PAPERBOARD PROTECTIVE CORNER AND METHOD FOR MANUFACTURING THE SAME
20240270472 ยท 2024-08-15
Assignee
Inventors
Cpc classification
B65D2581/053
PERFORMING OPERATIONS; TRANSPORTING
B65D81/054
PERFORMING OPERATIONS; TRANSPORTING
B65D71/0096
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
A paperboard protective corner and a method for manufacturing a paperboard protective corner, the paperboard protective corner comprising: a corner body made of a single paperboard sheet comprising first and second side edges, the single paperboard sheet being folded onto itself to form the paperboard protective corner, the single paperboard sheet including a plurality of folds, both the first and second side edges being received in a corresponding fold so as to be unexposed to an exterior of the paperboard protective corner.
Claims
1-11. (canceled)
12. A method for manufacturing a paperboard protective corner, the method comprising: providing a single paperboard sheet of unlaminated paperboard sheet having a thickness between about 6 pts and about 17 pts and comprising first and second side edges; folding the single paperboard sheet onto itself according to a first folding pattern to form an initial multilayered sheet; folding the initial multilayered sheet according to a second folding pattern to form a final multilayered sheet; and bending the final multilayered sheet at an apex of about 90 degrees to form the paperboard protective corner and to define first and second wings having each at least five layers from the single paperboard sheet, the first and second wings having first and second corner ends each comprising a plurality of folds.
13. The method of claim 12, wherein: folding the single paperboard sheet into the initial multilayered sheet comprises forming a first side portion, a second side portion and a central portion, and folding the initial multilayered sheet into the final multilayered sheet comprises: forming a first multilayer side portion, a second multilayer side portion and a central multilayer portion folded.
14. The method of claim 12, further comprising: moving the single paperboard sheet longitudinally along a paperboard protective corner production line.
15. The method of claim 13, wherein moving the single paperboard sheet longitudinally is performed simultaneously to at least one of folding the first side portion, folding the second side portion and folding the initial multilayered sheet.
16. The method of claim 14, wherein moving the single paperboard sheet longitudinally comprises moving the single paperboard sheet longitudinally at a speed of between about 0 m/s and 300 m/s.
17. The method of claim 14, wherein moving the single paperboard sheet longitudinally comprises moving the single paperboard sheet longitudinally at a speed of more than 200 m/s.
18-20. (canceled)
21. The method of claim 12, wherein the final multilayered sheet is folded according to a same folding pattern as the initial multilayered sheet, the second folding pattern being similar to the first folding pattern.
22. The method of claim 12, wherein folding the initial multilayered sheet into the final multilayered sheet provides the paperboard protective corner the first and second corner ends, the plurality of folds including a first plurality of folds located at the first corner end, the first plurality of folds including an outer fold, a first intermediate fold nested in the outer fold, a second intermediate fold nested into the first intermediate fold and an inner fold nested into the second intermediate fold.
23. The method of claim 22, wherein the plurality of folds further includes a second plurality of folds located at the second corner end, the second plurality of folds including a first outer fold and a second outer fold located adjacent to the first outer fold.
24. The method of claim 12, wherein bending the final multilayered sheet provides each of the first and second wings with nine layers from the single paperboard sheet.
25. The method of claim 12, wherein the single paperboard sheet has a grammage between about 100 g/m.sup.2 and about 380 g/m.sup.2.
26. The method of claim 12, wherein folding the initial multilayered sheet into the final multilayered sheet provides more than four folds in each of the first and second wings.
27. The method of claim 12, wherein folding the initial multilayered sheet into the final multilayered sheet provides five folds in each of the first and second wings.
28. The method of claim 12, wherein bending the final multilayered sheet provides the first wing and the second wing with a same length, the paperboard protective corner being symmetrical.
29. The method of claim 12, wherein folding the initial multilayered sheet further comprises: folding the initial multilayered sheet to form an intermediate multilayered sheet; and folding the intermediate multilayered sheet to form the final multilayered sheet.
30. The method of claim 29, wherein folding the initial multilayered sheet and the intermediate multilayered sheet is made according to the same folding pattern.
