MXPA06007773A - Method ofproducing cartons - Google Patents

Abstract

A process for forming cartons in which one or more reinforcing strips are laminated or adhered to a carton material using an extruded foamed adhesive or folded carton. Typically, the foamed adhesive is a water-based emulsion and applied in strips in either a continuous or non -continuous manner onto strips or substrates.

Description

METHOD FOR PRODUCING CARTON BOXES Field of the Invention The present invention relates generally to the manufacture of cartons, and more particularly, to a method for forming a piece for reinforced cartons having an extruded foamed adhesive applied to the cartons. materials for cardboard boxes for laminating a reinforcing material thereto and / or for joining edges or folded portions of the material for cartons to form a closed cardboard box. BACKGROUND OF THE INVENTION Cardboard boxes are typically formed from laminated cardboard pieces stamped or cut from sheets of a material for cardboard boxes and processed through a packaging machine. The laminated cardboard pieces may further have a reinforcing strip fixed thereto typically by the application of an adhesive. The pieces of laminated cardboard can then be further processed into cardboard boxes by cutting the pieces for cardboard boxes and / or folding and gluing the pieces into cardboard boxes for loading with products. Cardboard boxes typically also include flaps, which are folded, closed and sealed. Currently, the process for laminating together carton materials to form pieces for cartons generally includes roll-to-roll, roll-to-sheet or sheet-to-sheet processes using a liquid adhesive. The liquid adhesive is typically applied to a network of cardboard material either by laminating, extruding or spraying the adhesive onto the network, onto which a network or additional strips of material are applied. The laminate is then allowed to set and the adhesive is allowed to cure before the laminate can be transferred to a cutting line to die cut the car parts from the laminated carton material. Typically, cold setting adhesives are selected because of their low cost and ability to provide significant high / low temperature bonding qualities. Such cold setting adhesives typically do not degrade or decompose when exposed to high temperatures of heat or freezing. Additionally, cold-set adhesives tend to maintain their adhesion and resist fracture and breakage during handling. Unfortunately, the high moisture content of such cold-set adhesives requires a substantial amount of time to set and cure and can cause warping of the cartons due to the high amount of moisture applied to the carton from the liquid adhesive, and in addition it can flow or easily get out from between the surfaces of the coupled cardboard boxes as pressure is applied.

According to the foregoing, it can be seen that there is a need for a process and system for forming pieces for laminated cardboard boxes that address the above and other problems related in the prior art. SUMMARY OF THE INVENTION Briefly described, the present invention is directed generally to a system and method for forming reinforced cardboard boxes and / or flaps or sections of folded cardboard boxes attached to form closed cardboard boxes. In a first embodiment for forming reinforced cardboard boxes, a substrate of a reinforcing material is adhered to a material for cardboard boxes by the application of an extruded foamed adhesive along a line or processing path as part of a single layer. substantially continuous operation. Typically, the reinforcing material, which may include strips or a full-size cardboard network, thermoplastics or other natural or synthetic reinforcing materials, will be fed along a processing path from an upstream supply to the alignment and clutch with a material for cardboard boxes such as a netting material or sheet cardboard or paperboard. The strips or web of reinforcing material are initially passed adjacent to an extrusion head which applies a measured amount of a foamed adhesive along a surface of the strips or network of reinforcing material, in a desired pattern and / or at separate locations through the reinforcing material, including along the outer side edges of the strips or reinforcement net. After the foamed adhesive has been applied to the strips or web of reinforcing material, the material for cartons is fed into the clutch with the strips or network of reinforcing material. The strips or web of reinforcing material and the material for cardboard boxes are then passed through a rolling station. The rolling station typically includes at least one pair of pressure or compression rollers that compress or otherwise propel the strips or net of reinforcing material and the material for cartons into the sealing adhesive contact. After this, the material for cardboard boxes with the strips or network of reinforcing material laminated thereto is passed to a cutting station for cutting the sheets or pieces of the cardboard to form the reinforced cardboard boxes. In a further embodiment of the present invention, the foamed adhesive applicator