Field Of Invention

The invention relates to manufacture of storage bags made from tubular fabric and in particular to a device or an apparatus of and method for making composite bags where storage bags have a liner inserted into them.

Background Of Invention

Composite bags comprising storage bags provided with moisture-resistant liner are necessary for storing perishable materials such as food grains, sugar, and moisture sensitive material. Until recently, composite bag consisting of inner web, preferable made from plastic film, were made mainly in a manual process, causing lower production rate. Also, the quality of bags was sub-standard and variable as it depended on the operator skill. In some automated processes, the liner is inserted into outer bags that are already stitched at one end - therefore, the liner does not get stitched with the outer bag. In situations where the liner needs to be stitched with the outer covering, such processes are problematic. There is therefore a need to provide a method to overcome these drawbacks. In particular, there is a need to provide a method that produces a composite bag comprising an outer covering and a liner insert such that it maintains integrity of the liner, thereby making it suitable for specific storage applications including storage of perishable goods. There is also a need to provide a process that allows the flexibility of stitching the liner insert along with the stitching of the outer covering or stitching the outer covering without stitching the liner insert along with it.

Brief Description Of Figures

Figure 1 shows a block diagrams of the apparatus of the invention

Figure 2 shows a block diagram of the raffia bag at various stages of its production according to the invention

Figures 3 and 4 show composite bags with one end stitched

Figure 5 (5A to 5F) shows the various stages of insertion of the liner insert cut piece into the outer covering cut piece

Figure 6 (6A, 6B, 6C) is a schematic representation of the liner platform and liner insertion tubes

Summary of Invention:

The invention relates to manufacture of storage bags made from tubular fabric and in particular to a device or an apparatus of and method for making composite bags where storage bags have a liner inserted into them. Manual methods of inserting a liner into an outer covering to make composite bags are known, however, these are not suitable for automated bag making machines. The device of the invention discloses a liner insertion platform that is capable of movement in direction transverse to its own plane. It also discloses a pair of liner insertion tubes that wrap a heat sealed liner cut piece around them and insert it inside an outer covering cut piece. The invention also allows the liner cut piece to be placed either loosely inside or affixed to the outer covering to make a robust composite bag. The invention also discloses a method of making a composite bag using the device disclosed herein.

List of Parts:

1. Composite Bag; 1A - 8. Liner cutting unit; 8 A.

Composite cut piece; 1B - Liner sealing unit front end of the composite 9. Liner conveyor line cut piece; 1C - back end of 35 10. Liner insert or cut piece of the composite cut piece; 1D liner insert; 10A - forward

- folded composite cut end of liner cut piece 10B - piece; 1E - final backward end of the liner stitch/seam cut piece; 10C - heat sealed

2. Web puller units (2A - unit 40 liner cut piece; 10D - heat for outer covering web, 2B seal

- unit for liner web) 11. Transfer unit

3. Outer covering tubular 12. Liner insertion bed unit; fabric/web 12A - Suction blocks 12B -

4. Liner tubular fabric/web 45 Hose

5. Outer covering cutting unit 13. Outer covering platform;

6. Outer covering conveyor 13 A - Perforations; 13B - line Hose

7. Outer covering or cut piece 14. Liner feeding unit

of outer covering; 7A - top 50 15. Liner platform; 15A - layer of outer covering cut Liner insertion tubes piece; 7B bottom layer of 16. Folding unit

outer covering cut piece; 17. Stitching/seaming unit 7C - near end of outer 18. Stacking unit

covering cut piece; 7D - 55

Farther end of outer

covering cut piece

Detail Description Of Invention:

The invention discloses a device and a method to manufacture a composite bag (1) comprising an outer covering (or an outer bag) with a liner insertion (or simply a liner or an inner bag). The outer covering is made from woven or non-woven plastic fabric in a tubular form (e.g. a hose). The liner may be also made from plastic film or woven or non-woven plastic fabric in a tubular form (e.g. a hose). The liner may be in the form of a bag open at one end but heat-sealed at the other to form an integral heat-seam. An integral heat seam is a seam that is substantially moisture proof or leak proof.

One key aspect of the invention is that it optionally allows the liner insertion to be affixed to the outer covering. In other words, the liner insertion may remain loose inside the outer covering or it may be affixed to it depending on the user requirement.