31. The method of claim 12, further comprising applying adhesive to the single paperboard sheet.
32. The method of claim 12, wherein the single paperboard sheet and the initial multilayered sheet are folded such that the apex formed between the first and second wings resists a crushing force of at least 90 N.
33. The method of claim 32, wherein the first and second wings have a thickness of 2 mm or more, and wherein the apex formed between the first and second wings resists a crushing force of at least 300 N.
34. The method of claim 33, wherein the first and second wings have a thickness of between 2 mm and 5 mm, and wherein the apex formed between the first and second wings resists a crushing force of between 300 N to 5700N.
35. The method of claim 12, wherein folding the initial multilayered sheet comprises nesting the first and second side edges in or adjacent to a corresponding fold so as to be unexposed to an exterior of the paperboard protective corner.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0038] It will be appreciated that, for simplicity and clarity of illustration, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements or steps. In addition, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art, that the embodiments described herein may be practiced without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to obscure the embodiments described herein. Furthermore, this description is not to be considered as limiting the scope of the embodiments described herein in any way but rather as merely describing the implementation of the various embodiments described herein.
[0039] For the sake of simplicity and clarity, namely so as to not unduly burden the figures with several references numbers, not all figures contain references to all the components and features, and references to some components and features may be found in only one figure, and components and features of the present disclosure which are illustrated in other figures can be easily inferred therefrom. The embodiments, geometrical configurations, materials mentioned and/or dimensions shown in the figures are optional, and are given for exemplification purposes only.
[0040] Moreover, it will be appreciated that positional descriptions such as above, below, top, bottom, forward, rearward left, right and the like should, unless otherwise indicated, be taken in the context of the figures and correspond to the position and orientation in the paperboard protective corner and corresponding parts when being used. Positional descriptions should not be considered limiting.
[0041] The term point is used in the art to measure thickness of a paper sheet or of a paperboard sheet, where 10 points are equivalent to 0.010 in. or 0.25 mm.
[0042] Furthermore, the expressions bend and fold are meant in the sense of curving, deflecting or forming a curvature in a paper sheet.
[0043] The paperboard protective corners as described herein are primarily designed to protect corners or edges of products, such as cases stacked on a pallet during storage, transportation or shipping, home appliances and furniture, as examples only. The protective paperboard protective corners may be used with other types of devices and/or products, and in other fields, as apparent to a person skilled in those arts. The paperboard protective corners can also be referred to as edge protectors or angles.
[0044] In addition, although the preferred embodiments of the present invention are illustrated with certain geometrical configurations as explained herein, not all of these configurations and geometries are essential to the invention and thus should not be taken in their restrictive sense, i.e., should not be taken as to limit the scope of the present invention.
[0045] Referring to
[0046] The paperboard protective corner 100 is an elongated piece of rigid paperboard bent at an angle, usually 90? to form a first wing and a second wing, the paperboard protective corner 100 can be used to protect the edges or corners of unit loads from scratches or other impacts during transport. They may also be used to facilitate the wrapping of stacked products with stretch film.
[0047] In some embodiment, the paperboard protective corner 100 can have a length L of between about 1 m and about 6 m, or between about 2 m and 4 m, and preferably about 2 m.
[0048] In a preferred embodiment, the length of the first wing w1 equals the length of the second wing w2, such as the paperboard protective corner 100 is symmetrical. Alternatively, the length of the first wing w1 could be different than the length of the second wing w2, in an asymmetric configuration. The size of each wing w1, w2 can be between 15 mm and 80 mm, and preferably between 20 mm and 60 mm, and most preferably about 50 mm.
[0049] Referring to
[0050] Still referring to
[0051] Preferably, the paperboard sheet used to form the paperboard protective corners can be used directly from the paper rolls, without having to modify the width of the sheet, i.e., without having to cut the sheet longitudinally, and as explained above, a single sheet is used and folded to form the entirety of the paperboard protective corner.
