MXPA96005007A - Method and apparatus for cooling rellex bags - Google Patents

Abstract

The present invention relates to a method comprising: a) transferring a plurality of heat-sealed bags, the bags containing a product having a temperature between 38 ° C (100 ° F) and 100 ° C (212 ° F), even a cylindrical cooler having cooling water as the cooling medium b) spin and cool the bags until the temperature of the product drops to a temperature of between 10ºC (50ºF) and 21ºC (70ºF) c) transfer the cooled bags to a cooling bath that has a medium of liquid cooling with a temperature below 0ºC (32ºF), and d) moving the bags through the liquid cooling medium, and in contact with it, until the temperature of the product drops to a temperature of between -1.1ºC (30ºF) and 10ºC (50º

Description

METHOD AND JAPANESE FOR COOLING STUFFED BAGS Field of the Invention This invention relates, generally, to a method and apparatus for cooling filled bags, especially bags filled with a food product and which are filled in a vertical formation / filling / sealing process ("VFFS"). Background of the Invention Vertical Form / Fill / Seal Packaging Systems (VFFS) have proven to be very useful for packing a wide variety of products that can flow or be pumped. These products include various items, such as chocolate syrup, spaghetti sauce, mayonnaise and other food products and may also include non-food products. An example of such a system is the food packaging system, which can be pumped, Onpac 2000 B, sold by W. R. Grace & Co.-Conn. through his group Grace Packaging (Cryovac). The VFFS process is known to those skilled in the art and is described, for example, in the patent of E. U. A., No. 4,589,247 (Tsuruta et al). A product is introduced, which can flow or be pumped, through a vertical central filling tube, to a formed tubular film, which has been transversely sealed at its lower end and longitudinally. The bag is then completed by sealing the upper end of the tubular segment and separating the bag from the tubular film, above it. The selection of packaging materials is important and must correspond to the intended end use of the bag. For foods, such as tomato-based sauces, for example, a relatively low oxygen transmission laminate is usually required, in order to provide a long shelf life for the product. FS laminates, such as the FS 6055B, also sold by W. R. Grace & Co.-Conn. through its Grace Packaging group, are examples of suitable packaging materials for the VFFS process. This FS 6055 B is a laminate with an elevated barrier to oxygen, which offers a long life in ana-quel. It is also a material that is capable of, and in fact often used in, commercial applications where the food product is hot filled, typically at 82 to 932C, into the bag formed, during the VFFS process. Thus, this material offers the processor of food that can be pumped, both long shelf life and prolonged thermal stability, for many hot filled food products. These laminates are described, for example, in the patent of E. U. A., No. 4,746,562 (Fant). An alternative laminate is based on the Sclair ™ sealant film, an ethylene / alpha-olefin copolymer sold by DuPont Canada and is described, for example, in U.S. Patent No. 4,521,437 (Storms), incorporated herein by reference. A single layer commercial film by DuPont Canada is the FS-3. A commercial multilayer laminate is CL 303.

As indicated above, the balls are sometimes used in connection with the VFFS equipment to pack hot products, such as soups. These food products are often packaged at a temperature between 79 and 852C and, occasionally, close to 932C. A full bag can weigh several kilograms. In a typical packaging medium, which uses the current equipment of the technique, such as the Onpack system, thousands of hot filled bags can be produced in a relatively short time. They should be cooled as quickly as possible, to minimize bacterial growth within the package, and to maximize the shelf life of the product. This is an intimidating task, when one considers the heat capacity of thousands of bags filled at high temperatures and the fact that each bag will be cooled to an ideal temperature of about 4.52C.

A common industrial method of cooling a large number of hot filled bags is the use of a cylinder cooler. As an illustration, the filled bags (packages) are transported inside a 7.30 meter drum cylinder continuous cooler. There, the bags turn and cool in about 25 minutes, in chilled water, which has a temperature of about 1.67 to 3.33SC. The bags are then discharged from the cooler.

A controlled cylinder cooling process, using chilled water, has proven to be an effective method for cooling the heat-sealed bags of the VFFS system, from the hot fill temperature (eg 82dC) to room temperature (e.g. from 15.5 to 18.32C), Unfortunately, difficulties have been encountered for some time when using cylinder cooling as a method of further cooling the heat sealed bags of the VFFS system at a temperature of about 4.52C. The principle of difficulty can be found by considering the four corners that typically form a rectangular bag. As the product temperature approaches the 4.52C target, the corners become rigid and increasingly brittle. The sharp corners then become susceptible to the formation of small holes during the rotation and agitation of them, inside the cooled water.

The sharp corners also appear to be responsible for small perforations of the body of adjacent bags, as the revolving action continues to collide the bags with each other.

Either of these two phenomena can result in leaks that can not be accepted commercially and must be remedied.

This will be in contrast to stapled covers, which are bags with metal fasteners at their ends instead of transverse heat seals. An example is a bag made of the C-300 cover, also supplied by Cryovac. Because they do not have the four-cornered geometry of the full heat-sealed bags, the cylinder cooling of the stapled covers has proven to be an efficient and economical method of cooling the product.