Figure 1 shows the apparatus or device according to the invention to insert liners into an outer covering. The device of invention to manufacture the composite bag has two conveyor lines (6, 9) - one (6) to convey the outer covering cut pieces (7) and another (9) to convey the liner cut pieces (10).

Figure 2 shows the outer covering and liner at various stages of the composite bag production. As shown in Figures 1 (and corresponding bag/liner elements shown in Figure 2), the apparatus has two web puller units - a outer covering web puller for pulling the tubular web fabric (3) from which the outer covering is made (or the outer covering tubular web), and a liner web puller (2B) for pulling tubular liner fabric (4) (or a liner tubular web) for making the eventual heat sealed liner cut piece (10C) that is inserted into the eventual outer covering cut piece (7). The web puller units (2A, 2B) respectively pull (in the travel direction z - see Figure 2) the outer covering tubular fabric/web (3) and the liner tubular fabric/web (4) and process them into respective cut pieces (i.e. outer covering cut piece (7) and liner cut piece (10)) using respective cutting units (i.e. outer covering cutting unit (5) and liner cutting unit (8)). In the case of the liner fabric, a heat seal is placed at a predetermined location preferably before a cut is made at the heat-seal end of the linear cut piece. In another aspect of the invention, heat seal may be made after cutting the relevant end of the liner cut piece. With the help of a transfer unit (11), the outer covering cut piece (7) changes its travel direction to x (see Figure 2) and progresses from outer covering conveyer line (6) onto an outer covering platform (13) (which is a part of the liner insertion bed unit (12)) awaiting insertion of the heat sealed liner cut piece (10C). The outer covering cut piece (7) has two ends, namely a near end (7C) and a farther end (7D). The near end (7C) is the end near the liner feeding unit (14) and the farther end (7D).

When the tubular liner fabric/web (4) is drawn over the liner web puller (2B), it is provided with sufficient tension to facilitate its cutting. Compensation is also provided to allow distance between the cut edge and the line of sealing of the liner cut piece. The compensation is provided so that an additional region (R) or portion of fabric is provided to facilitate affixation of the liner cut piece (10) with the outer covering cut piece (7) to form a composite bag in which the liner cut piece (10) and the outer covering cut piece (7) are affixed together. Therefore, the placement of the liner insert inside the outer covering cut piece is such that its end near the folded end of the composite bag is placed beyond (see Figure 3) the final stitch/seam line (1E) which seals the composite bag.

The liner cut piece (10) has two ends - a forward end (10 A) and a backward end (10B). The forward end (10A) is the end that is cut first and the backward end (10B) is the end that is cut after the forward end. According to one aspect of the invention, the liner cut piece (10), which travels in direction x, is always heat- sealed at its one end - preferably the backward end (10B), which is the end that faces the heat sealing unit - before its full insertion into the outer covering cut piece (7). Heat seal (10D), which extends across the entire width (W) of the liner cut piece, is provided using a liner sealing unit (8A), which must be positioned preferably before the liner cutting unit (8) but certainly before the liner feeding unit (14). However, it is also possible to place the heat sealing unit after the liner cutting unit (8). Any type of sealing method may be used so long as it does not create perforations along the line of sealing. In one aspect of the invention, heat sealing of the liner cut piece (10) is carried out at any one of its two ends (10A or 10B).

The heat-sealed liner cut piece (10C) progresses onto a liner platform (15) (which is a part of a liner feeding unit(l4)) that is capable of moving (or rising and falling) transversely to its own plane (shown by a double arrow in Figure 5A). The liner platform is provided with soft porous medium (not shown) on its surface that receives the heat sealed liner cut piece (10C). The liner platform (15) is also provided with a pair of hollow liner insertion tubes (15 A) with perforations or openings, said tubes being capable of moving longitudinally on respective insertion rails (not shown). The arrangement of forward and lateral movement of liner insertion tubes (15 A) will be known to a person skilled in the art and does not need explaining in detail. The liner insertion tubes (15 A) are supplied with vacuum. The rotational, lateral and axial movements of the liner insertion tube are servo- controlled for greater accuracy.

