Patent Application
20160229146
The present invention relates to a machine and a method for manufacturing plastic bags or pouches with three gussets.
High speed machines and methods for manufacturing plastic bags or pouches in large quantities, are known. Also known are high speed machines and methods for manufacturing pouches with side gussets and bottom gusset. Manufacturing methods and machines are also known and available for producing standing plastic pouches. Plastic pouches with or without gussets can be produced having a top that can be closed and opened.
Machines for producing plastic pouches having gussets and methods for producing the same have been patented.
U.S. Pat. No. 7,331,917 discloses a Bag Making Machine which uses separate sources for the top and bottom or front and back plastic web panels requiring multiple accumulators. The separate feeding of the web panel films causes mismatch of designs necessitating a re-unification assembly to address the design matching problem. Apart from this, the machine according to this invention provides little flexibility in terms of the width of the plastic film that the machine can use.
US Patent application no. 2012/0231941 discloses a Plastic bag making apparatus wherein the gusset portions have been separately attached and temporarily fixed to the main two films. The gusset portions need to be separately attached because of which the process is long and to match the registration or print of the plastic bags becomes difficult. Such process has a need for re-unification assembly so as to overcome the barrier of mechanical distance and hence, the machine and method makes it difficult to manufacture gusseted plastic bags compromising production efficiency.
U.S. Pat. No. 6,796,932 discloses a manufacturing method and apparatus for manufacturing gusseted bag using two separate films and a bottom gusset. However, the bottom gusset structure is separately placed between the two layers of the main film and then heat-sealed to form the bottom gusset. In this invention two main plastic films and one bottom gusset plastic film have been used requiring multiple accumulators. The machine does enhance production efficiency, but it increases the cost of manufacturing the plastic bags with gussets as three separate plastic films have been used. The machine also requires large floor space for installation and operation.
The present invention alleviates the abovementioned disadvantages and shortcomings of the machines and processes for manufacturing plastic pouches with three gussets.
The principal object of the machine and method in accordance with the present invention is to provide a simplified machine for manufacturing plastic pouches or bags having two side gussets and one bottom gusset. Since the source of the panel plastic film unlike in the prior art is common the problem of mismatch in design registration is efficiently solved. This also eliminates the need for having more than one accumulator in longitudinal direction. Also, the need for having a means and a method to unite at some point the differently fed top and bottom halves of the plastic film is eliminated.
Additionally, the method of transforming the ends of the side gusset pieces into rhomboid shaped ends as disclosed in the present invention eliminates the need of complicated machinery and thereby provides an efficient, accurate and simplified method for producing the said rhomboid shaped ends. This also eliminates complicated machinery found in the prior art.
Having fewer components reduces not only the cost of the machine, but also reduces the floor space occupied by the machine. This is another object of the present invention.
The present invention is flexible to make plastic pouches that are tall and wide. The prior art machines cannot handle tall plastic bags clue to inflexibility of the machine to handle wide panel plastic film.
As aforementioned, the machine and the method in accordance with the present invention use a panel plastic film from a single unwinding reel as opposed to the different sources for providing top and bottom panel films as in the prior art.
The panel plastic film is longitudinally folded into top and bottom halves and is transported in longitudinal or machine direction. A slitter slits the panel plastic film along the longitudinal fold to cut the film into to and bottom halves. The top and bottom halves simultaneously get transported ensuring that any design common to the top and bottom halves will always accurately match unlike the prior art machines where the top and bottom halves originate from separate sources and at some stage, using complicated machinery, are united. The machine in accordance with the present invention, because of this unique feature of providing the top and bottom halves from folding the panel plastic film unwound from a single unwinding reel, requires only a single accumulator. This significantly reduces the complexity of the machine and requires fewer parts than the machines disclosed in the prior art.
