초록
▼
An automatic packaging apparatus is provided, having a conveyor, a continuous longitudinally folded web, and cutting and sealing mechanisms for forming flexible pouches from the web. Each flexible pouch has an open end and an overlap portion specifically suitable for operation with the apparatus of this invention. The open end is separated and a load is inserted into one of the flexible pouches. After the load is inserted, air is withdrawn and a gas is preferably injected into the flexible pouch by a plurality of flat-profile snorkels, or a single, wider...
An automatic packaging apparatus is provided, having a conveyor, a continuous longitudinally folded web, and cutting and sealing mechanisms for forming flexible pouches from the web. Each flexible pouch has an open end and an overlap portion specifically suitable for operation with the apparatus of this invention. The open end is separated and a load is inserted into one of the flexible pouches. After the load is inserted, air is withdrawn and a gas is preferably injected into the flexible pouch by a plurality of flat-profile snorkels, or a single, wider snorkel. The flexible pouch is then heat sealed to form a gas-tight seal. Controls, preferably including a servo mechanism, are used to simultaneously operate the cutting, sealing, fluid transfer and product infeed stations of the automatic packaging apparatus. As the flexible pouch moves from the fluid transfer station to the sealing station, the gas-tight seal is maintained.
대표
청구항
▼
1. A modified-atmosphere packaging apparatus comprising: an in-line bag making section including a side-sealing tool for periodically forming transverse side seals across a two-ply web of film having a distal closed longitudinal edge and a proximal open longitudinal edge, the transverse side seals having a distal end at the closed longitudinal edge and a proximal end proximate to the open longitudinal edge, to form a chain of bags in which each side edge of each bag is defined by one of the side seals, a distal edge of each bag comprises part of the clos...
1. A modified-atmosphere packaging apparatus comprising: an in-line bag making section including a side-sealing tool for periodically forming transverse side seals across a two-ply web of film having a distal closed longitudinal edge and a proximal open longitudinal edge, the transverse side seals having a distal end at the closed longitudinal edge and a proximal end proximate to the open longitudinal edge, to form a chain of bags in which each side edge of each bag is defined by one of the side seals, a distal edge of each bag comprises part of the closed longitudinal edge of the web, and an opening of each bag comprises part of the proximal longitudinal strip of the web, and to define a proximal longitudinal strip comprising the portion of the web extending between the open longitudinal edge and the proximal ends of the transverse side seals;a side-cutting tool for forming transverse cuts between the side seals defining the adjacent edges of each adjacent pair of bags, each transverse cut extending from the closed longitudinal edge to a proximal end of the transverse cut located approximately between the proximal ends of the corresponding side seals;a pair of longitudinally oriented, endless, opposed belts configured to grip at least a portion of the proximal longitudinal strip of the web between the opposed belts, to advance the proximal longitudinal strip of the web longitudinally, and to guide the plies of the proximal longitudinal strip around a spreader bracket at a product infeed station, the spreader bracket configured to expand to spread apart the plies of the proximal longitudinal strip at the opening of each bag to form an open mouth;a web conveyor configured to at least substantially support a portion of the web extending from the opposed belts to the closed longitudinal edge in a generally horizontal orientation and to advance said portion of the web longitudinally as the opposed belts advance the proximal longitudinal strip of the web longitudinally;a product infeed boom adapted to insert a load of product through the open mouth of each bag at the product infeed station and to discharge the inserted load of product inside each bag;a fluid transfer station including a snorkel having a fluid flow passage and adapted to be inserted between the opposed belts and into the opening of each bag, a vacuum source adapted to remove fluid from each bag through the snorkel passage, and a fluid source adapted to refill each bag with a replacement fluid through the snorkel passage;a proximal sealing station comprising a proximal sealing tool adapted to form a proximal seal on each bag, the proximal seal overlapping the side seals to form a sealed pouch containing the replacement fluid and a load of product; anda pre-perforation knife adapted to form a diagonal perforation across the proximal longitudinal strip, the diagonal perforation positioned to meet each transverse cut near the proximal end of the transverse cut and to extend at least from the open longitudinal edge of the web to the transverse cut, before the portion of the proximal longitudinal strip to be perforated is fed between the opposed belts. 