Abstract:
The invention relates to a method for manufacturing a spool of PVC film, fine characteristics of which make it possible to manufacture a stiff PVC film that is transparent, colored or metallic, partially coated front and back with a thermosealable lacquer, having a specific chemical composition, which conforms to a defined shape, both in design and angles, characterized in that the enamel-type substance is continuously applied on one side of the longitudinal PVC film, such that the substance is applied to the peripheral portion of said side of the PVC film, the substance not being applied to the center portion, and at continuous application of the enamel substance on the other side of the same longitudinal PVC film, such that the substance is applied to the entire said other side of the PVC film, the film being printed with a design. The problems of jamming of the material are avoided, thus optimizing the packaging speed and substantially improving the look of the final packaged product.

Description:
PURPOSE OF THE INVENTION 
       [0001]    The purpose of this Invention Patent application is to register a procedure to manufacture a structure in a film to pack candies; this film consists of remarkable innovations and advantages in comparison with the techniques used up to now. 
         [0002]    Concretely, the invention suggests the development of a procedure to manufacture a film reel which, due to its particular arrangement, allows the manufacturing of a transparent pigmented rigid film (which, in some cases, can be metallized); it is coated partially on both sides with a heat sealing resin of a specific chemical formulation and that is registered according to a particular geometry defined according to the design an angles. 
       BACKGROUND OF THE INVENTION 
       [0003]    Films used to pack or wrap products such as candies are well known in the current state of the art. 
         [0004]    The addition of certain coatings to the sides of those films is a decisive factor in the performance of the structure throughout the processes to pack products like square candies through folding. 
         [0005]    This supposes that some blocking problems can occur in the material sometimes. 
         [0006]    The presentation of the final packed product can be affected because the final creases are sometimes poorly folded. 
         [0007]    This invention contributes to solve this problem because it allows the manufacture of a suitable film used to wrap a certain food product and eliminates the material blockage problems; also, it improves the presentation of the final packed product and increases the packing/wrapping speed. 
       DESCRIPTION OF THE INVENTION 
       [0008]    The present invention has been developed to provide a procedure to manufacture a film used to wrap/pack candies; this packing procedure is done on a film that unrolls from a reel and characterizes essentially because it comprises the following steps once it unrolls from the reel:
       A. The continuous application of a resin-type product on one side of the film; the application is done on the peripheral region of the film side so that the central region of the side is not coated.   B. The continuous application of a resin-type product on the other side of the same film; the application is done on the entire surface of the film using a certain pattern.       
 
         [0011]    Additionally, the product applied in the procedure to manufacture a candy wrapping film is a vinyl resin. 
         [0012]    Preferably, the vinyl resin applied in the procedure to manufacture a candy package is a sealing resin. 
         [0013]    Alternatively, in the procedure to manufacture said film, the application is done using photoengraving printer. 
         [0014]    Besides, in the procedure to manufacture the film to wrap candies, at least one of the sides of the film is color printed before the application of this resin-type product. 
         [0015]    Thanks to this invention, a film is manufactured; said film is suitable for the packing of food or human consumption products, namely, caramels; it avoids the blockage material problems and improves substantially the presentation of the final packed product because it prevents the final creases to be poorly folded and increases the wrapping speed. 
         [0016]    Other features and advantages of the procedure to manufacture the film used to wrap candies are evident in the description of a preferred execution which is illustrated as a non-limiting example in the drawings attached herein which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1 .—This is a schematic representation of a preferred execution of the procedure to manufacture a film used to wrap candies, the purpose of this invention. 
           [0018]      FIGS. 2 and 3 .—These are schematic views of some details of the application and the result of the preferred method for the procedure to manufacture a film to wrap candies, the object of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EXECUTION 
       [0019]    As it is shown in  FIG. 1 , the procedure to manufacture the film to wrap candies, adapted for its execution on a film ( 12 ) that unrolls from a reel ( 11 ), after the unrolling  1  from the reel ( 11 ) comprises:
       A. A continuous application  2  of a resin-type product on one side of the film; the application ( 2 ) is done on the peripheral region of the film side ( 12 ) so that the central region of the side is not coated.   B. The continuous application  3  of a resin-type product on the other side of the same film ( 12 ); the application is done to the entire surface of the film ( 12 ) using a certain pattern.       
 