[0052] In one embodiment, the paperboard sheet 200 further has a thickness between about 6 pts and about 17 pts, or between about 5 pts and about 15 pts, the variation of the thickness affecting the resistance force of the paperboard protective corner 100. In one embodiment, the paperboard sheet 200 is a single layer or ply of unlaminated and non-corrugated paperboard. The paperboard sheet can be made of virgin kraft paper, or recycled kraft paper, or a combination of both. Some water-resistant paperboards can also be used. Alternatively, the paperboard sheet 200 could include any other suitable paperboard. More specifically, in one embodiment, the paperboard sheet 200 can have a grammage (or density) of between about 80 g/m.sup.2 and about 350 g/m.sup.2, and particularly between about 100 g/m.sup.2 and about 200 g/m.sup.2, and most preferably about 140 g/m.sup.2. The density selected for the paperboard sheet 200 can be a compromise between a high density for rigidity and a low density for flexibility and foldability.
[0053] It must of course be considered that the folding steps explained in the subsequent paragraphs are carried out in an automated manner on a production line, as a continuous or in-line process
[0054] In one embodiment, the paperboard sheet 200 can have a humidity ratio of less than 12%, preferably less than 9.5%, or preferably less than 8%, and still preferably between 4% and 8%. It is understood that a higher ratio of humidity will improve the foldability of the paperboard sheet 200 and will prevent tearing of the paperboard when folded. However, higher humidity ratio may reduce the edge crush resistance of the paperboard protective corner.
[0055] Referring to
[0056] Still referring to
[0057] In the illustrated embodiment, the paperboard protective corner 100 includes a corner body 102 extending between first and second corner ends 104, 106. The corner body 102 includes a first wing 108 and a second wing 110 angled relative to the first wing 108 to form a central apex 112 between the first and second wings 108, 110. In this embodiment, the first and second wings 108, 110 are angled relative to each other at an angle of about 90 degrees. Alternatively, the first and second wings 108, 110 could be angled at an angle of more or less than 90 degrees.
[0058] In the embodiment illustrated in
[0059] It will be understood that the paperboard protective corner 100 illustrated in
[0060] Since the paperboard protective corner 100 includes only a single cardboard sheet 200 having first and second side edges 202, 204, the paperboard protective corner 100 also includes only the two side edges 202, 204. In the illustrated embodiment, the cardboard sheet 200 is folded such that the first and second sheet side edges 202, 204 are not exposed to the exterior, but are instead received inside folds formed in the cardboard sheet 200. The exposed side edges of the sheet forming the paperboard protective corners can more easily be peeled off, which can possibly affect the integrity of the corner.
[0061] Forming the paperboard protective corner so that the side edges of the sheets are inside and embedded in the wings avoid their disbanding or peeling from the body of the corner.
[0062] Specifically, the first corner end 104 of the paperboard protective corner 100 includes four folds: an outer fold 114, a first intermediate fold 116 nested into the outer fold 114, a second intermediate fold 118 nested into the first intermediate fold 116 and an inner fold 120 nested into the second intermediate fold 118. In this embodiment, the second side edge 204 of the paperboard sheet 200 is adjacent the inner fold 120 and is received in the second intermediate fold 118 alongside the inner fold 120.
[0063] Still in the illustrated embodiment, the second corner end 106 of the paperboard protective corner 100 includes a first outer fold 122 and a second outer fold 124 located adjacent to the first outer fold 122. The second corner end 106 further includes an intermediate fold 126 nested into the outer fold 122 and an inner fold 128 nested into the intermediate fold 126. In this embodiment, the first side edge 202 of the paperboard sheet 200 is received in the second outer fold 124.
[0064] In this embodiment, the paperboard protective corner 100 therefore includes nine folds: four at each corner end 104, 106 and the central apex 112 forming a ninth fold. As stated above, these folds serve to strengthen and reinforce the paperboard protective corner 100.