station can be incorporated or replaced by the adhesive application station of a folder / glue line to form closed cardboard boxes. In such an embodiment, the foamed adhesive extrusion heads will be placed adjacent to the folded folding elements or systems, ie, bands, wheels, fingers, etc., of the plater / glue line and will apply the foamed adhesive in measured amounts and / or at separate locations along the flaps of the cardboard box that are folded together, including along the bottom edges thereof. After this, the flaps will be pressed towards the hermetic adhesive contact, in order to keep the sections or flaps of the cardboard box hermetically folded together and prevent the removal or separation of the flaps along the edges thereof. Still further, the present invention can be used for the application of both a cold-set foamed adhesive and a hot-melt adhesive to provide immediate adhesion of the sections or flaps together of the cartons for loading and handling of the boxes. cardboard closed as the cold-set adhesive is cured. Various objects, features and advantages of the present invention will become apparent to those of skill in the art upon reading the following specification when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a view schematically illustrating the process for forming parts for reinforced cardboard boxes according to the present invention. Figure 2 represents the extrusion heads that apply the foamed adhesive to the substrate of the carton. Figure 3 illustrates a configuration of the extrusion head for applying the foamed adhesive. Figure 4 shows the extrusion head in communication with the piece of cardboard box. Figure 5 illustrates schematically one embodiment of the apparatus for applying the foamed adhesive and forming the reinforced piece. Figure 6A is a schematic illustration of the process of the present invention for applying the foamed adhesive to the flaps of the folded carton along a folder / gluer line. Figure 6B is a schematic illustration of the compression bands of the process of Figure 6A. Detailed Description Referring now in greater detail to the drawings, in which like numerals indicate similar parts through the views, Figures 1, 5 and 6 schematically illustrate the process of the present invention for forming reinforced cartons and / or boxes of cardboard closed by the application of an extruded adhesive, foamed between the folded portions of a material for cardboard boxes 10 (Figure 6) and / or between the material for cardboard boxes 10 and a reinforcing material 11 (Figures 1 and 5). ), whose process can be carried out in a substantially continuous operation. The material for cardboard box is usually formed of a cardboard material, or can include other types of materials for natural and synthetic cartons including cardboard, various plastic materials, etc. The use of the foamed adhesive in the present invention allows a reduction in the amount of adhesive applied, which consequently reduces the water content applied to the materials for cardboard boxes, reducing the incidences of deformation and allowing shortening, faster curing times , as well as allowing greater precision in the application of the adhesive in the desired patterns and / or during compression. The foamed adhesive can be a water-based emulsion adhesive to which air is added under pressure to cause foaming of the adhesive. Examples of such water-based adhesives include, but are not limited to, ethylene vinyl acetate ("eva") adhesives and polyvinyl acetate ("pva"). The viscosity of the foamed adhesive can be in the range between about 300 to about 1000 centipoise at room temperature. If the foamed adhesive is fixatropic, the viscosity can vary up to about 7,000 centipoise at room temperature. Of course, the viscosity of the foamed adhesive can be selected from any range that allows the foamed adhesive to be extruded while remaining substantially in a fixed pattern when applied to the substrate. The foamed adhesive may further include bubbles having a diameter between about 20 to about 40 microns after mixing with air, which consequently expands the volume of the extruded adhesive, allowing less adhesive to be used to obtain the desired coverage. Further, the foamed adhesive tends to flatten during compression as the air bubbles are expelled from the foamed adhesive, rather than coming out from between the edges of the material as with conventional liquid adhesives. In a pivotal axis embodiment shown in Figures 1-5, the process of the present invention can be used for the application of a reinforcement material substrate 11 to a network or sheet 10 of material for cartons. In such a process, a strip or web of reinforcement material will be fed along a processing line in the direction of the arrows and on the rollers 13 (Figures 2 and 5) and towards an adhesive application station 14 where the reinforcement material passes adjacent to the extrusion heads 16 of the adhesive applicator station 14. As shown in Figure 2, the extrusion heads 16 will apply a foamed adhesive extruded to the strips or web of reinforcing material, the adhesive being