"A MULTI LAYER BAG SEPARATOR" FIELD OF THE INVENTION

The present invention relates to a multi layer bag separator. BACKGROUND Multi layer bags or sacks are used in many industries but in particular in food industries. The multi layer sacks normally consist of a paper outer bag also commonly referred to as a kraft bag. Contained within the outer bag is a plastic bag that retains the product to be transported by the multi layer bag. The inner bag is normally air and liquid impervious to protect its contents. Such an inner bag is normally of a plastics material whereas the outer bag may be of a paper based material. Alternative combinations of inner and outer bags may include the use of foil with kraft or plastic inner and kraft or plastic outer.

The outer bag provides protection to the inner bag during transportation of the multi layer bag. The outer bag will provide impact protection but also acts as a shield against contaminants coming into contact with the inner bag. The inner bag containing the product of the multi layer bag is normally destined for use in a clean room environment such as a hygienic processing plant. Contaminants such as oil, mud, water and other pollutants that are desired to be kept away from such a clean room environment are unable to make contact with the inner bag whilst it is in the outer bag. Accordingly separation of the inner bag and the outer bag will occur immediately prior to the inner bag proceeding to such a clean room environment. An uncontaminated inner bag can then be processed within such an environment whilst the outer bag that may contain surface contaminants, will not enter such a clean room environment. Removal of the inner bag from outer bag has traditionally been performed manually. This can be a time consuming exercise. Bags can be heavy and awkward to handle and therefore make such manual handling undesirable. Manual handling of the multi layer bag and the separation of the outer bag with the inner bag can also result in contamination of the inner bag from the people handling the inner bags. Accordingly there is a need to address such problems.

It is accordingly an object of the present invention to provide a device and related method for separating multi layer bags that addresses the abovementioned problems and/or which will at least provide the public with a useful choice. BRIEF DESCRIPTION OF THE INVENTION In a first aspect the present invention consists in a multilayer bag separator to separate a sealed product containing inner bag from an outer bag that envelopes said inner bag, the separator comprising:

(a) a bag conditioner to manipulate the multi layer bag and facilitate shifting of the inner bag, during a shifting action, away from one end of the outer bag and towards an opposite end to create a space at said one end in the multilayer bag where the inner bag does not reside

(b) an outer bag opener to, once a said shifting of the inner bag has occurred, create an opening at or proximate said one end in the outer bag so that the outer bag is in an opened condition whilst the inner bag remains sealed; and (c) an inner bag separator to, with the outer bag in its opened condition, effect a discharge of the inner bag from the outer bag.

Preferably said inner bag separator engages said multi layer bag in an initial condition where the multilayer bag has the opening of the outer bag in a location higher than the opposite end, said inner bag separator including a mechanism to invert the multilayer bag from the initial condition to discharge the inner bag from the outer bag though the opening, preferably under the influence of gravity.

Preferably said inner bag separator includes an outer bag faster to constrain the outer bag whilst allowing the inner bag to be moved freely relative thereto.

Preferably said inner bag separator includes a lifting mechanism to lift one of the inner bag and outer bag, relative to the other.

Preferably the outer bag is six faceted and rectangular in plan with two opposed side walls, two opposed end walls, and two opposed major face walls.

Preferably said outer bag is a pillow sack that includes a block bottom end wall and an opposed pinch top end and two opposed side walls and two opposed major face walls.

Preferably said bag conditioner comprises a bag punch to impart a sudden momentum change of said multi layer bag at least to loosen the content of the inner bag and increase fluidity of the content.

Preferably the bag conditioner comprises a massager to loosen the content of the inner bag and increase its fluidity before the inner bag is subjected to a shifting action.

Preferably the massager subjects the multilayer bag, prior to the shifting action, to compression in at least one direction.

Preferably the massager subjects the multilayer bag, prior to the shifting action, to compression in two orthogonal directions.

Preferably the massager includes at least one pair of pressure contact rollers in between which the multilayer bag passes and by which the multilayer bag is subjected to compression.

Preferably said bag conditioner comprises: a bag punch to impart a sudden momentum change of said multi layer bag at least to loosen the content of the inner bag and increase fluidity of the content, and a massager to further loosen the content of the inner bag and increase its fluidity before the inner bag is subjected to a shifting action.

Preferably the outer bag opener comprises a cutter to make a cut through the outer bag to create an opening into the outer bag.