[0065] For example, in one embodiment, the apex could have a resistance force of at least about 90 N or at least about 20 lbs, and specifically of between about 100 lbs or about 445 N to about 1280 lbs or about 5680 N, and more specifically of between about 200 lbs or about 890 N and 400 lbs or about 1780 N, depending on the wall thickness of the paperboard protective corner. It is noted that the wall thickness of the paperboard protective corner corresponds to the thickness of each of the first and second wings constituting the corner body of the paperboard protective corner. The resistance force of the apex may be determined experimentally. For example, in one embodiment, the paperboard protective corner 100 may be placed on two blocks, each block being 1.5 inches in width and being separated by about a distance D of about 8 inches, which distance corresponds substantially to the length of the paperboard protective corner to be tested. A force F is applied at a rate of roughly 2/minute to the middle of the paperboard protective corner 100 so mounted, at the apex 112, and the force F measured at the moment that the paperboard protective corner 100 fractures is the resistance force. Alternatively, different distance D (or different length L of the paperboard protective corner) can be considered, such as 10 inches for example. Highest distance D (i.e., highest length L of the paperboard protective corner) may result in lower resistance force F. In an embodiment, the experimental values obtained for a certain length L of the paperboard protective corner can be extrapolated for a different length L of the paperboard protective corner, while experimentation and measurement with the paperboard protective corner of the different length L is recommended for accurate results. Alternatively, the resistance of the apex and/or of the paperboard protective corner 100 may be measured using any other suitable method. It appears that the use of a single continuous sheet, rather than multiple layers of distinct, laminated sheets, allows the corner to better resist crushing forces applied at the apex, as there are no breaks and discontinuities in the material forming the entirety of the paperboard protective corner.
[0066] Table 1 below shows example results of resistance tests performed according to the testing protocol described above on a plurality of paperboard protective corners (14 samples) having different corner wall thicknesses ranging from about 3.5 mm to about 5 mm, and different humidity level ranging from about 4.6% to about 5.4% of humidity, the plurality of paperboard protective corners being configured as described above. Specifically, the tests were performed on corners having a length L of about 8 inches (20 cm), and with symmetrical wings, both having a width w1, w2 of about 2 inches (50 mm).
TABLE-US-00001 TABLE 1 Resistance force vs wall thickness and humidity level for several corners' samples Average Wall thickness Humidity Resistance Resistance (in/mm) (%) Sample # Force (N) Force (N) 0.14/3.5mm.sup. 5.4 #1 2680.3 2286.35 4.6 #2 2450.1 4.7 #3 2158.7 4.7 #4 1856.3 0.16/4 mm 5.4 #5 3374.6 3359.77 4.6 #6 3399.7 5 #7 3305 0.18/4.5 mm 5 #8 4043 4136.38 4.9 #9 4472.1 4.9 #10 3765.1 4.7 #11 4265.3 0.2/5 mm 4.7 #12 5389.5 5461.37 5.4 #13 5314.6 4.8 #14 5680
[0067] It can be observed that the corners having the above-described configuration have a substantially high resistance force, higher than the conventional corners. For example, for corners having a wall thickness of about 3.5 mm, the paperboard protective corner had an average resistance of about 2286 N. According to these results, it will be understood that it would be possible to manufacture a corner similar to the paperboard protective corner as described above with a wall thickness wt0 which would have substantially the same resistance than a conventional corner having a wall thickness t1, with wt0 being substantially smaller than wt1, thereby substantially reducing the required amount of paperboard needed to manufacture a paperboard protective corner. Moreover, this would also substantially reduce the weight and the space occupied by each corner, which may substantially reduce the costs associated with the transportation of the corners.
[0068] Still referring to Table 1, a resistance test was also performed on a paperboard protective corner as described above and having a wall thickness of about 4.5 mm and 5 mm. The resistance of the paperboard protective corner was observed to be between about 3765 N and 4470 N, and between about 5300 N and 5680N, respectively. It is noted that the average resistance force can be substantially a linear function or relation of the wall thickness. While Table 1 does not display the average resistance force for a wall thickness of 2 mm, by extrapolating the values of Table 1, it is noted that the resistance of the paperboard protective corner with a wall thickness of 2 mm can be at least 300N, or more preferably at least 350N. In other words, the apex of the paperboard protective corner having a wall thickness (or thickness of the first and second wings) of between 2 mm and 5 mm can resist to a crushing force of between 300N and 560N, respectively.
[0069] Still in this embodiment, having the ends 202, 204 of the paperboard sheet 200 received into the folds 118, 124 substantially prevents the ends 202, 204 from becoming undone, which could potentially cause the entire corner 100 to unravel. It also prevents the ends 202, 204 from being snagged, which could damage the corner and also cause the ends 202, 204 to become undone.
