POLYMERIC WRAPPING MATERIAL

Abstract

A wrapping material having three distinct polymeric layers interfaced with a woven polymeric scrim is disclosed. A first polymeric layer is formed by extruding a first polymeric coating onto the scrim. A second polymeric layer and a third polymeric layer are simultaneously formed by co-extruding a second polymeric coating onto the scrim and a third polymeric coating onto the second polymeric coating.

Claims

1. A wrapping material comprising: a sheet comprising a plurality of first polymeric tapes and a plurality of second polymeric tapes, the first and second polymeric tapes being interwoven; a first polymeric coating applied to a first side of the sheet; a second polymeric coating applied to a second side of the sheet; and a third polymeric coating applied to the second polymeric coating.

2. The wrapping material of claim 1, wherein the sheet has a width in the range of 1.22 m to 3.86 m.

3. The wrapping material of claim 1, wherein the sheet has a thickness in the range of 0.03 mm to 0.14 mm.

4. The wrapping material of claim 1, wherein the sheet has a weight in the range of 25 g/m.sup.2 to 100 g/m.sup.2.

5. The wrapping material of claim 1, wherein the first polymeric coating is substantially white in color.

6. The wrapping material of claim 1, wherein the first polymeric coating has an L* value>60, in the CIELAB color space.

7. The wrapping material of claim 1, wherein the first polymeric coating comprises at least one of polypropylene and polyethylene.

8. The wrapping material of claim 1, wherein the first polymeric coating forms a marking layer of the wrapping material, the marking layer suitable for printing indicia thereon.

9. The wrapping material of claim 8, wherein a thickness of the marking layer is in the range of 0.01 mm to 0.04 mm.

10. The wrapping material of claim 1, wherein a weight of the first polymeric coating is in the range of 10 g/m.sup.2 to 40 g/m.sup.2.

11. The wrapping material of claim 1, wherein the second polymeric coating is substantially black in color.

12. The wrapping material of claim 1, wherein the second polymeric coating has an L* value<30, in the CIELAB color space.

13. The wrapping material of claim 1, wherein the second polymeric coating comprises at least one of polypropylene and polyethylene.

14. The wrapping material of claim 1, wherein the second polymeric coating forms a UV-blocking layer of the wrapping material, the UV-blocking layer operable to block UV light from passing through the UV-blocking layer.

15. The wrapping material of claim 14, wherein a thickness of the UV-blocking layer is in the range of 0.005 mm to 0.038 mm.

16. The wrapping material of claim 1, wherein a weight of the second polymeric coating is in the range of 5 g/m.sup.2 to 38 g/m.sup.2.

17. The wrapping material of claim 1, wherein the third polymeric coating is darker than the first polymeric coating and lighter than the second polymeric coating.

18. The wrapping material of claim 1, wherein the third polymeric coating comprises at least one of polypropylene and polyethylene.

19. The wrapping material of claim 1, wherein the third polymeric coating forms a cover layer of the wrapping material.

20. The wrapping material of claim 19, wherein a thickness of the cover layer is in the range of 0.002 mm to 0.022 mm.

21. The wrapping material of claim 1, wherein a weight of the third polymeric coating is in the range of 2 g/m.sup.2 to 22 g/m.sup.2.

22. The wrapping material of claim 1, wherein the second polymeric coating forms a UV-blocking layer of the wrapping material, the UV-blocking layer operable to block UV light from passing through the UV-blocking layer; wherein the third polymeric coating forms a cover layer of the wrapping material; and wherein a combined thickness of the UV-blocking layer and the cover layer is in the range of 0.01 mm to 0.04 mm.

23. A method of manufacturing a wrapping material, the method comprising: providing a polymer feedstock; form first polymeric tapes from the feedstock; form second polymeric tapes from the feedstock; weaving the first polymeric tapes and the second polymeric tapes to form a polymeric scrim; applying a first polymeric coating to a first side of the polymeric scrim; and simultaneously applying a second polymeric coating to a second side of the polymeric scrim and a third polymeric coating to the second polymeric coating.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The general inventive concepts, as well as embodiments and advantages thereof, are described below in greater detail, by way of example, with reference to the drawings in which:

[0061] FIGS. 1A-1B illustrate a conventional polymeric wrapping material. FIG. 1A is a top plan view of the wrapping material. FIG. 1B is a detailed view of the sheet used to form the wrapping material.

