HK1261969A1 - System and method for producing a multilayered board having a medium with improved structure - Google Patents

Description

System and method for producing multi-ply paperboard with improved structured media

Technical Field

The invention relates to a paper product production technology, in particular to a paperboard product, a paperboard manufacturing method and a paperboard manufacturing machine.

Background

Modern paper making techniques use paper machines at paper mills to produce paper rolls, which in turn can be used by paperboard manufacturers to produce paperboard products (i.e., corrugated paperboard). As a result, paper rolls can be produced by continuously operating machines. Modern paper machines typically produce paper from a variety of materials, including wood pulp, which includes wood fibers (although other fibers may be used). The fibers tend to elongate and are adapted to align adjacent to each other. The fibers start in the form of a stock that can be fed from the headbox of the paper machine onto a moving screen. In modern paper machines, the fibers tend to align with each other and with the direction in which the screen moves. This aligned direction of the underlying fibers is referred to as the principal direction of the paper and is aligned with the machine direction. Thus, the primary direction is often simply referred to as the Machine Direction (MD), and the resulting paper has an associated MD value.

When the paper is used to make a paperboard product, portions or layers of the paperboard product can be corrugated. Conventional corrugators will corrugate the underlying sheet product in the Cross Direction (CD) of the sheet, and thus cannot take advantage of the natural strength variations of the sheet in the machine direction. Further, the greater natural strength quality of the paper in the machine direction is not available in the paperboard making solution with cross-corrugation technology. Still further, conventional corrugated media contains flutes that exhibit a sinusoidal shape due to the shape of the protrusions in the conventional corrugating roller pair. As a result, companies producing traditional paperboard products are still deeply involved in the obsolete production procedures that limit the strength of the paperboard products.

Disclosure of Invention

It is an object of the present invention to produce a paperboard product made from a paper product having an embossed medium with an improved structural profile.

In one aspect, a paperboard product according to the invention comprises: a sheet of media having a plurality of flutes, wherein at least one group of the plurality of flutes each comprise a first linear leg support structure, a second linear leg support structure, and an apex structure; and a paper facing coupled to the tip support structure.

In another aspect, a method of making a paperboard according to the present invention comprises: embossing the paper product to include a plurality of grooves, wherein at least a second plurality of the plurality of grooves each includes a first linear leg support structure, a second linear leg support structure, and an apex structure; and coupling the paper facing to at least a third plurality of vertex structures of the second plurality of grooves.

In yet another aspect, a paperboard making machine according to the present invention includes: an embosser configured to emboss the paper product to include a plurality of grooves, wherein at least a second plurality of the plurality of grooves each includes a first linear leg support structure, a second linear leg support structure, and an apex structure; and a combiner configured to couple the paper facing to at least a third plurality of linear tip support structures of the second plurality of flutes.

Drawings

The aspects and many of the attendant advantages of the claims will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

fig. 1 is an isometric cross-sectional view of an embossing medium that may be part of one or more paperboard products in accordance with one or more embodiments of the subject matter disclosed herein.

Fig. 2 is an isometric cross-sectional view of an embossing medium that may be part of one or more paperboard products and that has an adhesive applied to the tips of the media support structure according to one or more embodiments of the subject matter disclosed herein.

Fig. 3A-C are profile views of various groove profiles of media having improved structures according to embodiments of the subject matter disclosed herein.

Fig. 4 is an isometric cross-sectional view of a paperboard product having the embossing medium of fig. 1 in accordance with an embodiment of the subject matter disclosed herein.

Fig. 5 is a diagram of aspects of a machine configured to generate the paperboard product of fig. 4, according to an embodiment of the subject matter disclosed herein.

Detailed Description

The following discussion is presented to enable a person skilled in the art to make and use the subject matter disclosed herein. The general principles described herein may be applied to embodiments and applications other than those detailed above without departing from the spirit and scope of the present detailed description. The present disclosure is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed or suggested herein.

As an overview, the subject matter disclosed herein may relate to a system and method for producing paperboard products made from paper products having embossed media (sometimes referred to as embossed channels) with improved structural profiles. The improved structural profile may include a triangular groove pattern, wherein each groove may exhibit a first linear leg support and a second linear leg support that each support a central apex structure. The apex may have a substantially flat portion configured to engage the facing. Accordingly, the paperboard product may further comprise one or more facings (sometimes referred to as liners or walls) bonded to the embossing medium. Further, each "triangular" vertex may also have a groove or channel for receiving adhesive in a continuous and uniform manner.