applied foamed in most any pattern and in desired locations through the strips or network. For example, the foamed adhesive can be placed in substantially parallel straight lines 17 as shown in Figure 1 or the foamed adhesive can be placed in wave-like patterns. Additionally, the foamed adhesive can be applied in a continuous manner such as in strips or measured amounts or portions. As indicated in Figure 3, the extrusion heads 16 will include one or more holes or ports 18. The holes 18 typically have a diameter between about 0.01 to about 0.1 inches, although larger or smaller sizes may also be used. The holes can take the form of most of any of the geometric shapes but are typically circular in nature. The holes 18 generally align in essentially a straight line in the same plane, although other variant configurations may also be used as desired. In addition, although the holes 18 are typically round and similar in size as shown in Figure 3, the holes 18 need not be uniform in size or shape, but rather may be formed in varying sizes and configurations or shapes. Depending on the desired adhesive pattern to be placed on the reinforcement material, the holes 18 can also be separated at different intervals and have different shapes and sizes. A combination of one or more extrusion heads may also be used in the application of the foamed adhesive to one or more substrates. Extrusion is defined herein as the passage of a foamed adhesive through a hole under a certain pressure. As shown in Figure 1 in this first exemplary embodiment of the process including the apparatus for applying the foamed adhesive to a reinforcing material 11 for bonding to carton materials 10, an exemplary apparatus for performing such a process will generally comprise a station. of foaming 21, adhesive application station 14, and a rolling station 22. Foaming station 21 typically includes a storage tank or adhesive containment 23 for storing a supply of liquid adhesive. The tank 23 is connected to a skimmer 24 which is fluidly attached to the adhesive applicator station 14 which includes one or more extrusion head 16 for applying the foamed adhesive. The skimmer 24 introduces air under pressure into the liquid adhesive as it is withdrawn or pumped from the containment tank 23 through a pump 26. Typically, the liquid adhesive will also be filtered by a filter 27 placed between the containment tank 23. and the pump 26. A bypass valve 28 is also adapted between the pump 26 and the skimmer 24 to direct or spill excess adhesive flow from the tank to the adhesive applicator station 14. Additionally, several check valves can be placed in the system for regulating the flow of extruded, foamed adhesive. Generally a pressure regulator 30 will be placed along the flow line between the frother 24 and an overpressure chamber or distribution module 31, such as in the plenum chamber 31, for the adhesive applicator station 14 to regulate the flow pressure of the foamed adhesive in the system that is supplied to the extrusion heads 16 through the hoses or feed lines 32. Typically, the pressure of the system line is maintained at about 60 psi to about 100 psi, or in an alternative mode, between 75 psi and 85 psi. Of course, this pressure can be greater or lesser and will vary depending on the type of foamed adhesive used and the type of extrusion heads 16 selected. The adhesive flow pressure is monitored and deployed through a pressure gauge 33 installed along the distribution module. A shock suppressor 34 may also be added to the system and located between the skimmer 24 and the distribution module 31 to prevent or suppress surges in the flow of the foamed adhesive being pumped or fed to the extrusion heads 16. Figure 2 illustrates the reinforcing material substrate 11, shown herein as a series or reinforcing strips 36 which are fed or wound around the roll 13 and which is transported along its processing path 12 by a vacuum conveyor or belt 37, wherein the foamed adhesive is applied to the strips 36 through the extrusion heads 16. Figure 2 also shows both the use of a single extrusion head 16 which applies the foamed adhesive to a single strip, as well as multiple extrusion heads. extrusion that apply the foamed adhesive to a second single strip or network. Various combinations and configurations of different sizes of extrusion heads may also be used, as necessary or desired to apply desired patterns and / or quantities of adhesive and / or apply the adhesive at the desired locations. The foamed adhesive is also shown as being applied essentially in substantially straight parallel lines 17; however, various other patterns can also be applied. Figure 4 further illustrates an installation of multiple extrusion heads 16 in contact with the substrate of reinforcing material. Each extrusion head 16 can take any shape and is not limited to those depicted in the drawings as long as the foamed adhesive can be extruded onto the reinforcing material substrate. In addition, the different extrusion heads can also be controlled separately in order to apply different patterns and / or varying amounts of foamed adhesive