HK1261815B - System and method for producing multi-layered board having at least three mediums with at least two mediums being different - Google Patents

Description

System and method for producing multi-layer paperboard having at least three media, at least two of which are different

Background Art

Modern papermaking technology uses paper machines in 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 number of substances, including wood pulp comprising wood fibers (although other fibers can also be used). These fibers tend to stretch and are suitable for aligning adjacent to each other. The fibers begin in the form of a slurry that can be fed from the mixing box 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 alignment of the underlying fibers is called the principal direction of the paper and is consistent with the machine direction. Therefore, the principal direction is often referred to as the machine direction (MD), and the produced paper has an associated MD value.

When paper is used to make paperboard products, portions or layers of the paperboard product may be corrugated. Traditional corrugating machines corrugate the underlying paper product in the cross direction (CD) of the paper, failing to take advantage of the paper's natural strength variations in the machine direction. Furthermore, the paper's greater natural strength in the machine direction cannot be exploited by cross-corrugation technology in paperboard manufacturing solutions. As a result, companies producing traditional paperboard products remain stuck in outdated production processes that limit the strength of their paperboard products.

BRIEF DESCRIPTION OF THE DRAWINGS

The various aspects of the claims and the many attendant advantages will become more readily apparent and likewise better understood when reference is made to the following detailed description taken in conjunction with the accompanying drawings, in which:

1 is an isometric cross-sectional view of a corrugated media that can be part of one or more paperboard products according to one or more embodiments of the subject matter disclosed herein.

2 is an isometric cross-sectional view of relief media that can be part of one or more paperboard products according to one or more embodiments of the subject matter disclosed herein.

3 is an exploded isometric cross-sectional view of a paperboard product having two corrugated media and at least one embossed media according to an embodiment of the disclosed subject matter.

4 is an isometric cross-sectional view of a paperboard product having two corrugated media and at least one embossed media according to an embodiment of the disclosed subject matter.

5 is a diagram of aspects of a machine configured to produce the paperboard product of FIG. 3 and FIG. 4 according to an embodiment of the subject matter disclosed herein.

DETAILED DESCRIPTION

The following discussion is presented to enable one 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 described in detail above without departing from the spirit and scope of this 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.

In summary, the subject matter disclosed herein may relate to a system and method for producing a paperboard product made from a paper product having two corrugated media (sometimes referred to as corrugated flutes) and at least one embossed media (sometimes referred to as embossed flutes). Due to these three media, this paperboard product may sometimes be referred to as Triple Wall™ paperboard. The paperboard product may further include one or more facing layers (sometimes referred to as liners or walls) bonded to the corrugated media, the embossed media, or both. Generally speaking, corrugated media may be characterized in that the paper product exhibits flutes generated by a corrugation process such that the flutes are perpendicular to (or at least not aligned with) the machine direction of the paper product. That is, the corrugated media has flutes in the cross-direction of the paper. Embossed media may be characterized in that the paper product exhibits flutes generated by a linear embossing process such that the flutes are aligned with the machine direction of the paper product.

When a paperboard product is created with corrugated and embossed media bonded together and flanked by a facing layer on either exterior surface, the resulting paperboard product exhibits characteristics superior to conventional paperboard products using only corrugated media. This is because the embossed media is created using a linear embossing process that exploits the natural strength of the paper product in the machine direction. Additional variations on the basic concept of intersecting corrugated and linear embossed media in the same paperboard product are possible, including placing a facing layer between the corrugated and embossed media and having a facing layer on one or both 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 Figures 1-5.

Before discussing various embodiments, a brief discussion of cross-corrugation and linear embossing is provided. As briefly mentioned above, conventional paperboard products include conventionally produced corrugated media, such as cross-corrugated media. Cross-corrugated media has flutes formed perpendicular to the underlying fibers of the paper product. This results in the flutes not being aligned with the majority of the underlying fibers and, therefore, not utilizing the paper's natural strength in the MD (when compared to the CD). This inability to utilize the paper's MD results in lost opportunities when manufacturing paperboard products when achieving a specific board strength. In other words, more paper (heavier paper, larger flutes, etc.) must be used to achieve the desired paperboard strength.