First Embodiment9 Layers
[0070] Referring now to
[0071] As shown in
[0072] As shown in
[0073] In this configuration, folding the first side portion 210 over the central portion 214 forms a fold corresponding to the inner fold 120 of the first corner end 104 and folding the second side portion 210 over the first side portion 210 forms a fold corresponding to the second outer fold 124 of the second corner end 106.
[0074] In the illustrated embodiment, the width w0 of the first side portion 210 and the width w2 of the second side portion 213 are substantially the same than the width w4 of the central portion 214 of the paperboard sheet 200. Alternatively, the first side portion 210 and/or the second side portion 213 could have a width which is substantially smaller than the width of the central portion 214. The width w of the paper sheet thus corresponds to the sum of the widths w0, w2 and w3. The folds are formed from the sheet of paper that is continuously unwound from the paper roll at the start of the production line, by mechanical guides and fingers that gradually bend and form the folds 120 and 124, as the paper sheet passes through the guides.
[0075] As shown in
[0076] In one embodiment, the first multilayered intermediate sheet 300 is then folded onto itself again to increase the thickness of the paperboard protective corner 100 as well as to provide additional folds to the paperboard protective corner 100 to further strengthen the paperboard protective corner 100. Specifically, as shown in
[0077] As shown in
[0078] In the illustrated embodiment, the first and second multilayer side portions 306, 308 and the central multilayer portion 310 of the first multilayered intermediate sheet 300 have substantially the same width. Alternatively, the first multilayer side portion 306 and/or the second multilayer side portion 308 could have a width which is substantially smaller than the width of the central multilayer portion 310.
[0079] As shown in
[0080] In the illustrated embodiment, the second multilayered intermediate sheet 400 is then bent at an angle of about 90 degrees substantially at its center to form the central apex 112 and the first and second wings 108, 110 on either side of the central apex 112, as shown in
[0081] Referring now to
[0082]
Second Embodiment9 Layers
[0083] Referring to
[0084] As shown in
[0085] In the illustrated embodiment, the width w10 of the first side portion 1210 is substantially equal to 1/9.sup.th of the total width w of the paperboard sheet 1200, and the width w13 of the second side portion 1213 is substantially equal to ? .sup.rd of the total width w of the paperboard sheet 1200. The width w14 of the central portion 1214 is substantially equal to 5/9 .sup.th of the total width w of the paperboard sheet 1200.
[0086] As shown in
[0087] As shown in
[0088] In one embodiment, the second side portions 1213 includes a first side sub-portion 1302 located adjacent the second side edge 1204 and a second side sub-portion 1305 located adjacent a second outer fold 1124. The width of the second side sub-portion 1305 is substantially twice the width of the first side sub-portion 1302.
[0089] As shown in
[0090] As shown in
[0091] In the illustrated embodiment, the first and second side portions 1304, 1306 of the first multilayered intermediate sheet 1300 have a width ratio of substantially ?, i.e., the width of the first side portion 1304 is substantially ?.sup.th of the total width of the first multilayered intermediate sheet 1300, and the width of the second side portion 1306 is substantially ?.sup.th of the total width of the first multilayered intermediate sheet 1300.
[0092] As shown in
[0093] Referring to
[0094] In the illustrated embodiment, the third multilayered intermediate sheet 1500 is then bent at an angle of about 90 degrees substantially at its center to form the central apex 1112 and the first and second wings 1108, 1110 on either side of the central apex 1112, as shown in
Third Embodiment9 Layers
[0095] Referring to
[0096] As shown in
[0097] In the illustrated embodiment, the width w20 of the first side portion 2210 and the width w23 of the second side portion 2213 are substantially equal together and correspond substantially to 1/9.sup.th of the total width w of the paperboard sheet 2200. The width w24 of the central portion 2214 is substantially equal to 7/9.sup.th of the total width w of the paperboard sheet 1200.
[0098] As shown in
[0099] More specifically, the first side portion 2210 is folded onto the central portion 2214 such that the first face 2206 of the first side portion 2210 extends over the first face 2206 of the central portion 2214. The second side portion 2213 is also folded onto the first side portion 2210 such that the first face 2206 of the second side portion 1213 extends over the first face 2206 of the central portion 2214.