to the reinforcement material substrate. For example, instead of continuous lines of adhesive being applied across the substrate of reinforcing material, separate lines or spots of the foamed adhesive can be applied at selected locations where less adhesive may be needed. Furthermore, the use of different extrusion heads can also allow the use or application of different foamed adhesive materials, as well as the application of both hot-melt adhesive and a cold-setting adhesive to provide immediate adhesion of the carton. and the reinforcing materials for cutting and handling while the cold-setting adhesive is cured and for providing greater resistance to extreme temperatures, as described and claimed in co-pending US Patent Application, Series No., exhibition of which is incorporated herein by reference. Figure 5 illustrates in greater detail the process for forming the pieces 40 of reinforced cartons in which the substrate 11 of reinforcing material, shown here as strips 36, is generally fed from a supply (not shown) to the adhesive applicator station 14. The reinforcing material substrate, such as cat-box material 10, will typically be formed from paperboard or cartonboard materials, but may also be formed from other types of reinforcing materials, including plastic and / or other synthetic or natural materials, as will be understood by those skilled in the art. The reinforcing material may also include a net of length approximately equivalent to the material for cartons or may include one or more smaller rolls of reinforcing material that is pre-cut to a desired width as needed to form the reinforcing strips . These pre-cut strips will generally be fed directly from their supply roll (s), although it will also be understood by those skilled in the art, that a separation station upstream of the adhesive applicator station can also be used to separate the strips from a single supply roll. The reinforcing strips move along their processing path 12 and over the cylinders or rollers 13 while the strips pass through the foamed adhesive applicator station 14. At the foamed adhesive applicator station 14, the foamed extruded adhesive it is applied to the strips of reinforcing material in a desired pattern and at spaced locations across the width of the strips of reinforcing material, including along the side edges of the reinforcing material strips as shown in the Figures 2, 4 and 5. The placement of the adhesive at or along the edges of the strips is allowed by the use of foamed adhesive, which includes air bubbles formed therein such that, in the understanding, the air is It will release or be ejected from the adhesive, allowing it to be compressed, instead of the adhesive coming out from between the side edges of the reinforcement materials and the cation box. A sheet of material for cartons 10 will then be fed from a supply 41 (Figure 5) in a superposition relationship on the strips of reinforcement material having the applied foamed adhesive. As the material of the cardboard boxes and the reinforcement strips are put in alignment, are passed through the rolling station 22, which generally includes one or more pairs of pressure or compression rollers 42 and 43. As the material for cardboard boxes and the reinforcing strips are passed between the rollers of pressure, the pressure rollers engage and apply a sufficient compression force to squeeze or compress the reinforcement strips and the material for cardboard boxes together in adhesive contact. Additionally, a cutting station 44 downstream can be provided to form the pieces of the carton 40 from the laminated material. The part that forms the carton and the cutting process are further described in the U.S. Patent Application. published co-pending US20010048022A1, which is incorporated herein in its entirety. Figures 6A and 6B illustrate a further application of the principles of the present invention to apply a foamed adhesive material to a series of pieces of cardboard boxes 100 that move along an advance path 101 through a line or glue / folder system 102 (FIG. 6A) to form cathode boxes 103. As indicated in FIG. 6A, each of the pieces of the cartons is initially received at an upstream end 104 of the folder / glue line 102 in a flat, non-folded configuration, each of the pieces of the carton typically having a series of panels, such as panels 106, 107, 108 and 109, generally separated by fold lines indicated by dotted lines 111 It should be understood by those skilled in the art that although a piece with four panels has been shown for illustration purposes, various other types of carton parts can also be used. n that have different numbers of panels, including pieces of cardboard boxes with less or more than four folding panels. One of the end panels 109 typically further includes a projection or portion of projection 112 projecting laterally therefrom. The pieces of cardboard boxes 100 move along their path 101 over a series of advance or conveyor belts, including the lower band 113 and the upper band 114 which generally engages the upper surface of at least one of the panels , such as 108, in order