At the time of insertion of the heat-sealed liner cut piece (10C) into the outer covering cut piece (7), the outer covering cut piece (7) - which is a tubular object in a flat position - needs to have its one end opened, particularly the near end or the end that is nearest the liner feeding unit (14). In other words, the two layers, namely the top layer and the bottom layer (7 A, 7B) that form the outer covering cut piece (7) need to be separated from each other so that an opening may be formed through which the liner cut piece (10) may be inserted (Figure 5D). The layer separation activity is carried out using techniques involving suction or using mechanical gripping techniques known to persons skilled in the art. Vacuum may be applied to suction block(s) through hose pipe(s). Suction blocks (12A) are provided with perforations through which the vacuum is transferred to the top layer (7 A) of the outer covering cut piece (7). The portion of outer covering platform (13) on which the outer covering cut piece (7) lay may also be provided with suction means to keep the lower layer of the outer covering cut piece connected with the outer covering platform (13). The suction means may comprise perforations (13A) provided in the outer covering platform through which vacuum may be provided via a hose (13B).

Suction may be applied only to one layer of the outer covering piece or both layers.

The liner platform (15) rises (or moves towards the plane of the liner insertion tubes (15 A)) such that the heat-sealed liner cut piece (10C) comes under the action of vacuum supplied to the insertion tubes (15 A). Preferably, the liner platform (15) rises sufficiently so that the heat-sealed liner cut piece (10C) makes a contact with the insertion tubes (15 A). Due to the suction provided by the insertion tubes (15A), the heat-sealed liner cut piece (10C) is now removably attached to the insertion tubes (15A). At this time the liner insertion tubes (15A), with the help of rotational drivers (not shown) provided to them, simultaneously rotate in a clockwise direction (or axially inwards - see Figure 5B) - due to which the heat-sealed liner cut piece (10C) gets wrapped around the insertion tubes (15 A) - and, with the help of lateral movement means (not shown) provided to them, also move towards each other laterally. The clockwise direction of rotation is the clockwise direction of rotation when viewed from the side of the liner cutting unit (8). The heat-sealed liner cut piece (10C), under the action of gripping means, preferably vacuum, thus gets wrapped around the insertion tubes (15 A) which are now closer to each other than in their original positions and the liner platform (15) lowers away (see Figure 5C) from the liner insertion tubes (15 A) to receive next liner cut piece. The gripping means provided on the liner insertion tubes for the purpose of holding onto the heat sealed liner cut piece (10C) as it gets wrapped around the tubes (15A) are preferably in the form of a plurality of holes (not shown) that administer vacuum. The gripping means may also be in the form of a plurality of suction cups (not shown) provided on the surface of said insertion tubes (15 A) - the suction cups may be made of flexible material capable of exerting suction onto the heat sealed liner cut piece (10C) when pressed against it. The gripping means may also be in the form of any other mechanical clamps or grippers (not shown) provided on the surface of said insertion tubes (15 A).

As shown in Figure 6, the liner insertion tubes (15 A) with the heat-sealed liner cut piece (10C) wrapped around them then move forward, with the help of axial movement means (not shown), in z direction and position themselves between the two layers (7 A, 7B) of the outer covering cut piece (7) at its opened near end (7C). The liner insertion tubes (15 A) move in z direction by a distance such that the liner cut piece (10) is positioned inside the opened up outer covering cut piece (7) at a predetermined location. As illustrated in Figures 3 or 4 the predetermined location depends on whether the liner cut piece (10) is to be stitched/sealed along with stitching/sealing of the outer covering cut piece (7) to produce a composite bag (1) with one end stitched.

Once the liner cut piece (10) is placed at its predetermined location, the insertion tubes (15 A) rotate in an anticlockwise or counter clockwise direction (or rotate outward), and simultaneously also move laterally (Figure 5D). The anti-clockwise direction of rotation is the anti-clockwise direction of rotation when viewed from the side of the liner cutting unit (8). Following this, the active gripping (for example, vacuum) supplied to the liner insertion tubes (15 A) is switched off or disabled and the insertion tubes (15 A) retract backward in z direction to come out of the outer covering cut piece (7) and return to their position ready to receive next cut piece of liner. The simultaneous rotational and axial movement of the insertion tubes (15 A) without vacuum allows the liner cut piece (10) remain inside and on the bottom layer (7B) (Figure 5E) of the outer covering cut piece (7) while the insertion tubes (15 A) retract themselves out of the outer covering cut piece (7). Eventually, as the suction is turned off, the top layer (7 A) collapses onto the bottom layer (7B) with the heat sealed liner cut piece (10C) inside the outer covering cut piece (7) (Figure 5F). The outer covering cut piece (7) with the liner cut piece (10) inserted into it is termed as the composite cut piece (1A) that has a front end (1B) and a back end (1C). The front end (1B) is the end of the composite cut piece (1A) nearest the liner feeding unit (14). The composite cut piece (1 A) travels down the bag making line of the apparatus for further processing, which includes folding of the composite cut piece (1A) on a folding unit (16) (which produces a folded composite cut piece) to form a folded composite cut piece (1D), followed by providing a final stitch/seam (1E) (which produces a composite bag (1) stitched/sealed at one end) on a stitching/sealing unit (17) and stacking of the lined and stitched bags on a stacking unit (18). In a preferred embodiment, the front end (1B) is folded and stitched.