Linear embossed media differs from cross-corrugated media in that the flutes produced are aligned with the MD of the paper product. This results in the flutes being aligned with the majority of the underlying fibers and, therefore, utilizing the natural strength of the paper's MD (as compared to CD). Utilizing the paper's MD can improve paperboard product manufacturing efficiency when achieving a specific paperboard strength. That is, less paper (lighter paper, smaller flutes, etc.) must be used to achieve the desired paperboard strength. Aspects of making, manufacturing, and using linear embossed media are discussed in greater detail in U.S. Patent Application No. 15/077,250, filed on March 22, 2016, entitled "SYSTEM AND METHOD FOR INDUCING FLUTING IN A PAPER PRODUCT BY EMBOSSING WITH RESPECT TOMACHINE DIRECTION," the entire contents of which are incorporated herein by reference for all purposes. Therefore, for the sake of brevity, various aspects of linear embossed media will not be discussed further, and the discussion will now turn to Figures 1-5.

FIG1 is an isometric cross-sectional view of a corrugated medium 120 that can be part of one or more paperboard products according to one or more embodiments of the subject matter disclosed herein. This figure shows an isometric view of the corrugated medium 120 that can be formed by, for example, a conventional corrugating process. That is, flutes 121 are formed by passing a starting paper product through corrugating rollers in a cross-corrugation technique, such that the flutes 121 are formed perpendicular to (e.g., not aligned with) the majority of underlying fibers 125 of the paper product and not aligned with the machine direction 122. As briefly discussed above, because the flutes 121 are formed in the cross-direction of the paper (e.g., not aligned with the majority of underlying fibers 125), the cross-corrugated medium 120 does not take advantage of the paper product's natural strength in the machine direction.

While not utilizing the natural strength of paper in the machine direction 122, the cross-corrugated media 120 of FIG1 is relatively inexpensive to produce and is widely produced by readily available industrial corrugating machines. This corrugated media 120 may be a component/layer of a paperboard product as discussed below with reference to FIG3.

FIG2 is an isometric cross-sectional view of a relief medium 130 that can be part of one or more paperboard products according to one or more embodiments of the subject matter disclosed herein. This figure shows an isometric view of a portion of relief medium 130 that can be formed by a relief printing process. That is, grooves 131 are formed by passing a starting paper product through an embossing roller using a linear relief printing technique, such that the grooves 131 are formed to align with the majority of the underlying fibers 125 of the paper. The grooves 131 are also formed to align with the machine direction 122. When the linear relief medium 130 forms the grooves 131 in the machine direction 122 of the paper (e.g., to align with the majority of the underlying fibers 125), it takes advantage of the paper's natural strength in the machine direction 122. Thus, the linear relief medium 130 takes advantage of the paper's natural strength in the machine direction 122. This relief medium 130 can be another component/layer of a paperboard product, as discussed below with reference to FIG3 .

FIG3 is an exploded isometric cross-sectional view of a paperboard product 100 having two corrugated media 120 and 140 and at least one relief media 130, according to an embodiment of the disclosed subject matter. In this embodiment, the paperboard product 100 comprises five layers: a first facing layer 110, a first corrugated medium 120, a relief media 130, a second corrugated medium 140, and a second facing layer 150. As shown, the first facing layer 110 may form a topside outer wall coupled to one side of the first corrugated medium 120 (although the top/bottom orientation reference to alignment with the paperboard product 100 is arbitrary). Coupling may be achieved by applying an adhesive to the apex of each flute on the top side of the first corrugated medium 120, such that the first facing layer 110 is glued to the first corrugated medium 120 to which the adhesive is applied. In other embodiments, glue may be applied to the entire facing layer 110 prior to coupling to the first corrugated medium 120.