The slitting of the top and bottom halves by the slitter creates an initial gap between the top and bottom halves of the panel plastic film. The said gap is enlarged by a pair of timing belts positioned transversely such that the bottom portion of the top timing belt is substantially in contact with the top portion of the bottom timing belt. The said timing belts have teeth on the inside. The teeth of the timing belts mesh with the teeth on the sprockets on either side. The top half of the panel plastic film passes through the first timing belt such that the bottom surface of the top half of the panel plastic film is in contact with the top of the teeth on the lower portion of the top timing belt. Similarly, the bottom half of the panel plastic film passes through the bottom timing belt such that the top surface of the bottom half of the panel plastic film is in contact with the top of the teeth on the top portion of the bottom timing belt. Thus, the gap between the top and bottom halves of the panel plastic film will be substantially equal to the total of thicknesses of the top and bottom timing belts including the heights of the teeth on both the timing belts. The enlargement of the gap at this stage is required to allow insertion of the side gusset pieces between the top and bottom halves of the panel plastic film.
The machine in accordance with the present invention can have the feeding line for side gusset pieces that can be transversely positioned on either side of the machine depending on the requirements of the customer and space constraints. Side gusset film is unwound from an unwinding reel and is guided by a guide roller to be directed to an accumulator roller. The side gusset film exits a nip and gets folded by a folding device such that the folded portions are on the top and the total width of the top folded portions is substantially same as the width of the bottom portion of the side gusset film. A creasing device ensures that the front and rear folded edges maintain their crease. The side gusset film gets further transported in the transverse direction through an index nip and gets cut into side gusset pieces by a cutter. The rate of indexing depends on the positioning of the side gusset pieces between the top and bottom halves of the panel plastic film. In other words, the width of the plastic pouch will determine how far apart the side gusset pieces are positioned between the top and bottom halves of the panel plastic film which in turn determines the rate of indexation. Therefore, the wider the plastic pouch, the slower will be the rate of indexation and vice versa. The side gusset pieces get inserted between the top and bottom halves of the panel plastic film through the said enlarged gap.
A transverse heat sealer seals the side gusset pieces with the top and bottom halves of the panel plastic film. The seal is along the length of the side gusset pieces sealing the free edges of the top folded portions with the top half of the panel plastic film and the corresponding middle of the bottom portions of the side gusset piece with the bottom half of the panel plastic film.
The next stage is to give the ends of the side gusset pieces the shape of a rhomboid. The top half and the bottom half of the panel plastic film are pulled away from each other. This action opens the side gusset pieces in such a way that the cross-section of the space inside the side gusset pieces resembles a rhomboid like shape having a rounded corner on the front folded edge as well as on the rear folded edge of the side gusset piece ends. Using a roller, the said front rounded corner is pushed inwards near the vertical axis of the rhomboid shaped space and similarly, using another roller, the rounded rear corner is also pushed inwards to be near the said vertical axis. This action transforms the end of the side gusset pieces into rhomboid shaped ends that will now have a new front corner on the front folded edge and a new rear corner at the rear folded edge. Also, it will have a top corner at the seal and a bottom corner at the seal.
The pulling action of the top and bottom halves of the panel plastic film will result into a folded portion of the top half and similarly, a folded portion of the bottom half of the panel plastic film. The folded portions are relatively small in size compared to the remaining greater portions of the top and bottom halves and are generally perpendicular to the remaining greater portions of the top and bottom halves of the panel plastic film.
The edge of the folded portion of the top half will project beyond the top corner of the rhomboid shaped ends and likewise, the edge of the folded portion of the bottom half will project beyond the bottom corner of the rhomboid shaped ends. In other words, the combined height of the folded portions of the top half and the bottom half of the panel plastic film will be greater than the height of the rhomboid shaped ends.
Bottom gusset film unwinding from and unwinding reel is transported in transverse direction up to a point where a turn bar is provided which changes the direction as well as the orientation of the bottom gusset film which gets reoriented to be now transported in longitudinal direction such that the edges of the bottom gusset film remain horizontal, but in a plane perpendicular to the plane when it was being transported transversely. In this position, the bottom gusset film would be substantially parallel to the rhomboid shaped ends as well as the folded top and bottom portions of the panel plastic film. The bottom gusset film at this stage is substantially in contact with the full faces of the rhomboid shaped ends as also the folded top and bottom portions of the top and bottom halves of the panel plastic film.
