Abstract:
A packaging apparatus ( 30 ) for forming multi-compartmental packs comprises a first feed mechanism for feeding packaging material ( 31 ) to a forming station ( 12 ) adapted to form compartments in said material ( 31 ). The packaging apparatus ( 30 ) further comprises means for loading product into the compartments. a second feed mechanism for feeding a sealing material ( 32 ) to a sealing station ( 19 ), a peripheral sealing member ( 33 ) to secure the sealing material ( 32 ) to the packaging material ( 31 ) to form a peripheral seal, and one or more compartmental sealing members for forming at least one compartmental seal. Control means control the speed, position and seal parameters of the packaging apparatus ( 30 ).

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to packaging machines including packaging machines for use in producing high integrity packaging used, for example, for medical and pharmaceutical goods, and for general packing of foods and consumer goods.  
         BACKGROUND TO THE INVENTION  
         [0002]    Packaging used to protect certain medical products, for example, syringes, dressings or replacement organs such as skin, during transit and storage, needs to be of sufficient integrity in order that the contents are maintained in a locally sterile environment.  
           [0003]    The nature of the contents of the packaging and their use, means that a zero percent failure rate of the packaging must be achieved. Furthermore, the process by which the packaging is formed must also be capable of full validation. Quality control to ensure that this standard is achieved cannot be carried out by the use of a destructive sampling procedure. The process therefore is carried out using such strict control of the values of a number of parameters, the values for the parameters being known to give a package of a suitable quality.  
           [0004]    The need for the parameters to be closely monitored and maintained within strict limits means that the production of the packages is often slow.  
           [0005]    Prior art machines suffer from the drawback that when production needs to be switched from one type and/or size of packaging to another, converting the machine appropriately is time consuming and often labour intensive. Furthermore, the act of changing over can affect the consistency and accuracy of the seal.  
           [0006]    One such prior art machine available for packaging goods is that marketed by the present Applicant under the designation “MT 2500”. Using this machine, a base material having a plurality of compartments is passed to a loading station where product is loaded into individual pre-formed compartments. From the loading station, the base material is passed to a sealing station where an upper layer is then sealed to the base material over the product-bearing compartments by means of a single sealing platen. Changing the base material configuration and the pattern used for applying adhesives for the sealing platen is slow, with a resulting loss in production time. Tooling changes associated with this pattern are also expensive.  
           [0007]    It is an object of the present invention to provide a packaging machine which alleviates the above disadvantages and which allows the sealing station replacement to be eliminated for example when change-over from one product to another is required.  
           [0008]    It is a further object of the invention to provide a process for sealing a product in multi-compartmental packs which alleviates the above problems.  
         SUMMARY OF THE INVENTION  
         [0009]    According to the invention there is provided a packaging apparatus for forming multi-compartmental packs comprising:  
           [0010]    a first feed mechanism for feeding packaging material to a forming station adapted to form compartments in said material; means for loading product into the compartments;  
           [0011]    a second feed mechanism for feeding a sealing material to a sealing station;  
           [0012]    a pack sealing member adapted to secure the sealing material to the packaging material to form a peripheral pack seal and at least one compartment seal; and  
           [0013]    control means for controlling the speed, position and seal parameters of the packaging apparatus, said means controlling a further seal mechanism or mechanisms to seal the sealing material to the packaging material to form compartments within the peripheral seal of the packaging.  
           [0014]    Advantageously, the packaging apparatus comprises at least one further seal member which seals in a direction which is perpendicular to the feed direction of the packaging material.  
           [0015]    The further seal member is preferably moveable across the surface of the pack to produce a number of spaced seals within a pack.  
           [0016]    The position of the seals is conveniently controlled using control means which control the motion of the packaging relative to the sealing members. The control means controlling the motion of the packaging is conveniently a servomechanism.  
           [0017]    Preferably, the packaging apparatus comprises at least one further seal member which seals the sealing material to the packaging material in a direction parallel to the feed directions of the packaging material.  
           [0018]    The or each further seal member is advantageously a bar, roller or wheel.  
           [0019]    The or each further seal member is preferably heatable to thermally seal the sealing material to the packaging material. Advantageously, the pressure applied by the or each further seal member is monitored and controlled to ensure validation of the sealing process.  