Likewise, the second facing layer 150 can form a bottom outer wall coupled to one side of the second corrugated medium 140 (again, the top/bottom directional reference is arbitrary). The coupling can be through adhesive applied to the apex of each groove on the bottom side of the second corrugated medium 140, such that the second facing layer 150 is glued to the second corrugated medium 140 to which the adhesive is applied. In other embodiments, glue can be applied to the entire second facing layer 150 before coupling to the second corrugated medium 140.

Furthermore, the first corrugated medium 120 and the embossed medium 130 can be bonded together using an adhesive. Because the grooves of the first corrugated medium 120 are aligned in the cross direction and the grooves of the embossed medium 130 are aligned in the machine direction, the point of contact between the two media will be located at the intersection of the corresponding groove vertices. In this way, the first corrugated medium 120 and the embossed medium 130 are fixed relative to each other, because the adhesive directly secures one medium to the other. Similarly, the second corrugated medium 140 and the embossed medium 130 can also be bonded together using an adhesive. The grooves of the second corrugated medium 140 are also aligned in the cross direction, and the point of contact between the two media will be located at the intersection of the corresponding groove vertices. In this way, the second corrugated medium 140 and the embossed medium 130 are fixed relative to each other, because the adhesive directly secures one medium to the other.

When all three media are assembled and secured, the resulting paperboard product 100 is stronger than conventional paperboard products because the linear relief media 130 leverages the superior MD value of the underlying paper product. Furthermore, the three media can flank the first facing layer 110 and the second facing layer 150. As also seen in FIG4 , when assembled, the five layers include relief media 130 with grooves that are perpendicular (or at least non-uniform) to the grooves of the first corrugated media 120 and the second corrugated media 140. This results in additional paperboard strength because the grooves of the respective media are perpendicular (or at least non-uniform) relative to each other. Other embodiments, not shown, may include any combination of the three media and facing layers, such that at least one medium is corrugated media 120 or 140 and at least one medium is relief media 130.

In the embodiment shown in FIG3 , corrugated media 120 and 140 are shown as having a groove profile known as a C-groove. A groove profile is a set of standardized parameters that detail various groove measurements, such as groove height, groove spacing, and the number of grooves per linear foot. Other standardized groove profiles include A-groove, B-groove, E-groove, F-groove, and R-groove. Thus, in this embodiment, corrugated media 120 and 140 include a sinusoidal C-groove pattern. Furthermore, embossed media 130 is also shown as having a C-groove profile, but, of course, the grooves are linear relative to the machine direction of the underlying paper. Embossed media 130 may also have a different shape, as the groove profile is characterized by a triangular pattern. In other embodiments not shown, embossed media 130 may have a different groove profile than corrugated media 120, such as an E-groove profile.

Figure 4 is an isometric cross-sectional view of a paperboard product having two corrugated media and at least one embossed media according to an embodiment of the subject matter disclosed herein.This view shows the exploded view paperboard product 100 of Figure 3 in assembled form.

As discussed with reference to Figures 3 and 4, the flutes produced by the embossing medium 130 are aligned with the machine direction 122. Consequently, the underlying long fibers 125 (Figure 2) of the paper remain aligned with the flute direction. Aligning the underlying long fibers 125 (Figure 2) with the corresponding flutes results in the flutes being aligned with the paper's larger MD values (when compared to CD values). Cross-corrugation techniques inherently result in the flutes being aligned with the paper's CD values. In contrast, linear embossing processes utilize the paper's MD values by aligning the flutes in the machine direction. Consequently, flute-producing embossing processes allow for the use of less total fiber while achieving a specific strength in the resulting paperboard product, such as paperboard product 100.

This paperboard product with linear embossed media 130 further improves efficiency at several levels and successfully realigns the interests of papermakers and paperboard/box manufacturers. First, linear embossing allows papermakers to ignore any need to carefully control the alignment (or misalignment) of pulp fibers when first depositing onto the screen on the paper machine. To improve cross-direction strength, papermakers can use paper machines that include a stock box that weakens the natural alignment of the underlying long fibers in the machine direction. With linear embossing, the need for improved cross-direction strength is reduced or eliminated. As a result, papermakers can focus on improving the speed of the paper machine.