In one embodiment of the invention, the heat sealing to the liner cut piece is provided at its forward end (10A). In this case, it is the back end (1C) of the composite cut piece that will be folded and stitched.

Preferably in tandem with movement of the insertion tubes (15 A) in z direction to place the liner cut piece (10) into the outer covering cut piece (7), next liner cut piece is placed onto the liner insertion platform for making of the next composite bag.

Figures 3 and 4 show composite bags (1A) with liners inserted in them. Figure 3 shows a composite bag (1A) according to the invention where the liner insert (10C) is stitched along with the outer covering. Figure 4 shows a composite bag

(1A) where the liner insert (10C) resides loosely inside the outer covering (7) i.e. within the final composite bag (1 A). As stated earlier, one key aspect of the invention is the choice it offers to have the liner insert (10) to be affixed to the outer covering (7) near the sealed end of the liner insert (10). For this purpose, there’s an additional length or an extension of the liner insert tube provided beyond the heat seal (10D) sealing line (see Figure 3). Should the end user choose to affix the liner insert (10) to the outer covering

(7), a seal or a seam is provided by which the extension portion is affixed to the outer covering. The seam may be formed either by conventional stitching methods or by heat sealing or by using adhesives or using high energy techniques such as ultrasonic or laser technologies.

In the embodiment where the heat sealed liner cut piece (10C) resides loosely in the composite bag (1), there is no need (see Figure 4) to provide substantial additional length (R) of the liner insert cut piece, as there is no requirement to seal the liner integrally with the outer covering cut piece (7). In this case, the additional length (R) is simply a nominal length that is required to provide a robust heat seal (10D). In this case, the placement of the liner insert inside the outer covering cut piece is such that its end near the folded end of the composite bag is placed before (see Figure 4) the final stitch/seam line which seals the composite bag.

A method of making a composite bag (1) is also disclosed. The method allows a person skilled in the art to use the device disclosed herein and manufacture composite bags (1) with liner inserts (10). The method starts with pulling an outer covering tubular web (3) using an outer covering web pulling unit (2 A), and forming outer covering cut pieces (7) using an outer covering cutting unit (5). As a step of the method, another pulling unit (2B) pulls a liner tubular fabric/web (4) and forms liner cut pieces (10) using a liner cutting unit (8). Next step involves sealing one of the two ends of the liner cut piece (10). Preferably the backward end (10B) is heat sealed to make a heat sealed liner cut piece (10C). Following this, a transfer unit (11) transfers said outer covering cut piece (7) to a liner insertion bed unit (12). Also, the heat sealed liner cut piece (10C) is transferred to the liner feeding unit (14). Next, the method proposes to insert the liner cut piece (10) into the outer covering cut piece (7) to form a composite cut piece (1A) having a front end (1B) and a back end (1C), following which the method discloses to transfer the composite cut piece (1A) to a folding unit (16) where the farther end (1C) of said composite cut piece (1A) is folded, preferably at its front end (1B). This is followed by transferring the folded composite cut piece (1 A) to a stitching/seaming unit (17) where the folded end of composite cut piece is stitched/seamed.