The next stage is to vertically heat-seal the bottom gusset with the rhomboid shaped ends along the vertical axis of the rhomboid shaped ends of the side gusset pieces. The bottom gusset also gets sealed with the top and bottom folded portions of the top and bottom halves of the panel plastic film where the top and bottom folded portions respectively project above and below the top and bottom corners of the rhomboid shaped ends.
The top and bottom halves of panel plastic film together with side gusset pieces and the vertically sealed bottom gusset film with the rhomboid shaped ends as well as the folded portions of the top and bottom halves of panel plastic film get further transported in longitudinal direction. The bottom gusset film with the rhomboid shaped ends as well as the folded portions of the top and bottom halves of panel plastic film pass through an index nip.
The next step is to collapse the bottom gusset film with the rhomboid shaped ends as well as the folded portions of the top and bottom halves of panel plastic film such that the rhomboid shaped ends have the top corners substantially contacting the bottom corner resulting in a triangular top part and a triangular bottom part. At this stage, the top and bottom edges of the bottom gusset film also would be substantially in contact with each other as well as the edge of the top half and the edge of the bottom half also would be substantially in contact with each other. It can be seen that at this stage, the folded portions of the top and bottom halves of the panel plastic film get unfolded.
The so collapsed top and bottom halves of panel plastic film together with side gusset pieces and the bottom gusset film with the rhomboid shaped ends as well as the folded portions of the top and bottom halves of panel plastic film get further transported in longitudinal direction and are ready for final longitudinal and transverse sealing before getting cut into pouches.
A longitudinal heat sealer seals the top edge of the bottom gusset film with the edge of the top half of the panel plastic film and simultaneously, in a reciprocating action, the bottom edge of the bottom gusset film gets longitudinally sealed with the edge of the bottom half of the panel plastic film.
A transverse heat sealer seals the top edge of the side gusset pieces with the edge of the top half of the panel plastic film in a reciprocating action, the bottom edge of the side gusset pieces get sealed with the bottom half of panel plastic film.
The transverse sealing also seals the front collapsed edge of the bottom gusset film with the corresponding collapsed edge of the side gusset piece in the front. Similarly, the rear collapsed edge of the bottom gusset film gets sealed with the corresponding collapsed edge of the side gusset piece in the rear.
The next step is to cut along the transverse seal and more than one cut may be required to produce plastic pouches having two side gussets and one bottom gusset.
The machine in accordance with the present invention is designed and arranged to efficiently make plastic bags or pouches, each of which includes two side gussets and a bottom gusset.
Plastic bags and pouches come in a wide variety. Most plastic bags will have something printed on them. The printing may include words or artwork. Many times, the artwork on the front and the back sides of the plastic bags or pouches will be identical and symmetrical. Such plastic bags or pouches may be transparent, translucent, or opaque. In any case, whether the plastic bags or pouches are transparent, translucent, or opaque, the artwork on both the sides must match. This poses a technical problem which most manufacturers struggle to solve. Complicated and expensive machineries have been invented and developed. Some have even been patented as described hereinabove. Such matching of the artwork or design or print registration in the machine in accordance with the present invention is achieved accurately and in a simplified manner. Also, the insertion and placement of the side gussets between the top and bottom panel plastic films or front and back as the case may be, is achieved in a simplified manner utilizing fewer machine components.
The principles of operation of the machine in accordance with the present invention and the method of using the machine to produce plastic pouches with two side gussets and a bottom gusset will be described hereinbelow with reference to the accompanying drawings.
The machine in accordance with the present invention includes several parts. In the description of the machine in accordance with the present invention, the machine direction is referred to as the longitudinal direction as the transformation of the panel plastic film or the mother film into final products such as plastic bags or pouches occurs in this direction. The panel plastic film or mother film will have to be fed into the machine. In the machine in accordance with the present invention, this is done using an unwinding means and a folding means positioned such that the feeding of the panel plastic film or mother film occurs in a direction transverse to the longitudinal or machine direction. This feeding line is positioned to be on a side that is opposite to the side where such feeding lines for side gussets and bottom gusset film are located in the machine in accordance with the present invention. Location of such feeding lines could be altered to suit the floor space available and according to the choice of the plastic bag or pouch manufacturer.