[0062] FIG. 2 is a diagram showing different layers of a first conventional coated polymeric wrapping material.

[0063] FIG. 3 is a diagram showing different layers of a second conventional coated polymeric wrapping material.

[0064] FIGS. 4A-4C are diagrams illustrating a coated polymeric wrapping material, according to an exemplary embodiment. FIG. 4A is a top plan view of the wrapping material.

[0065] FIG. 4B is a detailed view of the sheet used to form the wrapping material. FIG. 4C is a diagram showing different layers of the wrapping material.

[0066] FIG. 5 is a flowchart of a method of forming a coated polymeric wrapping material, according to an exemplary embodiment.

[0067] FIGS. 6A-6C illustrate a system for wrapping an article with a coated polymeric wrapping material, according to an exemplary embodiment. FIG. 6A is a diagram showing a piece of the wrapping material being separated from a roll in proximity to the article. FIG. 6B is a diagram showing the piece of wrapping material being fit over/around the article. FIG. 6C is a diagram showing the piece of wrapping material being secured to/around the article.

DETAILED DESCRIPTION

[0068] Several illustrative embodiments will be described in detail with the understanding that the present disclosure merely exemplifies the general inventive concepts. Embodiments encompassing the general inventive concepts may take various forms and the general inventive concepts are not intended to be limited to the specific embodiments described herein.

[0069] The general inventive concepts encompass a wrapping material comprising a polymeric sheet on which are formed three distinct layers, i.e., a marking layer, a UV-blocking layer, and a cover layer. While the polymeric sheet is the structural backbone of the wrapping material, the combination of coatings applied thereto impart functionality and synergies not realized in conventional wrapping materials. Furthermore, since at least two of the coatings are applied to the polymeric sheet simultaneously, less material can be used in forming the resulting layers, while also achieving increased manufacturing efficiency (e.g., reduced production time).

[0070] The general inventive concepts also encompass a wrapping material comprising a polymeric sheet, wherein the wrapping material includes both a UV-blocking layer and a cover layer, and wherein the UV-blocking layer is sandwiched between the polymeric sheet and the cover layer. In some exemplary embodiments, the wrapping material also includes a marking layer.

[0071] In some exemplary embodiments, the polymeric sheet is a woven scrim formed from polymeric tapes. In some exemplary embodiments, the polymeric tapes are made of at least one of polypropylene and polyethylene.

[0072] An exemplary polymeric wrapping material 400, which encompasses the general inventive concepts, is shown in FIGS. 4A-4C. The wrapping material 400 is formed as a sheet 402 having a sheet length S.sub.L and a sheet width S.sub.W. In some exemplary embodiments, the sheet width S.sub.W is in the range of 1.22 m to 3.86 m. In some exemplary embodiments, the sheet length S.sub.L is greater than the sheet width S.sub.W. In some exemplary embodiments, the sheet length S.sub.L is at least two times greater than the sheet width S.sub.W. In some exemplary embodiments, the sheet length S.sub.L is at least three times greater than the sheet width S.sub.W.

[0073] It is also contemplated that the wrapping material 400 could be made larger by joining (e.g., welding, sewing, gluing) multiple sheets 402 together. For example, if x sheets 402 are joined together or otherwise interfaced with one another, then the sheet width S.sub.W could be extended to almost any size, such as in the range of 1.22 m*x to 3.86 m*x.

[0074] By way of example, for those applications where the wrapping material 400 will be packaged on a roll for use downstream, the sheet length S.sub.L and the sheet width S.sub.W are selected to correspond to a desired package size. In this case, a user can install the roll of the wrapping material 400 in a manner whereby the wrapping material 400 can be unrolled and pieces cut off for use thereof (see FIGS. 6A-6C). It will be appreciated that the roll could be used in a manual wrapping process or an automated wrapping process.

