How to reinforce cardboard containers

Abstract

A method for reinforcing a standard, regular slotted, top-loaded corrugated container having outer and inner linerboard layers with a fluted or corrugated intermediate layer bonded between both outer linerboard layers, characterized in that three paper patches are bonded onto the inner or outer linerboard of the container board web sheet.

Description

[Background Technology]

[0001] Reducing packaging raw materials is important for preserving the environment for the future. This invention reduces material consumption by up to 30% by increasing the top compression and side panel impact strength of corrugated cardboard cases. Regular slotted corrugated (top-load) containers are made from up to 100% recyclable and biodegradable materials. Single-ply corrugated boards have outer and inner kraft paper linerboards, with a middle corrugated (corrugated) kraft paper linerboard layer between the two. According to this invention, three kraft paper patches (3-4% of the total kraft paper web sheet area of ​​the container board) are glued onto the inner or outer linerboard of the container board web sheet, respectively, overlapping the upper and lower top and bottom horizontal panel flaps arising from the container sleeve surrounding the fold line. Furthermore, the top and bottom sections of the container board containing the kraft paper patches overlap the top and bottom sections of the corner panels of the container board after slot insertion in the next manufacturing station, a fifth panel at the fourth panel corner is glued, and the container panels are folded into a finished container. In regular slotted corrugated containers, only three corners require reinforcement, since the fourth corner is already reinforced by the overlapping corrugated cardboard of the container's fifth panel. A fourth reinforced paper corner patch is optional. First, adhesive is applied by a flexographic printing press onto the inner or outer kraft linerboard layer of the containerboard web sheet in a pattern and location similar to the kraft patch applied by compression in the following sequential production station. One low-volume, affordable kraft patch cutting and feeding method involves feeding the kraft web from a roll with dual feed rollers, stopping the kraft web at the required kraft patch length, and using a serrated cutting blade to cut the kraft web to the correct patch length. Multiple interlocking linerboard web bridges are not cut, maintaining the perforated kraft web connection and ensuring the next linerboard patch can be fed without jamming. A jam-proof kraft web guide, fixed between each feed roller, begins below the periphery of the outer roller and extends over it at an angle of approximately 60° to 90°.The kraft paper patches are connected across the entire width of the kraft paper web by multiple small linerboard web bridges, allowing the connected kraft paper patches (webs) to be transferred to a rotating vacuum drum (requiring small-diameter transfer rollers), allowing each kraft paper patch to be fed onto a continuously moving inner or outer linerboard container board web sheet. A 25mm diameter drive shaft has ball bearings between each group of two or three dual kraft paper supply and vacuum drum transfer rollers. A 45mm diameter concentric sleeve design is connected to the 25mm diameter drive shaft by concentric spacer sleeves between each concentric drive roller, and is secured to both ends of the 25mm drive shaft by double-slotted disc springs. The dual web supply and vacuum drum transfer concentric drive rollers have a linear knurled surface drive pattern, which includes an upper arch panel with multiple linear micro-tooth profiles around its periphery with a smooth circular surface. The serrated cutting blades below the dual supply rollers are actuated by a crankshaft driven by a stepper motor. After the kraft paper web perforation lines emerge from the vacuum drum's dual feed rollers, one kraft paper patch is peeled off the kraft paper web by the vacuum drum. The kraft paper patch then moves along the rotating vacuum drum surface, where it is compressed and sealed by adhesive areas onto the continuously moving outer linerboard surface of the container board web sheet. The vacuum drum rotates continuously. The vacuum drum does not have a perforated vacuum section across the entire drum width, but rather has four to six perforated circular vacuum lane panels around the drum surface connected to a central bearing sleeve. Ball bearings rotate around an inner, stationary, non-rotating shaft, which is attached to a vacuum interrupter bracket, ultimately positioned one per vacuum line (see side view of section in Figure 3). A second high-capacity kraft paper web cutting and feeding method uses a servo motor driven by a servo drive connected to a microprocessor to drive and position a drive shaft with a serrated cutting blade, which requires the blade to rotate on a larger circular orbit.The shaft with the serrated blades must operate at a minimum speed that is consistent with the kraft paper web speed during the perforating moment when the serrated blades perforate the kraft paper web and enter the anvil grooves of the dual rollers. The serrated perforating rollers have elastomeric compression cushions protruding from both sides of the serrated perforating blades. The front of the elastomeric cushions rise slightly above the edges of the multiple serrated cutting blades, maintaining the kraft paper web in a firm position during perforation. Because the patched kraft paper does not need to reach both ends of the container sleeve precisely, the web width of the two kraft paper rolls can cover all container sizes. In principle, only the corrugated container crease lines for the top and bottom panels need to be overlapped by the kraft paper patch. The kraft paper patching cycle begins with a section of the correct kraft paper patch length being perforated by the serrated cutting blades and then sliding on the rotating vacuum drum, where it is held in a "holding" position by the dual vacuum drum web transfer rollers. The kraft paper patch is delivered when the web perforation line exits the vacuum drum dual web patch transfer roller, which ejects the entire kraft paper patch onto the rotating vacuum drum as it rotates, precisely feeding and compressing it onto the adhesive area on the moving outer linerboard of the container web sheet. If the kraft paper patch does not match the adhesive mark on the patched paper after it is glued onto the corrugated container web sheet, adhesive that may be a different color than the linerboard web will appear outside the kraft paper patch area. The color matching mark sensor sends a reference signal to the microprocessor, and the servo controller adjusts the servo motor sawtooth blade position to correct the kraft paper patch release time for additional kraft paper patches. Rotating nylon brushes with non-sticky, fixed Teflon adhesive scrapers and vacuum cleaners to remove residual adhesive from any continuous rollers may be redundant if there is a precise adhesive pattern. Unfortunately, the third kraft paper patch application method would slow machine production speed by picking each kraft paper patch one by one from a stack of already finished cut-to-size kraft paper patches.As the rotary suction device rotates around the second outer circular periphery, it picks up linerboard patches from the top of the linerboard patch stack, adjusting the speed to the same as the continuously cut corrugated web sheets, and accurately feeds and places the kraft paper patches onto the adhesive pattern printed on the continuously cut outer linerboard of the container board web sheets.Two automatically interchangeable kraft paper patch trays are equipped with stepping motors that drive the bottom of the patch trays up and down and are controlled by photoelectric sensors to control the top kraft paper patch level so that it always has the same position. Summary of the Invention [Problem to be solved by the invention]