to pull the pieces of the cartons forward along their advance path 101 as indicated in Figure 6A. As the pieces of the cartons move along the folder / glue line 102 a first end panel 106 generally engages and moves up and over its adjacent panel 107, bending along the line of folding 111 between the panel 106 and the panel 107 when engaging with a first folding mechanism 116. The first folding mechanism 116 typically includes one or more bars, rods or plates that extend adjacent to the path of advance of the parts of the box of cardboard along the folding / gluing line in such a position that as the pieces of the carton are pulled along the folding / gluing line, their outer panels 106 will be engaged and will guide along the folding mechanism in order to cause the outer panels to be bent into a substantially flat configuration of overlap on the upper part of the upper surface of the adjacent panel 107. After that the first outer panel 106 has been folded in a flat position lying on top of its adjacent panel 107, the panel 106 will generally be additionally engaged by a compression band 117 extending along the path of travel of the pieces of the cardboard box. The compression band 117 applies a compressive force against the folded panels to keep the panel 106 in its folded condition substantially flat on the top of the panel 107. At approximately the same time, the pieces of the cardboard box will typically be passed adjacent to the adhesive application station 120, which typically includes one or more application or extrusion heads 121. The adhesive application station 120 is generally substantially the same as the adhesive application station. 14 discussed above with respect to Figures 1, 2 and 5 and receives a cold-set, foamed, extruded adhesive material from a supply, which is applied in a desired pattern along the projection 112 of the panel 109 of each 100 piece of cardboard box. However, it will be understood by those skilled in the art that although a single extrusion head 121 has been shown, multiple extrusion heads can be used to apply the foamed adhesive material extruded at the desired points along the pieces of the packaging boxes. cardboard as needed for the folding and gluing of various flaps or panels for different designs of the pieces of cardboard boxes. For example, some pieces / cartons can have more than 20 or more points or areas in which the adhesive will typically be applied. Additionally, the foamed adhesive material is generally a cold set foamed adhesive, typically an EVA or PVA adhesive, although other types of adhesive materials, including hot melt adhesives, may also be used, as discussed above. As further illustrated in Figures 6A, after the adhesive material 122 has been applied along its projection 112, each piece of the carton will pass into the clutch with a second folding mechanism 125. As with the first mechanism When folding, the second folding mechanism 125 will generally include a rod or guide plate extending along and over the folder / glue line 102. As a result, as the cardboard boxes engage the second folding mechanism, their panels 109 are folded progressively in a planar configuration over the top of the panels 108, 107 and the pre-folded panel 106. The folded cartons are then typically clutched by a compression mechanism such as a wheel 126, although the webs can be other similar mechanisms for applying a compressive force along the fold line between panels 108 and 109 to help support the panel 109 in its folded configuration laid flat to form a cardboard box 103. After this, each carton is passed to the clutch with a series of pick-up or compression strips 127 and 128, as illustrated in Figure 6B. The compression bands 127 generally clutch and collect the cartons with the cartons held in a disposed arrangement in order to keep the cartons in their flat folded configurations as the cartons pass between the compression bands for setting the foamed, extruded adhesive material and thus forming the finished cartons 103. It will be understood by those skilled in the art that although the present invention has been discussed above with respect to various preferred embodiments and / or features thereof, it can be numerous changes, modifications, additions and deletions without departing from the spirit and scope of the invention as set forth in the following claims.

Claims (22)

1. CLAIMS 1. A method for forming a piece for reinforced cardboard boxes, comprising: moving at least one strip of reinforcing material along a processing path; extruding a foamed adhesive onto at least one strip of reinforcing material in a desired pattern; moving a cardboard box material towards alignment with the at least one strip of reinforcing material; and forming the piece for cardboard boxes from the material for bound cardboard boxes and at least one strip of reinforcing material.
2. 2. The method of claim 1, wherein the foamed adhesive is a water-based emulsion.
3. 3. The method of claim 2, wherein the foamed adhesive emulsion is selected from the group consisting essentially of ethylene vinyl acetate and polyvinyl acetate emulsions.