         [0022]    As it is shown in  FIG. 2 , the first continuous application  2  is done right after the film unrolls  1  from a reel ( 11 ). 
         [0023]      FIG. 2  shows that the application  2  is done on the peripheral region of the film side ( 12 ) so that the central region of the side is not coated. 
         [0024]    Next,  FIG. 3  shows that a second continuous application  3  of a resin-type product is done on the other side of the same film ( 12 ); the application  3  is done to the entire surface of the film ( 12 ) using a certain pattern. 
         [0025]    In some preferred alternative executions, at least one side of the film ( 12 ) is color printed before the application  2  and  3  of this resin-type product. 
         [0026]    In preference, the film ( 12 ) is a PVC polymer with a plasticizer-free formulation that gives the film ( 12 ) the necessary rigidity to be folded. The substrate is generally transparent, but some applications may require it to be pigmented (especially, in white) or have a metallic finish, that is, with a superficial aluminum deposit that can be 0.0.3 microns thick. 
         [0027]    Once extruded, the film ( 12 ) is very stable and has the capacity to receive both the color inks and the sealing resin coatings on its surface. 
         [0028]    In this preferred execution, the film ( 12 ) is a PVC film of K57 Polyvinyl Chloride, a Carboxylate stabilizer, and the impact modifier methacrylate butadiene styrene (MBS). 
         [0029]    In this preferred execution—in which the substrate is PVC—the resin-type product is a vinyl resin because it performs better given the coating composition formulation. It must be complemented by an ester-type organic solvent and specific additives to achieve other properties such as antistatic agents, carnauba-like sliding waxes, and antistatic agents obtained from quaternary ammonium salts. 
         [0030]    Concretely, the vinyl resin in this preferred execution is a sealing resin with a dispersion of copolymers of a vinyl resin in a mixture of ester-type organic solvents and a set of additives that improve substantially its performance in machinery. The sealing resin is supplied liquid to the printer; and in the printing process all the solvent evaporates using large drying tunnels. 
         [0031]    The main purpose of the sealing resin is to fuse on the surface of the film ( 12 ) once it achieves the adequate temperature through a contact clamp. These fusion allows the creation of a cohesive seal with itself and adhesive seal with the substrate. This guarantees tightness and integrity of the package with the product. 
         [0032]    The formulation of the sealing resin is actually a dissolution of a vinyl resin that attains 10% of solids in a solvent medium of ethyl acetate and n-propyl acetate. The formula is complemented with a liquid antistatic agent of the quaternary ammonium salt type, a silica antifoaming agent, and a carnauba-like natural wax to facilitate sliding. 
         [0033]    The solid resin is dissolvent in a reactor with a cooling jacket; such reactor has been previously supplied with the solvents and all the additives. The result is a transparent varnish-type resin which fluidity features allow it to be applied on the surface of the substrate, thus leaving the solid component on the substrate and permitting the evaporation of the solvent by means of passing from the liquid state to the gaseous. 
         [0034]    The main properties of the sealing resin are summarized in the following table and must be subject to strict control during the manufacturing and storage process. 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Property 
                 Detail 
               
               
                   
                   
               
             
             
               
                   
                 Viscosity 
                 19 seconds in Zahn Cup No. 2 
               
               
                   
                 Solids 
                 10% 
               
               
                   
                 Appearance 
                 Transparent 
               
               
                   
                 Volatile [substances] 
                 90% 
               
               
                   
                 Starting temperature 
                 120° C. 
               
               
                   
                   
               
             
          
         
       