The steps of transferring the outer covering cut piece (7) to the liner insertion bed unit, and that of transferring the heat sealed liner cut piece (10C) onto the liner platform (15) may take place simultaneously or one after the other in any sequence, so long as the outer covering cut piece (7) with its layers (7 A, 7B) separated is ready to receive the heat sealed liner cut piece (10C) within it. In one key aspect of the method of invention, the step of inserting said liner cut piece (10) into said outer covering cut piece (7) comprises a number of special manoeuvres. These are:

a. Receiving on the liner platform (15), the heat sealed liner cut pieces (10C) following which moving the liner platform (15) transverse to its own plane toward said liner insertion tubes (15 A) capable of movement transverse to its plane.

b. Using active gripping supplied by gripping means provided on the surface of the liner insertion tubes (15 A), collecting the heat sealed liner cut piece (10C) onto the pair of liner insertion tubes (15 A), followed by rotating the liner insertion tubes (15 A) clockwise with the help of the rotational drivers (not shown) and moving them laterally, with the help of lateral movement means (not shown), towards each other, thereby wrapping, with the help of gripping means provided on the liner insertion tubes (15 A) said heat sealed liner cut piece (10C) around said liner insertion tubes (15 A). The clockwise direction of rotation is the clockwise direction of rotation when viewed from the side of the liner cutting unit (8).

c. Applying suction to the bottom layer (7B) of said outer covering cut piece (7) and by applying a suction block (12A) to the top layer (7 A) of said outer covering cut piece (7) to lift it (7 A) away from the bottom layer (7B) of said outer covering cut piece (7) to form an opened end of outer covering cut piece (7) facing the liner cut piece (10). d. Moving forward the liner insertion tubes (15 A) using suction from the liner platform (15) for placing the tubes (15 A) with the liner cut piece (10) wrapped around them, inside the opened end of said outer covering cut piece.

e. Rotating the liner insertion tubes (15 A) anticlockwise with the help of the rotational drivers (not shown), and moving them laterally away from each other with the help of the lateral movement means (not shown), whereafter turning off or disabling the active gripping supplied to said liner insertion tubes (15 A) and retracting said liner insertion tubes (15 A). The anti- clockwise direction of rotation is the anti-clockwise direction of rotation when viewed from the side of the liner cutting unit (8).

In one aspect of the method disclosed here, the gripping may be carried out by the active gripping means - provided on the liner insertion tubes for the purpose of holding onto the heat sealed liner cut piece (10C) as it gets wrapped around the tubes (15 A) - that are preferably in the form of a plurality of holes (not shown) that administer vacuum. The gripping may be carried out by gripping means that may also be in the form of a plurality of suction cups (not shown) provided on the surface of said insertion tubes (15 A). Here the suction cups may be made of flexible material capable of exerting suction onto the heat sealed liner cut piece (10C) when pressed against it. Finally, the gripping may also be carried out by the gripping means which may also be in the form of any other mechanical clamps or grippers (not shown) provided on the surface of said insertion tubes (15 A). All steps of the methods disclosed herein using the device of the invention are controlled and synchronised by a PLC (programmable logical controller) or similar technology.

It is noted that using the device disclosed here and the method of using it, a composite bag (1) is manufactured. One key aspect of the composite bag (1) manufactured according to the device and method of the invention is that the heat sealed liner insert cut piece (10C) may be loosely placed inside said outer covering cut piece (7), before said outer covering cut piece (7) is folded and stitched at its end near which the heat seal (10D) is situated. The affixation of said liner inert cut piece (10) to said outer covering cut piece (7) is done using a technique such as stitching, ultrasonic welding or laser welding. It is evident from the foregoing disclosure that the invention has a number of embodiments.

1. A device for manufacturing a composite bag (1), said bag comprising an outer covering and an inner lining, said device comprising an outer covering puller unit and a liner pulling unit, said pulling units pulling an outer covering tubular web (3) and a liner tubular web (4) over to respective cutting units (5, 8), i.e. an outer covering cutting unit (5) and a liner cutting unit (8), to cut said outer covering tubular web (3) and said liner tubular web (4), respectively, into outer covering cut pieces (7) having a top layer (7 A) and a bottom layer (7B) and liner cut pieces (10), a sealing unit (8 A) to provide a heat seal (10D) in the liner tubular web (4) near one end (10A or 10B) of the heat sealed liner cut piece (10C) that would be eventually formed, a transfer unit (11) for changing the direction of travel of said outer covering cut piece (7) and transferring it onto a liner insertion bed unit (12) where said heat sealed liner cut piece (10C) is inserted into said outer covering cut piece (7) to make a composite cut piece (1A), a folding unit (16) to provide fold at one end (1B or 1C) of the composite cut piece (1A) near where the heat sealed end of the heat sealed liner cut piece (10C) is situated, a stitching/seaming unit (17) to stich the fold, characterised in that said liner feeding unit (14) comprising a liner insertion tool which incorporates a liner platform (15) and two liner insertion tubes (15 A) provided with active gripping means on the surfaces of said tubes (15 A), wherein said liner platform (15) receives said heat sealed liner cut pieces (10C) from said liner sealing unit (8 A) or from said liner cutting unit (8), said liner platform (15) being capable of movement transverse to its own plane, and said liner insertion tubes (15 A) being capable of collecting said heat sealed liner cut pieces (10C) from said liner platform using gripping provided by said gripping means for placing them inside the outer covering cut piece (7) to form a composite cut piece (1A) having two ends (1B, 1C), followed by retracting themselves out of said composite cut piece (1 A), whereafter said composite piece (1 A) is sent to further processing units (16, 17) to make the composite bag (1).

