Abstract:
A packaging apparatus forms a completely sealed composite package. The apparatus employs a continuous process which involves conditioning a surface of the package substrate. The substrate includes an adhesive coating that can be reactivated by infra-red radiation and adheres the package substrate to a juxtaposed face of a second surface. The apparatus uses rollers ( 102, 104, 118, 120 ) to compress the two surfaces together to complete the construction process.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a method and apparatus for adhering one surface to another, and more particularly to cartons and packaging systems. 
         [0002]    The invention is concerned with a method and apparatus for adhering packaging substrates which have been conditioned with an adhesive coating. 
         [0003]    The invention has potential applications in many types of consumer packaging but offers many benefits in pharmaceutical packaging where tamper evident and child proof features are important characteristics of the packaging, and where conventional gluing technologies such as hot melt gluing are less suitable. Additionally, the pharmaceutical industry requires stringent quality control checks as well as a high rate of output in order for the packaging methods to be viable and cost effective. One common type of pharmaceutical package is a foil-backed PVC and Aclar/PVC blister pack which contains pharmaceutical products such as prescription drugs. The blister pack needs to be sealed within an outer protective layer such as a paperboard sleeve. A paperboard sleeve is advantageous because it can provide printed instructions for administering the prescription drugs on the paperboard package as well as providing a protective outer. Such packages require the blister packs to be secured by both their front and back, to produce a child resistant package. 
         [0004]    Current commercial blister card sealing systems operate intermittently, using a hot platen to seal a blister between two layers of paperboard, to create a paperboard—blister—paperboard sandwich. Prior to such sandwiching, the paperboard blank is provided with an extruded or press-applied adhesive on one side, with graphics being printed on the opposite laminated side. The adhesive is reactivated by heating, and current hot platen sealers require around two second of heating and compression to securely adhere a blister pack within a paperboard package. This causes the process to be slow and therefore costly. 
         [0005]    In known processes, one mould of a platen sealer, the female, is generally not heated because heating this would lead to heating of the blister contents and heating of the blister packs can have a detrimental effect to the contents. However, a disadvantage of this technique is the reduction in the quality of the adhesive bond between the blister and paperboard layers of the package and a further increase in the time taken to produce each packaged blister pack. 
         [0006]    A further disadvantage of current packaging systems is that they require physical contact between the substrate and the heating element and this may have a detrimental effect on the printed surface of substrates, thereby reducing the aesthetic appearance of the packaging. The hot mould directly contacting the flammable paperboard package can also be dangerous. 
         [0007]    Additionally, pharmaceutical industry regulations require stringent checking of the quality of blister packs containing medication and very careful and close monitoring of the drugs throughout the packaging process. 
         [0008]    It is therefore desirable to provide a packaging machine which provides for quicker production of packaged drug blisters whilst also providing a method and system for monitoring the blisters and rejected any packages falling outside the necessary standard whilst maintaining a high throughput of packages from the machine. It is also desirable to provide a system which can control the correct packaging of the blisters and minimize the number of incorrectly packaged blisters. 
         [0009]    The present invention seeks to overcome the limitations of the prior art, and offers improved throughput of cartons in the packaging apparatus in a continuous packaging assembly line. 
       SUMMARY OF THE INVENTION 
       [0010]    According to a first aspect of the invention, a method of adhering a first and second surface together comprising the steps of, supplying the first and second surface to a conveyor means conveying the first surface to a means for conditioning the first surface such that it can be adhered to the second surface, and/or bringing said first and second surface into pressure contact so that adhesive portions of the first surface are adhered to a juxtaposed face of the second surface characterised in that the first surface is in continuous motion during the conditioning of the first surface and the first and second surfaces are in continuous motion during pressure contact. 
         [0011]    Preferably the first surface comprises an adhesive coating which is conditioned by heat. The means for conditioning the first surface may comprise a heating element. 
         [0012]    Additionally the second surface comprises an adhesive coating which may be conditioned by heat and the second surface is conveyed to a heating element for conditioning of the adhesive coating. The first and second surfaces may be compressed together. 
         [0013]    Alternatively the first surface forms a front panel of an outer package and the second surface forms part of an article to be secured within the outer package and the outer package comprises a rear panel surface and the article has a second article surface, wherein the method comprises the further steps of: conveying the rear panel to a conditioning means for conditioning such that it can be adhered to the second article surface and bringing the rear panel and the second article surface into pressure contact so that adhesive portions of the rear panel are adhered to the second article surface thereby adhesively securing the article within the outer package. 
         [0014]    Alternatively the steps of conditioning the first surface and bringing the first surface and second surface into pressure contact occur substantially simultaneously. The heating element may condition the adhesive coating by convection. 
         [0015]    Additionally the method may further comprise the step of monitoring the condition of the first and/or second surface, preventing the first and second surface being brought into pressure contact if the integrity of the first and/or second surface is outside pre-determined criteria and/or rejecting an object comprising the first and/or second surface if the first and second surfaces have not been brought into pressure contact. The steps may be coordinated by a control means. 
         [0016]    According to a second aspect of the invention a method of monitoring the integrity of first and/or second surfaces of an object may comprise the steps of using at least one sensor to monitor the integrity of the first and/or second surface, sending a signal to a control means indicating the integrity of the first and/or second surface, preventing the first and second surface from being brought into pressure contact if the integrity of the first and/or second surface is outside predetermined criteria and/or rejecting said object if the first and/or second surfaces do not comply with the predetermined criteria. 
         [0017]    Preferably the integrity of the first and/or second surface may be monitored by measuring the temperature of the first and/or second surface prior to bringing the first and second surfaces into pressure contact. 
         [0018]    Additionally comprising a series of steps before the step of supplying the first and second surfaces to the conveyor means, the series comprising the steps of: determining if the conditioning means is ready for conditioning the first surface, and if so then, supplying a test surface to the conveyor means, conveying the test surface to the conditioning means, monitoring the integrity of the test surface when it is conveyed from the conditioning means and if the integrity of the test surface is within predetermined criteria, supplying the first and second surfaces to the conveyor means, or if the integrity of the test surface is outside predetermined criteria, preventing said first and second surfaces from being supplied to the conveyor, and if the conditioning means is not ready to condition the first surface, then causing an alert to be issued that the conditioning means is not so ready. 
         [0019]    Preferably the purpose of monitoring the first and/or second surface is to determine if the first and/or second surfaces have been conditioned sufficiently to adhere them together. 
         [0020]    According to a third aspect of the invention an apparatus for adhering first and second surfaces together the apparatus comprising a conveyor means for conveying the first surface to conditioning means for conditioning the first surface such that the first surface has an adhesive property, means for applying the second surface to the first surface such that when they are brought into pressure contact the first and second surfaces are adhered together, and means for applying pressure to both the first and second surfaces characterised in that the conveying means is adapted to keep the first surface in continuous motion during the conditioning process and to keep the first and second surfaces in continuous motion during pressure contact. 
         [0021]    Preferably the means for conditioning the first surface comprises a heating element. The second surface may comprise an adhesive coating which is conditioned by heat and conveyor means is provided to convey the second surface to a heating element. 