4. 4. The method of claim 1, wherein the foamed adhesive is extruded in a discontinuous pattern.
5. The method of claim 1, wherein moving the material for cartons into alignment with the at least one strip of reinforcing material includes feeding the material for cartons in contact with the at least one strip of web material. reinforcement and pushing the material for cartons and at least one strip of reinforcement material together to set the adhesive to hold the material for cartons and at least one strip of reinforcement material together.
6. The method of claim 1, wherein driving the web of cardboard and at least one strip of reinforcing material together includes passing the web of cardboard and at least one strip of reinforcing material through compression rolls.
7. 7. A method for forming pieces for reinforced cardboard boxes, comprising moving a reinforcing material and a material for cardboard boxes along a processing path toward the clutch relative to each other; extruding a foamed adhesive in a desired pattern between the reinforcing material and the material for cartons; adhering the reinforcement material and the material for cardboard boxes together to form a material for laminated reinforcement cardboard boxes; and cutting the pieces for cardboard boxes from the material for laminated reinforced cardboard boxes as it continues along the processing path.
8. The method of claim 7, wherein the foamed adhesive is a water-based emulsion.
9. The method of claim 8, wherein the foamed adhesive emulsion is selected from the group consisting essentially of ethylene vinyl acetate and polyvinyl acetate emulsions.
10. The method of claim 7, wherein the foamed adhesive is extruded in a discontinuous pattern.
11. 11. A system for producing cardboard boxes, comprising: a supply of material for cardboard boxes along a processing path; a foamed adhesive applicator station positioned along the processing path to apply a foamed adhesive extruded to the carton material in a desired pattern; and a rolling station downstream of the foamed adhesive applicator station and adapted to engage and propel the material for cartons into contact with the folded portions of the material for cartons or with strips of reinforcing material that are applied to the material for cardboard boxes to form a material for laminated cardboard boxes and / or folded and closed cardboard boxes.
12. The system of claim 11, wherein the rolling station includes at least one pair of compression rollers or bands.
13. The system of claim 11, and further comprising a cutting station for forming the pieces for cardboard boxes from the laminated material.
14. The system of claim 11, further including a foaming station fluidly connected to the foamed adhesive applicator station for supplying the foamed adhesive to the extrusion head station.
15. 15. The system of claim 14, wherein the foaming station includes a storage tank that supplies an adhesive to a skimmer.
16. 16. The system of claim 11, wherein the foamed adhesive is a water-based emulsion.
17. The system of claim 16, wherein the foamed adhesive emulsion is selected from the group consisting essentially of ethylene vinyl acetate and polyvinyl acetate emulsions.
18. 18. A system for producing parts for reinforced carrd boxes comprising: a supply of reinforcement material strips fed along a processing path to the clutch with a material for carrd boxes; a foaming station fluidly connected to a foamed adhesive application station for applying a foamed adhesive to the strips of reinforcing material; a rolling station downstream of the foamed adhesive applicator station adapted to engage and drive the strips of reinforcing material and a material for cartons towards the contact so that the strips and the material for cartons are held together for form a laminated material; and a cutting station for forming the pieces for cardboard boxes from the laminated material.
19. The system of claim 18, wherein the foaming station includes a storage tank that supplies an adhesive to a skimmer.
20. The system of claim 18, wherein the foamed adhesive is a water-based emulsion.
21. The system of claim 20, wherein the foamed adhesive emulsion is selected from the group consisting essentially of ethylene vinyl acetate and polyvinyl acetate emulsions.
22. 22. A system for forming, folding and gluing cardboard boxes as the cartons move along a processing path through a product packaging line, comprising: a first folder for clipping and folding a first series of flaps of cardboard boxes towards a closed position; an adhesive applicator station having at least one extrusion head for applying an extruded foamed adhesive in a desired pattern to at least one flap for cartons; a second folder for engaging and folding a second series of flaps for cardboard boxes to a closed position; and a rolling station running under the second folder to apply a compressive force to the folded cardboard flaps for setting the foamed adhesive applied to the flaps for cardboard boxes.