2. The device as disclosed in embodiment 1, characterised in that said liner insertion bed unit (12) comprises a outer covering platform (13) and a layer separation device, said layer separation device operated using mechanical grippers to separate layers from each other.

3. The device as disclosed in embodiments 1 to 2 characterised in that said layer separation device comprising perforations (13A) provided in said outer covering platform (13) through which suction is applied to said outer covering cut piece (7) once it is received on said outer covering platform (13), and at least one, preferably two, suction block (12A) that attaches itself to the top layer (7 A) of said outer covering cut piece (7) and, using suction, lifts it away from the bottom layer (7B) to open up the end (7C) of said outer covering cut piece (7) that faces said liner feeding unit (12).

4. The device as disclosed in embodiments 2 and 3, characterised in that for placing said heat sealed liner cut piece (10C) into said outer covering cut piece (7), said liner insertion tubes (15 A) rotate in a clockwise direction when viewed from the side of said liner cutting unit (8) and laterally towards each other such that said heat sealed liner cut piece (10C) gets wrapped around said liner insertion tubes (15 A) and whereafter said liner insertion tubes (15 A) move axially forward into said open end (7C) of said outer covering cut piece (7).

5. The device as disclosed in embodiment 4, characterised in that said liner insertion tubes (15 A) have an arrangement for axial movement, rotational drivers for each insertion tubes (15 A) for rotating each of said tubes (15 A) around their longitudinal axis, an arrangement for lateral movement of said insertion tubes (15 A) for moving them towards and away from each other, and surface of each insertion provided with active gripping means to provide active gripping to the liner surface, wherein said rotational drivers, said arrangement for lateral movement, and said provision for gripping liner surface allow said pair insertion tubes (15A) to place said heat sealed liner cut piece (10C) inside said outer covering cut piece (7) to form a composite cut piece (1A).

6. A device as disclosed in embodiment 5, characterised in that said gripping means is a plurality of holes provided in the walls of said insertion tubes (15 A) that administer vacuum.

7. A device as disclosed in embodiment 5, characterised in that said gripping means is a plurality of suction cups provided on the surface of said insertion tubes (15 A).

8. A device as disclosed in embodiment 5, characterised in that said gripping means is mechanical clamps or grippers provided on the surface of said insertion tubes (15 A).

9. The device as disclosed in embodiments 1 to 8, characterised in that said folding unit (16) is capable of receiving said composite cut piece (1A) and has arrangement to fold the front end (1B) of said composite cut piece (1 A) and/or to insert a filling valve and thereafter transporting said folded composite cut piece (1D) to said stitching/seaming unit (17).

10. A device as disclosed in embodiment 9, characterised in that said liner platform (15) is provided with soft porous medium on the surface that receives the heat sealed liner cut piece (10C).