         [0022]    Additionally wherein a compression means may be provided for compression of the first and second surfaces together. The heating element may emit infra-red radiation. 
         [0023]    Preferably the conveyor means may comprise a belt which is constructed from fire retardant material (such as metal) and the conveyor means may comprise means for compensation of expansion and contraction of the belt. 
         [0024]    Additionally the apparatus may further comprise sensors to monitor operation of the apparatus and may further comprise control means for controlling operation of the apparatus. 
         [0025]    Additionally the apparatus may further comprise means for conducting an initial warm up run wherein the conditioning means is assessed for its readiness to condition the first surface by conveying a test surface to the conditioning means for conditioning the test surface and then monitoring the integrity of the test surface, and means automatically to prevent the first surface from being conveyed to the conditioning apparatus if the test surface is impaired. 
         [0026]    Alternatively the apparatus may further comprise a system for monitoring the integrity of the first and/or second surfaces wherein said monitoring system comprises at least one sensor for monitoring the integrity of the first and/or second surface, said at least one sensor being coupled to the control means for receiving a signal from the at least one sensor, wherein the control means analyses the signal and determines whether or not the integrity of the first and/or second surface complies with predetermined criteria. 
         [0027]    Additionally the control means causes and/or prevents an action from being carried out by a part of the apparatus. The control means may prevent the second surface from being brought into contacting relationship with the first surface. 
         [0028]    Alternatively the control means may cause an object comprising the first and/or second surface to be rejected for not complying with said predetermined criteria. 
         [0029]    According to fourth aspect of the invention an apparatus for monitoring the integrity of first and/or second surfaces of an object comprising: at least one sensor to monitor the integrity of the first and/or second surface, the at least one sensor being coupled to a control means for receiving a signal from the or each sensor indicating the integrity of the first and/or second surface, a means for preventing the first and second surfaces from being brought into pressure contact if the integrity of the first and/or second surface is outside predetermined criteria and/or a means for rejecting the object if the first and/or second surfaces do not comply with the predetermined criteria. 
         [0030]    Preferably the integrity of the first and/or second surface may be monitored by measuring the temperature of the first and/or second surface and the predetermined criteria is a temperature range at which an adhesive bond between the first and second surfaces is achieved. 
         [0031]    Additionally the integrity of the first and/or second surface may be monitored prior to bringing the first and second surfaces into pressure contact. 
         [0032]    Additionally the purpose of monitoring the first and/or second surface is to determine if the first and/or second surfaces have been conditioned sufficiently to adhere them together. 
         [0033]    According to a fifth aspect a method for forming a sealed composite package, which may employ a continuous process, involving the steps of (i) conditioning a surface of the package substrate having an adhesive coating by irradiating the surface using infra-red radiation (ii) adhering the package substrate to a juxtaposed face of a second surface and (iii) compressing the two surfaces together using rollers to complete the construction process. 
         [0034]    According to a sixth aspect an apparatus for forming a completely sealed composite package, the apparatus may employ a continuous process involving conditioning a surface of the package substrate, the package substrate having an adhesive coating which is reactivated by infra-red radiation and which adheres the package substrate to a juxtaposed face of a second surface, the apparatus using rollers to compress the two surfaces together to complete the construction process. 
         [0035]    According to a seventh aspect a method of adhering first and second surfaces together comprising the steps of, supplying the first and second surfaces to a conveyor means, bringing said first and second surfaces into contact with each other, conveying the first surface to means for conditioning the first surface such that it can be adhered to the second surface, and applying pressure to both the first and second surfaces so that adhesive portions of the first surface are adhered to a juxtaposed face of the second surface, characterised in that the first and second surfaces are in continuous motion during the conditioning of the first surface and the pressure application. 
         [0036]    According to an eighth aspect, the invention provides an apparatus having means for executing a process on an article while the article is in motion, the apparatus comprising a checking means for assessing whether the processing means is ready to execute said process, the checking means comprising a first monitoring means for monitoring the operation of the processing means, means for supplying a test article to the processing means and for maintaing the test article in motion whilst the process is executed, and comprising a second monitoring means for monitoring the integrity of the test article once the process has been executed, the first and second monitoring means each being coupled to a control means for determining whether the processing means is ready before the process is executed on an article and for causing the process to be executed. 
         [0037]    Preferably the process is an infra-red heating process and the article is a paperboard blank and wherein each of the first and second monitoring means are temperature sensors and the control means may be a computer processing unit. 
         [0038]    According to a ninth aspect, the invention provides a method of checking the capability of an apparatus for processing an article, comprising the steps of determining if a processing means is ready for processing an article, and if so, then supplying a test article to a conveying means, conveying the test article to the processing means, monitoring the integrity of the test article when it is conveyed from the processing means and if the integrity of the test article is within predetermined criteria, allowing the apparatus to process the article, or if the integrity of the test article is outside predetermined criteria preventing the apparatus from processing the article, and if the processing means is not ready to process an article, then causing an alert to be issued that the processing means is not so ready and thereafter preventing the apparatus from operating. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]    Three exemplary embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which; 
           [0040]      FIG. 1 . shows a perspective view of a packaging machine according to a first embodiment of the invention; 
           [0041]      FIG. 2  shows a perspective zoomed in view of an in-feed section of the packaging machine of  FIG. 1 ; 
           [0042]      FIG. 3  shows a perspective zoomed in view of a conditioning section of the packaging machine of  FIG. 1 ; 
           [0043]      FIG. 4  shows a perspective zoomed in view of a second delivery and compression section of the packaging machine of  FIG. 1 ; 
           [0044]      FIG. 5  shows a zoomed in view of a final section of the packaging machine of  FIG. 1 ; 
           [0045]      FIG. 5   a  shows an enlarged view of a compression section shown in  FIG. 5 ; 
           [0046]      FIG. 6  shows an example of a blank which may be constructed into a sealed carton by the packaging machine of  FIG. 1 ; 
           [0047]      FIG. 7  shows an example of an insert which may be sealed within the carton constructed from the blank of  FIG. 6 , by the packaging machine shown in  FIG. 1 ; 
           [0048]      FIG. 8  shows an enlarged view of a rejection section of a packaging machine according to a second aspect of the invention; 
           [0049]      FIG. 9  shows a schematic of a first step in the rejection of a package constructed by the packaging machine of the second aspect; 
           [0050]      FIG. 10  shows a schematic of a second step in the rejection of a package; 
           [0051]      FIG. 11  shows a schematic of a third step in the rejection of a package; 
           [0052]      FIG. 12  is a schematic illustration of a rejection system provided within the packaging machine of the first embodiment; 
           [0053]      FIG. 13  is a schematic representation of sensors and control means provided within the rejection system which are used to control the rejection of faulty packages; and 
           [0054]      FIG. 14  is a schematic flow chart illustrating a warm up mechanism according to a third aspect of the invention; 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0055]    The present invention provides a packaging machine which can condition a surface of a continually moving substrate in preparation of adhering one or both surfaces of the substrate to a second substrate. Particularly the packaging machine  50  of the preferred embodiment of the invention can reactivate an adhesive agent provided on a substrate, such as a paperboard carton blank  10 . The packaging machine  50 , as shown in  FIG. 1  conditions the continuously moving blank  10 , using heat, and can also perform a series of folding and compression steps which may be required to construct a carton or other sealed item from the blank or substrate  10 . 
