There is a need to improve the automation and consistency of the current systems. Current systems require up to three persons to operate effectively. These systems produce completed pallets at a rate of up to about one per minute. The new methods and apparatus, with preferred embodiments, provide automated systems capable of reliably producing a finished pallet every 30 seconds, with fewer persons needed to operate the system.
Current systems require manual manipulation of the bags and the plastic sheets, and staples to hold plastic materials in place. The new systems eliminate the need for manual manipulation, and the need for staples.
A pallet bearing a plurality of containers of fresh perishables is placed on a conveyor. The perishables load is conveyed to a station where the unitized load is squeezed and lifted from the pallet, or is squeezed and the pallet lowered from the load, and a plastic sheet is automatically inserted on the pallet in the gap created above the pallet and below the suspended load. The margins of this bottom sheet extend beyond the edges of the pallet on all sides. See Bolejack, et al. U.S. Pat. Nos. 5,014,495; 5,111,639, and 5,314,286; and Forgnone, et al., U.S. patent application Ser. No. 10/785,868, filed in the United States Patent and Trademark Office Feb. 24, 2004, entitled “Apparatus And Methods For Enclosing Product Units,” for disclosures of such apparatus and methods.
After the sheet is in place, and the containers of perishables are placed atop the pallet and sheet, the resulting pallet unit is conveyed to a bagging station. There, a plastic bag is automatically applied from above the palletized unit. The bag is stretched over, and then down the exterior surfaces of the stacked unit. Once the stretched film is released, the film, which forms a bag, is effectively pulled tightly against the exterior surfaces. Tension of the stretched bag against the pallet unit surfaces is also sufficient to brace/stabilize the palletized unit.
The new system may automatically position and fold the overhanging margins of the bottom sheet upwards, against the sides of the perishables containers atop the pallet. The system then holds the sheet margins in a vertical position long enough for the descending bag to overlap and capture the sheet margins, and to hold the margins in the vertical, upward position against the perishables containers, inside the margins of the stretched bag. The bag opening is preferably positioned above the plane of the pallet surface, leaving a portion (e.g., two inches) of the vertically positioned bottom sheet exposed. The bag overlaps the remaining portions of the bottom sheet. Because the bag has been stretched, the elasticity of the bag pulls tight against, and holds the sheet margins in place. Once held by the stretched bag, the system holding the sheet margins upwards is withdrawn or cycled off. Alternatively, the sheet margins may overlie the margins at the opening of the bag.
Some perishables items require only one gas to create an appropriate modified atmosphere. For strawberries, this gas may be carbon dioxide. Typically, after bagging and sealing, any gases may be injected. Alternatively, gases may be delivered over the perishables inside the bag as the bag is stretched over the perishables containers prior to sealing. A shrink hood stretching mechanism stretches the bag out and down adjacent to each corner of the unitized perishables. Gas delivery nozzles for creating a modified atmosphere environment inside the bag may be positioned under each corner of the bag stretching device. When activated, these nozzles deliver appropriate quantities of one or more gasses inside the bag to form a desired modified atmosphere as the bag is pulled and stretched over the unitized loads.
After leaving the bagging station, an in line tape or stretch wrap seal may be applied to the bag margins which overlap the vertically-positioned bottom sheet margins. The bag margins preferably lie substantially flat against the margins of the sheet and the container surfaces, providing a substantially smooth surface for tape or stretch film to be applied. Once properly applied, a seal is formed and substantially no gases may escape from the interior of the bag. These flat surfaces may also facilitate heat sealing of the bag to the sheet margins. See, e.g., Bolejack, et al. U.S. Pat. Nos. 5,014,495; 5,046,302; 5,111,639; and 5,314,286; Forgnone, et al. U.S. Pat. No. 6,532,717; and MacLeod, et al. U.S. Pat. No. 4,821,489, describing such methods and apparatus.
The permeability of the bag is preferably tailored to a specific perishable item. To form and maintain a desired modified atmosphere inside the sealed bag, the type and weight of the perishables must be determined. By weighing each pallet, the respiration load of the perishable inside the enclosed bag can be determined. Based on this data, a system for punching or cutting calibrated holes in the pallet bag, forms one or more appropriate openings in the bag, and/or an appropriate hole such that a breathing membrane or label may be placed over such a hole. The size of hole and type of label varies with the type/variety and weight of the perishables item, and with the gas permeability of the bag. The breathing labels and/or calibrated holes help to maintain a desired controlled or modified atmosphere inside a bag, by balancing the desired components, e.g., carbon dioxide and oxygen, with the film permeability and perishable respiration load.