[0002] SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome the above-mentioned problems and drawbacks associated with known methods of reinforcing corrugated containers in the prior art.

[0003] Another object of the present invention is to provide a more economical corrugated container having reduced paperboard weight.

[0004] It is yet another object of the present invention to provide a corrugated cardboard container that reduces consumption of natural resources. [Brief explanation of the drawings]

[0005] [Figure 1] An isometric view of a corrugated cardboard container with linerboard patched around the vertical outer corners and overlapping the horizontal top and bottom panel edges of the container [Figure 2] FIG. 1 is a side view of a rotating adhesive applicator applying adhesive spots onto the inner or outer linerboard layer of a corrugated container board sheet in a glue pattern and location generally identical to that of the kraft paper linerboard patches applied in a continuous manufacturing process. [Figure 3]A side view of one manufacturing method in which kraft paper patches are cut and applied by a vacuum drum to a continuously moving corrugated container board web sheet outer kraft paper linerboard. DETAILED DESCRIPTION OF THE INVENTION

[0006] 2 is a side view of a flexographic adhesive application printing unit, which prints an adhesive pattern onto the inner or outer linerboard of container board web sheet 1. From adhesive tray 2, fountain roller 3 picks up an adhesive layer as it rotates and supplies the adhesive layer to rotating anilox roller 5, which then provides a uniform adhesive layer to flexographic plate 6 fixed to plate cylinder 7, which then rotates and transfers the adhesive pattern onto the linerboard of container board web sheet 1 by impression cylinder 8.