Thus,
The panel plastic film 10, if it is having identical or symmetric design or artwork on the top and bottom halves or the front and back sides, the design or artwork will be accurately matched or registered here itself with the folding into two equal halves.
The folded panel plastic film 10, now having the top half 30 and bottom half 40, is transported using guide rollers 23 in longitudinal direction 50 to a single accumulator 70 through a capstan nip 60. Since the machine in accordance with the present invention uses a single source for the top and bottom halves 30 and 40 respectively of the panel plastic film 10, it uses only a single accumulator 70 in the longitudinal direction 50. Thus, the machine in accordance with the present invention provides for accurate design registration using fewer components and a simplified method as will be explained hereinbelow.
The folded panel plastic film 10 into top and bottom halves 30 and 40 respectively is further transported in longitudinal direction 50 through an index nip 80. Film slitter 90 slits along the fold the folded panel plastic film 10 into top and bottom halves 30 and 40 respectively. The slitter also creates an initial gap between the top half 30 and bottom half 40.
In order to enlarge the initial gap created by the film slitter 90 between the top half 30 and bottom half 40 of the panel plastic film 10 top and bottom timing belts (not shown) are used that are positioned transversely on the machine such that the top half 30 and bottom half 40 of the panel plastic film 10 contact the teeth of the timing belts. The teeth of the timing belts mesh with the teeth on the sprockets on either ends. The relative positioning of the top and bottom timing belts is such that the outer toothless surfaces thereof are contacting each other substantially the entire length and width of the belts. In other words, the bottom part of the top timing belt is substantially fully in contact with the top part of the bottom timing belt. The top half 30 of the panel plastic film 10 is in contact with the teeth of the top timing belt on the bottom part and the bottom half 40 of the panel plastic film 10 is in contact with the teeth of the bottom timing belt on the top part. Thus, the gap between the top half 30 and bottom half 40 of the panel plastic film 10 will be substantially same as the thicknesses of the bottom part of the top timing belt and the top part of the bottom timing belt including the heights of the teeth thereon.
Now, the side gusset pieces 95 at the stage when the gap between the top half 30 and bottom half 40 is enlarged, is ready to be placed between the said top half 30 and bottom half 40 of the panel plastic film 10. Transfer assembly 400 further transports side gusset pieces 95 for placement of the side gusset pieces 95 between top half 30 and bottom half 40 of the panel plastic film 10. The length of the side gusset pieces 95 is generally less than the width of the top half 30 or bottom half 40. The length of the side gusset piece 95 is such that the leading end of the side gusset pieces reach the far edge of the top half 30 and bottom half 40; however, the trailing end remains inside the edge of the top half 30 and bottom half 40. The indexing of the side gusset pieces 95 is timed in accordance with the width of plastic pouch 260. For example, for a wider plastic pouch 260, the indexing of side gusset pieces 95 would be done at a slower rate so that the side gusset pieces 95 are placed between top half 30 and bottom half 40 further apart from each other. Similarly, for a narrower plastic pouch 260, the indexing of the side gusset pieces 95 will be done at a faster rate so that when the side gusset pieces 95 are placed between top half 30 and bottom half 40, the distance between them will be smaller.
As described hereinabove, the length of side gusset pieces 95 can be same as the width of top half 30 and bottom half 40; however, the length is so chosen that it is generally shorter than the width of top half 30 or bottom half 40 leaving a small portion of the top half 30 and bottom half 40 that will not be in contact with side gusset pieces 95. This small portion without such contact would be generally on the side where the side gusset pieces 95 are transversely transported from.