[0100] As shown in
[0101] As shown in
[0102] As shown in
[0103] As shown in
[0104] As shown in
[0105] The second multilayered intermediate sheet 2500 includes four layers for the first and second side portions 2510, 2512, and includes one layer for the central portion 2508. In particular, the first and second side portions 2510, 2512 have a width significantly equal to the width of the central portion 2508.
[0106] Referring to
[0107] In the illustrated embodiment, the fourth multilayered intermediate sheet 2600 is then bent at an angle of about 90 degrees substantially at its center to form the central apex 2112 and the first and second wings 2108, 2110 on either side of the central apex 2112, as shown in
Fourth Embodiment9 Layers
[0108] Referring to
[0109] As shown in
[0110] In the illustrated embodiment, the width w30 of the first side portion 3210 and the width w33 of the second side portion 3213 are substantially equal together and correspond substantially to 2/9.sup.th of the total width w of the paperboard sheet 3200. The width w34 of the central portion 3214 is substantially equal to 5/9.sup.th of the total width w of the paperboard sheet 1200.
[0111] As shown in
[0112] More specifically, the first side portion 3210 is folded onto the central portion 3214 such that the first face 3206 of the first side portion 3210 extends over the first face 3206 of the central portion 3214. The second side portion 3213 is also folded onto the first side portion 3210 such that the first face 3206 of the second side portion 3213 extends over the first face 3206 of the central portion 3214.
[0113] As shown in
[0114] As shown in
[0115] As shown in
[0116] Specifically, the first side edge 3202 and the second side edge 3204 of the paperboard sheet 3200 are both located in the middle layers of the first and second side portions 3410, 3412, such that both first side edge 3202 and second side edge 3204 are recovered by the fold of the first and second side portions 3410, 3412.
[0117] As shown in
[0118] Referring to
[0119] In the illustrated embodiment, the third multilayered intermediate sheet 3500 is then bent at an angle of about 90 degrees substantially at its center to form the central apex 3112 and the first and second wings 3108, 3110 on either side of the central apex 3112, as shown in
[0120] As can be appreciated, the different embodiments described above are all formed of two multilayered sheets, where the wings of the paperboard protective corner comprise 9 layers in total from the same folded sheet, with the side edges of the sheet located and hidden inside the wings. It is believed that the combination of using a single continuous sheet folded at the corner ends preserves the integrity of the raw material forming the corner and thus allows providing resistance to crushing forces applied on the apex of at least 90 N, and preferably at least 200N, and preferably at least 300N for a corner wall thickness of 2 mm, without having to add a reinforcing core to the corner, nor using laminate made of several distinct sheets.
Fifth Embodiment5 Layers
[0121] Turning to
[0122] In this embodiment, the first corner end 104 includes first and second folds 108, 110 and the first side edge 202 of the paperboard sheet 200 received between the first and second folds 108, 110. The second corner end 106 includes an outer fold 112 and an inner fold 114 nested in the outer fold 112, the second side edge 204 of the paperboard sheet 200 being received in the outer fold 112 alongside the inner fold 114.
[0123] As shown in
[0124] In the illustrated embodiment, the width w0 of the first side portion 210 and the width w3 of the second side portion 213 are substantially equal together and correspond substantially to ?.sup.th of the total width w of the paperboard sheet 200. The width w4 of the central portion 214 is substantially equal to ?.sup.th of the total width w of the paperboard sheet 200.
[0125] In a preferred embodiment, the width w0 of the first side portion 210 can be significantly smaller than the width w3 of the second side portion 213, to ensure that the first side edge 202 of the paperboard sheet 200 is well nested and well protected between the first and second folds 108, 110.
[0126] As shown in
[0127] As shown in
[0128] As shown in
[0129] Referring to
[0130] In the illustrated embodiment, the second multilayered intermediate sheet 400 is then bent at an angle of about 90 degrees substantially at its center to form the central apex 107 and the first and second wings 109, 121 on either side of the central apex 107, as shown in
[0131] In this embodiment, the paperboard sheet 200 comprises five folds, including two folds at each corner end and the central apex 107 forming the fifth fold. Similar to the 9-layer paperboard protective corners, the side edges are hidden and nested inside the wings of the corner. This version of the paperboard protective corner is also manufactured in a continuous, in-line process, with the folds being formed as the paperboard sheet interacts with guides located along the production lines.