When the paperboard product is produced such that the embossing medium comprises a linear leg structure flanked by a generally flat apex groove profile, the resulting paperboard product and overall structure is improved over conventional resulting paperboard with corrugated medium. Further, the embossing medium may be generated using a linear embossing program that utilizes the natural strength of the paper product in the machine direction. Additional arrangements are possible with the basic concept of cross corrugated medium and linear embossing medium in the same paperboard product, including disposing a facing between the corrugated medium and the embossing medium and having a facing on one or both of the exterior walls of the paperboard product. This advantage and additional aspects of various embodiments of the subject matter disclosed herein are discussed below with reference to fig. 1-5.

Before discussing various embodiments, a brief discussion regarding cross-corrugation and linear embossing is presented. As briefly mentioned above, conventional paperboard products contain conventionally produced corrugated media (sometimes referred to as corrugated fluting), such as cross-corrugated media. The cross-corrugated media has flutes formed perpendicular to the lowermost fibers of the paper product. This can result in grooves that are not aligned with most of the underlying fibers and therefore do not take advantage of the natural strength of the MD value of the paper (when compared to the CD value). Failure to utilize the MD value of the paper can result in lost opportunities in making the paper board product when a particular board strength is to be achieved. That is, more paper (heavier paper, larger flutes, etc.) must be spent to achieve the desired paperboard strength.

Linear embossed media differ from cross-corrugated media in that the grooves produced are aligned with the MD value of the paper product. This results in the grooves being aligned with the majority of the underlying fibers and thus takes advantage of the natural strength of the paper MD values (as compared to the CD values). The use of the paper MD value can improve the manufacturing efficiency of the paperboard product when a particular paperboard strength is to be achieved. That is, less paper (lighter paper, smaller flutes, etc.) must be spent to achieve the desired paperboard strength. The aspects of making, creating and using linear EMBOSSING media are discussed IN greater detail IN U.S. patent application No. 15/077,250 entitled "SYSTEM and method FOR grooving IN PAPER PRODUCTs BY EMBOSSING against machine sides" (SYSTEM and method FOR manufacturing IN a PAPER PRODUCT BY EMBOSSING WITH RESPECT machine direct), filed on 2016, 3, 22, which is incorporated herein BY reference IN its entirety FOR all purposes. Accordingly, for the sake of brevity, aspects of linear embossing media will not be described in detail, and will now be discussed with reference to FIGS. 1-5.

Fig. 1 is an isometric cross-sectional view of an embossing medium 130 that may be part of one or more paperboard products in accordance with one or more embodiments of the subject matter disclosed herein. This figure shows an isometric view of a portion of an embossing medium 130 that may be formed by an embossing procedure. That is, the grooves 131 are formed by passing the initial sheet product through an embossing roller using a linear embossing technique such that the grooves 131 are formed to conform to a majority of the underlying fibers 125 of the sheet. The grooves 131 are also formed to coincide with the machine direction 122. The linear embossing medium 130 takes advantage of the natural strength of the paper in the machine direction 122 when forming the grooves 131 in the machine direction 122 of the paper (e.g., in accordance with the majority of the underlying fibers 125). Thus, the linear embossing medium 130 utilizes the natural strength of the paper in the machine direction 122. This embossing medium 130 may be a component/layer of a paperboard product as discussed below with reference to fig. 4.

Further, as shown in fig. 1, the grooves 131 may form a triangular pattern when viewed in a cross-sectional view. This groove pattern having a triangular repeating shape is hereinafter referred to as a groove profile. In the embodiments discussed in the remaining figures, the groove profile provides an improvement in the structural integrity of the embossed media when compared to groove profiles that exhibit curvilinear or sinusoidal groove profiles. Such curved or sinusoidal flute profiles are common in conventional cross-corrugated media. Thus, the triangular flute profile as shown in FIG. 1 is also superior to corrugated media in terms of media strength and structural integrity. Various reasons why this and other similar groove profiles exhibit superior strength and structural integrity are presented below with reference to fig. 2-3.

Fig. 2 is an isometric cross-sectional view of an embossing medium 130 that may be part of one or more paperboard products and having an adhesive 201 applied to an apex structure of a media support structure according to one or more embodiments of the subject matter disclosed herein. In fig. 2, a close examination of the embossing medium shows a series of grooves forming an isosceles triangle groove profile. The groove profile may comprise a series of support structures each comprising three sections. In this example, the three portions are a first leg support structure 211, a second leg support structure 212, and an apex structure 210. As shown, the apex structure 210 is disposed between the first leg support decoupling strand 211 and the second leg support structure 212. In this example support structure, then, each support structure may have an apex facing upward (although upward is any direction that is simply shown according to the drawings).