[0007] Figure 3 shows a side view of one simple kraft paper patching unit. The kraft paper web 9 is fed by dual feed rollers 10, actuated by a dancer bar 11. The kraft paper web 9 continues onto a main feed roller 12 and enters dual kraft paper web feed rollers 14, which have non-slip outer web-gripping surfaces. The kraft paper web 9 receives support from dual vacuum drum kraft paper transfer rollers 17, which feed a continuous kraft paper web. A precise kraft paper patch length is cut by a serrated cutting blade 15 until stopped by a stepper motor or electromagnetic coupling, driven by a crankshaft 16 with a stroke length of less than 5 mm. Fixed, jam-proof kraft paper web guides 13 are oriented between each feed roller, starting below the outer roller periphery and extending beyond the feed roller periphery at an angle of approximately 60° to 90° in the web feed direction. The kraft paper patch 22, still attached to the kraft paper web by a number of small kraft paper web connecting bridges, slides around the rotating vacuum drum 23 until its end exits the dual vacuum drum kraft paper transfer roller 17, where the kraft paper web connecting bridges peel off and the kraft paper patch 22 is securely attached to the rotating vacuum drum 23. The rotating vacuum drum 23 receives a vacuum from the outside of the drum via a non-rotating vacuum manifold 19, which is interrupted by a non-rotating vacuum interrupting bracket 21 inside the drum. As the kraft paper patch 22 moves with the vacuum drum 23, it merges onto the continuously moving container board web sheet and is adhesively compressed and bonded to the continuously moving outer linerboard of the container board web sheet by an impression cylinder 24. The non-rotating vacuum interrupting bracket 21 interrupts the vacuum at the perforated vacuum drum surface, releasing the kraft paper patch 22 from the rotating drum, and the impression cylinder 24 attaches the kraft paper patch 22 to the outer linerboard of the corrugated web sheet. A rotating nylon brush 18 and a stationary Teflon scraper 20 loosen residual adhesive from the rotating vacuum drum surface, which is picked up by a vacuum supply line 20 .

[0008] The present invention should not be construed as limited to the above examples, but rather should be understood to encompass equivalent methods and processes of all manner to which the present invention may be applicable, as well as numerous structures, which will be readily apparent to those skilled in the art to which the present invention is directed upon review of the specification.

Claims

1. 1. A method of reinforcing a regular slotted (top-loaded) corrugated container having outer and inner linerboard layers with a corrugated (corrugated) intermediate layer bonded between both outer linerboard layers, wherein the single-wall container board has three reinforced panel corners and a fifth panel section of a fourth panel is bonded / bonded to a first container body panel; Three separate plain paper strips are laminated uniformly to the inner linerboard of the single-wall plain paper board of the container by adhesive, each of the plain paper strips passes through an upper fold / crease line for a top closed end panel flap of the container, one end of the plain paper strips is slotted in two, a portion of the slotted plain paper strip is laminated to a side section edge region of one top closed end panel flap, and the other portion of the slotted plain paper strip is laminated to one of the other top closed end panel flaps. and for bottom closure of the container, the other end of the plain paper strip passes through a lower fold / crease line for a bottom closing end panel flap of the container, one end of the plain paper strip is slotted in two, a portion of the slotted plain paper strip is laminated to the side section edge region of one bottom closing end panel flap, and the other portion of the slotted plain paper strip is laminated to the side section edge region of one of the other bottom closing end panel flap.

2. 10. The method of reinforcing a regular slotted (top loaded) corrugated board container according to claim 1, characterized in that three separate paper strips are laminated onto the outer linerboard of the flat single wall board of said container.

3. 3. A method for reinforcing regular slotted (top-loaded) corrugated board containers according to claim 1 or 2, characterized in that at least one single paper strip is compressed and laminated to the adhesive area of ​​the moving inner or outer linerboard of said container board web sheet by a rotating vacuum drum.