Preferably the outer bag opener comprises arms to insert into the multilayer bag through only one of the walls of the outer bag, said arms movable relative to each other to, when moving away from each other, tear the outer bag to widen the opening in the outer bag. Preferably the outer bag opener comprises: a cutter to make a cut through the outer bag to create an opening into the outer bag, and arms to insert into the cut made by said cutter and into the multilayer bag said arms movable relative to each other to, when moving away from each other, tear the outer bag to widen the opening in the outer bag.

Preferably the outer bag opener further comprises an air lance to penetrate one of the walls of the outer bag in a location to allow an air jet to blow against an inner side face of the outer bag adjacent said opening to enlarge the opening prior to the arms being inserted into the opening. Preferably the bag conditioner comprises a bag shifter that engages with the outer bag to hold the outer bag without restricting relative movement of the outer bag relative the inner bag, the engagement including applying a momentum change to the multi layer bag via the outer bag to thereby encourage the inner bag to move towards said opposite end. Preferably the bag shifter is a table that includes a surface to receive a multilayer bag and that can establish a frictional interface with the outer bag of a coefficient of friction that, during the momentum change, will resist relative movement of the outer bag with the surface.

Preferably the table is pivotally mounted to pivot once a bag is receives thereon to effect the momentum change reliant on at least gravity to encourage movement of the inner bag towards the opposite end.

Preferably the table is presented with said surface inclined to the horizontal to receive a multilayer bag by dropping thereon and to effect the momentum change by deceleration of the bag. Preferably the bag shifter includes a vibrator to subject the multilayer bag to vibrations.

Preferably the bag conditioner comprises (a) the bag shifter and (b) at least one of the bag punch and massager that subject the bag to the condition prior to the bag shifter. Preferably the bag conditioner further comprises an outer bag lifter that comprises a bag gripper that, after the inner bag is shifted by the bag shifter toward said opposite end, grips the outer bag at its said one end and to then lift the one end upwards

Preferably the multilayer bag is in an orientation where the one end and opposite ends are in a vertical alignment during lifting.

Preferably the bag lifter also comprises and outer bag clamp that engages the outer bag on opposed sided and intermediate of the one end and opposite end, when the multilayer bag is in an orientation, to hold the outer bag during lifting by the bag gripper. Preferably the bag separator is set up as a multi stage device that sequentially processes multiple multiwall bags wherein outer bag opener is at a stage intermediate in the sequence to the bag conditioner and the inner bag separator stages.

In another aspect the present invention consists in a bag separator machine that sequentially processes multilayer bags of a kind that. includes an outer bag enveloping a product containing inner bag to separate the inner bag from the outer bag, the separator machine comprising: at one stage in the sequence, a bag conditioner stage to manipulate the multi layer bag and facilitate shifting of the inner bag, during a shifting action, away from one end of the outer bag and towards an opposite end to create a space at said one end in the multilayer bag where the inner bag does not reside, at other stage in the sequence, an outer bag opener stage to, once a said shifting of the inner bag has occurred, create an opening at or proximate said one end in the outer bag so that the outer bag is in an opened condition whilst the inner bag remains sealed; and at a further stage in the sequence, an inner bag separator stage to, with the outer bag in its opened condition, effect a discharge of the inner bag from the outer bag, wherein said other stage is intermediate of said one stage and said further stage.

In another aspect the present invention consists in a bag separator machine that sequentially processes multilayer bags of a kind that includes an outer bag enveloping a product containing inner bag to separate the inner bag from the outer bag, the separator machine comprising:

at one stage in the sequence, a bag conditioner stage to manipulate the multi layer bag and facilitate shifting of the inner bag, during a shifting action, away from one end of the outer bag and towards an opposite end to create a space at said one end in the multilayer bag where the inner bag does not reside, by way of a massager to loosen the content of the inner bag and increase its fluidity before the inner bag is subjected to a shifting action, and a bag shifter that, after the massager, engages with the outer bag to hold the outer bag without restricting relative movement of the outer bag relative the inner bag, the engagement including applying a momentum change to the multi layer bag via the outer bag to thereby encourage the inner bag to move towards said opposite end, and an outer bag lifter that comprises a bag gripper that, after the inner bag is shifted by the bag shifter toward said opposite end, grips the outer bag at its said one end and to then lift the one end upwards, at other stage in the sequence, an outer bag opener stage to, once a said shifting of the inner bag has occurred, create an opening at or proximate said one end in the outer bag so that the outer bag is in an opened condition whilst the inner bag remains sealed; and at a further stage in the sequence, an inner bag separator stage to, with the outer bag in its opened condition, effect a discharge of the inner bag from the outer ^ba g> wherein said other stage is intermediate of said one stage and said further stage.