Another disadvantage of the rotary cylinder cooling systems is related to the nature of the cooling medium and the packaged product itself. The products cooled to 4.52C in water having a temperature of 1.67 to 3.3SC, becomes increasingly more difficult as the temperature of the product approaches the temperature of the cooling water. This difficulty is aggravated when high viscosity and / or high fat foods are packed. Such products tend to form an insulating coating of the cooled product, just inside the material of the bag, with a relatively hot center in the core or center of the bag. Thus, the dilemma facing the food processor is that, on the one hand, the use of a stirring system to improve heat transfer, results in increased damage to the filled bags, with a higher incidence of leaks; and on the other hand, a reduction in agitation makes it more difficult and costly to lower the temperature of the product to the desired end point. One solution to this problem is to use, instead of a rotary cylinder cooler, a large spiral freezer or blow or discharge. Both methods use sub-zero air at high speed to cool the product. They offer an effective alternative, but very expensive in terms of capital investment, and operating costs. They also require more physical space than a rotary cylinder cooling system. For these reasons, they are beyond the reach of many small and medium-sized food processors. Such systems also, generally, are not as efficient as cooling in a liquid medium. Another solution is to pack and place bags on pallets from the cylinder cooler and immediately move the pallet inside a blown-type freezer, to bring product temperatures below 4.52C and thus meet safety and quality requirements. This is also expensive and not efficient. Therefore, there is a need for an efficient and economical method and apparatus for cooling a filled bag. Compendium of the Invention The invention, in one aspect, is directed to a method comprising the transfer of a plurality of bags, which contain a product with a temperature between 38 and 100ac, to a rotary cylinder cooler, having cooled water as the medium of cooling, subjecting the bags to rotation and cooling until the temperature of the product decreases to between 10 and 212C; transfer the cooled bags to a cooling bath using a liquid cooling medium, with a temperature lower than 0 ^ C; and moving the bags through the liquid cooling medium until the temperature of the product falls to a temperature between -1 and 102C, The invention, in another aspect, is directed to an apparatus comprising an element for transferring a plurality of bags, which contain a product with a temperature between 38 and 100SC, to an element of rotation and cooling; this element rotates and cools the bags, until the temperature of the product falls to between 10 and 212C, this element has water cooled as the cooling medium; an element for transferring the cooled bags to a cooling bath; which uses a liquid cooling medium having a temperature of less than 02c; and an element to move the bags through the liquid cooling medium, until the temperature of the product falls to a temperature between -1 and 10ac The bags are preferably heat sealed bags, more preferably bags made in a forming / filling / sealing apparatus.

The product preferably has a temperature between 60 and 99se, more preferably between 65.5 and 962C and even more preferably between 71 and 93ac. A particularly preferred range of product temperature is between 74 and 88 sc and more preferably between 76.7 and 852 c.

The bags preferably rotate and cool until the temperature of the product falls to a temperature between 12.8 and 18.3SC, more preferably to about 15.52c.

The liquid cooling medium having a temperature less than OdC is preferably the brine or the glycol.

This liquid cooling medium having a temperature of less than 0 c is preferably at a temperature of -12c or less, more preferably at -42c or less and still more preferably at -6.672C or less.

The liquid cooling medium having a temperature of less than 02c is preferably stirred.

The bags are moved through the liquid cooling medium until the temperature of the product drops to preferably at a temperature of 1.67 to 12.82C, more preferably between 2.3 and 112c and even more preferably to about 4.52c and especially to 4.52c.

The element for transferring a plurality of bags is preferably a conveyor belt or channel.

The element for rotation and cooling is preferably a drum / cooler cylinder, more preferably a rotating drum / cooler cylinder and especially preferred a rotating drum / cooler continuous cylinder.

The element for transferring the cooled bags to a cooling bath is preferably a conveyor belt or gutter.

The cooling bath is preferably a continuous cooling bath.

The rotation of the bags is preferably stopped before they are transferred to the cooling bath.

Description of the Preferred Modes Any conventional rotary cylinder with cooling capacity, such as the rotary drum coolers, available from Lyco or Baader, is useful in connection with this invention. Any conventional brine or glycol bath is useful in connection with this invention.

Any conventional element for moving bags, such as a conveyor belt, elevated suspensions, gutters, hoppers, etc., are useful in connection with this invention. The invention can be further understood with reference to the following Examples and Tables.

Examples 1 to 7 A plastic tub, with a volumetric capacity between 189.25 and 227.1 liters, was used as a brine tank. A section of the PVC pipe, with a diameter of 1.27 cm was used to build a system to filter the compressed air from the bottom of the bath. The tank was filled with 127 kilograms of water and 18.15 kilograms of salt (sodium chloride). The resulting solution was a 13% by weight salt solution. The final volume of the brine solution occupied a space of 76.2 x 50.8 x 25.4 centimeters. The compressed air acted to stir the brine and ensure a uniform temperature of the brine around each bag.