In another embodiment, the system may automatically convey a pallet bearing a plurality of containers of fresh perishables to a squeeze station where the unitized load is squeezed and separated from the pallet, and a plastic sheet is automatically inserted on the pallet in the gap created above the pallet and below the suspended load. The margins of this bottom sheet extend beyond the edges of the pallet on all sides. After the sheet is in place, and the containers of perishables are positioned atop the pallet and sheet, the resulting pallet unit is conveyed to a folding station.
At the folding station, a folder system senses the presence of a load bearing pallet, and activates a corner fold-forming system that folds the margins of the pallet sheet upwardly against the load at all four corners of the pallet. The system then heat seals each corner fold, simultaneously or seriatim.
The system then conveys the palletized load to the bagging unit, where a bag is automatically applied. The descending bag overlaps and captures the sheet margins inside the margins of the stretched bag. The bag opening is preferably positioned above the plane of the pallet surface, leaving a portion (e.g., two inches) of the vertically positioned bottom sheet exposed. The bag overlaps the remaining portions of the bottom sheet. Because the bag has been stretched, the elasticity of the bag pulls tight against, and holds the sheet margins in place. Alternatively, the system may be configured to stretch and place the bag over the palletized load, and the margins of the bottom sheet may then be folded or otherwise placed upwardly outside the margins of the bag/enclosure.
The system then automatically conveys the palletized, bagged load to a modified atmosphere delivery station. There, the bag is automatically perforated with a gas injector, and one or more gasses are injected into the bag. The nature and quantity of these gasses is based upon the height and weight of the palletized perishables, which the system measures, and upon the nature of the perishables, and may be computed, by a computer or otherwise, preferably from a look-up table that uses the weight, height and nature of perishable data to determine the nature and quantity of gases to inject.
The system then conveys the bagged, gasified, palletized load to a taping station, where the system automatically applies tape to the periphery of the palletized load at the junction of the bag's opening and the margins of the pallet sheet. The tape may be delivered from a tape roll by a pressure roller that follows and presses the tape against the palletized load. The tape may then be automatically cut from the tape roll when the taping of the palletized load is completed.
The system conveys the palletized, bagged, gasified, taped, or otherwise sealed load to an offload station for delivery elsewhere.
The various features and advantages of this invention will become apparent in light of the following detailed description, taken together with the accompanying drawings, in which:
A plurality of pallets, each loaded with perishables, may be brought to in-feed 11, e.g., by forklift. In-feed 11 conveys the pallets, one at a time, to squeeze station 12. At squeeze station 12, hydraulically actuated, one or two pairs of opposed vertical walls are activated to engage and squeeze the pallet load of containers of perishables above the pallet with sufficient force to permit the floor plate beneath the pallet to be lowered from the load supporting position, or to raise the pallet load from the pallet. See, e.g. Bolejack, et al. U.S. Pat. Nos. 5,014,495, 5,046,302; 5,111,639, and 5,314,286; Forgnone, et al. U.S. Pat. No. 6,532,717; and MacLeod, et al. U.S. Pat. No. 4,821,489, describing such methods and apparatus. After the pallet and load have been separated from one another, a plastic sheet is automatically placed on the pallet in the gap formed between the unitized load and the pallet. The inserted sheet then rests on the pallet's upper surface. This sheet is generally flat, and the margins of the sheet extend beyond the edges of the pallet. After placement of the sheet on the pallet, the pallet may then be raised, or the pallet load may be lowered, to replace the perishables containers onto the plastic sheet atop the pallet. The pallet, with its plastic sheet and perishables atop the plastic sheet, is then conveyed on path 13 into bagging station 14.
At bagging station 14, a plastic bag of appropriate size, shape, type and gas permeability is automatically applied. The bag is formed from tube stock which descends from a supply above the pallet of perishables, and is formed into a bag. The bag is stretched to fit over the perishables and unitized containers of perishables. Simultaneously, the system automatically positions the overhanging margins of the deck sheet upwards to a vertical position against the sides of the perishables containers. The system holds these margins in this position for a time sufficient for the descending bag to overlap and capture these margins in the vertical upward position against the sides of the containers, and now inside the stretched pallet bag. The margins at the opening of the bag are positioned above the pallet, leaving a portion of the vertically-extended sheet margins exposed. Because the bag has been stretched, and released against the load, the elasticity of the bag pulls tight against, and holds the vertically positioned margins of the sheet in place. Thereafter, the system holding the sheet margins vertically upwards is withdrawn or cycled off Bagging apparatus of this type use, for example, automatic systems from Lachenmeier, Beumer, and Moeller stretch hood systems.