Preferably the inner product containing bag contains a powder. Preferably the powder is milk powder.

In another aspect the present invention consists in a method for separating multi layer bags of a kind that includes an inner bag containing product that is enveloped by a protective outer bag, the outer bag being rectangular in plan with two opposed side walls, two opposed ends one of which is a pinch top end, and two

opposed side walls and two opposed major face walls, the method comprising the steps of: creating an opening in the outer bag at where head clearance is provided at the pinch top end of outer bag between the inner bag and outer bag when the multi layer bag is an orientation where the pinch top end is positioned above the other end; tilting the multi layer bag to lower the opening to allow discharge of the inner bag from the outer bag under the influence of gravity to thereby separate the inner bag from the outer bag. Preferably the step of conditioning the multi-layer bag prior to cutting to establish said head space.

Preferably said conditioning manipulates the multi layer bag to facilitate shifting of the inner bag, such that during a shifting action, the inner bag moves away from said pinch top end of the outer bag and towards an the other end to create said head space at said one end in the multilayer bag where the inner bag does not reside

Preferably during tilting, the outer bag is held whilst the inner bag is free to more through said opening.

Preferably said conditioning may include punching the bag to loosen its contents.

Preferably said conditioning includes massaging the multilayer bag to loosen the content of the inner bag and increase its fluidity before the inner bag is subjected to a shifting action.

Preferably said opening includes cutting the outer bag. Preferably said opening further includes, after cutting, a tearing of the outer bag to enlarge the opening made during cutting.

Preferably air is blown onto an inner wall of the outer bag in a location to allow the cut opening to be enlarged prior to said tearing.

Preferably said conditioning includes shifting the inner bag relative the outer bag by engaging the outer bag to hold the outer bag without restricting relative

movement of the outer bag relative the inner bag and applying a momentum change to the multilayer bag via the outer bag to thereby encourage the inner bag to move towards said opposite end.

Preferably said shifting is by rotating the multilayer bag to an orientation where the pinch top end become more elevated relative the other end.

Preferably said shifting is by vibrating the multi layer bag when in an orientation where the pinch top end is more elevated relative the other end.

Preferably said conditioning includes lifting the pinch top end of the outer bag when the multilayer bag is in an orientation where the pinch top end is vertical aligned with the other end.

Preferably said bag punch is to impact one of the end walls of the multi layer bag.

Preferably the bag during its conditioning is subjected to at least one instance of a momentum change that may be effected by a shaking or dropping of the multi layer bag such as in a vertical orientation.

Preferably the shaking or dropping may utilise a bag grip that holds the outer bag.

Preferably the bag grip may hold the outer bag at an end at where said opening is to be created Preferably the massager subjects the bag to compression in a direction or orthogonal directions that are transverse to the bag top end to bottom end direction.

Preferably the space between the each pair of pressure contact rollers can be adjusted to accommodate multi layer bags of different sizes. In a further aspect the present invention consists in a system as herein described with reference to any one or more of the accompanying drawings.

In a further aspect the present invention consists in a bag separator as herein described with reference to any one or more of the accompanying drawings.

As used herein the term "and/or" means "and" or "or", or both.

As used herein "(s)" following a noun means the plural and/or singular forms of the noun.

The term "comprising" as used in this specification means "consisting at least in part of. When interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as "comprise" and

"comprised" are to be interpreted in the same manner.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations- of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

Where reference herein is made to fluidity it is to be understood to relate to the ability of a substance to flow. It is not necessarily limited to liquids but also to powders or particulate matter.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is a plan view of a device of the present invention,

Figure 2 is a perspective view of a slight variation of the system of Figure 1, Figure 3 is a perspective view of part of the device of Figure 2, Figure 4 is a perspective view of another part of the device of Figure 2, Figures 5 to 9 illustrate a sequence in the processing of a multi layer bag by the device of the present invention,