         [0056]    Referring to the drawings, there is shown in  FIG. 6  one example of a blank  10 , formed from paperboard or other suitable material, for forming a carton to be constructed and loaded by a packaging machine  50  of one or more aspects of the present invention. The paperboard blank  10  may be impregnated or coated on one or more sides by a heat reactivating adhesive agent. Appropriate coated substrates of this type are available, for example, from MeadWestvaco Corporation, sold under the trademarks Printkote EasySeal® or Printkote EasySeal® Plus. 
         [0057]    In this embodiment a unitary blank  10  comprises a series of panels hinged one to the next. Front panels  12 ,  14  are hinged to rear panels  16 ,  18  along a fold line  20  which bisects the blank  10 . In this embodiment the front and rear panels  12 ,  14 ,  16  and  18  are coated on an inside face with a heat reactivating adhesive agent. The front and rear panels  12 ,  14 ,  16  and  18  also comprise a series of apertures  22  designed such that two blister packs  4  can be inserted and sealed within a package formed from the blank  10 . An example of a blister pack  4  is shown in  FIG. 7 . Each blister pack  4  comprises a main panel  6 , which may be formed from aluminium foil; each blister pack  4  also comprises a series of blisters  3 , each for containing a medicament. In this embodiment a blister pack  4  is secured to each of the front panels  12  and  14  using the heat reactivating adhesive. The rear panels  16 ,  18  are then folded about fold line  20  and secured to the main panel  6  of the blister pack  4  using the heat reactivating adhesive, to form a completely sealed package  126 . 
         [0058]    It is envisaged that the blank  10  can vary depending upon the shape and/or quantity of articles to be packaged and accordingly, a machine in accordance with one or more aspects of the present invention is adjustable in numerous respects so that it can process a wide variety of such blanks and is not limited to the specific example outlined above. Indeed a machine of the present invention may be used to package and seal items other than a blister pack within a paperboard carton. For example it is envisaged that any material coated or impregnated with a heat reactivating adhesive could be processed using a machine of the present invention. A packaging machine of the present invention may also be adapted for use with other heat reactivating agents or heat curable material and is not limited to use with substrates such as and Printkote EasySeal® and Printkote EasySeal® Plus. It is also envisaged that a packaging machine of the present invention may be adapted to continuously condition a surface of a substrate for adhesion to a second surface by means other than heat reactivation. It is further envisaged that instead of the unitary blank  10 , two or more non-hinged, separate blanks may be used with the present invention to create a carton. It is still further envisaged that any number of blister packs, such as one or more than two packs, may be inserted and sealed within a package according to the present invention. 
         [0059]    Referring now to  FIG. 1  of the drawings, there is shown a machine  50  for processing blanks  10  of the type outlined above. The upstream end of the machine  50  is further illustrated in  FIG. 2 . The upstream end of the machine  50  includes a first hopper  54 , or other suitable storage means in which a multiplicity of blanks  10 , in flat condition, are held ready for processing. As shown in  FIGS. 1 and 2  the blanks  10  are sequentially removed from the first hopper  54  by suitable feeder means, for example, a rotary vacuum feeder  56 . The rotary vacuum feeder  56  comprises two pairs of suction cups  58  each being connected to a drive shaft  60  by a drive rod  62 . Drive means  64 , for example a servo motor, rotates the drive shaft  60 . A cam track and cam rod (not shown) may be provided to define a uniform path for the suction cups as the drive shaft is rotated. 
         [0060]    The first hopper  54  is, in this embodiment, a ‘gravity feed’ type whereby the blanks  10  are held on the first hopper  54  at an incline to provide a positive feed. Thus, as shown in  FIG. 2 , a blank  10  in flat collapsed condition is removed from the first hopper  54  and is rotated by the vacuum feeder  56  to the in-feed end of the machine. The blank  10  is then placed onto suitable conveying means, which in this embodiment of the invention is an endless metallic belt  66 ,  68 , which is provided on either side of a track  70 . The blank  10  is placed onto the track  70  and suitable means, for example leading and trailing lugs  72 ,  74  which are mounted upon the endless metallic bands  66 ,  68 , are used to convey the carton blank  10  down stream to a first heating station, shown generally at  76 . The metallic bands  66 ,  68  are tensioned between rotating pulleys  78  which are positioned, one at the upstream end and one at the down stream end of the machine  50 . The endless metallic belts  66 ,  68  convey the blanks  10  into and through first and second heating sections  76 ,  114 . The metallic belts  66 ,  68  are arranged to follow a return path which is outside of the heating stations, this allows the metallic bands  66 ,  68  to cool during the return path. The metallic bands  66 ,  68  are also provided with an idler wheel disposed adjacent the rotating pulleys  78  which enables the tension in the metallic belts  66 ,  68  to be adjusted in response to any changes caused by the heating and cooling of the metallic belts  66 ,  68 . In other embodiments it is envisaged that other means may be used to cool the metallic bands, for example, a water cooling system or cooling fan may be employed. It is also envisaged that the endless belts may be formed of other material such as fire retardant material. In other embodiments of the invention the blank  10  may actually rest upon upper edges of the metallic bands and the lugs and or track may therefore not be necessary. 
         [0061]    The first heating station  76  is shown in  FIG. 3 . The first heating station  76  is comprises a hood  80  which encloses a section of the track  70 . A heating element  82  is provided, which in this embodiment of the invention is a series of medium wavelength infra-red strip lamps  82 . The infra-red lamps  82  radiate heat energy directly onto the blanks  10 . The blank  10  absorbs the broad wavelength infra-red radiation and thus the surface temperature of the blank  10  and the temperature of the heat reactivating adhesive are increased. As the blank  10  traverses the track  70  beneath the infra-red lamps  82  the heat sensitive adhesive is reactivated. 
         [0062]    The temperature (T 1 ) of the infra-red heating element  82  in the first heating element  82  may be monitored by one or more, closely positioned, temperature sensors. A cooling-fan is employed to control the temperature (T 1 ) of the infra-red heating element  82 . In this embodiment of the invention the infra-red heating element  82  is a series of three parallel elongate elements. However it is envisaged that the orientation of the elongate elements may differ and indeed alternative shaped elements could be used without departing from the scope of the invention. 
         [0063]    The length of track  70  enclosed by the hood  80  and the linear speed at which the blanks are conveyed through that length of track  70  determines the time period in which the blanks  10  are exposed to the heat radiating from the infra-red lamps  82 . The intensity of the heat radiation from the infra-red lamps  82  and the time period of exposure determine the temperature increase of the blank  10  and heat reactivating adhesive. The linear speed of the conveyor and intensity of the infra-red lamps  82  are constant and predetermined to achieve a pre-selected temperature increase. In this embodiment of the invention a temperature increase of the blank  10  to around 150 degrees Celsius is required to activate the adhesive. In other embodiments of the invention, the speed of conveyance of the blanks  10 , the length of the heating element  82  and the intensity of the radiation may each be adapted in order to achieve a desired temperature increase of the blank  10  during the continuous conditioning stage. In this way other heat reactivated agents and package materials other than paperboard can be accommodated by the packaging machine  50 . 
