluorescent light from the adhesive. 25 The adhesive may be applied using any suitable technique including lick rollers, feed and pressure rollers, jet application, pad and stamp application and so forth. The images captured are then processed and analysed to 30 detect the presence of defects in the application of the adhesive applied to the packages. Computer analysis of the images captured may include values being allocated to pixels of the image that represent any one of a combination of: 35 e the presence of the adhesive in a predetermined area; e the absence of the adhesive in the predetermined area or pixel; 2972760_1 (GvHMatters) P88580.AU 7/12111 - 14 * the thickness of the adhesive applied in the predetermined area or pixel; and " the size, shape, and configuration of the adhesive applied in the predetermined area or pixel. 5 As can be seen in Figure 2, the adhesive is typically applied in straight glue lines of preferred length and width. It will be appreciated that the process can be used for any package, and for any processing line that 10 handles the packages at any rate. In addition, the adhesive may be applied to more than one section of the package including multiple flaps extending from the side walls of the sacks. The sections to which adhesive is applied may be disposed on the same or opposite sides of 15 the package. We have found that a digital camera available from Congex and processor for operating computer imaging software such as software available under the trade mark Insight are 20 capable of accurately capturing images and analysing the images by comparison of the images. Two possible examples will now be described. In the first example, and according to the preferred embodiment, the 25 software may include algorithms that pixelate images captured and analyse the images by assigning values to the pixels based on brightness of the respective pixels. The algorithms may then include detecting the presence of 30 particularly bright pixels, which may indicate the present of defect of faults in the adhesive applied, which can lead the packaging being rejected. The analysis may include increasing the brightness of the 35 pixels to increase the contrast between the pixels representing the presence of adhesive and pixels that representing the absence of adhesive. The algorithms may 29727601 (GHMatters) P88580.AU m2/Il - 15 then include determining the boundary of the area to which the adhesive is applied and then determining whether adhesive is present outside the boundary, for example, as may be the situation in which hairs, line or strands of 5 adhesive extend from the Ares in which adhesive is applied to the packages. According to a second example, the software include algorithms that analyse the images captured by comparing 10 the values representing to the brightness of pixels of the images captured to a set of reference data. A set of reference data can be pre-obtained by selecting a sample sack to which adhesive has been applied and 15 manually determining that the adhesive applied to the sample is free of defects. Once this determination has been made, the camera is operated to capture an image and the computer software operated to the convert the image into the set of reference data which is stored for 20 comparison to data of images captured during continuous operation of the process. It is possible that the set of reference data may also be updated continuously or periodically so as to comprise a running set of reference data. For example, the running set of reference data may 25 be based on averages, means, or distributions of data captured during operation of the process. One of the advantages of using the Cognex camera and Insight image processing software is that the hardware and 30 computer software is capable of monitoring the quality of the adhesive applied to the sacks during normal operation of the processing line. For example, images of the sacks can be captured at a rate of up to 20 packages per second, and suitably at rate in the range of 5 to 15 packages per 35 second. Once a defect in the adhesive of a sack has been detected, 29727601 (GHMatters) P88580.AU 7/12/11 - 16 ideally the sack is rejected from the processing line so that sack will not be included further in the processing line. 5 As can be seen in Figure 2, the adhesive is typically applied in straight glue lines 10 of preferred length and width. It will be appreciated that the process can be used for any package, and for any processing line that handles the packages at any rate. In addition, the 10 adhesive may be applied to more than one section of the package including multiple flaps 11 extending from the side walls 12 of the sacks 13. The sections to which adhesive is applied may be disposed on the same or opposite sides of the package. 15 Figures 3a to 3d schematic illustrate four common defects in the application of an adhesive to packages. Figure 3a illustrates a strip of adhesive having a protruding blob 14 that causes the surrounding adhesive to bond 20 inadequately. Figures 3b and 3c illustrate glue hairs and strands 15 drawn from the strip of glue 10. The hairs and strands 15 can cause a reduction in the thickness of adhesive applied to the adhesive strip. Figure 3d illustrates the situation in which the adhesive strip 10 25 spreads above the intended an upper boundary 16 of the glue strip identified by the dashed line. Those skilled in the art of the present invention will appreciate that many variations and modifications may be 30 made to the preferred embodiment without departing from the spirit and scope of the present invention. 29727601 (GHMatters) P88580.AU 7/12/11

Claims (24)

1. A process of monitoring the application of an adhesive to packages in a processing line, the process 5 includes the steps of: a) applying the adhesive to at least one section of the packages, wherein the adhesive applied can be used to seal different parts of each package together; 10 b) exposing the section of the packages to which the adhesive has been applied to a light source; c) capturing images of the sections to which adhesive is applied either during step b) and/or after step b); d) detecting the presence of defects in the adhesive 15 applied by analysing the images captured; and e) treating the packages determined to have at least one section in which the adhesive is defective.