[0075] As another example, for those applications where the wrapping material 400 will be used to create a pre-sewn cover, the sheet length S.sub.L and the sheet width S.sub.W are selected to correspond to the desired dimensions of the cover. Again, it will be appreciated that the cover could be used in a manual wrapping process or an automated wrapping process.

[0076] It will be appreciated that the general inventive concepts are readily applicable to other dimensions for S.sub.L and S.sub.W. Furthermore, the wrapping material 400 could be modified (e.g., cut, folded) to wrap smaller-sized articles, while multiple sheets could be combined (e.g., welded, stitched) to wrap larger-sized articles.

[0077] The sheet 402 of the wrapping material 400 is generally composed of polypropylene (PP) tapes that are woven together to form the wrapping material 400. More specifically, as shown in FIG. 4B, first PP tapes 410 that are fed in a machine direction indicated by arrow 420 are woven with second PP tapes 412 that are fed in a cross-machine (or transverse) direction indicated by arrow 422. The first PP tapes 410 are considered warp tapes, while the second PP tapes 412 are considered weft tapes. The machine direction 420 is parallel to the sheet length S.sub.L and perpendicular to the sheet width S.sub.W. The cross-machine direction 422 is parallel to the sheet width S.sub.W and perpendicular to the sheet length S.sub.L.

[0078] Each of the first PP tapes 410 and the second PP tapes 412 can have any suitable width. These widths can vary from 2 mm to 8 mm. The tapes 410, 412 can have different widths relative to each other in different embodiments.

[0079] For example, in one exemplary embodiment, the sheet 402 is formed with a ratio of 2:1 warp tapes to weft tapes. Put another way, in this embodiment, there are roughly 10 warp tapes per inch and roughly 5 weft tapes per inch. Since 1 inch equals 25.4 mm, the tape widths are selected to approximate these dimensions. More specifically, in this embodiment, the first PP tapes 410 have a width of 2.5 mm and a weight of 888 dTex; the second PP tapes 412 have a width of 5.1 mm and a weight of 1,260 dTex.

[0080] In some exemplary embodiments, production of the sheet 402 is completed by application of a polypropylene coating thereon. The polypropylene coating can be applied in any suitable manner, such as by extrusion coating. The coating can be applied to either side or both sides of the sheet 402. This coating is intended to close the interstices between the tapes 410, 412 to form a weather (e.g., moisture) barrier.

[0081] The first PP tapes 410 and the second PP tapes 412 can be woven in any conventional manner, such as by a standard loom. If a circular loom is used to increase throughput, the resulting cylindrical member can be slit to form a flat sheet (e.g., the sheet 402).

[0082] The sheet 402 includes two main faces 404 and 406. The faces 404, 406 are opposite one another. The face 404 is considered the outer face, while the face 406 is consider the inner face. When the sheet 402 is installed (e.g., wrapped around a quantity of lumber), a significant portion (if not all) of the outer face 404 remains visible, while a significant portion (if not all) of the inner face 406 cannot be seen. In other words, the inner face 406 is the side of the sheet 402 that contacts the lumber, while the outer face 404 is the side of the sheet 402 that does not contact the lumber.

[0083] The sheet 402 includes a first polymeric coating 430 on the outer face 404 that forms a relatively uniform marking layer 432 (see FIG. 4C). In some exemplary embodiments, the polymeric coating 430 comprises polypropylene. In some exemplary embodiments, the coating 430 is extruded onto the outer face 404. In some exemplary embodiments, the coating 430 covers the entire outer face 404 of the sheet 402. The coating 430 has a white, white-like, or lighter colored appearance that readily supports the inclusion of text, symbols/logos, pictures, or the like (collectively “indicia” 408) thereon. For example, this indicia 408 can be applied to the set coating 430 on the outer face 404 by printing. The light color of the coating 430 can be achieved by pigments, fillers (CaCo.sub.3), etc.