         [0064]    The blanks  10  may also be heated by convection currents flowing within the hood, however in this embodiment of the invention the air flow within the hood  80  is controlled by an extraction fan. The extraction fan enables the amount of air and resulting convection currents to be controlled. In other embodiments, the ambient temperature within the hood  80  may be finely controlled by use of temperature sensors and a computerised feedback system coupled to the sensors and the hot air extraction system. Smoke detectors may also be positioned within the hood  80  as an additional safety precaution. 
         [0065]    A guide panel  92  is provided above the blanks  10  to secure and guide the blanks  10  as they traverse the track  70  beneath the first heating station  76 . The guide panel  92  maintains the blanks  10  in a flat condition so that the exposed surfaces of the blanks  10  are evenly heated by the radiating heating element  82 . The guide panel  92  is shaped so that no specific portion of the blank  10  is completely and continually obscured from exposure to the radiating heating element  82 . In other embodiments of the invention it is anticipated that the guide panel  92  could be contoured to deliberately obscure a specific portion of the blank  10  or other substrate from exposure to the heating element  82 . It is also envisaged that the guide element  92  could be cooled; for example the guide element may be a copper or other heat conductive metal tube which could be cooled by water flowing within the tube. The guide element  92  may also be provided with sensors to detect the presence of a blank  10  or may be provided with smoke, temperature or other safety sensing means. 
         [0066]    After the blanks  10  have been heated within the first heating station  76 , they are successively transferred to a loading station  84 ; this is shown in  FIG. 4 . The loading station  84  comprises a suitable delivery means, such as a magazine or second hopper  86 , of the gravity feed type, to sequentially deliver the blister packs  4 . The second hopper  86  feeds pairs of blister packs  4  onto a delivery wheel  88 . The delivery wheel  88  is provided with a series of shaped receiving troughs each of which can accommodate a blister pack  4  from the second hopper  86 . A pair of blister packs  4  is received by two adjacent shaped troughs at the top of the delivery wheel  88 , which is then rotated in a clockwise direction. 
         [0067]    The delivery wheel  88  is driven by a servo motor and further comprises a guide frame  90 , which is provided to prevent the blister packs  4  from falling free of the delivery wheel  88  as it is rotated. A second rotary vacuum feeder  98 , which comprises one pair of suction cups  100  sequentially removes one pair of blister packs  4  from the bottom of the delivery wheel and places them onto a blank  10 . The conveyance of the blanks  10  into alignment with the blister packs  4  as they are delivered is synchronized by a control means, such as a computer coupled to the servo motors used to drive the belts  66 ,  68  and delivery wheel  88 . The blisters  3  of the blister packs  6  are received in the apertures  22  of the blank  10 . The second hopper  86  and delivery wheel  88  are located in close proximity to the end of the first heating station  76  so that the blank  10  is maintained sufficiently close to the temperature required to reactivate the heat sensitive adhesive. The blister packs  4 , if only one side of which are aluminium coated are placed onto the front panels  12 ,  14  of the blank  10  with the aluminium sides facing upwards. The non-aluminium side is then secured in place onto the blank  10  by the reactivated adhesive on the front panels  12 ,  14 . 
         [0068]    The blanks  10  with the blister packs  4  are then sequentially fed between two compressing rollers  102 ,  104 . The rollers  102 ,  104  are spaced apart and each compressing roller  102 ,  104  comprises at least one shaped pad  106 ,  108 . The pads  106 ,  108  are each sized and shaped to accommodate two blister packs  4  disposed adjacent one another and to protect the blister packs  4  from damage. The blank  10  with the blister packs  4  adhered to the front panels  12 ,  14 , is fed between the rollers  102 / 104 . The adhesive on the rear panels  16 ,  18  may still be activated and so the rear panels  16 ,  18  of the blank  10  pass between the spaced rollers  102 ,  104  without making contact with the rollers  102 ,  104 . 
         [0069]    Compressing roller  102  is rotated by a drive means in a clockwise direction, whilst the compressing roller  104  is rotated by a similar drive means in an anticlockwise direction. In this way as the rollers  102 ,  104  rotate the blank  10  and blister packs  4  are fed through. The timing of the rollers  102 ,  104  is such that the shaped pads  106 ,  108  simultaneously contact the underside of the front panels  12 ,  14  of the blank  10  and the main panel  6  of the blister packs  4 . Thus the rear panels  16 ,  18  pass through the roller without making contact and pressure applied to the blank  10  and blister packs  4  ensures that the blister packs  4  are adhered to the front panels  12 ,  14 . In other embodiments of the invention, it is envisaged that the compression stage, which ensures that the two surfaces are securely adhered, may not be required or may be achieved by means other that the use of rollers. It is also envisaged that the compression stage could be performed simultaneously with the conditioning of the first surface. It is also envisaged that the compression of the two surfaces could in fact be employed to condition one or both surfaces for gluing, if for example compression reactivating adhesive was employed. 
         [0070]    The blanks  10 , with two blister packs  4  adhered to the front panels  12 ,  14 , traverse the track  70 , being conveyed by the lugs  72 ,  74  mounted upon the metallic bands  66 ,  68 . A flipper  110 , which comprises moveable arms  112 , is provided downstream of the compression rollers  102 ,  104 . The moveable arms  112  are positioned such that they intercept the leading edge of a blank  10 . The moveable arms  112  are, in this embodiment, spring loaded and provide a means for folding the carton blank  10  about fold line  20 . The rear panels  16 ,  18  are brought into face contacting relation with the main panel  6  disposed above the front panels  12 ,  14  respectively. The moveable arms  112  resist the forward motion of the rear panels  12 ,  14 , thus causing the panels to be folded about fold line  20 . As the rear panels  16 ,  18  are lifted out of the plane of the front panels  12 ,  14 , the moveable arms  112  are caused to be displaced above the track. Once the folding is complete the moveable arms  112  can return to their original starting position in preparation of intercepting a successive blank  10 . 
         [0071]    The folded blank  10  is conveyed further downstream to a second heating station  114 . The second heating station  114  is similar to the first heating station  76  and therefore is not described in detail. The heat activated adhesive on the inner face of the rear panels  14 ,  16  is reactivated by an infra-red heating element similar to that described in the first heating station  76 . Radiation is exposed to the outer surface of the rear panels  16 ,  18  and is absorbed by the rear panels  16 ,  18 , sufficiently to reactivate the adhesive agent on the inner surface of the panels. During the second heating phase, any exposed part of the aluminium blister pack  4  may reflect any incident infra-red radiation and thus prevent undesirable heating of the blister pack  4  and medicaments contained within the blisters  3 . 