Sixth Embodiment11 Layers
[0132] Turning now to
Adhesive
[0133] It will be understood that an adhesive such as glue or the like is further applied to the paperboard sheet 200 to allow the paperboard protective corner 100 to retain its final configuration. In one embodiment, the adhesive may be applied along the entire paperboard sheet 200 prior to folding. In another embodiment, the adhesive may be applied between each folding step as required. For example, stations to apply adhesive can be located near or between the mechanical guides that form the folds. Alternatively, the adhesive may be applied in any other suitable manner. The adhesive can include polyvinyl alcohol, polyvinyl acetate, sodium silicate-based glue, or polyurethane-based glue. In some embodiment, starch-based glue can be used, which will consistently increase rigidity but is not hydrophobic. The adhesive can be applied with a roller coat, a spray, a brush, a trowel, or any suitable tool.
Additional Embodiments
[0134] Alternatively, the paperboard protective corners as described above can further comprise an adhesive strip applied along the length of the protective corner, on each internal side of the first and second wings, to facilitate proper fixation on the goods to be protected. The paperboard protective corners as described above can further comprise a coating, such as a Michelman? water-based coating for allowing the paperboard protective corner to adhere, grip or stick onto the product on which it is applied, preventing the paperboard protective corners to slide down from the goods to be protected.
Production Line
[0135] As explained previously, the paperboard protective corner 100 is preferably made on a paperboard protective corner production line which is configured to allow a plurality of paperboard protective corners to be manufactured successively. Specifically, the paperboard sheet 200 is unwound from a paper roll and is substantially long to allow the different folding and gluing steps to take place along the line, using static guides or mechanized fingers. The production line is configured to move the paperboard sheet 200 along a travel path, using for example rollers provided along the line, in a longitudinal direction (corresponding to a longitudinal direction of the paperboard protective corner) substantially continuously during the manufacturing process. The production line further includes folding stations that are located along the travel path, each folding station being configured to perform one or more of the folding operations disclosed above. For example, in one embodiment, the production line could include a first folding station configured for folding the first side portion 210 onto the central portion 214, a second folding station for folding the second side portion 213 onto the first side portion 210, a third folding station for folding the first side portion 306 of the multilayered intermediate sheet 300 onto the central portion 310, a fourth folding station for folding the second side portion 308 onto the first side portion 306 and a bending station to bend the second multilayered intermediate sheet 400 at an angle of about 90 degrees substantially at its center to form the central apex 112. In one embodiment, the production line can further include a cutting station located downstream from the folding station(s) to cut the paperboard protective corner to a desired length.
[0136] In one embodiment, the folding stations perform the folding operations while the paperboard sheet moves continuously along the travel path. More specifically, the production line can be configured to perform the above folding operations while the paperboard sheet moves along the travel path at a substantially constant speed. In this case, manufacturing the paperboard protective corner 100 using a single paperboard sheet may allow the paperboard sheet to be moved along the travel path at a substantially higher speed than if the corner was made from multiple paperboard sheets, which may therefore increase the production rate of the paperboard protective corners. For example, in one embodiment, the paperboard sheet may be moved longitudinally along the travel path at a speed of between about 0 m/s and 300 m/s, or at a speed of more than 200 m/s. Alternatively, the paperboard sheet may be moved along the travel path at any other suitable speed.
[0137] In one embodiment, the paperboard sheet 200 could be an existing paperboard sheet having a standard width and the folding operations disclosed above could form a paperboard protective corner 100 having a desired size. This would allow paperboard protective corners of the desired size to be manufactured without having to pre-cut the paperboard sheet to reduce its width in order to obtain a paperboard protective corner 100 having the desired size. Alternatively, the paperboard sheet 200 could be pre-cut to reduce its width in order to obtain a paperboard protective corner having the desired size.
[0138] It will be understood that the configuration and folding patterns described above are merely provided as examples and that various alternative configurations could be considered. In all possible alternative configurations, the first and second side edges 202, 204 of the cardboard sheet 200 are well nested in a fold, to prevent the first and second side edges 202, 204 to be free and subject to peeling.
[0139] While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto.