[0001]    The present invention relates to conveyor belts for transporting products for processing in such as for example a freezer or refrigeration unit. 
         [0002]    Known freezing systems use a belt fabricated from stainless steel rods, drive links and wire to convey the products for processing, such as freezing or chilling. The construction of known belts and the materials used provide for many “trap points” for bacteria growth, such trap points known as “harborages”. Such belt construction has limited flexibility, cannot be molded to accommodate an exterior surface or entire shape of a product to be processed, and cannot retain cryogen substances to chill, freeze or crust freeze the product. Known belt also cannot hold liquid nitrogen (N 2 ) to be in contact with the product to be frozen. Additionally, such known type of belt permits products to stick to the belt, wherein the product is damaged, especially when the product is removed or separated from the surface of the belt upon conclusion of freezing. Moreover, such a known type of belt construction requires additional energy to cool the belt to the required operating temperature for transporting the product. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    For a more complete understanding of the present embodiments, reference may be had to the following drawing figures taken in conjunction with the description of the embodiments, of which: 
           [0004]      FIG. 1  discloses a top perspective view of a thermoformed film belt freezer embodiment of the present invention; 
           [0005]      FIG. 2  discloses a top perspective view of another thermoformed film belt freezer embodiment of the present invention; and 
           [0006]      FIG. 3  discloses a top perspective view of still another thermoformed film belt freezer embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0007]    The embodiments of  FIGS. 1-3  use a plastic film, such as a polyethylene film, as a belt to be moved through a refrigeration unit, such as a tunnel freezer, to transport or convey a product such as for example a food product for processing. The present embodiments substantially reduce if not eliminate the product sticking to the belt. 
         [0008]    One of the present embodiments provides for the plastic film to be thermoformed with a plurality or a myriad of pockets formed in the film in which product to be frozen is received in the pockets. Thereafter, the pocketed film is moved to the freezer wherein liquid cryogen such as for example liquid nitrogen, liquid carbon dioxide or other liquid cryogen, is dispensed such as by spraying the product disposed in the pockets. The plastic film may also be moved through an immersion bath in the freezer wherein the pockets are filled with the liquid cryogen for freezing the individual products in their respective pockets. 
         [0009]    Alternatively, the plastic film can be used as a continuous loop. When extreme hygienic conditions are warranted, the plastic film can be used for a single pass through the freezer, after which the used plastic film is collected on a spool for either of destruction or recycling. Moreover, the plastic film can be used for a set period of time, such as one factory shift, or for a predetermined amount of product to be processed. Cleaning of the plastic film belt may not be necessary because the belt only has to be used for a single pass or limited passes through the freezer. The cost to fabricate the film belt is quite low compared to related steel constructions, and maintenance can be, in certain circumstances, completely unnecessary. 
         [0010]    Referring to  FIG. 1  there is shown a thermoformed plastic film belt freezer system embodiment  10 . The freezer  10  includes a plastic film belt  12  which originates from a spool  14  or drum of the film belt  12  for transporting or conveying product  16 , such as for example food product, through a freezer  18 . The film belt  12  is returned to a take-up spool  20  or drum, whereupon the used film can be discarded, destroyed or removed for subsequent melting such as to recycle the film for subsequent use. Alternatively, the spool  20  can be omitted and the film belt  12  continues to the spool  14  as indicated by the broken line  22  such that the film belt  12  is a continuous loop transporting the product  16  to the freezer  18 . The freezer  18  is provided with an inlet  17  and an outlet  19  between while a freezer chamber  21  is disposed. Cryogenic gas or liquid such as nitrogen or carbon dioxide is dispensed in the freezer chamber  21  to the product  16 . 
         [0011]    The product  16  is provided to the film belt  12  at a charging region for transport as indicated by arrow  24 . The product  16  is conveyed through the freezer chamber  21  of the freezer  18 , after which the frozen product is removed from the film belt  12  at a discharge region as indicated by arrow  26 . A return run of the film belt  12  to the spool  20  or alternatively to the spool  14  is indicated generally at  28 . Arrow  30  indicates the direction of movement of the film belt  12 , while arrow  32  indicates a return run of the film belt  12 . 
         [0012]    Referring to  FIG. 2  there is shown another thermoformed plastic film belt freezer embodiment  110 . The freezer  110  includes a plastic film belt  12  which originates from a spool  14  or drum of the film belt  12  for transporting or conveying product  16 , such as for example food product, through a freezer  118 . The film belt  12  is returned to a take-up spool  20  or drum, whereupon the used film can be discarded, destroyed or removed for subsequent melting such as to recycle the film for subsequent use. Alternatively, the spool  20  can be omitted and the film belt  12  continues to the spool  14  as indicated by the broken line  22  such that the film belt  12  is a continuous loop transporting the product  16  to the freezer  118 . The freezer  118  is provided with an inlet  117  and an outlet  119  between which a freezer chamber  121  is disposed. Cryogenic gas or liquid such as nitrogen or carbon dioxide is dispensed in the freezer chamber to the product  16 . 