2. The process according to claim 1, wherein the 20 processing line includes any one or a combination of: i) manufacturing operations including cutting material to form blanks of the packages; ii) folding the blanks to form the packages; iii) loading contents into the sacks, and iv) stacking the sacks either before or after the 25 sacks have been loaded.

3. The process according to claim 1 or 2, wherein the step of treating the packages determined to have at least one defect in the adhesive includes removing the 30 respective packages from the processing line.

4. The process according to any one of claims 1 to 3, wherein steps b) to d) are carried out at a rate of at least 1 package per second. 35

5. The process according to any one of the preceding claims, wherein step a) includes applying the adhesive to 2972760 1 (GHMatters) P88580.AU 7/12/11 - 18 the sections of the package such that the sections include areas of the adhesive and areas that are free of the adhesive. 5

6. The process according to any one of the preceding claims, wherein the packages are paper sacks for containing powdered material.

7. The process according to any one of the preceding 10 claims, wherein the packages are paper sacks containing edible powdered material including, but by no means limited to, powdered milk products.

8. The process according to any one of the preceding 15 claims, wherein the packages include paper based material to which the adhesive is applied, and the paper based material has different light radiating properties to the adhesive applied. 20

9. The process according to any one of the preceding claims, wherein the light source includes light from the visible and non-visible spectra.

10. The process according to any one of the preceding 25 claims, wherein step c) includes capturing images in which light radiating from the adhesive and the material of the package, and the light radiating from the adhesive includes either one or a combination of reflected light or emitted light. 30

11. The process according to claim 10, wherein the light source emits ultraviolet light and the adhesive has either one or a combination of the following properties: i) reflects incidental ultraviolet light, and/or ii) emits a 35 fluorescence, and the reflectivity or the emissivity of the adhesive is different to the reflectivity and the emissivity of the material of the packages. 2972760_1 (GHMatters) P88580.AU 7/12/11 - 19

12. The process according to claim 11, wherein the fluorescence emitted by the adhesive is a function of either one or both visible and non-visible light. 5

13. The process according to any one of the preceding claims, wherein the images are captured using a digital photo receiver. 10

14. The process according to any one of the preceding claims, wherein step d) includes conducting analysis of the images captured by comparing radiant light of the adhesive applied to the packages to radiant light of the material of the packages. 15

15. The process according to any one of the preceding claims, in which a program operated by a processor carries out step d) wherein image analysis includes the brightness in each pixel of the image being assigned a value, and 20 when a value of one or a group of pixels equals or exceeds a predetermined value, a defect in the adhesive applied is determined.

16. The process according to claim 15, wherein the image 25 analysis includes detecting defects by determining boundaries of the areas in which the adhesive is intended to be applied to the packages, and determining the presence of the adhesive outside the boundaries as a function of the brightness of the images outside the 30 boundaries.

17. The process according to claim 15 or 16, wherein the values representing the brightness of the pixels is a function of the fluorescence captured in the image(s). 35

18. The process according to any one of the preceding claims, in which a program operated by a processor carries out step d) wherein image analysis of the images captured involves comparing a set of data, representing the images 2972760_1 (GIHMatters) P88580.AU 7/1 211 - 20 captured in step c), to a reference set of data, and determining differences between the set of data and the reference set of data to determine defects in the adhesive applied. 5

19. The process according to claim 18, wherein the process includes a preliminary step of capturing an image of one or more of the packages having the adhesive that is free of defects, and retaining data of the image(s) 10 captured free of defects for use as the reference set of data.

20. The process according to any one of the preceding claims, wherein step d) includes determining when adhesive 15 is present in areas that are intended to be free of the adhesive.

21. The process according to any one of the preceding claims, wherein step d) includes determining when the 20 adhesive is absent from areas in which adhesive is intended to be present.

22. The process according to any one of the preceding claims, wherein step d) includes determining when the 25 adhesive is applied non-uniformly in the section in which the adhesive is applied.

23. The process according to any one of the preceding claims, wherein the defects that are detected are in the 30 form of one or more of: blobs of excessive adhesive; or strands, string lines or angel hairs in the adhesive applied. 35

24. An apparatus that monitors for defects in the application of adhesive to packages in a manufacturing line, the apparatus includes: an applicator that applies adhesive to at least one 2972760_1 (GIHMatters) P88580.AU 7/12/11 - 21 section of the packages, wherein the adhesive applied can be used to seal two parts of each package together; 5 a light source that emits lights to the section of the packages to which the adhesive has been applied to a light source; an image capturing device that captures images of the 10 sections either whilst or after the light source has emitted light at the adhesive; a processor that detects the presence of defects in the adhesive applied by analysing the images 15 captured; and a treating station that treats the packages determined to have at least one section in which the adhesive is defective. 20 2972760_1 (GHMatters) P88580.AU 7/12/11