For the same reason, the support structures of the second series may also each comprise three parts, but from a downward facing perspective. In this regard, the leg support structure 212 also forms a leg support structure for a downward facing triangle. Thus, the three portions are a first leg support structure 214, a second leg support structure 212, and an apex structure 213 disposed between the first leg support structure 214 and the second leg support structure 212. It should be noted that the second leg structure 212 is the same second leg support structure with respect to the upward apex 210 and the downward facing layer apex 213. The groove profile can then be thought of as a series of alternations of an upward layer vertex 210 and a downward layer vertex 213, with alternating linear leg support structures (e.g., 211, 212, and 214) disposed therebetween.

Each apex 210 and 213 can be formed to be generally flat so as to provide a uniform surface to receive adhesive 201 from a machine for positioning the apex and apply a continuous line of adhesive to each apex. The embossing medium 130 may then be secured to the facing layer 140 at the apex where the adhesive 201 is ready. In other embodiments, each vertex 210 and 213 may have a groove to facilitate receiving adhesive. With the grooves, the adhesive will tend to remain in place as the embossing medium 130 is moving through the paperboard making machine. This grooved apex embodiment is discussed below with reference to figure 3C.

The embodiment as discussed with reference to fig. 1-2 has an embossed medium 130 that exhibits an isosceles triangular groove profile with superior strength and improved support structure. One reason this embodiment provides superior strength is that the leg support structures 211, 212, and 214 are linear. That is, the leg support structure is not curved, and thus tends to remain fixed and rigid when various forces are applied from various directions. In sinusoidal corrugated media, the "legs" are more like a continuous curve of a sinusoidal pattern. Thus, the "apex" of each groove may be the top side of any portion of the sinusoidal curve that exhibits a curved, smooth transition to the media that ultimately forms a quasi-flat apex. Due to the curved, smooth transition on either side of the apex of conventional corrugated media, the apex may translate forward and backward in an undesirable manner. With the linear leg support structures 211, 212, and 214, a more defined structure is provided that resists unpredictable movement and failure points.

Further, it is known that the proverb has a cloud, and the shortest distance between two points is a straight line. As used herein, the shortest distance between each apex facing the top side and the apex facing the bottom side is the linear leg support structure. Thus, having a triangular groove profile necessarily uses less overall paper to create embossed media (as compared to sinusoidal corrugated media). Other embodiments may include different shapes for the groove profile, including zig-zag, trapezoidal, or any manner of geometry that exhibits linear leg support structures flanked by alternating top and bottom vertices. Three such embodiments are shown and discussed next in fig. 3A-C.

Fig. 3A-C are profile views of various groove profiles of media having improved structures according to embodiments of the subject matter disclosed herein. In fig. 3A, a first isosceles triangular groove profile 300 is shown. This groove profile 300 is also shown in fig. 1 and 2, but this figure provides a cross-sectional view of the actual groove profile. In this embodiment, each recess includes a first linear leg support structure 301 and a second linear leg support structure 302 each coupled to one vertex 303 disposed therebetween. The vertex 303 is disposed substantially flat and in a plane parallel to what may be coupled to the final facing (via adhesive or other means-not shown). Further, the width of the apex 303 in this embodiment is about one tenth the length of each linear leg support structure 301 and 302. Accordingly, this embodiment may be referred to as a narrow apex groove profile 300.

In this embodiment, the angle of each leg 301 and 302 relative to each vertex 303 may be about 60 degrees. However, any number of leg angles may be implemented. Thus, the first and second linear leg structures 301, 302 may be fixed at an angle of between about 30 and 60 degrees relative to the apex 303 plane.

In fig. 3B, a second isosceles triangular groove profile 320 is shown. The groove profile 320 view provides a cross-sectional view of an actual groove profile, which reveals a first linear leg support structure 321 and a second linear leg support structure 322 each coupled to one vertex 323 disposed therebetween. Further, apex 323 is disposed substantially flat and in a plane parallel to that which may be coupled to the final facing. Unlike fig. 3A, the width of the apex 323 in this embodiment is about one-fifth the length of each linear leg support structure 321 and 322. Accordingly, this embodiment may be referred to as a wide apex groove profile 320.

In fig. 3C, a third isosceles triangular groove profile 340 is shown. This groove profile 340 view provides a cross-sectional view of the groove profile that reveals a first linear leg support structure 341 and a second linear leg support structure 342 each coupled to one vertex 343 disposed therebetween. As previously described, the vertex 343 is disposed substantially flat and in a plane parallel to that which can be coupled to the final facing. Unlike fig. 3A and 3B, apex 343 includes grooves or channels for receiving adhesive prior to coupling to a facing (not shown). In this embodiment, the width of apex 343 is about one-fifth the length of each linear leg support structure 321 and 342. Accordingly, this embodiment may be referred to as a wide trench apex groove profile 340. Other groove profiles are contemplated, but are not described in detail for the sake of brevity.