In preferred embodiments, as a bag descends over the perishables on the pallet, one or more gasses appropriate for creating a desired modified atmosphere inside the bag, and over the perishables, may be injected under the bag to blanket or cover the perishables as the bag is stretched over the perishables load. For this purpose, nozzles may be positioned under one or more corners of the bag so the bag descends over the perishables so that the gas is delivered at up to four locations, to form a desired modified atmosphere inside the bag.
The bagged palletized perishables leave bagging station 14 and passes on path 15 to sealing station 16. There, a taping mechanism applies tape or other suitable material where the bag overlaps the decking sheet, preferably around the entire circumference of the bagged palletized containers of perishables creating a substantially air-tight seal. The sealed palletized bagged perishables unit then passes on path 15 to weighing scale 18, for weighing. Using the weight of this unit, and the nature and temperature of the perishables, the respiration load for the perishable can be determined. From scale 18, the unit passes on path 17 to station 19 where, based in part on the measured weight, or respiration load, calibrated holes are formed in the bag as appropriate to maintain the desired modified atmosphere within the bag. Labels, membranes or other such devices may also, or alternatively, be applied to the bag to modify the permeability of the bag, and maintain a desired modified atmosphere within the bag for the respiration load as determined.
After the hole-punch and the calibrated membrane application processes, the completed, bagged, unitized pallet containing a desired modified atmosphere moves along on exit conveyor 19. A forklift can then remove the unitized pallet load for storage/distribution.
In system 10E, conveyor 12A moves a plurality of pallets, each loaded with a plurality of containers of perishables, e.g., strawberry containers, stacked on the upper surface of the pallet. As an example, a pallet may carry 16 tiers, with six trays in each tier, and have an overall height of about 90 inches. Each tray may contain a plurality of strawberry baskets. The pallet itself may have a circumference in the range of 150 to 200 inches, and be rectangular or square in shape. Where the perishable is strawberries, the strawberries are preferably cooled to a temperature of about 33 degrees F. The perishables are preferably cooled to, and maintained at an optimum storage temperature, before the bagging operation begins.
A plurality of pallets, each loaded with perishables, may be brought to in-feed 12A, e.g., by forklift 18A. In-feed 12A automatically conveys the pallets, one at a time, to squeeze station 100.
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Tape head 502 moves in a plane parallel to the sides 106 of the palletized containers to contact the leading corner of the pallet unit. The leading edge of tape adhesive surface is delivered from a plane parallel to the sides 106 of the palletized containers, and is pressed against and tacks to the overlapping margin of the decking sheet and the plastic bag/enclosure. The height of the tape is pre-positioned to cover this margin. The pallet rotates, pulling tape off a tape roll and through dispenser roller heads and mechanisms 510. Pressure rollers 510, which follow behind the tape dispensing head press and adhere the tape to the overlapping margin of the bag/enclosure and the decking sheet, creating a seal. The dispensing head and pressure rollers articulate around pallet corners as the pallet rotates. After a 360 degree rotation, the palletized perishables stop rotating. The tape dispenser moves away from the palletized perishables, e.g., by about 6 inches.
An automatically actuated pressure rod pulls the tape tightly between two rollers which are positioned in parallel inside the tape dispenser head. Taut tape is automatically cut in a plane parallel to the sides of the palletized perishables with an air actuated knife. The tape head dispenser then moves out and away from the palletized perishables. Thereafter, the sealed palletized perishables unit exits the sealing station.
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This application is a continuation-in-part of U.S. patent application Ser. No. 11/390,947, filed with the U.S. Patent and Trademark Office on Mar. 27, 2006. The fresh perishables trade uses modified atmosphere technologies on bagged, or otherwise enclosed, and sealed, pallet unit quantities of perishables to preserve freshness and reduce market losses during distribution. Current systems require that a pallet bag be placed over a unitized pallet of perishables, which are placed in containers. The pallet bag is then sealed to a plastic sheet positioned on top of the pallet under the unitized containers of perishables. Once the pallet bag is sealed, desired quantities of one or more gasses are injected into the pallet bag, creating a modified atmosphere, which benefits the enclosed perishables. Bolejack, et al. U.S. Pat. Nos. 5,014,495; 5,046,302; 5,111,639; and 5,314,286; Forgnone, et al. U.S. Pat. No. 6,532,717; and MacLeod, et al. U.S. Pat. No. 4,821,489 describe such methods and apparatus.
Number | Date | Country | |
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Parent | 11390947 | Mar 2006 | US |
Child | 12075537 | US |