         [0013]    The product  16  is provided to the film belt  12  at a charging region for transport as indicated by arrow  24 . The product  16  is conveyed through the freezer chamber  21  of the freezer  118 , after which the frozen product is removed from the film belt  12  at a discharge region as indicated by arrow  26 . A return run of the film belt  12  to the spool  20  or alternatively to the spool  14  is indicated generally at  128 . Arrow  30  indicates the direction of movement of the film belt  12 , while arrow  132  indicates a return run of the film belt  12 . 
         [0014]    As shown in  FIG. 2 , the inlet  117 , outlet  119  and freezer chamber  121  are constructed and arranged to receive both runs of the film belt  12 . That is, upon depositing of the product  16  onto the film belt  12  for freezing, the film belt  12  enters the inlet  117  with the product  16  carried thereon to provide the product to the freezer chamber  121 , after which the belt leaves the freezer chamber  121  by the outlet  119 . Thereafter, the product  16  is discharged from the freezer  110  at  26 , after which the belt is brought to a return run  128  in the direction of the arrow  132  such that the film belt  112  also moves during the return run through the outlet  119  into the freezer chamber  121  and then through the inlet  117  where it is collected on the spool  20  or alternatively the spool  14 . In this manner of construction and operation, usually where the belt will be captured on the spool  14 , the belt can be cooled or frozen on the return run  128  so that the temperature difference between the plastic belt  12  for retrieving the product  16  at the charging region  24  is not as great as it would be with the return run  128  exposed to the ambient atmosphere external to the freezer chamber  121 , for example as shown in the embodiment of  FIG. 1 . 
         [0015]    Referring to  FIG. 3  there is shown a thermoformed plastic film belt freezer embodiment  210 . The freezer  210  includes a plastic film belt  12  which originates from a spool  14  or drum of the belt film  12  for transporting or conveying product  16 , such as for example food product, through a freezer  218 . In the embodiment of  FIG. 3 , a thermoforming device  50  is arranged such that the film belt  12  passes therethrough. The device  50  forms a plurality and in many instances a multiplicity of pockets  52  in the film belt  12 . Each one of the pockets is of sufficient dimensions to receive one of the products  16  or a plurality of the products dispensed from a dispenser device  54  disposed above the film belt  12 . Each pocket  52  will receive one or a plurality of the products  16  therein for introduction into the freezer chamber  221  via the inlet  217 . As that portion of the film belt  12  is conveyed through the freezer chamber  221 , cryogenic liquid or gas is dispensed to contact the product  16  and also is retained or settled in each one of the pockets  16  to provide for increased freezing or crust freezing of the product  16  during its transport. Arrow  30  indicates the direction of movement of the film belt  12 . 
         [0016]    Thereafter, the film belt  12  departs the freezer chamber  218  through the outlet  219  whereupon the belt is collected on a take-up spool  56  or drum. In this manner of construction, the film belt  12  is used for one pass through the freezer chamber  221 . Additionally, when the spool  14  of film belt  12  has been completely used, the film belt  12  is rolled up completely upon spool  56  for either permanent destruction or recycling into a form similar to the original form of the film belt  12  for reuse with the freezer embodiment  210 . The frozen product  16  is released from the pockets  52  at the discharge region shown by the arrow  26  when the film belt  12  is collected upon the spool  56 . Alternatively, once the device  50  has provided the pockets  52  in the film belt  12 , the device can be removed and the film belt constructed and arranged as a continuous loop for movement around the spools  14 , 56  for use for a select period of time or until such time as the film is considered contaminated or less than optimal for freezing applications. 
         [0017]    Regarding the thermoforming device  50 , such a device is distributed by Multivac Inc. of Kansas City, Mo. U.S.A. 
         [0018]    It will be understood that the embodiments described herein are merely exemplary, and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as described and claimed herein. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired result.
The following paragraph is to replace the previous version of the abstract, and includes markings to show all the changes made relative to the previous version: An apparatus and method for chilling or freezing a product includes a freezer having a freezing chamber therein in which a cryogenic substance is provided, and an inlet and an outlet in communication with the freezing chamber; and a plastic film belt constructed and arranged to transport the product from the inlet through the freezing chamber for exposure to the cryogenic substance to the outlet for removal of the product for further processing. The plastic film belt may be formed with one or a plurality of pockets to transport a corresponding amount of product.