Fig. 4 is an isometric cross-sectional view of a paperboard product 400 having an impression medium 130 with an improved groove structure according to an embodiment of the subject matter disclosed herein. In this embodiment, the paperboard product comprises four layers: a first facing 110, a corrugated medium 120, an embossed medium 130, and a second facing 140. As shown, the first facing 110 may form a top side outer wall coupled to one side of the first corrugated media 120 (although the top/bottom direction reference to the alignment of the paperboard product 100 is arbitrary). The coupling may be by adhesive applied to the apexes of the grooves on the top side of the corrugated media 120, such that the facing 110 is glued to the corrugated media 120 with adhesive applied therein. In other embodiments, the glue may be applied to the entire facing 110 prior to coupling to the corrugated media 120.

Likewise, the second facing 140 may form a bottom side outer wall coupled to one side of the embossed medium 130 (again, the top/bottom directional reference is arbitrary). The coupling may be by adhesive applied to the apexes of the grooves on the bottom side of the media 130, such that the face layer 140 is glued to the embossed media 140 with adhesive applied therein. In other embodiments, the glue may be applied to the entire face layer 140 prior to coupling to the embossing medium 130.

Further, the corrugated medium 120 and the embossing medium 130 may also be bonded to each other using an adhesive. Because the flutes of the corrugated media 120 are aligned in the cross direction and the flutes of the embossed media 130 are aligned in the machine direction, the contact points between the two media will be at the intersections of the apexes of the respective flutes. In this manner, the corrugated medium 120 and the embossed medium 130 are fixed relative to each other because the adhesive secures one medium directly to the other.

When all four mediums are assembled and secured, the resulting paperboard product 400 is stronger than a conventional paperboard product because the linear embossing medium 130 contains a groove profile that exhibits superior strength due to the linear leg structure of each groove. Further, the adhesive may be applied more accurately to the vertices continuously and uniformly in a predictable and repeatable manner, since portions of the adhesive do not spill over to the legs as would be the case with sinusoidal vertices that do not have flat receiving areas. As shown in fig. 4, a paperboard product 400 contains corrugated media 120. In other embodiments, the corrugated medium 120 may not be present, such that the topside facing layer 110 is glued to each topside vertex of the embossed medium and the topside facing layer 140 is glued to each bottom side vertex of the embossed medium 130. Next, additional aspects of the paperboard product 400 of fig. 4 are discussed with reference to the machine of fig. 5.

Fig. 5 is a diagram of aspects of a machine 500 configured to generate the paperboard product of fig. 4, according to an embodiment of the subject matter disclosed herein. In this embodiment, the machine includes four paper feed rollers 510, 520, 530, and 540 for creating a paperboard product. The feed rollers include a first facestock feed roller 510, a corrugated media feed roller 520, an embossed media feed roller 530, and a second facestock feed roller 540. It should be noted that the sheet wound on the corrugating medium feed roller 520 is before corrugating and the sheet wound on the embossing medium feed roller 530 is before embossing. The weight and composition of the paper for each respective feed roller may be different and specifically designed for the respective purpose.

The sheets from each roll may be unwound from each respective roll and fed toward a combiner 550 configured to combine the layers of sheets together to form the resulting paperboard product. At least some of the paper from the feed rollers may pass through a station for forming the paper into media before entering the combiner 550. As used herein and in the industry, media may refer to paper products that have been formed into paper with flutes. Accordingly, the corrugated media feed roller 520 may feed the paper into the first and second corrugating rollers 521a and 521b, which are aligned with respect to each other. As the paper exits the corrugating station (e.g., corrugating rollers 521a and 521b), it becomes corrugated media 120. The corrugated media 120 is then fed into a combiner 550 for combination with other materials. Similarly, the embossing medium feeding roller 530 may feed the sheet into the first and second embossing rollers 531a and 531b aligned with each other. When the paper leaves the embossing station (e.g., embossing rollers 531a and 531b), it becomes the embossing medium 130 as discussed above with reference to fig. 1. The embossing medium 130 is then fed into a combiner 550 for combination with other materials.