The folded side gusset film 330 gets cut into side gusset pieces 95. The free edges of the top folded portions 335 and 336 will not be in contact with each other and there will be a longitudinal gap 333 between the said edges. The side gusset pieces 95 will be transported in transverse direction 290 and later on will be transported in the longitudinal direction 50 together with the top and bottom halves 30 and 40 respectively. The thin and flat space at the end of the side gusset piece 95 defined by the bottom edge 334, the edge 335a of the top front folded portion 335, and the edge 336a of the top rear folded portion 336 subsequently takes the shape similar to a rhomboid in which the front corner 96 and rear corner 98 will become part of a somewhat generous radius as described hereinafter. The front fold 331 is formed between the top front folded portion 335 and the bottom portion of the side gusset piece 95. Similarly, the rear fold 332 is formed between the top rear folded portion 336 and the bottom portion of the side gusset piece 95.
Now referring to
At this stage, a pair of rollers (not shown) are brought in contact with the end of side gusset piece 95 such that contact of front corner 96 with the roller pushes the said front corner 96 rearwards and similarly, contact of rear corner 98 pushes the said rear corner 98 forward. Thus, the rollers push the said front corner 97 and rear corner 98 inwards into the rhomboid shaped cross sectional gap of the side gusset piece 95 so as to form another rhomboid shape of the end of the side gusset piece 95 with parts of the end of the side gusset piece 95 folded in the manner described. Now referring to
As can be seen, longitudinal dotted line 415 divides into substantially equal top and bottom halves the rhomboid shaped end 410. Since the side gusset pieces 95 shown in the said figure are shorter in length than the width of top half 30 and bottom half 40, slight portion 35 of the top half 30 will be there between the top corners 97 and 98 and the edge of to half 30 and likewise, slight portion 45 of the bottom half 40 will be there between the bottom corner 105 and the edge of the bottom half 40.
As the top half 30 and bottom half 40 together with side gusset pieces 95 are further transported in longitudinal direction 50, the folded portions 36 and 46 of the top half 30 and bottom half 40, together with the rhomboid shaped ends 410 and the bottom gusset film 430 are also transported in the longitudinal direction 50; however, the folded portions 36 and 46 of the top half 30 and bottom half 40, together with the rhomboid shaped ends 410 and the bottom gusset film 430 pass through a pair of vertical guide rollers 510. A vertical heat sealer 530 vertically seals along the vertical axis 416 of the rhomboid 410 extending the seal in upward direction beyond the top corners 97 and 99 to the top edges of the bottom gusset film 430 and folded portion 36 of the top half 30 and in downward direction beyond the bottom corner 105 to the bottom edges of the bottom gusset film 430 and folded portion 46 of the bottom half 40. Thus, vertical seal 540 seals the bottom gusset film 430 with the rhomboid shaped ends 410 of the side gusset pieces 95 and also respectively the folded portions 36 and 46 of the top half 30 and bottom half 40.
After the vertical seal 540, the top half 30 and bottom half 40 together with side gusset pieces 95 are further transported in longitudinal direction 50, the folded portions 36 and 46 of the top half 30 and bottom half 40, together with the rhomboid shaped ends 410 and the bottom gusset film 430 are also transported in the longitudinal direction 50; however, the folded portions 36 and 46 of the top half 30 and bottom half 40, together with the rhomboid shaped ends 410 and the bottom gusset film 430 pass through another pair of vertical guide rollers 540.
The vertically sealed bottom gusset film 430 as described hereinabove is then collapsed along longitudinal dotted line 415 such that the location of the top corners 97 and 99 and that of the bottom corner 105 of the rhomboid shaped end 410 would be substantially same. In other words, viewing from the top, after the said step of collapsing, the ends of the sick gusset pieces 95 would be of triangular shape 560. As can be understood, there will be a top triangular shape 560 and a similar bottom triangular shape 560 substantially overlying each other. The base of the triangular shape 560 would fall along, the longitudinal dotted line 415.
The top and bottom halves 30 and 40 of the panel plastic film 10 with the side gussets 95 and the bottom gusset film 430 sealed as aforementioned, get transported further in longitudinal direction 50 through a pair of rollers 570.
A longitudinal heat sealer 140 seals the top edge of the bottom gusset film 430 together with the edge of the top half 30 and the bottom edge of the bottom gusset film 430 with the edge of the bottom half 40 as shown in
Next step is to cut using cutter 200 along the transverse seal 250. Such cutting may be required more than one time. After such cut, plastic pouch 260 is produced.