     
         [0035]    In a preferred execution, applications  2  and  3  of the resin-type product on the film ( 12 ), such as the sealing resin, is done by a printer or lacquer using the rotogravure method. 
         [0036]    Rotogravure presses have a unit to which an engraved cylinder is attached at certain ceil and depth pitches. This cell-like engraving holds the exact quantity of resin; and after a turn and the direct contact with the substrate in a continuous process, it is spread on the surface; and the solvent evaporation process starts immediately after as a result of the temperature of the hot air tunnels. 
         [0037]    In addition to controlling the conditions of the process and the application of the sealing resin, the successful performance of the structure is based on the dimensions, spatial layout, geometry, and angles in which the resin is applied upon the film area. 
         [0038]    This configuration allows each of the creases to ensure the product&#39;s tightness and seal required for its distribution and consumption while it makes it easy to open. That is, it has a tight seal but can still be opened easily. 
         [0039]    This product&#39;s specialization is the result of a thorough investigation of the seal&#39;s behavior until a fine adjustment was achieved to obtain a different result. 
         [0040]    The geometry defined to apply the temperature sensitive resin is essential for the good performance of the structure. Other important aspect that complements the necessary features of the structure is the difference between the interior and exterior resins. 
         [0041]    Ensuring an adequate coating of each of the film&#39;s ( 12 ) sides is a significant contribution for the optimal performance of the package structure. One film ( 12 ) side receives the consecutive diamond-shape pattern ( FIG. 3 ) in a machine-direction orientation and a point of contact in one of its vertices. On the other side of the film ( 12 ) the application  2  is done continuously in no particular design ( FIG. 2 ). 
         [0042]    The interior resin follows a continuous application pattern as it can be seen in  FIG. 2  (shaded area), and it is aligned with the extrusion direction of the film ( 12 ); it is spatially located toward the external edges of the reel ( 11 ). These film edges will fold to form the sealing flaps of the product (cube). 
         [0043]    The resin-free area in the center of the reel ( 11 ) (unshaded area of  FIG. 2 ) is an important area to hold the product that will be packed; as it is a food product it cannot be in touch with the coating. Additionally, due to friction coefficient conditions, it prevents the candy to slide during the packing process. 
         [0044]    The engraving with of the two continued resin bands has been calculated particularly for the length of the sealing flaps, e.g. 13 millimeters. The width of the reel ( 11 ) is, for example, 46 millimeters. 
         [0045]    The exterior resin is the most important coating for the performance of the product. Unlike the interior resin, the continuous vertex-aligned diamond-shape geometry covers the entire area of the reel ( 11 ) ( FIG. 3 ). The colored area identifies the presence of resin while the unshaded area is resin-free. This configuration ensures that the sealing strength obtained reach a perfect level to guarantee the tightness and the product can be easily opened when consumed. 
         [0046]    The design shows clearly two diamond rows ( 121 ) separated, for example, 6 millimeters between edges, a 90° angle, and a wall thickness of 1 millimeter. The diamond row is located symmetrically toward the edge of the reel and reinforces the sealing ( FIG. 3 ). 
         [0047]    The remaining rows form a grid ( 122 ) with a smaller contact area; their distance between vertices is, for example, 4.2 millimeters at a 74° angle, and a wall thickness of as much as 0.5 millimeters. 
         [0048]    A commonly used interval of angles can range 45 to 90 degrees because it is the common interval to make the candy package creases. A 74° alternate angle is useful to fill in the free spaces left by the 90-degree grid. 
         [0049]    The total width of a packing machine feeding reel ( 11 ) (this machine is not the purpose of this invention) is, for instance, 46 millimeters. 
         [0050]      FIG. 3  shows detail of the geometrical layout; however, the resin coating is actually transparent so, it can be unnoticed at a glance. 
         [0051]    With the procedure to manufacture the film used to wrap candies under the present invention, one can manufacture a film suitable for the packing of food or human consumption products such as candies; the film eliminates the material blockage problems and improves substantially the presentation of the final packed product because the creases are properly folded; it also enhances the packing speed to a pace of 1,200 candies per minute. 
         [0052]    The final product resulting therefrom is a printed film ( 12 ) reel with two resins and the pattern mentioned. 
         [0053]    This film has all the process conditions described above; and all the control parameters that ensure its properties must be completely defined in the film. 
         [0054]    The finished film containing these characteristics can be used to pack a square caramel (in the shape of a cube) using a machine that integrates the reel with the caramels; it uses folding devices and takes advantage of the heat transferred by conduction through some electric resistances. 
         [0055]    The film can also be printed in 1-8 colors according to the graphic information and the product image supplied by the client. 
         [0056]    Said film can be used in machines at different speeds; in general, if accompanies the in-line cutting process of the candy to be packed where the feeding, package folding, and sealing steps are executed. This sealing is achieved using an electrical resistance with a temperature control that ensures a minimum variation of the value set in order to obtain complete tightness. 
         [0057]    Details, shapes, dimensions, and other accessory elements, as well as the materials used in the procedure to manufacture the film used to pack candies under this invention can be conveniently substituted by other equivalent materials or accessory elements that do not differ from the essence of the invention or the field defined by the claims included hereinafter.