Figure 10 is a side view of a bag conditioning station showing a tilt table, Figure 11 is a plan view of a device of the present invention, Figure 12 is a side view of part of the device of Figure 11, Figure 13a is a side view of part of the device of Figure 11 showing the pinching arms 151 in an open position,

Figure 13b is a side view of part of the device of Figure 11 showing the pinching arms in a closed position,

Figure 14 is a side view of a bag in the cutting station,

Figure 15 is a perspective view of a cutter assembly, Figure 16 is a perspective view of a bag with a suction pad,

Figure 17 is a cross-sectional view of a bag with an air injector and a suction pad acting thereon,

Figure 18 is a view of a bag in which the incision is being widened,

Figure 19 is a side view of a bag on a bag inverter, Figure 20 is a side view of a bag _^ which has been inverted, and

Figure 21 is a perspective view of a device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

With reference to Figure 1 there is shown a plan view of a device of one preferred form of the present invention. Multi layer bags which preferably consist of a kraft outer and a plastic inner bag are loaded for advancement to a conditioning station 3. Such loading may occur manually or may occur automatically such as by way of a side conveyor 1. The side conveyor 1 may include accumulation facilities to allow for accumulation of bags and rate control of bags for delivery to the rest of the device. Automatic loading may occur by robotic transfer from a pallet. The multi layer bags 10 are advanced sequentially through the device of the present invention. Interval spacing may be defined by the device or may be predefined such as by selection of an appropriate rate of loading.

The multi layer bags 10 are preferably of a rectangular plan view. They may otherwise be square. The bags may have a block top and/or block bottom. Alternatively the bags may be pillow bags or pinch top and block bottom or similar..

Each multi layer bag, as shown for example with reference to Figure Ia, may include an upper main panel 11 and corresponding lower main panel (not shown), an end panel 12 and corresponding opposed end panel (not shown) and a side panel 13 and corresponding opposed side panel (not shown). The bag may generally have a longitudinal direction in direction L-L as shown in Figure Ia.

The inner bag 15 that is retained within the outer bag 16 of the multi layer bag 10 may be affixed to the outer bag 16 or may merely sit loosely within the outer bag 16. The inner bag may be attached to the outer bag at one or both of the ends 12.

The inner bag 15 seals a product such as milk powder or other product or other foodstuffs or the like. The outer bag 16 may have a proximate but not necessarily tightly fitting form about the inner bag 15.

A bag pusher 2 may be utilised to transfer bags from the side conveyor 1 (if used), to the bag conditioning station or stations.

The bag pusher 2 may also assist in conditioning of the bag. The bag pusher 2 preferably includes an impact plate 19 that can impact against an end wall of the bag. Impacting of an end wall of the bag by the bag pusher 2 can result in an inward (and in direction L-L) displacement of the end wall of the bag (both of the inner and outer bag). This pushing in of the end wall can facilitate subsequent steps in the processing of the bag. There may be a stop 22 which is able to be raised to a height above the conveyor 1. Ordinarily, the stop 22 will be retracted to a height below the conveyor. When a bag is positioned adjacent to the bag pusher 2, the stop 22 may raise. The bag pusher 2 may then impact against an end wall of the bag, squeezing it against the raised stop 22. The bag pusher 2 may have sensors to detect the pressure it is exerting on the bag and/or the physical position of the bag pusher 2 in relation to the bag. After the bag pusher 2 has squeezed the bag against the stop 22, the stop 22 will retract and the bag pusher 2 may then push the bag from the side conveyor to the condition station.

Conditioning of the bag occurs at least in part by the conditioning rollers as shown. A first pair of side conditioning rollers 20 and 21 are provided to compress the sides of the multi layer bag towards each other. An upper surface roller 23 engages the upper panel 11 of the bag and compresses the upper and lower panels towards each other. The bag advancing through the conditioning station 3 may be subjected to further side wall conditioning by a second pair of side rollers 24 and 25. The rollers 20, 21, 23, 24 and 25 encourage an elongation of the multi layer bag,

loosens the internal material that may have some rigid constitution as a result of being at rest and compacted for a certain time and generally makes the content of the outer bag 16 more fluid. Such conditioning facilitates shifting of the inner bag within the outer bag. As a consequence further conditioning of the bag can be more easily achieved to create a head space between the inner and outer bags.