The machine in accordance with the present invention has been described in detail hereinabove; however, the best mode of performing the present invention is to have the feeding line for the panel plastic film on one side of the machine and to have the feeding lines for the side gusset and bottom gusset on the other side of the machine. The machine in accordance with the present invention will use only one accumulator in the longitudinal direction to reduce the number of parts and also to make the foot-print of the machine as small as possible.
In the best mode of performing the present invention, heat sealers are used which permit the sealing of the side gusset pieces 95 with the panel plastic film 10 and the sealing of the bottom gusset film 430 with the panel plastic film 10 as well as the side gusset pieces 95, the reason being the choice of the material for the side gusset film. Due to the material chosen for the side gusset film 280, due to heat, the side gusset film 280 will not have a tendency to stick to some portions of itself. Likewise, the material chosen for the bottom gusset film 430 is also such that it will not have a tendency to stick with portions of itself under heat.
As aforementioned, the machine and the method in accordance with the present invention use a panel plastic film 10 from a single unwinding reel 15 as opposed to the different sources for providing top half 30 and bottom half 40 of the panel plastic film 10.
The panel plastic film 10 unwinding from the said unwinding reel 15 is longitudinally folded into top and bottom halves 10 and 40 respectively and is transported using a nip 23 in longitudinal or machine direction 50. A slitter 90 slits the panel plastic film 10 along the longitudinal fold to cut the film into top and bottom halves 30 and 40 respectively. The top and bottom halves 30 and 40 respectively simultaneously get transported ensuring that any design common to the top and bottom halves 30 and 40 respectively will always accurately match. The machine in accordance with the present invention, because of this unique feature of providing the top and bottom halves 30 and 40 respectively from folding the panel plastic film 10 unwound from a single unwinding reel 15, requires only a single accumulator roller 70.
The slitting of the top and bottom halves 30 and 40 respectively by the slitter 90 creates an initial gap between the top and bottom halves 30 and 40 respectively of the panel plastic film 10. The said gap is enlarged by a top timing belt and a bottom timing belt that are part of transfer assembly 400 positioned transversely such that the bottom portion of the top timing belt is substantially in contact with the top portion of the bottom timing belt. The said timing belts have teeth on the inside. The teeth of the timing belts mesh with the teeth on the sprockets on either side. The top half 30 of the panel plastic film 10 passes through the first timing belt such that the bottom surface of the top half 30 of the panel plastic film 10 is in contact with the top of the teeth on the lower portion of the top timing belt. Similarly, the bottom half 40 of the panel plastic film 10 passes through the bottom timing belt such that the top surface of the bottom half 40 of the panel plastic film 10 is in contact with the top of the teeth on the top portion of the bottom timing belt. Thus, the gap between the top and bottom halves 30 and 40 respectively of the panel plastic film 10 will be substantially equal to the total of the thicknesses of the top and bottom timing belts including the heights of the teeth on both the timing belts. The enlargement of the gap at this stage is required to allow insertion of the side gusset pieces 95 between the top and bottom halves 30 and 40 respectively of the panel plastic film 10.
Side gusset film 280 is unwound from an unwinding reel 270 and is guided by a nip 285 to be directed to an accumulator roller 300. The side gusset film 280 exits a nip 310 and gets folded by a folding device 320 such that the folded portions are on the top and the total width of the top folded portions 335 and 336 is substantially same as the width of the bottom portion of the side gusset film 280. The side gusset film 280 is further transported in transverse direction 290 and a creasing device 340 ensures that the front and rear folded edges 331 and 332 respectively maintain their crease. The side gusset film 280 exiting the creasing device 340 is directed by a pair of guide rollers 345 to another accumulator roller 350. The side gusset film 280 is further transported in transverse direction 290 going around a tail feed 360. There is provided a print mark sensor 370 which senses print or design registration of the side gusset film 280. The side gusset film 280 gets further transported in the transverse direction 290 through an index nip 380 and gets cut into side gusset pieces 95 by a cutter 390. The rate of indexing depends on the positioning of the side gusset pieces 95 between the top and bottom halves 30 and 40 respectively of the panel plastic film 10. In other words, the width of the plastic pouch 260 will determine how far apart the side gusset pieces 95 are positioned between the top and bottom halves 30 and 40 respectively of the panel plastic film 10 which in turn determines the rate of indexation. Therefore, the wider the plastic pouch 260, the slower will be the rate of indexation and vice versa. The length of the side gusset pieces 95 will not be more than the width of the top and bottom halves 30 and 40 respectively of the panel plastic film 10 and generally, the length will be shorter than the width of the top and bottom halves 30 and 40 respectively of the panel plastic film 10. The side gusset pieces get inserted between the top and bottom halves 30 and 40 respectively of the panel plastic film 10 through the said enlarged gap.