2. The apparatus of claim 1, further comprising bearings configured for mounting the web in a roll for rotational movement of the roll relative to the apparatus, the bearings positioned for feeding the web from the roll onto the web conveyor and the proximal longitudinal strip of the web between the opposed belts; andan unwind motor configured to rotate the roll in an unwinding direction as the web conveyor advances the web. 3. The apparatus of claim 1, the vacuum source comprising a pump and a vacuum reservoir disposed between and in communication with the pump and the snorkel and configured to provide at least substantially instantaneous vacuum pressure to each bag when the snorkel is in communication with the bag. 4. The apparatus of claim 1, the vacuum source being adapted to remove air and the fluid source being adapted to refill each bag with a gaseous composition. 5. The apparatus of claim 1, the pre-perforation knife comprising a row of evenly spaced-apart, aligned cutting teeth, each cutting tooth including a pair of opposed angled tooth edges, the angled tooth edges meeting to define a cutting point at first ends of the angled tooth edges, and a pair of opposed vertical tooth edges extending from second ends of the angled tooth edges in a direction away from said cutting point, the vertical tooth edges of each tooth being substantially parallel and spaced apart a first predetermined distance to define a perforation cut length, and the neighboring vertical tooth edges of adjacent teeth being substantially parallel and spaced apart a second predetermined distance to define a perforation cut gap distance, the pre-perforation knife being adapted to form a perforation in a film comprising a plurality of aligned cuts of the perforation cut length separated from one another by the perforation cut gap distance when the pre-perforation knife penetrates the film to a depth within a range of depths corresponding to the vertical extent of the vertical tooth edges. 6. The apparatus of claim 1, further comprising a second pair of longitudinally oriented, endless, opposed belts adapted to grip a portion of the web located below the proximal ends of the side seals after the portion of the web advances past the spreader bracket, the second opposed belts adapted to maintain an at least substantially gas-tight seal in each bag as the bag is advanced from the fluid transfer station to the proximal sealing station and at least until the bag is sealed to form the sealed pouch, the proximal sealing tool adapted to form the proximal seal on an exposed portion of the bag adjacent to the proximal side of the second opposed belts. 7. The apparatus of claim 1, further comprising a center seal assembly including a base and a center-sealing head, the base comprising a resilient sealing foot pad , such that when the center-sealing head is pressed onto each bag, a continuous, generally longitudinal center seal is formed, overlapping the side seals that define the side edges of the bag, the center seal located between the closed longitudinal edge and the proximal ends of the side seals. 8. The apparatus of claim 7, the center seal assembly base further comprising a longitudinal guide member attached to the foot pad and to a stationary part of the apparatus proximate to an infeed end of the web conveyor, the guide member adapted to hold the foot pad in a stationary position and to guide the web over the foot pad as the web is advanced. 9. The apparatus of claim 1, further comprising a control system for inserting the load of product into each bag, the control system including a photo eye and a timer,the photo eye adapted to detect an obstruction of a photo beam when a front end of a load of product being inserted by the product infeed boom traverses the photo beam, to detect a subsequent removal of the obstruction when a tail end of the load passes beyond the photo beam, and when the subsequent removal of the obstruction is detected, to signal a timer to begin counting down a predetermined amount of time required for the product infeed boom to advance the tail end of the product from the location of the photo beam to the opening of the bag, andthe timer adapted to signal the control system after the lapse of the predetermined amount of time to stop the advance of the product infeed boom and to discharge the load of product into the bag. 10. The apparatus of claim 1, the product infeed boom being adapted to advance a predetermined distance so that, when a first load of product is at a predetermined location on the product infeed boom, the first load is inserted into one of the bags at a predetermined location within the bag. 11. The apparatus of claim 10, further comprising an endless boom conveyor belt mounted to the product infeed boom for supporting the first load on the product infeed boom and advancing the first load relative to the product infeed boom,the boom conveyor belt configured to advance the product a predetermined distance relative to the product infeed boom as the product infeed boom is retracted from the bag to discharge the first load from the boom at the predetermined location within the bag. 12. The apparatus of claim 11, the boom conveyor belt configured to support and advance a second load of product said predetermined distance relative to the product infeed boom, to move the second load from an initial location on the product infeed boom to the predetermined location on the product infeed boom, while simultaneously discharging said first load from the product infeed boom at the predetermined location within the bag. 13. The apparatus of claim 1, further comprising a raising and lowering mechanism configured to adjust the vertical position of a bag located at the fluid transfer station relative to the snorkel. 