         [0072]    To complete the sealing process the folded blank  10  is conveyed to a final compressing section  116  as shown in  FIG. 5 . The final compressing section  116  comprises two rollers  118 ,  120 , one of which is provided with a series of indentations which receive the blisters  3  of the blister pack  4  as shown in  FIG. 5   a . The folded blank  10  is sandwiched between the rollers to ensure that the rear panels  16 ,  18  are securely adhered to the outer face of the blister pack. In this way the machine  50  constructs a fully sealed package  126 , which is formed by a continuous process. The blister pack  4  may be sized smaller than the front or rear panels  12 ,  14 ,  16  and  18  and in which case portions of the front panels  12 ,  14  will be directly adhered to portions of the rear panels  16 ,  18 . 
         [0073]    The machine  50  of the present invention is also provided with a series of safety sensors. An emergency operating condition may be triggered by one or more of the sensing elements feeding back an alerting signal. For example a smoke detector within the hood  80  of the first heating station  76  may feedback a signal to indicate the presence of smoke. This alert can trigger an emergency condition whereby the delivery of carton blanks  10  and blister packs  4  from the first and second hoppers  54 , is stopped by the servo motors operating the rotary vacuum feeders  56 . The conveying means however continues to operate so that any remaining blanks  10  are removed from beneath the first and second heating stations  76 , thus reducing the risk of a blank  10  combusting within the machine  50 . A series of control sensors are also provided to monitor the presence of a blank  10  and blister pack  4  during the construction process. 
         [0074]    Further modifications may be made without departing from the scope of the invention. For example, it is envisaged that the step of conditioning the first surface in preparation for adhering to a second surface may be achieved by means other than using heat radiation to reactivate a heat sensitive adhering agent already coated upon the first substrate. In other embodiments it is envisaged that the substrate may be provided with an adhesive agent which is reactivated by pressure, for example, a micro capsule type agent which may be coated on the substrate and which can be activated by compressing the first and second surfaces and thereby adhering the surfaces together. Alternatively the adhesive agent provided on the first surface may be reactivated by contact with water or steam. This conditioning may be performed prior to compressing the first and second surfaces together or indeed in conjunction with the compression stage. Furthermore, the first substrate may be conditioned by coating or impregnating the surface with an adhesive agent during the continuous conditioning process. For example an adhesive may be sprayed or applied by other means, to coat the surface of the first substrate during the continuous conditioning process. 
         [0075]    It is also envisaged that other suitable conveying means may be employed without departing from the scope of the invention. For example endless side lug chains may be used, with leading and trailing lugs mounted upon the endless chains. It is envisaged that the endless chains could be spaced from the main track such that the endless chains do not pass through the conditioning section, which may be of a temperature not suitable for any lubricant used on the endless chains. In such an embodiment it is envisaged that the lugs mounted on the lug chains may extend sufficiently from the lug chains to convey a blank  10  along the track  70 . Alternatively endless lug chains may be used and positioned such that they do pass through the heating stations but they may be provided with high temperature lubricant or indeed shielded from the radiating heat or provided with a cooling means. 
         [0076]    Furthermore it is anticipated that where the conditioning phase is achieved by means of radiation, the wavelength of the radiation may differ from the broad wavelength infra-red range. For example in some applications microwave radiation could be used to condition the surface of a substrate in preparation of adhering the surface to a second substrate. It is also envisaged that a computer controlled and dynamic heating process could be used in which the temperature within a heating station  76  is ramped up and ramped down to provide a more gradual heating process. Separate infra-red lamps  82  may be needed in such an embodiment to allow the intensity of the infra-red lamps to be individually controlled along the linear path of the heating station  76 . 
         [0077]    It can be appreciated that various changes may be made within the scope of the present invention, for example, the size and shape of the hoppers and track may be adjusted to accommodate cartons of differing size or shape. It is also possible that the length and/or number of heating stations may be adjusted to facilitate the construction of an alternative carton.  FIGS. 8 to 14  illustrate further aspects of the present invention, which will now be described by way of example only and to illustrate some of the changes or additions that can be made, whilst keeping within the scope of the present invention. 
         [0078]    In a second embodiment of the invention, the packaging machine  350 , which is similar to the packaging machine  50  of the first embodiment, further comprises a rejection system  440 . The rejection system  440  has a rejection mechanism  330  provided at the output end of the packaging machine  350  as shown in  FIG. 8 . The rejection system  440  further comprises a control means  400  coupled to the rejection mechanism  330 . The control means  400  is coupled to one or more sensors (S) which monitor the state and quality of the blanks throughout the construction process. 
         [0079]    For applications such as in the pharmaceutical industry where the packaged article is a blister pack of medication, it is desirable that the blister pack is firmly held within the package. Paperboard material comprises a series aligned cellulose fibres which are bonded together. The heat reactivated adhesive provided on the paperboard blank is sufficiently strong to create an adhesive bond between a paperboard surface and another surface such that if the two substrates are pulled apart, before the adhesive bond will break, the fibre bond of the paperboard material will first be forced to tear. In order to achieve this bond, the heat reactivating adhesive must be sufficiently heated and the surfaces to be bonded together may need to be compressively contacted. Additionally it is important that during the conditioning phase the package and the packaged article are monitored to ensure that the article is in no way damaged or spoiled. The quality checks and safety sensors of the packaging machine are provided to ensure the integrity of the package and the packaged article, where integrity should be taken to mean the quality of being unimpaired. 
         [0080]    Various, safety sensors which may monitor the state of the packaging machine  350  may also be coupled to the control means  400 . The quality and safety sensors (S) which monitor the state of the blanks and condition of the packaging machine  350  communicate with the control means to which they are coupled. Signals or data messages transmitted from the sensors (S) to the control means  400  may give rise to a rejection signal or alert. The rejection signal or alert signal indicates that either a particular blank in the production process has failed to meet necessary standards or that a fault or hazard exists in the packaging machine  350 . 
         [0081]    In order to track the progress of each individual blank through the packaging machine, each pitch of the conveyor means is allocated a unique identifier. The progress of each blank can then be followed by the control means  400 . If at some point during the progress of a blank through the construction process a sensor (S) feeds back a signal which gives rise to a rejection signal, the control means  400  registers that the blank located at that uniquely identifiable pitch should be rejected. The rejection signal is logged against the specific pitch so that the faulty blank or carton can be identified at the rejection mechanism  330  and discarded therefrom. 
         [0082]    The rejection mechanism  330 , as shown in  FIG. 8 , comprises an overhead lug belt  334 , which is provided with lugs  336 . The lugs  336  of the overhead belt  334  convey a constructed carton or finished package  326  from the compressing rollers  318  along a guide rail  340 . The guide rail  340  is provided with a moveable section or displaceable portion  332 . During the construction of the package  326  the temperature and position of the blank are monitored by the sensors (S). If a package does not meet the required standards a rejection signal will be recorded against the pitch of the conveyer containing the package  326 . The progress of the package  326  through the packaging machine  350  will be tracked and the faulty package  338  will be rejected when it reaches the rejection mechanism  330 . The faulty package  338  will be extracted by the displaceable portion  332 . The displaceable portion  332  is positioned in the plane of the guide rail  340  and can be moved into an open position to facilitate the removal of a faulty package  338 . The displaceable portion  332  is hinged to the guide rail and can be pivoted about the hinged connection, it is anticipated that other means for displacing the displaceable portion could be used. The displaceable portion  332  is also positioned above a rotary air cylinder  328 . The rotary air cylinder  328  can provide an air jet to assist the rejection of the faulty package by propelling it from the displaceable portion  332  into a waste outlet (W). 