Seven trials were made, each involving a different product in the bag. The products were identified, along with the average weight of the bag, in Table 1. Prior to each test, the temperature of the brine solution was lowered to -6.672C, adding dry ice to the brine tank. After the dry ice dissolved, each test operation was started. TABLE 1 At the start of each test, ten packages were taken directly from the output of a 61 cm continuous Lyco drum cylinder cooler. Each package was shaken and mixed thoroughly. An average temperature of the ten bags was then calculated and recorded as the initial product temperature for brine cooling. Then the packages were discarded. The next ten packages left from the Lyco cooler were then placed directly in the brine tank. At five minute intervals, a package was removed from the brine tank. The package was then thoroughly mixed and the temperature of the product recorded. That package was then excluded from the rest of the trial. Once the product has reached 4.52C or less, the test is completed. At the end of each trial, the remaining packages in the brine tank were removed and used to obtain an average product exit temperature. The results of the seven tests are summarized in table 2. As an example, "brine ^" refers to the temperature of the brine bath used to cool the product of Example 1 (the bean with bacon soup) at various time intervals . The "Product!" 11 refers to the temperature of the product of Example 1 (bean with bacon soup), at various time intervals.The temperatures are in degrees centigrade.

TABLE 2 It can be seen that all seven products were cooled below 4.5 ° C in less than 30 minutes, most in less than 25 minutes. During these tests, it was not possible to maintain a constant temperature of the brine. Therefore, as the temperature of the product decreases, the temperature of the brine rises through each test. It is evident that the cooling rate decreased significantly as the difference between the temperature of the product and the brine decreases. In a conventional brine cooler, a more constant temperature can be maintained.

The invention has been described in detail with particular reference to specific embodiments, but it will be understood that variations and modifications may be made within the spirit and scope of the invention.

Claims (20)

1. A method, which comprises: (a) transferring a plurality of bags, these bags contain a product which has a temperature between 38 and 100 ° C, to a cylinder cooler, having cooled water, as a cooling medium; (b) spin and cool the bags until the temperature of the product drops to a temperature between 10 and 212C; (c) transferring the cooled bags to a cooling bath, which has a liquid cooling medium, which has a temperature of less than 0 C; and (d) moving the bags through the liquid cooling medium, until the temperature of the product drops to a temperature between -1.1 and 102C.

2. The method according to claim 1, wherein the bags are heat sealed bags.

3. The method according to claim 1, wherein the bags are manufactured in a forming / filling / sealing apparatus.

4. The method according to claim 1, wherein the product has a temperature, at the time of transfer of the bags in step a), between 60 and 99se.

5. The method according to claim 1, wherein the bags are rotated and cooled until the temperature of the product drops to a temperature between 12.78 and 18.332C.

6. The method according to claim 1, wherein the liquid cooling medium has a temperature of less than 02c in brine or glycol.

7. The method according to claim 1, wherein the liquid cooling medium having a temperature of less than 02c, is at a temperature of -1.112c or less.

8. The method according to claim 1, wherein the liquid cooling medium, having a temperature of less than 02c, is stirred.

9. The method according to claim 1, wherein the bags are moved through the liquid cooling medium, until the temperature of the product falls to a temperature between 1.67 and 12.76 C.

10. The method according to claim 1, wherein the rotation of the bags is stopped before these bags are transferred to the cooling bath.

11. An apparatus, which comprises: (a) an element for transferring a plurality of bags, these bags contain a product having a temperature between 38 and 100 ° C, to an element for rotation and cooling; (b) an element for the rotation and cooling of the bags, until the temperature of the product falls to a temperature between 10 and 2iac, this element has cooled water as the cooling medium; (c) an element for transferring the cooled bags to a cooling bath, which uses a liquid cooling medium having a temperature me (d) an element for moving the bags through the liquid cooling medium, until The temperature of the product drops to a temperature between - 1.1 and 102C.

12. The apparatus according to claim 11, wherein the bags are heat sealed bags.

13. The apparatus according to claim 11, wherein the bags are manufactured in a forming / filling / sealing apparatus.

14. The apparatus according to claim 11, wherein the liquid cooling medium having a temperature of less than 0 C is the brine or the glycol.

15. The apparatus according to claim 11, wherein the liquid cooling medium, having a temperature of less than 02c, is at a temperature of -1.112c or less.

16. The apparatus according to claim 11, wherein the element for transferring a plurality of bags comprises a conveyor belt or a gutter.

17. The apparatus according to claim 11, wherein the element for rotation and cooling comprises a drum / cooler cylinder.

18. The apparatus according to claim 11, wherein the element for rotation and cooling comprises a rotating drum / cooler cylinder.

19. The apparatus according to claim 11, in which the element for transferring the cooled bags to a cooling bath comprises a conveyor belt or a gutter.

20. The apparatus according to claim 11, wherein the cooling bath comprises a continuous cooling bath.