Further, the embossing medium feed 530 may be first fed into a conditioner 560 that may condition the paper prior to embossing. Such conditioning may include wetting the paper, heating the paper, cooling the paper, applying chemicals to the paper, and various other forms of altering the basic state of the paper to better prepare the embossing. In this sense, the conditioning stage can be viewed as "relaxing" the underlying fibers of the paper so that the paper can be in a more compliant state for easier handling, so as to avoid tearing and ripping. This condition can remove or modify the inherent stiffness in the paper and reduce the extent of possible fiber damage that will occur during the stretching process during embossing. In one embodiment, the conditioner may (fully or partially) immerse the web under treatment in a liquid (e.g., water, a recyclable solvent, etc.). The liquid may be heated or unheated to achieve the desired paper compliance/plasticity conditions.

Once through embossing rollers 531a and 531b, embossing medium 130 may travel to applicator 570 to apply adhesive to the newly formed apex. The applicator may include a device for identifying the location of each apex and then aligning a series of adhesive dispensers with the identified apexes. In other embodiments, the adhesive may be transferred to the flute tips with rubber roll(s) in which the paper contacts the adhesive film and adheres to the flute tips. In this way, the adhesive can be precisely applied in a continuous and uniform manner. The first facing 110, corrugated medium 120, embossed medium 130, and second facing 140 are then combined in a combiner using various techniques such as bonding, curing, wetting, drying, heating, and chemical treatment. The resulting paper product 400 has at least one cross-corrugated medium 120 and at least one linear embossing medium 130, wherein the linear embossing medium comprises a groove profile with an improved structure.

While the subject matter discussed herein is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and have been described above in detail. It should be understood, however, that there is no intention to limit the claims to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the claims.

Claims (20)

1. A paperboard product, comprising:

a paper media having a plurality of flutes, wherein at least one group of the plurality of flutes each comprises a first linear leg support structure having a first length, a second linear leg support structure having a first length, and an apex structure having a second length that is one-tenth the first length; and

a paper facing coupled to the apex structure.

2. The paperboard product of claim 1, further comprising a second facing fixed relative to the paper media.

3. The paperboard product of claim 1, further comprising a second paper medium fixed relative to the paper facer.

4. The paperboard product of claim 1, wherein the first and second linear leg structures are fixed at an angle of between 30 and 60 degrees relative to the paper facing.

5. The paperboard product of claim 1, wherein each apex structure comprises a flat portion parallel to the paper face layer.

6. The paperboard product of claim 1, wherein each apex structure further comprises a flat portion having a groove configured to direct an adhesive to couple each apex structure to the paper facer.

7. A paperboard product according to claim 1, further comprising a continuous line of adhesive coupled between each apex structure and the paper facing.

8. The paperboard product of claim 1, wherein the plurality of flutes further comprise:

a first plurality of grooves each having an apex structure coupled to the paper facing such that the paper facing is secured to the paper media on a first side; and

a second plurality of grooves each having a vertex structure coupled to a second paper facing such that the second paper facing is secured to the paper media on a side opposite the first side.

9. A method of making paperboard, comprising:

embossing a sheet of media to include a plurality of grooves, wherein at least a second plurality of the plurality of grooves each include a first linear leg support structure having a first length, a second linear leg support structure having a first length, and an apex structure having a second length that is one tenth of the first length; and

coupling a paper facing to at least a third plurality of apex structures of the second plurality of flutes.

10. The method of making paperboard of claim 9 further comprising embossing a groove in each apex structure.

11. The method of paperboard making of claim 9, further comprising heating the paper media prior to embossing.

12. The method of paperboard making of claim 9, further comprising wetting the paper media prior to embossing.

13. The paperboard making method of claim 12, further comprising drying the paper medium after embossing.

14. The method of paperboard making of claim 9, further comprising curing the paper medium after embossing.

15. The method of making paperboard of claim 9, further comprising gluing the paper media to the paper facing.

16. The method of paperboard making of claim 9, further comprising securing a second facing relative to the paper media.

17. The method of making paperboard of claim 9, wherein the embossing further comprises embossing a first set of apex structures facing a first direction and embossing a second set of apex structures facing a second direction opposite the first direction.

18. A paperboard making machine, comprising:

an embosser configured to emboss a paper media including a plurality of grooves, wherein at least a second plurality of the plurality of grooves each includes a first linear leg support structure having a first length, a second linear leg support structure having a first length, and an apex structure having a second length that is one tenth of the first length; and

a combiner configured to couple a paper facing to at least a third plurality of linear apex structures of the second plurality of grooves.

19. A board making machine according to claim 18, further comprising an adjuster configured to adjust the paper media prior to embossing.

20. The paperboard making machine of claim 18, wherein the combiner further comprises an adhesive applicator configured to position each apex structure and apply a continuous line of adhesive to each apex structure.