The conditioning by the pressure rollers may also result in a separation of any zones of engagement between the inner and outer bags. Some multi layer bags will include weld points where the inner and outer bags have been welded or tacked together. Conditioning can help facilitate the separation of such tack points. The pairs of contact rollers 20 and 21 and optional contact rollers 24 and 25 may include advancement guides 30 that will guide a bag advancing towards the contact rollers to the appropriate condition for advancement.

The pairs of contact rollers may also be mounted in a manner to allow for their spacing in a direction transverse to the direction of advancement of the bags to be adjusted. Such adjustment may be desirable for the purposes of accommodating different bag widths. Likewise the contact roller 23 may be adjusted in height above the conveyor on which each bag is advanced through the conditioning station 3 to allow for bags of a different thickness to be advanced through the conditioning station 3. The pressure rollers can help facilitate an elongation of the bag as a result of the orthogonal application of pressure between several of the walls of each bag passing through the rollers. Where the bag end has been pushed by the bag pusher 2 such elongation may cause for the outer bag at the pushed in end, to pop out whereas the inner bag is likely to stay pushed in. This can facilitate a separation of the inner and outer bag at the pushed in end which will help facilitate subsequent steps in the processing of a bag by the present invention.

A hydraulic or pneumatic ram of the pusher 2 may be used to impact the side walls to also effect a shift. One of the end walls such as end wall 12 can receive direct impact when the multi layer bag is in alignment therewith. The punch impacts against the multi layer sack in a direction parallel to direction L-L.

By punching an end of the multi layer bag the contents of the outer bag 16 may shift towards the opposite end of the multi layer bag or may loosen the contents somewhat.

Having passed through the conditioning rollers, further conditioning of the bag to create head space may be performed. Preferably such is achieved by dropping the bag into or on the chute 36 as shown in Figure 4. This dropping may help consolidate the content at and away from die headspace.

With the bag on the chute 36 as for example shown in Figure 4, a vacuum cup 66 as shown in Figure 3 may grab the outer bag. From the position of the bag in the chute as shown in Figure 4, the bag may be transferred upwards as shown with reference to Figure 5 whereupon the upper end 12 may then be gripped by the clamp 37. At this point a blade such as a rotating knife can create a cut in the top of the kraft bag. A small cut across the top of the bag is desired. Preferably the small cut is made immediately adjacent and on the bag side of the clamp 37. A full bag width cut may also be made thereby separating the clamp 37 and part of the bag held by the clamp from the remainder of the bag. A small cut is desired so that when the bag is tipped upside down the inner bag is still retained by the outer bag.

The clamp 37 may include proximity or contact sensors that sit within the claws of the clamp. The sensors can sense a reaching of the bag 10 to an appropriate height, being lifted by the vacuum cup or cups 66 so that when such a position is reached it is known that the clamp can close thereby holding onto the bag 10.

Air jets or grips or claws or the like may be used to help facilitate opening of the outer bag once the small cut has been made or during cutting of the outer bag. The bag 10 may then be tilted forward by moving the clamp 37 from a position shown in Figure 5 to a position shown for example in Figure 6.

The clamp 37 with the bottom end of the bag supported by a bottom plate 39 of the chute, can then be tilted forward as shown with reference to Figure 6. The outer bag in an opened condition at its upper end 12 may then become supported by a tilt table 41. The tilt table 41 may include grippers, claws or suction pads to

hold the bag as it transitions from its initial transferred position as shown in Figure 7 to a substantially vertical or downwardly inclined position as shown in Figure 8. The transfer table may include a shaking mechanism to shake the bag up and down to help facilitate a separation of the inner bag 15 relative the outer bag 16. With reference to Figure 1, the emptied outer bag 16 may then be gripped by grippers 46 to transfer the emptied outer bag to a disposal conveyor 47 to dispose of the outer bag appropriately.

The inner bag 15 may be transferred by way of a conveyor to a different destination. With reference to Figure 9 there is shown a variation to the invention described with reference to Figure 1. The outer bag 16 may be held by a clamp 194 during discharge of the inner bag 15 from the outer bag 16 and which may also after discharge transfer the outer bag to a waste conveyor 47.

With reference to Figure 10 there is shown a variation of a preferred form of the present invention described with reference to Figures 1-9. Having passed through the conditioning rollers of conditioning station 3, the bag may come to rest on the tilt table 136. The tilt table 136 may pivot about an axis 137. The axis 137 may be placed midway along the table length. A pneumatic ram 138 may be coupled to the tilt table 136 so that it can cause the tilt table to rotate about axis 137 to an inclined position. Figure 10 shows the table in its horizontal condition and inclined position 139. Alternatively, any other means for causing rotation of the tilt table may be employed.