A transverse heat sealer 100 seals the side gusset pieces 95 with the top and bottom halves 30 and 40 respectively of the panel plastic film 10. The seal is along the length of the side gusset pieces 95 sealing the free edges of the top folded portions 335 and 336 respectively with the top half 30 of the panel plastic film 10 and the corresponding middle of the bottom portion of the side gusset piece 95 with the bottom half 40 of the panel plastic film 10.
The next stage is to give the ends of the side gusset pieces 95 the shape of a rhomboid. The top half and the bottom half 30 and 40 respectively of the panel plastic film 10 are pulled away from each other. This action opens the side gusset pieces 95 in such a way that the cross-section of the space inside the side gusset pieces resembles a rhomboid like shape having a rounded corner 96 on the front folded edge 331 as well as a rounded corner 98 on the rear folded edge 332 of the side gusset piece ends. Using a roller (not shown), the said front rounded corner 96 is pushed inwards near the vertical axis 416 of the rhomboid shaped space and similarly, using another roller (not shown), the rounded rear corner 98 is also pushed inwards to be near the said vertical axis 416. This action transforms the end of the side gusset pieces 95 into rhomboid shaped ends 410 that will now have a new front corner 96a on the front folded edge 331 and a new rear corner 98a at the rear folded edge 332. Also, it will have top corners 97 and 99 at the seal 405 and a bottom corner 105 at the seal 405.
The pulling action of the top and bottom halves 30 and 40 respectively of the panel plastic film 10 will result into a folded portion 36 of the top half 30 and similarly, a folded portion 46 of the bottom half 40 of the panel plastic film 10. The folded portions 36 and 46 are relatively small in size compared to the remaining greater portions of the top and bottom halves 30 and 40 respectively and are generally perpendicular to the remaining greater portions of the top and bottom halves 30 and 40 respectively of the panel plastic film 10.
The edge of the folded portion 36 of the top half 30 will project beyond the top corners 97 and 99 of the rhomboid shaped ends 410 and likewise, the edge of the folded portion 46 of the bottom half 40 will project beyond the bottom corner 105 of the rhomboid shaped ends 410. In other words, the combined height of the folded portions 36 and 46 respectively of the top half 30 and the bottom half 40 of the panel plastic film 10 will be greater than the height of the rhomboid shaped ends 410.
Bottom gusset film 430 unwinding from and unwinding reel 420 is transported in transverse direction 435 and is directed to go around an accumulator roller 450 using a nip 440 positioned before and a nip 460 after the said accumulator roller 450. The bottom gusset film 430 is further transported in the transverse direction 435 using two separate guide rollers 470 and 480. There is provided a turn bar 500 which changes the direction as well as the orientation of the bottom gusset film 430 which gets reoriented to be now transported in longitudinal direction 50 such that the edges of the bottom gusset film 430 remain horizontal, but in a plane perpendicular to the plane when it was being transported transversely. In this position, the bottom gusset film 430 would be substantially parallel to the rhomboid shaped ends as well as the folded top and bottom portions 36 and 46 respectively of the panel plastic film 10. The bottom gusset film 430 at this stage is substantially in contact with the full faces of the rhomboid shaped ends 410 as also the folded top and bottom portions 36 and 46 respectively of the top and bottom halves 30 and 40 respectively of the panel plastic film 10.