4. 4. The method for reinforcing regular slotted (top-loaded) corrugated board containers according to any one of claims 1 to 3, characterized in that a servo motor drives a rotating shaft, and a serrated perforating blade has a plurality of intermittent uncut paper web bridge sections, and the serrated perforating blade edge cuts perforation lines in the paper web which is continuously moving against a rotating (second) anvil roller, and during the cutting moment, the second rotating anvil roller overlaps the outer cylindrical outer periphery, and the serrated perforating blade edge enters a groove generally across the second rotating anvil roller during the cutting moment.

5. 5. The method of reinforcing regular slotted (top-loaded) corrugated board containers according to any one of claims 1 to 4, characterized in that the web is held between two dual intermittently operating rotating rollers, and in a non-moving position, the serrated perforating blades are between the serrated perforating blades, having a plurality of intermittent uncut paper web sections, and cut substantially straight perforation lines across the paper web perforation lines against a permanent fixed slotted anvil.

6. 6. A method for reinforcing regular slotted (top-loaded) corrugated board containers according to any one of claims 1 to 5, characterized in that the paper strips are picked up one by one from a stack of paper strips by a vacuum device, and moved and laminated to the bonding area of ​​the inner or outer linerboard of the single-wall flat container board sheet by the rotating vacuum suction device.

7. 7. A method for reinforcing regular slotted (top-loaded) corrugated board containers according to any one of claims 1 to 6, characterized in that the adhesive pattern and the paper strip on the inner or outer linerboard of the single-walled planar container board have generally the same surface pattern.

8. 8. The method of reinforcing regular slotted (top-load) corrugated containers according to any one of claims 1 to 7, characterized in that a color registration mark sensor registers a colored adhesive mark on the linerboard ahead of a paper strip and sends a signal to a microprocessor with a servo motor controller to advance the paper strip on the linerboard, or if the colored adhesive mark passes the trailing end of the paper strip using the color registration mark sensor, sends a signal to the microprocessor with a servo motor controller to retard the paper strip on the linerboard.

9. 9. The method for reinforcing regular slotted (top-loaded) corrugated board containers according to any one of claims 1 to 8, characterized in that the color matching mark sensor registers the printed color marks on the container board sheet and sends a registration signal to a microprocessor having a servo motor controller to position the paper web sawtooth rotary cutting blade shaft, cut the perforation line at the exact paper strip peeling position to separate one paper strip from the paper web by the rotating vacuum drum, and accurately attach the surface of the separated paper strip onto the adhesive mark printed on the moving container board sheet.

10. A method for reinforcing regular slotted (top loaded) corrugated containers according to any one of claims 1 to 9, characterized in that the paper strip rotates around a rotating perforated vacuum applicator drum, an outer non-rotating vacuum supply line and an inner non-rotating vacuum shut-off bracket.

11. 11. The method for reinforcing regular slotted (top-loaded) corrugated containers according to any one of claims 1 to 10, characterized in that the rotating paper strip vacuum application drum is fed by a line of multiple identical dual feed and transfer rollers with protruding web guides and concentric distance spacers between the dual feed and transfer rollers, each of the dual feed and transfer rollers being connected to and driven by one or two drive shafts.

12. 12. The method of reinforcing regular slotted (top loaded) corrugated containers according to any one of claims 1 to 11, characterized in that at least one fixed adhesive scraper and at least one rotating nylon brush collect residual adhesive from the rotating vacuum drum by a vacuum inlet / hose cleaner, removing said residual adhesive from said adhesive scraper and said rotating nylon brush.

13. 13. The method of reinforcing regular slotted (top-loaded) corrugated board containers according to any one of claims 1 to 12, characterized in that the paper strip adhesive has a different color from the brown linerboard web and is recognizable by a color matching mark sensor to identify the color difference between the paper strip adhesive and the linerboard web.

14. 14. The method of reinforcing a regular slotted (top-loaded) corrugated board container according to any one of claims 1 to 13, characterized in that the corrugated board container has three or four crossed reinforcing paper strip corner sections, and the corrugated board container design can differ from a regular (top-loaded) corrugated board container design.

15. A method for reinforcing regular slotted (top loaded) corrugated board containers according to any one of claims 1 to 14, characterised in that the paper strips are attached and laminated by adhesive to either side of three successively moving single wall board paper layers or container board sheets.

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