As the tilt table rotates, friction may hold the outer bag in place during rotation. A surface or surfaces of the tilt table on which the bag rests may be defined by a material having a high coefficient of friction. The inner bag and/or its contents may slide to a lower position within the outer bag. This may create a head space between the top of the inner bag and an end (e.g. top) of the outer bag. When the tilt table is in position 139 a conveyor (such as one forming part of the tilt table) may move the bag off the tilt table so that it comes to rest in a vertical position such

as position 141. Alternatively, there may not be a conveyor and the bag may simply slide off the tilt table and come to rest at position 141.

With reference to Figure 11 there is shown a plan view of this alternative embodiment of the present invention. After the tilt table 136 deposits the bag at position 141, the bag may move along a conveyor towards the separating station 150. The separating station 150 includes the pinching arms 151.

When the bag approaches the separating station 150 it is positioned by two fixed guiding rails 152. The guiding rails 152 are located either side of the bag, as the bag moves along the conveyor the guiding rails 152 may help to ensure the bag is in the correct position to be clamped by the lifting clamp 160.

As shown in Figure 12, above the pinching arms 151 is a lifting clamp 160. The clamp 160 includes clamp jaws 165 that can move towards and away from each other. Each clamp 160 may be attached to a vertically moveable arm 161. The or each arm 161 may be raised or lowered by any suitable means such as pneumatics, hydraulics and/or motors. When the bag has been moved to a position such that it is directly beneath the clamp 160, the arms 161 will lower the clamp 160. When the clamp 160 is aligned with an upper portion 162 of the bag, it will close. The head space inside the bag helps to ensure that the closed clamp 160 only clamps the outer bag. Preferably, the inner bag will not be clamped. The arms 161 may then be raised, which will raise the bag (at least partially the outer bag), and consolidate the position of the inner bag at the bottom of the outer bag, further ensuring there is a head space between the upper extent of the inner bag and the upper extent of the outer bag.

With reference to Figure 13a and Figure 13b, the pinching arms 151 may pivot to move from an open position to a substantially closed position to make contact with the raised bag. The pinching arms 151 preferably contact the bag at a position approximately 2/3rds the way up the bag and on the major faces of the bag as shown in Figure 13b. The pinching arms 151 may also hold the bag during pulling by the clamp 160 to aid in the forming of the top of the bag. Pressure and friction can ensure the pinching arms 151 can hold the bag.

The clamp 160 will open and the bag may be supported momentarily by the pinching arms 151. The pinching arms may then release the bag, and it will be dropped back to the conveyor. This lifting and pinching process prepares the top of the bag so that it "points". It may -then be cut with a blade, and ensures that the inside bag is not at a height in which it could be cut by the blade.

The bag may then move along a conveyor 390 to the cutting station 170 as shown in Figure 11.

Figure 14 is a side view of a bag in the cutting station 170. When the bag enters the cutting station 170 the upper most extent of the outer bag may be clamped and pulled upwardly so that a cutting surface of the outer bag is in tension. The cutting surface being in tension may aid in the cutting process.

Figures 14 and 15 show a cutter assembly arm 172 which may have a motor 173 and a blade 171 located thereon. The cutter assembly arm 172 may also have a suction cup 174. The cutter assembly arm 172 may move from a position in which the blade

171 is not in contact with the bag, to a position in which the blade 171 makes contact with the cutting surface of the bag. The cutter assembly arm 172 may be moveable through the use of hydraulics, pneumatics and/or motors. When the blade 171 makes contact with the cutting surface of the bag a cut 175 is made into the cutting surface of the outer bag.

The blade 171 is preferably a circular rotating knife driven direcdy, or through a transmission from the motor 173. Alternatively, the blade may be a straight edge linearly reciprocating blade.

After the blade 171 makes an initial incision into the cutting surface of the bag, the cutter assembly arm 172 may move along a portion of the width of the bag, therefore lengthening the si2e of the cut in the bag. A pneumatic cylinder 180 may cause the cutter assembly arm 172 to move in a direction A-A as shown in Figure 15 so that the blade 171 makes an incision along a portion of the width of the bag. Alternatively a motor, or any other moving means may cause the cutter assembly arm 172 to move in the direction A-A.