[0084] The sheet 402 also includes a second polymeric coating 440 on the inner face 406 that forms a relatively uniform UV-blocking layer 442 (see FIG. 4C). In some exemplary embodiments, the polymeric coating 440 comprises polypropylene. In some exemplary embodiments, the coating 440 covers the entire inner face 406 of the sheet 402. The coating 440 has a black, black-like, or darker colored appearance that is effective at limiting passage of UV light through the wrapping material 400. The UV-blocking layer 442 effectively prevents (or otherwise substantially reduces) the passage of UV light through the wrapping material 400 to avoid or mitigate any resulting discoloration (e.g., darkening) of the covered lumber.

[0085] The sheet 402 also includes a third polymeric coating 450 that forms a relatively uniform cover layer 452 (see FIG. 4C). In some exemplary embodiments, the polymeric coating 450 comprises polypropylene. The third polymeric coating 450 is situated on the second polymeric coating 440, such that the UV-blocking layer 442 is sandwiched between the inner face 406 of the sheet 402 and the cover layer 452. The third polymeric coating 450 will typically have a color that approximates a color of the article to be wrapped. In other words, the color of the cover layer is chosen to minimize the visual impact on the wrapped article should any of the cover layer transfer from the wrapping material to the wrapped article. Thus, in some instances, the cover layer could simply be a colorless (clear) coating. In the case of wrapping lumber, the coating 450 could have a beige, beige-like, or wood-colored appearance that is effective at limiting transfer of portions of the UV-blocking layer 442 onto the lumber. The wood-like color of the coating 450 can be achieved by pigments, fillers, etc. Because of its wood-like color, any transfer of portions of the cover layer 452 onto the lumber are less problematic and, thus, less likely to require remediation.

[0086] In some exemplary embodiments, the coatings 440 and 450 are co-extruded (that is, simultaneously applied) onto the inner face 406, with the coating 440 being applied directly onto the inner face 406 and the coating 450 being applied onto the coating 440. As a result, a thickness and/or weight of the layers 442, 452 can be more readily reduced as compared to the situation where the coatings 440 and 450 are separately extruded.

[0087] In general, co-extrusion refers to the extrusion of multiple layers of material simultaneously. This process utilizes multiple extruders to melt and deliver a steady volumetric throughput of different viscous resins to a single die and extrude the resin in the desired form. The layer thicknesses can be controlled by the relative speeds and sizes of the individual extruders delivering the materials.

[0088] In some exemplary embodiments, a (single ply, non-folded) thickness WL.sub.t of the sheet 402 (i.e., the woven polypropylene scrim) is in the range of 0.03 mm to 0.2 mm. In some exemplary embodiments, the thickness WL.sub.t is in the range of 0.033 mm to 0.07 mm. In some exemplary embodiments, the thickness WL.sub.t is about 0.058 mm.

[0089] In some exemplary embodiments, a thickness ExL.sub.t of the marking layer 432 is in the range of 0.01 mm to 0.04 mm. In some exemplary embodiments, the thickness ExL.sub.t is about 0.021 mm.

[0090] In some exemplary embodiments, a thickness CoExL.sub.t corresponding to the combined thicknesses of the UV-blocking layer 442 and the cover layer 452 is in the range of 0.01 mm to 0.04 mm. In some exemplary embodiments, the thickness CoExL.sub.t is about 0.021 mm.

[0091] In some exemplary embodiments the thickness WL.sub.t is greater than the sum of the thicknesses ExL.sub.t and CoExL.sub.t.

[0092] In some exemplary embodiments the thickness ExL.sub.t is about the same (i.e., +/−50% and, in some instances, +/−10%) as the thickness CoExL.sub.t.

[0093] In some exemplary embodiments, a weight/loading (gsm) of the polymer forming the sheet 402 (i.e., the woven polypropylene scrim) is in the range of 25 g/m.sup.2 to 100 g/m.sup.2. In some exemplary embodiments, the weight of the sheet 402 is in the range of 33 g/m.sup.2 to 71 g/m.sup.2. In some exemplary embodiments, the weight of the sheet 402 is about 58.3 g/m.sup.2.