         [0083]    Schematic illustrations showing the operation of the displaceable portion  332  to reject a faulty package  338  are shown in  FIGS. 9-11 . It is envisaged that means other than the displaceable portion  332  could be used to extract a faulty package  338  without departing from the scope of the present invention. For example an articulated arm could be used to pick a faulty package  338  up from the conveyer means or indeed the conveyer means could have channels to provide a different path for the faulty package  338  compared to the path of an acceptable finished package  326 . 
         [0084]    An example rejection system  440  which may be used to monitor the progress of a blank through the packaging machine  350  will now be described in more detail.  FIG. 12  shows a schematic of the packaging machine  350 , rejection system  440  and sensors (S) which are provided at each section of the packaging machine  350 . Since the blister packs contain medicaments the state of the packs, for example their temperature, must be monitored closely. Each sensor (S) is used to detect a fault with a blank, for example the temperature of the blank being outside an accepted range. If any of the quality sensors detects a fault with a blank, the control means  400  will identify the blank by its pitch position and register that the identified blank should be rejected at the output end. The quality sensors are coupled to the control means  400 , which is in turn coupled to the rejection mechanism  330 . 
         [0085]    Safety sensors are also provided which are used to monitor the operation of the packaging machine, for example if the temperature of the heating element is outside an acceptable operating range, this will be detected by a temperature sensor  408  positioned in close proximity to the heating element  82 . The safety sensors are connected to the control means  400 ; in an alternative embodiment they may each be provided with individual control means. In this way if a fault is detected by a safety sensor, the control means to which it is coupled could be directly coupled to an alarm or warning light for alerting an operator of a hazard without first having to couple to the control means  400 . Information collected from both the safety and quality sensors can be collated by the control means  400  and analysed for the purpose of fault finding or for improving the efficiency of the packaging machine  350 . 
         [0086]    The control means  400  can be configured to cause the packaging machine  350  to shut down in response to a safety sensor detecting a fault with the machine. The fault detected may invoke a particular shut down or emergency condition. To shut down the packaging machine  350 , the rotary vacuum feeders in the blank and blister pack feed sections  342 ,  344  are stopped. The conveyor means may continue to operate for a set period after the blanks and blisters have stopped being fed in order to remove any paperboard blanks and/or blister packs which may be beneath the heating elements so that the risk of fire is reduced. The hoods of the first and second heating sections may also be provided with a mechanism to allow the hoods to be automatically lifted above the conveyer track in response to a received signal which has been transmitted by the control means  400  during a shut down or emergency operating condition. Each hood may be controlled and operated individually in response to the fault detected. 
         [0087]    The rejection system  440  and quality and safety sensors provided in the present invention will now be described in more detail with reference to  FIGS. 12 and 13 . 
         [0088]      FIG. 12  shows a schematic of the packaging machine  350  and rejection mechanism  330 . At the in feed end of the packaging machine  350 , a sensor  402  is provided to detect if the first hopper is empty of blanks. Such sensors  402  are known in the art and can detect the presence of a carton blank. The sensor  402  is coupled to the control means  400  and can be used to raise an alarm if the first hopper is empty of blanks. If the first hopper is empty, a second signal may be transmitted from the control means  400  to the second hopper of the blister feed  344 . The second hopper of the blister feed  344  may comprise a mechanism which can prevent a blister from being fed. Therefore the unnecessary waste of blisters can be prevented by not feeding blisters when there is no blank present to receive them. 
         [0089]    Also, within the blank feed section  342 , sensors (S) are provided to detect a blank which has not been correctly fed from the hopper. A blank can be misfed for example if after being picked up by the suction cups, it is incorrectly placed on the track or if two blanks are erroneously picked up simultaneously. The sensor  404  can detect that a blank has been misfed and is coupled to the control means  400 . The sensor  404  may employ a series of optical beams to detect the leading and trailing edges of the blanks. An error in the placement of a blank may be detected by the optical beam being interrupted too soon or not being interrupted at all if a blank is missing. If a blank is misfed the control means  400  can identify the pitch of the blank and register a reject logic against the pitch. The misfed blank will then be rejected when it reaches the rejection mechanism  330 . A second signal may also be transmitted by the control means  400  to the second hopper of the blister feed  344  to trigger the mechanism to prevent a blister from being fed. In this way the unnecessary rejection and waste of blister packs is prevented. 
         [0090]    A correct-blank-type sensor  406  is also provided within the blank feed section  342 . The correct-blank-type sensor  406  is used to monitor the type of blank which has been placed on the track from the hopper. The sensor  406  is used to detect that the correct type of blank is present. It is envisaged that this sensor  406  may be a barcode reader positioned to read a barcode printed on each blank. The barcode can be used to identify the type of blank, for example a type of blank specifically printed for containing a particular course of a medication. The blank identity can then be checked by the control means  400  to ensure that the correct blank has been placed on the conveyor. It is envisaged that other means for identifying and checking that the correct carton has been placed on the conveyor could also be used, for example a camera could be positioned to monitor the colour of the graphics printed on the blank. The correct-blank-type sensor  406  is coupled to the control means  400  and if an incorrect blank is detected a reject signal will be registered against the pitch where the fault was detected. A second signal may also be transmitted from the control means to prevent a blister from being fed onto the incorrect carton blank and therefore prevent unnecessary waste of pharmaceutical products contained within the blister packs. 
         [0091]    A series of conveyor sensors  424  may be present periodically throughout the packaging machine  350 . The conveyor sensors  424  may be positioned on the track and can be used to monitor the progress of the conveyed blanks. The conveyer sensors  424  can detect a missing blank or may detect a jam on the conveyor if two or more blanks become staggered. The conveyer sensors  424  may operate in a similar manner to the sensor  404  for detecting a misfeed. An optical beam or pair of optical beams, spaced along the track at intervals determined by the blank type, can be used to detect the leading and trailing edges of a blank. The conveyor sensors  424  are each coupled to the control means  400 . If a fault is detected a rejection signal may be sent to the rejection mechanism  330  to reject the faulty package  328 . If a jam is detected in the packaging machine the control means  400  may be configured to alert a machine operator of the location of the jam. 
         [0092]    A variety of safety and quality sensors (S) are located in the first heating section  376 . A heating element sensor  408 , which is coupled to the control means  400 , is provided to detect if the heating element is operating. It is envisaged that the heating element sensor  408  may be coupled to the heating element&#39;s power supply. The heating element sensor  408  may operate by detecting that an electrical current is drawn by the heating element from the power supply. If the sensor  408  detects that no current is drawn by the heating element, the control means  400  can be used to indicate that a fault exists with the heating element. The control means  400  may also initiate a shut down procedure in response to the detected fault with the heating element and the hood of the first heating station  376  may automatically be lifted above the conveyor to allow access to the heating element and to facilitate any repair work which may be necessary. 