14. The apparatus of claim 1, said snorkels comprising a plurality of openings in communication with said snorkel passage to permit fluid flow into and out of said bag along a plurality of alternate flow pathways corresponding to the plurality of openings. 15. The apparatus of claim 1, further comprising an output conveyor disposed in line with the web conveyor at a downstream end of the web conveyor, the output conveyor configured to receive a sealed pouch conveyed onto a belt of the output conveyor by the web conveyor and to convey the sealed pouch in a downstream direction while the web conveyor is stationary, to cause the sealed pouch to separate from the web by tearing the proximal longitudinal strip along the diagonal perforation. 16. A method of packaging a load of product in a sealed pouch comprising: providing a two-ply web of film having a closed longitudinal edge and an open longitudinal edge;feeding the web past a side-sealing tool for periodically forming transverse side seals across the web;using the side-sealing tool to periodically form transverse side seals on the web having a distal end at the closed longitudinal edge and a proximal end proximate to the open longitudinal edge, to form a chain of bags in which each side edge of each bag is defined by one of the side seals, a distal edge of each bag comprises part of the closed longitudinal edge of the web, and an opening of each bag comprises part of the proximal longitudinal strip of the web, and to define a proximal longitudinal strip comprising the portion of the web extending between the open longitudinal edge and the proximal ends of the transverse side seals;providing a side-cutting tool for forming transverse cuts in the web;using the side-cutting tool to periodically form transverse cuts between each adjacent pair of bags, the transverse cuts being at least substantially coextensive with the transverse side seals;providing a pair of longitudinally oriented, endless, opposed belts configured to grip at least a portion of the proximal longitudinal strip of the web between the opposed belts and to advance the proximal longitudinal strip longitudinally;providing a web conveyor configured to at least substantially support a portion of the web extending from the opposed belts to the closed longitudinal edge in a generally horizontal orientation and to advance said portion of the web longitudinally as the opposed belts advance the proximal longitudinal strip of the web longitudinally;providing a product infeed station comprising a spreader bracket;advancing the opposed belts to guide the plies of the proximal longitudinal strip over the spreader bracket at the product infeed station;expanding the spreader bracket to form an open mouth at the opening of a bag located at the product infeed station;providing a product infeed boom adapted to support a load of product for insertion into the bag;positioning a load of product on the product infeed boom;inserting the product infeed boom through the open mouth of the bag to insert the load of product into the bag;discharging the inserted load of product from the product infeed boom to a location inside the bag;providing a fluid transfer station including a snorkel having a fluid flow passage adapted to be selectively in communication with a vacuum source and a fluid source;advancing the opposed belts and the web conveyor to position the bag containing the inserted load of product at the fluid transfer station;inserting the snorkel between the opposed belts and into the opening of the bag;operating the vacuum source to remove fluid from the bag through the snorkel passage;operating the fluid source to refill the bag with a replacement fluid through the snorkel passage;providing a proximal sealing station comprising a proximal sealing tool adapted to form a proximal seal on each bag;advancing the opposed belts and the web conveyor to position the bag containing the inserted load of product and the replacement fluid at the proximal sealing station;operating the proximal sealing tool to form a proximal seal overlapping the side seals to form a sealed pouch containing the replacement fluid and a load of product;providing a pre-perforation knife adapted to form a perforation in the web; andoperating the pre-perforation knife to form a diagonal perforation across the proximal longitudinal strip, the diagonal perforation positioned to meet each transverse cut near the proximal end of the transverse cut and to extend at least from the open longitudinal edge of the web to the transverse cut, before the portion of the proximal longitudinal strip to be perforated is fed between the opposed belts. 17. The method of claim 16, further comprising providing bearings for mounting the web in a roll for rotational movement of the roll relative to the apparatus;mounting the web in a roll on the bearings;feeding the web from the roll onto the web conveyor and the proximal longitudinal strip of the web between the opposed belts;providing an unwind motor configured to rotate the roll in an unwinding direction; andoperating the unwind motor to rotate the roll in the unwinding direction and simultaneously operating the web conveyor and the opposed belts to advance the web. 18. The method of claim 16, further comprising providing a pump and a vacuum reservoir comprised in the vacuum source, the vacuum reservoir disposed between and in communication with the pump and the snorkel, andoperating the vacuum source to provide at least substantially instantaneous vacuum pressure to a bag when the snorkel is inserted in the bag. 19. The method of claim 16, further comprising operating the vacuum source to remove air from a bag and the fluid source to refill the bag with a gaseous composition. 