The next stage is to vertically heat-seal the bottom gusset film 430 with the rhomboid shaped ends 410 along the vertical axis 416 of the rhomboid shaped ends 410 of the side gusset pieces 95. The bottom gusset film 430 also gets sealed with the top and bottom folded portions 36 and 46 respectively of the top and bottom halves 30 and 40 respectively of the panel plastic film 10 where the top and bottom folded portions 36 and 46 respectively project above and below the top corners 97 and 99 and the bottom corner 105 of the rhomboid shaped ends 410.
The top and bottom halves 30 and 40 respectively of panel plastic film 10 together with side gusset pieces 95 and the vertically sealed bottom gusset film 430 with the rhomboid shaped ends 410 as well as the folded portions 36 and 46 of the top and bottom halves 30 and 40 respectively of panel plastic film 10 get further transported in longitudinal direction 50. The bottom gusset film 430 with the rhomboid shaped ends 410 as well as the folded portions 36 and 46 respectively of the top and bottom halves 30 and 40 respectively of panel plastic film 10 pass through an index nip 550.
The next step is to collapse the bottom gusset film 430 with the rhomboid shaped ends 410 as well as the folded portions 36 and 46 respectively of the top and bottom halves 30 and 40 respectively of panel plastic film 10 such that the rhomboid shaped ends 410 have the top corners 97 and 99 substantially contacting the bottom corner 105 resulting in a triangular top part and a triangular bottom part. At this stage, the top and bottom edges of the bottom gusset film 430 also would be substantially in contact with each other as well as the edge of the top portion 36 and the edge of the bottom portion 46 also would be substantially in contact with each other. It can be seen that at this stage, the folded portions 36 and 46 respectively of the top and bottom halves 30 and 40 respectively of the panel plastic film 10 get unfolded.
The so collapsed top and bottom halves 36 and 46 respectively of the panel plastic film 10 together with side gusset pieces 95 and the bottom gusset film 430 with the rhomboid shaped ends 410 as well as the folded portions 36 and 46 respectively of the top and bottom halves 30 and 40 respectively of panel plastic film 10 get further transported in longitudinal direction 50 and are ready for final longitudinal and transverse sealing before getting cut into pouches 260.
A longitudinal heat sealer 140 seals the top edge of the bottom gusset film 430 with the edge of the top half 30 of the panel plastic film 10 and simultaneously, in a reciprocating action, the bottom edge of the bottom gusset film 430 gets longitudinally sealed with the edge of the bottom half 40 of the panel plastic film 10.
A transverse heat sealer 160 seals the top edge of the side gusset pieces 95 with the edge of the top half 30 of the panel plastic film 10 in a reciprocating action, the bottom edge of the side gusset pieces 95 get sealed with the bottom half 40 of panel plastic film 10.
The transverse sealing also seals the front collapsed edge of the bottom gusset film 430 with the corresponding collapsed edge of the side gusset piece 95 in the front. Similarly, the rear collapsed edge of the bottom gusset film 430 gets sealed with the corresponding collapsed edge of the side gusset piece 95 in the rear.
The next step is to cut along the transverse seal 250 and more than one cut may be required to produce plastic pouches 260 having two side gussets and one bottom gusset.
The principle of operation of the machine in accordance with the present invention as also the invented method of producing plastic pouches with two side gussets and one bottom gusset has been described in detail hereinabove can be applied with some variations in the machine which contains numerous components and the method which involves several steps.
As a person skilled in the art will readily understand from the detailed description of the present invention, merely because some changes may be made to the machine or to the method disclosed hereinabove without departing from the spirit and scope of the present invention, so modified machine or method should not be construed to fall outside the scope of the present invention as disclosed and claimed herein. All matters disclosed hereinabove or as shown in the accompanying drawings ought to be interpreted as illustrative and not in a limiting sense.
The following claims are intended to cover all of the generic and specific features of the present invention described hereinabove and all the statements of scope of the present invention regardless of the grammatical or linguistic variations might be said to fall therebetween.
| Number | Date | Country | Kind |
|---|---|---|---|
| 3018/MUM/2013 | Sep 2013 | IN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IN2014/000449 | 7/4/2014 | WO | 00 |