           [0020]    According to a further aspect of the invention there is provided a process for forming multi-compartmental packs, comprising the steps of:  
           [0021]    (i) presenting a first packaging material having pre-formed compartments therein, adapted to receive product, to a product loading station;  
           [0022]    (ii) moving a second packaging material material onto the pre-formed first packaging material having compartments and product contained therein such that the second packaging material overlays the first packaginq material;  
           [0023]    (iii) sealing about their periphery the second packaging material material to the first  
           [0024]    (iv) packaging material to form a pack; and  
           [0025]    (iv) applying a further sealing member to subdivide the pack into compartments.  
           [0026]    Preferably, the further sealing member sub-divides the pack in a direction perpendicular to the direction of motion of the first and second packaging materials.  
           [0027]    Advantageously, a second further sealing member is applied to apply seals perpendicularly to those applied by the further sealing member.  
           [0028]    The second packaging material is preferably heated to seal it to the first packaging material.  
           [0029]    The invention includes within its scope a production system for producing products sealed in high integrity packaging comprising a packaging machine as described herein. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]    The present invention will now be described more particularly, with reference to the accompanying drawings which show by way of example only, two embodiments of packaging apparatus according to the invention. In the drawings:  
         [0031]    [0031]FIG. 1 is a schematic diagram of a packaging machine according to the prior art;  
         [0032]    [0032]FIG. 2 is a schematic diagram of a packaging machine according to a first embodiment of the invention;  
         [0033]    [0033]FIG. 3 is a top plan view of a pack produced by the packaging machine of FIG. 2, showing the compartments formed;  
         [0034]    [0034]FIG. 4 is a schematic diagram of a packaging machine according to a second embodiment of the invention; and  
         [0035]    [0035]FIG. 5 is a top plan view of a pack produced by the machine illustrated in FIG. 4. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    In a known apparatus, such as that shown in FIG. 1. a base-material  10  is unfurled from a mill roll  11 . From the mill roll  11 , the base-material  10  is passed through a thermoforming station  12  where compartments adapted to receive products are formed in the base-material  10  by a combination of the use of a forming tool (not illustrated) and pressure differential across the two surfaces of the base-material  10 .  
         [0037]    The base-material  10  is passed to a product loading area  13 , where the product is placed into the compartments in the base-material  10 . The upper top-material  14  is unfurled from the upper mill roll  15  and is guided over guide rollers  17  and  18  so that the upper top-material  14  flows co-directionally just above the base-material  10 .  
         [0038]    The base-material  10  and the upper top-material  14  are sealed together at the sealing station  19 . The sealing station  19  comprises a bottom die  20  which is guided on tooling grade pillars and bushes (not illustrated) to ensure correct alignment. The heated sealing platen  21  is pressed down onto the upper surface of the upper top-material  14 , the heat from the sealing platen  21  being sufficient to seal the upper top-material  14  to the base-material  10 . The bottom die  20  and the sealing platen  21  are so configured that both the seals parallel and perpendicular to the longitudinal axis of the base-material  10  are applied to complete the sealing of an individual compartment. The sealed packaging is passed to the knife station  22  and the slitting station  23  to cut the assembled products into the final individual packs.  
         [0039]    When production needs to be switched to a different product having a different individual compartment and pack size, the forming tool, sealing platen  21 , and bottom die  20  need to be replaced with ones having the appropriate shape and size. Although replacement of the forming tool is normally a simple and quick operation, replacement of the sealing platen is not. Moreover, specific sealing platens need to be formed for each product.  
         [0040]    With reference to the drawings embodying the invention, the first embodiment of the packaging machine, generally referenced  30 , as illustrated in FIG. 2, includes thermo-forming members, for forming the base material  31  which thermoforming members are substantially identical to those known in the prior art and as exemplified in the machine of FIG. 1.  
         [0041]    Also substantially identical is the mechanism by which the thus formed base-material  31  is brought together with the upper top-material  32 . In the machine  30  however, the sealing station  33  seals the upper top-material  32  to the base-material  31  simply about the periphery of the thermo-formed material as illustrated in FIG. 3. The seal, shown as the shaded area  50  in FIG. 3 isolates the products in compartments  51  from the environment although not from one another. This isolation allows the control maintained over contact between the products in the compartments  51  and the environment to be relaxed for the subsequent steps and allows savings in terms of instrumentation and running costs,to be realised.  