         [0093]    A first temperature sensor  410  is also provided within the first heating section  376  to measure the temperature of the heating element. The temperature may be continuously monitored whilst the packaging machine  350  is in operation to ensure that the heating element temperature is within an acceptable range. The information regarding the temperature of the heating element is transmitted to the control means  400 . If the operating temperature is within an unacceptable range, which may be hazardous or may affect process efficiency, the control means  400  may invoke an emergency shut down of the packaging machine or initiate other courses of action depending upon the circumstances. However under normal operating conditions, the control means  400 , which is also directly coupled to the heating element, can adjust the amount of electrical power supplied to the heating element in order to regulate its temperature. The temperature of the heating element is thereby controlled accordingly with the surface temperature of the blanks, which is measured by a third temperature sensor  414  after the blanks have been conditioned in the first heating section  376 . 
         [0094]    Smoke detectors may also be provided in the hood of the first heating section  376 . If the presence of smoke is detected an alarm may be immediately raised and the emergency shut down condition may be invoked. 
         [0095]    A second temperature sensor  412  may also be provided within the first heating section  376  to monitor the temperature (T 1 ) of the ambient air. The second temperature sensor  412  is also coupled to the control means  400  and the information from the second temperature sensor  412  is transmitted to the control means  400 . The control means  400  may be configured such that the received information can be used to alter the amount or rate of air extraction from the hood of the heating station in order to control the amount of heating of the blanks as they are conveyed through the heating sections. The control means  400  may therefore be coupled to the extraction fan to increase or decrease the rate of revolution of the fan or may be coupled to an inlet and/or outlet valve provided on the air extraction mechanism of the hood to dynamically control the amount of air within the heating section  376 . 
         [0096]    Finally a third temperature sensor  414 , such as a pyrometer, is provided at the down stream end of the first heating station  376 . This is used to measure the surface temperature (T 3 ) of each blank after it has been heated by the heating element. The temperature sensor  414  is, in this embodiment of the invention, a non-contact sensor which employs infra-red radiation to determine the surface temperature of the blank. The third temperature sensor  414  is coupled to the control means  400  and measures the blank temperature at a spot on the surface of the blank. If the temperature of the heated blank is not within an accepted range a signal will be transmitted by the control means  400  and the blank will be rejected by the rejection mechanism  330 . In this embodiment the temperature sensor is positioned within close proximity to the out feed end of the heating station and therefore within close proximity to the second hopper which supplies the blister packs. The close proximity of the blister feed  344  to the third temperature sensor  414  means that the delivery of the blister onto the faulty blank cannot be prevented and therefore the blister and blank both have to be rejected. In other embodiments it is envisaged that the third temperature sensor  414  could be located to allow the blister feed to be prevented or indeed another mechanism for preventing a blister from being placed onto a faulty blank could be employed. It is also anticipated that more than one temperature sensor  414  could be employed to monitor the temperature of the blank. This may be especially useful if the surface is selectively heated to achieve different temperatures at different points on the blank to selectively reactivate the adhesive. 
         [0097]    At the blister feed section  344  a sensor  416 , coupled to the control means  400 , is provided to monitor the contents of the second hopper and an alert signal can be transmitted if the hopper is empty. A further sensor  418  is employed to check that the blisters have been placed on a blank at all and that any blisters placed are aligned correctly on the blank. If any fault is detected a rejection signal will be logged and the package will be discarded by the rejection mechanism  330 . A correct-blister-type sensor  420  is also provided to detect if the incorrect type of blister pack is fed onto a carton blank. The correct-blister-type sensor  420  is coupled to the control means  400  and if the incorrect type of blister is detected a reject signal will be transmitted by the control means to the rejection mechanism  330  to reject the blank and blister. 
         [0098]    A pressure sensor  422  is provided between the compression rollers  318  to detect any abnormality in the pressure applied by the rollers to the package being formed. The pressure sensor  422  may detect that the package has been incorrectly fed between the rollers and that the content of the blister may therefore have been damaged. If the pressure sensor  422  detects that the compression rollers  318  have applied a pressure to the package which is outside of an acceptable range, the control means  400  will transmit a rejection signal and the package will be discarded by the rejection mechanism  330 . In this way any blank which is not securely sealed or contains a damaged blister pack will be identified and rejected. 
         [0099]    The packaging machine of the present invention is provided with a similar set of sensors in the second heating section  314  to those of the first heating section  376 . Therefore the sensors of the second heating section  314  and second compression section  318  will not be described in detail. The second heating section is provided with a heating element sensor  408  and first, second and third temperature sensors  410 ,  412 ,  414  which are each coupled to the control means  400  and monitor the operation and temperature of the heating element, the ambient air (T 2 ) within the hood and the temperature of the conditioned blank surface. The second compression roller  318  is also provided with a pressure sensor  422  to ensure that the conditioned first surface is securely adhered to the second surface and that no damage to the blister pack occurs. The third temperature sensor  414  of the second heating station may be employed to measure either the temperature of the blank or of the aluminium face of the blister pack. It is anticipated that, if required, two sensors  414  could be used to measure the temperature of both the blank and the aluminium face of the blister pack. 
         [0100]    The packaging machine  350  may also be provided with a safety sensor to monitor the temperature of the cooling agent used within the guide panels  92 . 
         [0101]    It is envisaged that the rejection system  440  may be altered without departing from the scope of the present invention. For example it is anticipated that the control means  400  may also be coupled to the drive means of various components of the packaging machine  350 . For example the control means  400  may be coupled to a servo motor used to drive the second rotary vacuum feeder for feeding the blisters onto the blanks. The control means  400  could therefore be configured to respond to the sensor  416 , which is provided at the blister feed section  344  to detect an empty hopper. If the sensor  416  detects an empty hopper, the control means  400  could automatically respond by stopping the rotary vacuum feeder. 
         [0102]    In other embodiments of the invention it is also envisaged that the rejection mechanism  330  may be adapted to accommodate different sized articles or indeed more than one rejection mechanism may be provided. It is envisaged that means other than the displaceable portion  332  could be used to extract a faulty package  338  without departing from the scope of the present invention. For example an articulated arm could be used to remove a faulty package  338  from the conveyer means or indeed the conveyer means could have channels to provide a different path for the faulty package  338  to the path of a satisfactory finished package  326 . 
         [0103]    It is also anticipated that an alternative sensor to the third temperature sensor may be employed without departing from the scope of the present invention. The integrity of the blank, carton or other object may be monitored throughout the construction process however the third temperature sensor is provided to specifically monitor the integrity of the first and/or second surface to ensure that the first and/or second surfaces of an object are correctly conditioned in preparation of being adhered together. For example it is envisaged that if the first and or second surfaces of the blank, carton or other object are conditioned by means other than heat, such as by humidity or by pressure, the sensor provided to monitor the integrity of the carton to ensure that the first and or second surfaces of the carton are properly conditioned may be a humidity sensor or pressure sensor rather than a temperature sensor. It is envisaged that the sensor employed to monitor the integrity and conditioning of the first and or second surfaces, may be coupled to the control means to allow for interactive adjustment of the conditioning means in response to the amount of conditioning of the first and or second surfaces. For example a humidity sensor may feed back a signal to the control means indicating that the measured humidity of the first surface is outside predetermined criteria. This may result in the object comprising the first surface being rejected by the rejection mechanism but may also result in the control means transmitting a signal to the means for conditioning the first surface, i.e. a humidity source. The control means may cause the amount of humidity provided by the source to be adjusted in response to the integrity of the first surface being measured and being found to not comply with predetermined criteria regarding the humidity of the surface required for adhesion. The operating conditions of the packaging machine  450  can thereby be interactively controlled to ensure that the down time for correcting the operating conditions is minimized and to refine the quality control of the package to ensure that the integrity of the package is maintained within an accurate quality range. 