[0094] In some exemplary embodiments, a weight/loading (gsm) of the first polymeric coating 430 is in the range of 10 g/m.sup.2 to 40 g/m.sup.2. In some exemplary embodiments, the weight of the first polymeric coating 430 is in the range of 18 g/m.sup.2 to 24 g/m.sup.2. In some exemplary embodiments, the weight of the first polymeric coating 430 is about 21 g/m.sup.2.

[0095] In some exemplary embodiments, a weight/loading (gsm) of the second polymeric coating 440 is in the range of 5 g/m.sup.2 to 38 g/m.sup.2. In some exemplary embodiments, the weight of the second polymeric coating 440 is in the range of 13.5 g/m.sup.2 to 18 g/m.sup.2. In some exemplary embodiments, the weight of the second polymeric coating 440 is about 14.5 g/m.sup.2.

[0096] In some exemplary embodiments, a weight/loading (gsm) of the third polymeric coating 450 is in the range of 2 g/m.sup.2 to 22 g/m.sup.2. In some exemplary embodiments, the weight of the third polymeric coating 450 is in the range of 4.5 g/m.sup.2 to 6 g/m.sup.2. In some exemplary embodiments, the weight of the third polymeric coating 450 is about 6 g/m.sup.2.

[0097] In some exemplary embodiments, a combined weight/loading (gsm) of the second polymeric coating 440 and the third polymeric coating 450 is in the range of 10 g/m.sup.2 to 40 g/m.sup.2. In some exemplary embodiments, the combined weight of the second and third polymeric coatings 440, 450 is in the range of 18 g/m.sup.2 to 24 g/m.sup.2. In some exemplary embodiments, the combined weight of the second and third polymeric coatings 440, 450 is about 20.5 g/m.sup.2.

[0098] In some exemplary embodiments, the weight/loading of the first polymeric coating 430 is greater than the weight/loading of the second polymeric coating 440.

[0099] In some exemplary embodiments, the weight/loading of the first polymeric coating 430 is greater than the weight/loading of the third polymeric coating 450.

[0100] In some exemplary embodiments, the weight/loading of the second polymeric coating 440 is at least two times greater than the weight/loading of the third polymeric coating 450.

[0101] In some exemplary embodiments, the weight/loading of the second polymeric coating 440 is at least three times greater than the weight/loading of the third polymeric coating 450.

[0102] In some exemplary embodiments, the weight/loading of the third polymeric coating 450 is at least two times greater than the weight/loading of the second polymeric coating 440.

[0103] In some exemplary embodiments, the weight/loading of the third polymeric coating 450 is at least three times greater than the weight/loading of the second polymeric coating 440.

[0104] In some exemplary embodiments the weight/loading of the first polymeric coating 430 is about the same (i.e., +/−50% and, in some instances, +/−10%) as the combined weight of the second and third polymeric coatings 440, 450.

[0105] Because the second polymeric coating 440 and the third polymeric coating 450 are applied simultaneously (i.e., co-extruded), a thickness and/or weight of each of the coatings 440, 450 can be reduced relative to separately applying each coating. Likewise, the reduction in time and/or labor achieved by co-extruding the coatings 440, 450 is another advantage.

[0106] An exemplary method 500 of forming a polymeric wrapping material (e.g., the polymeric wrapping material 400), which encompasses the general inventive concepts, is shown in FIG. 5.

[0107] As a first step, the method 500 contemplates provision of a polymer feedstock in step 502. Any suitable polymer can be used. In some exemplary embodiments, the polymer feedstock is polypropylene. In some exemplary embodiments, the polymer feedstock is polyethylene. In some exemplary embodiments, the polymer feedstock includes multiple distinct polymers.

[0108] Next, in step 504, the polymer feedstock is processed to form polymer tapes. As described herein, different polymer tapes (e.g., warp tapes 410, weft tapes 412) can be formed. The tapes can differ, for example, by width, weight, polymer type, etc.

[0109] In step 506, the polymer tapes are woven to form a polymeric scrim (e.g., the sheet 402). An optional coating (e.g., a polymeric coating) can be applied in step 508 to complete formation of the scrim. The optional coating is used to form the polymeric scrim, separate from the other functional coatings described herein. In some exemplary embodiments, the optional coating is substantially colorless (i.e., a clear coating).