         [0042]    Once the peripheral seal  50  has been formed, the sealed product passes to a secondary sealing region, the secondary sealing station  34 . A sealing bar (not illustrated), orientated perpendicularly to the flow, indicated by the arrow in FIG. 3, on the packaging material, seals by the use of heat and pressure the upper-material  32  to the base-material  31  along seal  52 . Once the seal  52  has been formed, the sealing bar is lifted from the upper top-material  32  and the packaging material moved via a servomechanism to ensure that the sealing bar is positioned over the next area to be sealed. Again the sealing bar is lowered onto the upper top-material  32  and forms a further seal. This process is repeated until all the required individual seals have been formed. The individual compartments are thereby isolated and the products contained therein sealed in.  
         [0043]    The packs are then passed to the knife station  35  and the individual compartments separated from one another.  
         [0044]    In use the base material  31  having pre-formed compartments therein is presented to a product loading area  13 , where the product is loaded into said base material  31 . Upper top material  32  is then moved on to the base material  31  such that the upper top-material  32  overlays the base material  31 . The upper top material  32  is sealed to the base material  31  about their periphery. A sealing bar is then used to form further seals between the upper top-material  32  and the base material  31  to subdivide the pack into compartments.  
         [0045]    According to a further embodiment of the method, further sub-dividing seals may be applied by the application of a further sealing member which applies seals which are substantially perpendicular to those applied by the first sealing bar.  
         [0046]    Advantageously heat is supplied to seal the first packaging material to the second packaging material.  
         [0047]    In a further embodiment of a packaging apparatus, generally referenced  60 , according to the invention, shown in FIG. 4, a further series of seals, perpendicular to those illustrated in FIG. 2 are introduced at a third sealing station  61 . Sealing is achieved in a manner corresponding to that illustrated in FIG. 2. A second sealing bar (not illustrated), oriented in the direction of flow (indicated by the arrow in FIG. 5) of the packaging material is pressed against the upper top-material  62 . The upper top-material  62  is sealed to the base-material  63  by heat and pressure applied by the sealing bar. The sealing bar is lifted from the formed seal, and the packaging material, under the control of the servomechanism moved by a pre-set amount. A further seal  53  is formed between the upper top-material  62  and the base-material  63 . As shown in FIG. 5, repeated sealing by the sealing bars forms a matrix-like series of seals to form individual compartments containing the product.  
         [0048]    The formed products are then passed to a knife station  64  and a slitting station  65  to cut the product into individual packs.  
         [0049]    In a yet further embodiment of the invention, relative motion between the packaging material and the or each sealing bar is achieved by controlled motion of the sealing bar relative to the packaging material. The motion can be controlled by a servomechanism.  
         [0050]    It will of course be recognised that individual seals parallel to the packaging material can be formed first, followed by any perpendicularly oriented seals, where these are required. As an alternative to a sealing bar, a sealing roller or wheel could be used. When such a roller is used, sealing is achieved by applying pressure to the roller to maintain it in contact with the packaging material. The roller is then moved linearly along the region to be sealed.  
         [0051]    In a yet further embodiment of the invention (not illustrated), the sealing bar may be rotatable in the plane of the packaging material. In this embodiment once the sealing bar has produced a number of parallel compartmental seals it may be rotated through 90° to allow a further series of seals to be provided perpendicular to the first set of seals.  
         [0052]    Where the seal is produced thermally, the sealing member has means to maintain the surface in contact with the packaging material at the necessary elevated temperature. It also has means to record the temperature which is monitored. Should the temperature move outside pre-set values then the packaging process is temporarily halted to allow the correct temperature to be reached. Once this temperature has been reached then the process can be restarted.  
         [0053]    Using the machine described above a 400×400 mm pack is sealed at sealing station  33 . By use of the sealing bar in the second sealing station  34 , the initially sealed pack is subdivided into two 400×200 mm packs.  
         [0054]    By suitable setting of the servomechanism driving the packaging material the 400 ×400 mm pack described above could easily be subdivided into three 400×133 mm packs, four 400×100 mm packs or five 400×80 mm packs etc. The further sealing bar oriented perpendicularly to the first sealing bar in the secondary sealing station could then subdivide these packs further.  
         [0055]    It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the invention.