11. A method of manufacturing a composite bag using any of the devices claimed in claims 1 to 10, said method comprising the following steps: a. pulling said outer covering tubular web (3) and forming outer covering cut piece (7);

b. pulling said liner tubular web (4) and forming liner cut piece (10);

c. sealing one end (10A or 10B) of said liner cut piece (10) to form a heat sealed liner cut piece (10C);

d. using said transfer unit (11), transferring said outer covering cut piece (7) to said liner insertion bed unit (12);

e. transferring said heat sealed liner cut piece (10C) to said liner feeding unit

(14);

f. inserting said heat sealed liner cut piece (10C) into said outer covering cut piece (7) to form a composite cut piece (1A) having a front end (1B) and a back (1C) end;

g. transferring said composite cut piece (1A) to a folding unit (16) where one end (1B or 1C) of said composite cut piece is folded, said end being the end near which the heat sealed end of the heat sealed liner cut piece (10C) is situated; h. transferring said folded composite cut piece (1D) to a stitching/seaming unit (17) where the folded end of composite cut piece is stitched/seamed;

characterised in that said step f of inserting said heat sealed liner cut piece (10C) into said outer covering cut piece (7) comprises:

i. receiving on said liner platform (15) said heat sealed liner cut pieces (10C) following which moving said liner platform (15) transverse to its own plane toward said liner tubes (15 A); 11. using active gripping supplied by said gripping means, collecting said heat sealed liner cut piece (10C) onto said pair of liner insertion tubes (15A), followed by rotating said liner insertion tubes (15A) clockwise and moving them laterally towards each other, thereby wrapping said heat sealed liner cut piece (10C) around said liner insertion tubes (15 A);

iii. separating the top layer (7 A) of said outer covering cut piece (7) to lift it away from the bottom layer (7B) of said outer covering cut piece (7) to form an opened end of outer covering cut piece (7) said opened end facing said heat sealed liner cut piece (10C);

iv. moving forward said liner insertion tubes (15A) and placing them inside the opened end of said outer covering cut piece (7);

v. rotating said liner insertion tubes anticlockwise and moving them laterally away from each other, whereafter disabling active gripping supplied to said liner insertion tubes (15 A) and retracting said liner insertion tubes from inside of said outer covering cut piece (7).

12. A method as disclosed in embodiment 11, characterised in that steps b and c of claim 11 may be carried out in the reverse order.

13. A method as disclosed in embodiment 12, characterised in that separating of layers (7 A, 7B) of step iii of claim 11 comprises applying suction to the bottom layer (7B) of said outer covering cut piece (7) and applying at least one suction block (12A) to the top layer (7 A) of said outer covering cut piece (7) to lift it away from the bottom layer (7B) of said outer covering cut piece (7). 14. A method as disclosed in embodiment 13, characterised in that separating layers (7 A, 7B) of said step iii of claim 11 comprises applying mechanical grippers to said top and bottom layers to separate them from each other.

15. A method as disclosed in embodiment 11, characterised in that said gripping of step ii is applied by said gripping means that is in the form of a plurality of holes in the walls of said liner insertion tubes (15 A) that administer vacuum to said heat sealed liner cut piece (10C).

16. A method as disclosed in embodiment 11, characterised in that said gripping of step ii is applied by said gripping means that is in the form of a plurality of suction cups provided on the surface of said insertion tubes (15 A) that apply pressure on said heat sealed liner cut piece (10C).

17. A method as disclosed in embodiment 11, characterised in that said gripping of step ii is applied by said gripping means that is in the form of mechanical clamps or grippers provided on the surface of said liner insertion tubes (15 A).

18. A composite bag (1), said composite bag (1) made from a composite cut piece (1A) comprising an outer covering cut piece (7) and a heat sealed liner insert cut piece (10C), characterised in that said heat sealed liner insert cut piece (10C) may be loosely placed inside said outer covering cut piece, before said outer covering cut piece is folded and stitched at its one end (1B or 1C).

19. The composite bag (1) as claimed in claim 18, characterised in that said loosely placed heat sealed liner insert cut piece (10C) may be affixed to said outer covering cut piece (7). 20. The composite bag (1) as disclosed in embodiment 19, wherein the affixation of said heat sealed liner inert cut piece (10C) to said outer covering cut piece (7) is done using a technique such as stitching, ultrasonic welding or laser welding.

21. A composite bag as disclosed in embodiments 19 or 20, wherein said heat sealed liner insert cut piece (10C) when placed inside said outer covering cut piece (7) is positioned such that an additional free region (R) of liner insert cut piece (7) is positioned so as to facilitate folding of said additional free region (R) along with folding of the end of said outer covering cut piece (7) near which the heat seal (10C) is situated.

While the above description contains much specificity, these should not be construed as limitation in the scope of the invention, but rather as an exemplification of the preferred embodiments thereof. It must be realized that modifications and variations are possible based on the disclosure given above without departing from the spirit and scope of the invention. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.