         [0104]    In other embodiments of the invention it is also envisaged that an extinguishing system may be provided in case of a fire or emergency. The extinguishing system may be coupled directly to a smoke detector or may be coupled to the control means  400  which could deploy the extinguishing system in the event of smoke and/or high blank temperature being detected. The extinguishing system may be a gas extinguisher, such as carbon dioxide. 
         [0105]    A third aspect of the invention relates to an initial start-up operation of the packaging machine  50  which was described in the first embodiment with reference to  FIGS. 1-8 . Reference to these figures will be made in connection with the foregoing description since features shown therein will also be relevant to the description of the initial start-up operation of the packaging machine  50 . Reference will also be made to  FIG. 14  which shows a schematic flow chart illustrating exemplary steps that can be taken to ensure that the packaging machine is operating under the correct conditions during the initial start-up operation. 
         [0106]    The initial start up operation is intended to ensure that the mechanisms for conditioning a package blank for adhesion with an article, such as a blister pack, to be securely contained within the package are operating correctly before any such articles are fed from the article feed  86 . In the specific embodiment herein described the conditioning means is provided by first and second heating elements  76  and  80  which are shown in  FIG. 1 . The additional aspect of an initial start up operation will therefore be described in the context of a packaging machine employing a heating means  82  for conditioning a carton blank. However it should be understood that the initial start-up operation to be described is not limited in its application to a packaging machine having heating means and could readily be applied to a packaging machine utilizing other conditioning means. 
         [0107]    The first step of the initial start-up is a slow-run warm up  530 , wherein the first and second heating elements  76 ,  114  are activated. The conveyer means  66 ,  68  is also activated but no blanks or blisters are fed from their respective hoppers  54 ,  86 . The temperature T 1  of the ambient air inside the hood  80  of the first heating station  76  is measured by a temperature sensor  412 . The temperature T 1  is measured for a time t during which time the measured temperature T 1  is checked against a desired operational temperature which is required for conditioning a blank. When T 1  reaches the conditioning temperature, or is within an acceptable temperature range for conditioning, for example 150° C.+/−5° C., a bell will sound or another signal will be given. The bell or signal indicates that the first conditioning means, in this case first heating station  76  is ready for conditioning a substrate, such as the paperboard blank of the present example. This step is illustrated by step  512  in  FIG. 14 . 
         [0108]    If however during a pre-set time limit t max  T 1  has not reached the required temperature  558 , then the slow run warm up  530  will be stopped and an alarm signal or error report will be sent from the central control means  400  to indicate to an operator that there is an error with the first conditioning means  76 . This will indicate for example that one of the infra-red heating lamps  82  of the first heating section  76  is not working and enable a machine operator to address the problem. In checking the correct operation of the machine before sending any blisters  4 , the need for rejecting and hence wasting any pharmaceutical preparations is alleviated. This step is shown in steps  558  and  560  of  FIG. 14 . 
         [0109]    A similar method is used to control and check the operation of the second conditioning element, which in this example is a second heating section  114 . In other embodiments it is envisaged that there may be more or less than two conditioning elements and that where more than one conditioning element is used, each element may condition a substrate using a different technique. However in the embodiment presently described, a second heating section  114  is employed and the temperature T 2  of the ambient air within the hood  80  of the second heating section  114  is measured to check whether the second conditioning element is ready for conditioning. Again T 2  will be measured  612  until either the correct temperature is reached or the time for which T 2  should be measured (t max ) is reached. Again if T 2  has not reached an optimum operating temperature, an alerting signal will be raised and the slow run warm-up  530  will be stopped  564 . The machine operator will know that a problem exists with the second conditioning means  114 . The steps  612 ,  570  and  564  are illustrated schematically in  FIG. 14 . 
         [0110]    If T 1  and T 2  are both measured to be within the optimum conditioning range  586  a single blank will be feed  542  and conveyed through the packaging machine  50 ,  350  to check that the blank will be conditioned correctly. In order to carry out an accurate assessment of the conditioning of the blank, the blank is conveyed at full speed so that it is present beneath the infra-red heating lamps for the correct amount of time. When the blank exits the first heating section  76  a temperature sensor  414  is used to accurately measure the surface temperature of the blank. The preferred type of temperature sensor  414  is a pyrometer, which is a non-contact sensor employing infra-red radiation to determine the surface temperature of the blank. The third temperature sensor  414  is coupled to the control means  400  and measures the blank temperature at a spot on the surface of the blank. If the temperature T 3  of the conditioned blank is not within an accepted range a signal will be transmitted by the control means  400 . If only one test blank has been conveyed than a further blank will be fed and its temperature T 3  measured after the first conditioning means. If the measurement of T 3  is again not within a range which is acceptable for ensuring proper adhesion of the substrate surfaces by the heat reactivated adhesive, a signal will be sent by the control means  400  to stop the packaging machine  50 ,  350 . If however temperature T 3  is measured and found to be correct a bell will sound to indicate that this is the case. Whatever the outcome of the measurement of T 3  the first or second test blank will be conveyed through the second heating section and its temperature T 4  will be measured immediately it exits the second conditioning section. If T 4  is not correct and if only one test blank has been fed  552  a second test blank will be fed  542  and T 4  measured again  614 . If T 4  is still measured  614  to be outside the optimum range the packaging machine  50 ,  350  will be stopped  580  and an error report sent via a signal from the control means  400  to alert the operator to the problem. The steps  614 ,  552  and  580  are illustrated in  FIG. 14 . 
         [0111]    If however T 3   514  and T 4   614  are both correct  584 , then the packaging machine  50 ,  350 , is operating correctly and ready to run. The machine will continue to run at full speed with blanks and blisters both being fed at full speed. The operation of the machine thereafter is controlled and the quality of the packaged blisters monitored as described with reference to  FIG. 13 . 
         [0112]    It will be apparent that changes may be made to the foregoing without departing from the invention described. For example the way in which the readiness of the or each conditioning element is assessed before a substrate is conveyed for conditioning may depend upon the way in which the conditioning is carried out. For example if the conditioning means is a humidifying means then a humidity sensor will be employed to check that the conditioning means is ready. Additionally the way in which alarm signals or indicating bells are arranged can easily be varied depending upon the types of test carried out and the methodology of the control means. Furthermore it is envisaged that this aspect of the invention may be used in conjunction with or separately from the packaging apparatus of the first and second embodiments.