[0110] Once the scrim has been formed, it is coated with a first polymeric coating (e.g., the coating 430) in step 510. For example, the first polymeric coating is extruded onto the scrim.

[0111] Finally, in step 512, a second polymeric coating (e.g., the coating 440) and a third polymeric coating (e.g., the coating 450) are simultaneously applied to the scrim. For example, the second and third polymeric coatings are co-extruded onto the scrim. In this example, the second polymeric coating directly contacts the scrim, while the third polymeric coating is separated from the scrim by the second polymeric coating.

[0112] An exemplary system 600 for wrapping a package 602 (e.g., lumber on a pallet) will be described with reference to FIGS. 6A-6C. The system 600 includes a roll 604 of wrapping material 606 (e.g., the wrapping material 400 described above). The package 602 rests on a surface 608. In some exemplary embodiments, the surface 608 is a conveyor (manual or automated) that moves in a direction indicated by the arrow 620. In the case of a conveyor, the package 602 can be moved into a desired position for wrapping.

[0113] As an initial step, a quantity of the wrapping material 606 is unrolled from the roll 604 and cut or otherwise separated therefrom to create a piece 610 of the wrapping material 606, as shown in FIG. 6A. The piece 610 of the wrapping material 606 is allowed to fall (in a controlled or uncontrolled manner) onto the package 602, as shown by the arrows 622.

[0114] As the piece 610 of the wrapping material 606 drapes around the package 602, the piece 610 effectively covers a top surface of the package 602, as well as a substantial portion (if not all) of each of the four sides of the package 602 (see FIG. 6B). In this manner, ends/edges 612 of the piece 610 of the wrapping material 606 approach positions where the piece 610 can be attached directly to the package 602 or otherwise in a manner that secures the piece 610 relative to the package 602. In some exemplary embodiments, the regions 612 can be reinforced to better hold the fastening means (e.g., staples).

[0115] As the piece 610 of the wrapping material 606 is fully positioned on the package 602, one or more fasteners 614 (e.g., belts) are applied to secure the wrapping material 606 to or around the package 602 (see FIG. 6C). Thereafter, the wrapped package can be moved, such as along the surface 608, and another package 602 positioned on the surface 608 for wrapping with the wrapping material 606.

[0116] As shown in FIG. 6B, the wrapping material 606 can have information 630 (e.g., the indicia 408) printed on an outer surface of the wrapping material 606. The information 630 can include branding information (e.g., names, logos), information on the contents of the package 602 being wrapped, shipping information, regulatory information, etc.

[0117] Although the exemplary system 600 is described in the context of wrapping five sides of the package 602, it will be appreciated that the general inventive concepts encompass methods of wrapping fewer or more sides of a package.

[0118] The resulting improved polymeric wrapping materials disclosed and suggested herein (e.g., the wrapping material 400) are effective in wrapping large bulk items, such as lumber, while avoiding drawbacks (e.g., the discoloration of the lumber) resulting from conventional wrapping materials. Thus, costly and time-consuming remedies, such as sanding, cleaning, or otherwise treating affected portions of the lumber, can be avoided or at least mitigated.

[0119] In some embodiments, it may be possible to utilize the various aspects of the general inventive concepts introduced herein in combination with one another. Additionally, any particular element recited as relating to a particularly disclosed embodiment should be interpreted as available for use with all other disclosed or suggested embodiments, unless incorporation of the particular element would be contradictory to the express terms of the embodiment. Furthermore, all combinations of method or process steps as used herein can be performed in any order, unless otherwise specified or clearly implied to the contrary by logic or the context in which the referenced combination is made.

[0120] The scope of the general inventive concepts presented herein are not intended to be limited to the particular exemplary embodiments shown and described herein. From the disclosure given, those skilled in the art will not only understand the general inventive concepts and their attendant advantages, but will also find apparent various changes and modifications to the devices and systems disclosed. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the general inventive concepts, as described and/or claimed herein, and any equivalents thereof.