Figure 16 shows a bag with a cut 175. A suction cup 174 may be connected to the cutter assembly arm and employed to make contact with the outer bag at a point below, but proximate to, the incision. The suction cup 174 may move to assist in opening the cut 175. The outer bag may comprise of more then one ply of material. The suction cup 174 only acts on the exterior ply, therefore the plies of the outer bag may separate as the exterior most ply is pulled by the suction cup 174.

With reference to Figure 17 an air injector 176 may be used as well as the suction cups. The air injector 176 may pierce the outer bag from the opposite side of the bag to the suction cup 174. The air injector preferably has a sharp tip to ensure it can penetrate through the layer(s) of material which the outer bag consists of. Once the air injector 176 has penetrated the outer bag, it may blow air into the bag at a proximate position to the cut 175, to further assist in opening the incision 175 and to separate the opposed major surfaces of the outer bag. The air injector 176 may influence any plies that have been separated as a result of the suction cup. Those separated plies may be blown outwardly, towards the exterior most ply. The suction cup 174 and the air injector 176 may both ensure that a suitably open cut 175 is prepared.

With reference to Figure 18 the cut 175 of the bag is shown. Hooks 177 and 178 may be moveably attached to the cutter assembly arm so that they can move and laterally with reference to the bag. After the air injector 176 and the suction cup 174 have prepared the cut 175, the hooks 177 and 178 may move downwardly so that the ends of the hooks are located inside the cut 175, and therefore inside the bag. The hooks may then move horizontally, in an opposite direction to one another, as indicated by the arrows on Figure 18. As the hooks 177 and 178 move horizontally, the incision may be enlarged by ripping of the outer bag, preferably to the point in which the full width of one side of the outer bag is ripped opened. Ripping of the bag reduces the likelihood of paper fragments falling from the outer bag and creating contaminants.

The bag may then be moved, preferably by a conveyor, to the bag removal station 200 as shown with reference to Figure 11.

Figure 19 is a side view of a bag on a conveyor 201 in position to be upturned by a bag inverter 202. A clamp 203 may exert pressure on the bag to secure it to one of the outer surfaces 204 of the bag inverter 202. The clamp 203 is preferably actuated by a pneumatic ram which is located on the bag inverter 202. Alternatively, the clamp 203 may be actuated by any other suitable means.

The clamp 203 may also include a vacuum which acts on the clamping surface of the bag. The vacuum may provide a suction force on the bag, which, in combination with clamping the bag to the outer surface 204 helps to ensure the bag is secured in place before being inverted.

When the bag is secured to the outer surface 204, the bag inverter will rotate 180 degrees about axis 205 so that it is in the position as shown in Figure 20. Preferably the bag inverter rotates counter-clockwise with reference to Figures 19 and 20. Alternatively, the bag inverter may rotate clockwise with reference to

Figures 19 and 20. Rotation of the bag inverter may be caused by a motor and/or a pneumatic or hydraulic system.

Figure 20 shows bag removal paddles 210 which may compress upon the base of the now inverted bag. As the paddles 210 squeeze the bag the clamp 203 may release its pressure on the bag. The inner bag may therefore slide downwardly, out of the opening in the outer bag.

The curved surface of the outer surface 204 may facilitate the inner bag from dropping out of the outer bag smoothly and onto an exit conveyor 211. The exit conveyor 211 may take the now separated inner bag for further processing or handling as desired. Further processing of the now separated inner bag may include cleaning. The bag may travel on a conveyor through a cleaning station. Air blowers may be incorporated into the cleaning station to blow air onto the bag to remove dust or any other foreign material.

As the inner bag slips out of the outer bag the paddles 210 may further compress onto the empty outer bag, securing it. The paddles 210 may then lift the empty outer bag away from the bag removal station 200 for disposal.

Figure 21 shows a perspective view of the invention as described in Figures 10-20.

The single cut of one side of the outer bag ensures there is one unitary item (the outer bag) to dispose of after the inner bag has been removed.

Bags that may be separated by the invention include bags containing milk powder. The bags in their pre separated and pre conditioned condition may be vacuum packed and/or of a loose powder packed nature.

At the conditioning station, vibration may be used to loosen the powder to become more fluid. This may be achieved by a vibrating conveyor and/or by having non-circular contact rollers.

The tilt table may also be shaken/vibrated.