20. The method of claim 16, further comprising providing a second pair of longitudinally oriented, endless, opposed belts adapted to grip a portion of the web located below the proximal ends of the side seals after the portion of the web advances past the spreader bracket;feeding the portion of the web between the second opposed belts to maintain an at least substantially gas-tight seal in each bag as the bag is advanced from the fluid transfer station to the proximal sealing station and at least until the bag is sealed to form the sealed pouch; andoperating the proximal sealing tool to form the proximal seal on an exposed portion of the bag above the second opposed belts. 21. The method of claim 16, further comprising providing a center seal assembly including a base and a center-sealing head, the base comprising a resilient sealing foot pad adapted to provide a surface against which the center-sealing head may be pressed onto each bag to form a seal;and operating the center seal assembly to form a center seal on a bag, the center seal overlapping the side seals that define the side edges of the bag and located between the closed longitudinal edge and the proximal ends of the side seals that define the side edges of the bag. 22. The method of claim 21, further comprising providing a longitudinal guide member comprised in the center seal assembly, the longitudinal guide member attached to the foot pad and to a stationary part of the apparatus proximate to an infeed end of the web conveyor; andfeeding the web over the guide member to guide the web over the foot pad as the web is advanced. 23. The method of claim 16, further comprising providing a control system for inserting the load of product into each bag, the control system including a photo eye and a timer;operating the photo eye to detect an obstruction of a photo beam when a front end of a load of product being inserted by the product infeed boom traverses the photo beam, to detect a subsequent removal of the obstruction when a tail end of the load passes beyond the photo beam, and when the subsequent removal of the obstruction is detected, signaling a timer to begin counting down a predetermined amount of time required for the product infeed boom to advance the tail end of the product from the location of the photo beam to the opening of the bag, andsignaling the control system after the lapse of the predetermined amount of time to stop the advance of the product infeed boom and to discharge the load of product into the bag. 24. The method of claim 16, further comprising positioning a first load of product at a predetermined location on the product infeed boom;advancing the product infeed boom a predetermined distance to insert the first load into one of the bags at a predetermined location within the bag. 25. The method of claim 24, further comprising providing an endless boom conveyor belt mounted to the product infeed boom for supporting the first load on the product infeed boom and advancing the first load relative to the product infeed boom; andoperating the boom conveyor belt to advance the product a predetermined distance relative to the product infeed boom as the product infeed boom is retracted from the bag to discharge the first load from the boom at the predetermined location within the bag. 26. The method of claim 25, further comprising operating the boom conveyor belt to support and advance a second load of product said predetermined distance relative to the product infeed boom, to move the second load from an initial location on the product infeed boom to the predetermined location on the product infeed boom, while simultaneously discharging said first load from the product infeed boom at the predetermined location within the bag. 27. The method of claim 16, further comprising providing a raising and lowering mechanism configured to adjust the vertical position of a bag located at the fluid transfer station relative to the snorkel, the bag containing a product load, the product load and bag being relatively positioned to define a fluid flow channel;advancing the web conveyor and the opposed belts to advance a bag to the fluid transfer station; andoperating the raising and lowering mechanism to adjust the vertical position of a bag located at the fluid transfer station to align the fluid flow channel with an opening in the snorkel in communication with the snorkel passage. 28. The method of claim 16, further comprising providing an output conveyor disposed in line with the web conveyor at a downstream end of the web conveyor, conveying a sealed pouch onto a belt of the output conveyor by simultaneously advancing the web conveyor and the output conveyor, and subsequently advancing the output conveyor while keeping the web conveyor stationary to generate a friction force between the output conveyor belt and the sealed pouch, the friction force causing the sealed pouch to separate from the web by tearing the proximal longitudinal strip along the diagonal perforation.
