Abstract:
This utility model corresponds to a special mold-design used to manufacture paperboard bags. The mold-design is a piece of creased paper, which makes it possible for a modified gluing-folding machine to perform a series of liner steps to finish the bag, the process ending with the step in which the product is rotated to glue the bottom. The process is fully automated.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a mold-design to manufacture expansible-side paperboard bags using a fully automatic gluing/folding machine.  
           [0003]    2. Description of the Prior Art  
           [0004]    Over the years, paper bags or bags made with natural cellulose for various uses, have been manufactured using traditional methods.  
           [0005]    Originally, molds were made, on which bag makers would cut sheets of paper to different sizes to manually fold the pieces of material from which the bags would in turn be made. Then, the folds were made and were immediately pressed down into bag shape.  
           [0006]    The bottoms of the bags were, and in some cases still are, glued, or a piece of any thicker material is simply placed at the bottom to prevent the bottom from splitting and prevent the bag&#39;s contents from falling out.  
           [0007]    Most bags are manufactured with a conventional gluing-folding machine, which is available to the general public. The machine performs half of the manufacturing process, and the bags are hand finished by experienced personnel.  
           [0008]    The advantage of this mold-design and improvement of the expansible-side paperboard bag folding-gluing machine is that the entire manufacturing process is automated, eliminating the need for manual labor. The bag mold-design is placed on the machine by an automatic feeder and the only manual work required is fitting the string handle and packing. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0009]    The mold-design for the bag manufacturing process using the creased paperboard mold-design, with a modified folding-gluing machine is described below, illustrating the various steps in the process with the following figures:  
         [0010]    The mold design used to make the bag is a mold with a four-section structure (FIG. 1. 1 ); the first section is the upper lap and its opposite side is called the upper face; the second section is the side lap and its opposite side is called the left-hand expansible side; the third section is the lower lap and its opposite side is called the lower face; and the fourth section is the side lap and its opposite side is called the right-hand expandable side. The latter section includes a gluing stub, and the side laps are creased down the middle so that they can be easily folded.  
         [0011]    The bags are also creased along the side laps and between the upper and lower laps. The edges of the upper and lower laps are cut on an angle, and the edges of the side laps are cut at a right angle, with a small diagonal cut where they meet the edge of the upper or lower laps, and the laps are creased along with their entire length, the creasing of all laps allowing for suitable fold when gluing the bags. On the side opposite the cuts, the mold-design section is straight, with only four holes used to insert two pieces of string to be used as handles.  
         [0012]    Once the mold design (FIG. 1. 1 ) is ready, an automatic feeder (FIG. 2. 1 ) places it on the machine.  
         [0013]    The product immediately enters the machine on conveyer belts (FIG. 2. 2 ) that guide the bag mold/design to the folding guides (FIG. 2. 3 ). These guides fold the right-hand expansible side along its entire length, using the crease at the center of the expansible side mold-design.  
         [0014]    Immediately thereafter, a strategically placed hook pulls the gluing stub and when the hook passes the mold-design, a magnet returns it to its original position. A smaller guide is used to ensure consisting folding. Simultaneously with steps  2  and  3 , a folding guide folds the entire length of the left-hand expansible side.  
         [0015]    In order to obtain a uniform, even fold along the length of the expansible sides, the mold-design passes through a compression band that keeps the folds compressed, and keeping the right and left-hand expansible sides and the right-hand lap completely flat (FIG. 3. 1 ).  
         [0016]    An electric eye determines the part of the side gluing stub on which glue will be applied, and then shoots the glue automatically, leaving a hot layer on the bag side or gluing stub.  
         [0017]    Simultaneously with the preceding action, the upper half of the bag and the upper lap are folded by a bouncing belt (with an up and down movement) and are then joined to their counterparts, permitting adhesion to the gluing stub. Due to the type of flue used, this bond dries almost immediately.  
         [0018]    The bag is immediately removed on a special conveyer belt that raises the upper lap of the bottom with a hook that keeps the lap folded backwards. When the upper lap of the base is folded, it pulls the left and right-hand expansible sides leaving two triangles on each side where the bottom will be, the side laps and the upper and lower laps.  
         [0019]    An electric eye then enters, detects the product, sees how the upper lap of the bottom is kept raised, and with an insertion attachment inserts a square or rectangular bottom (FIG. 4. 1 ), depending on the shape of the finished bag, which should be equal or similar to the surface area of the bag&#39;s bottom, for added strength. This additional bottom section is optional.  
         [0020]    The product enters a second automatic feeder, which sends the bag on to special belts on which the bottom side laps are folded. These sidelaps fall on or cover the triangles formed by folding the expansible sides so that the previously placed bottom section is placed correctly.  
         [0021]    An electric eye immediately detects the product and an automatic injector shoots glue onto the already folded side sections.  
         [0022]    A hook pulls the upper lap of the bottom section to ensure that it is glued where the glue was applied, covering half of the bottom, in other words, half of each side lap, and at the same time, the previously placed bottom section is adjusted.  
         [0023]    The product then passes through a speed differential and is rotated 90 degrees from right to left on the conveyer belts, so that it continues rotating in the same direction as the belt, but in a different position. Thus, the last part of the gluing process can be completed without rotating 90 degrees, without which bag manufacture would not be possible.  
         [0024]    A last electric eye detects the bag and shoots hot glue along the width of the bottom section.  
         [0025]    The lower lap of the bottom section (FIG. 5. 1 ) is folded by a guide belt system that moves the lap upwards. The lap is then glued automatically to complete the gluing and folding process (FIG. 5. 1 ).  
         [0026]    The bag then enters a drying tunnel where the drying process is completed.  
         [0027]    It should be pointed out that the entire process is linear, which means that the product is produced at a low cost.  
         [0028]    At the end of the drying tunnel, the bags pass on to a table.  
         [0029]    Quality control is applied on this table.  
         [0030]    String handles are attached to the finished bag.  
         [0031]    If the product passes the quality control test, it is sent for packing.  
         [0032]    The gluing-folding machine is described below, and the aspects that differentiate it from conventional machines are also described:  
         [0033]    The first part of the machine is designed to produce pre-folded linearly glued boxes, boxes with internal compartments, pillow boxes, double-wall boxes and retail products with special finishes. This machine has a circulation tunnel through which the product passes in forty seconds. It also has an attachment that handles final folding of the product, giving it great versatility for processing custom manufactured products.  
         [0034]    The second part of the machine is the gluing-folding section, which has a circuit with special features in the rear section for final product assembly.  
         [0035]    It also has the following special attachments:  
         [0036]    An automatic compressed air suction feeder;  
         [0037]    An automatic attachment to manufacture boxes with a bottom section;  
         [0038]    Re-directing unit which rotates the product 90 degrees for finishing;  
         [0039]    A special inserter that makes it possible to insert the bottom during the  
         [0040]    folding and gluing process to make the base of the product stronger;  
         [0041]    A fast-drying hot glue application system;  
         [0042]    A central control system.