Secondly, paperboard manufacturers can produce paperboard products using less paperboard material. The linear relief layer 130 discussed herein results in fluted media requiring less material to produce. That is, in a conventional corrugator, the paper required for fluting is greater than the paper required for the facing portion (in a linear fashion). Therefore, the efficiency gain is twofold: by aligning the MD values in both the flutes and the facing, less paper is used overall to produce the corrugated paperboard, and the resulting paperboard product is stronger.

The embodiment discussed with reference to Figures 1-4 has corrugated media 120 and 140 exhibiting sinusoidal flutes. Furthermore, embossed media 130 is shown as having a triangular flute profile. However, other embodiments may include different flute shapes for either media, including zigzag, trapezoidal, or any other curved shape. Next, additional aspects of the paperboard product of Figures 1-4 are discussed with reference to the machine of Figure 5.

FIG5 is a diagram of aspects of a machine 400 configured to produce the paperboard product 100 of FIG3 and FIG4 according to an embodiment of the subject matter disclosed herein. In this embodiment, the machine includes five paper feed rollers 410, 420, 430, 440, and 450 for producing the paperboard product. The feed rollers include a first facing layer feed roller 410, a first corrugated media feed roller 420, an embossing media feed roller 430, a second corrugated media feed roller 440, and a second facing layer feed roller 450. It should be noted that the paper wrapped around the corrugated media feed rollers 420 and 440 is prior to corrugation, and the paper wrapped around the embossing media feed roller 430 is prior to embossing. The weight and composition of the paper for each respective feed roller may vary and be specifically designed for the respective purpose.

Paper from each roll can be unwound from each respective roll and fed toward a combiner 450 configured to combine the layers of paper together to form a resulting paperboard product. In various embodiments, the combination of feed rollers in machine 400 can differ from that shown in FIG5 . For example, the configuration of feed rollers shown in FIG5 can produce a paperboard product having additional layers. This additional layer can be one or more additional liners between the media, allowing for the production of a paperboard product having six or seven layers. Additional layers in paperboard products are well understood by those skilled in the art, so the remainder of the discussion with reference to FIG5 will focus on the paperboard product embodiment of FIG3 and FIG4 .

Before entering the combiner 450, at least some of the paper from the feed rollers may pass through a station for forming the paper into media. As used herein and in the industry, media may refer to a paper product that has been formed into a sheet of paper having fluted sheets. Thus, a first corrugated media feed roller 420 may feed the paper into first and second corrugating rollers 421a, 421b, which are aligned relative to one another. When the paper leaves the first corrugating station (e.g., corrugating rollers 421a and 421b), it becomes the first corrugated media 120, as discussed above with reference to FIG. 1 . The first corrugated media 120 is then fed into the combiner 450 for combination with other materials. Similarly, a second corrugated media feed roller 440 may feed the paper into third and fourth corrugating rollers 441a, 441b, which are aligned relative to one another. When the paper leaves the second corrugating station (e.g., corrugating rollers 441a and 441b), it becomes the second corrugated media 140. The second corrugated media 140 is then fed into a combiner 450 to be combined with other materials.

Similarly, the embossing media feed roller 430 can feed the paper into the first embossing roller 431a and the second embossing roller 431b, which are aligned with each other. When the paper leaves the embossing station (e.g., embossing rollers 431a and 431b), it becomes the embossing media 130 as discussed above with reference to FIG2. The embossing media 130 is then fed into the combiner 450 to be combined with other materials.

In the embodiment of producing the paperboard product of FIG3 , the first facing layer 110, the first corrugated medium 120, the relief medium 130, the second corrugated medium 140, and the second facing layer 150 are combined in a combiner 450 using various techniques such as bonding, curing, wetting, drying, heating, and chemical treatment. The resulting paperboard product 100 has two intersecting corrugated media 120 and 140 and at least one linear relief medium 130.

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. However, it should be understood that there is no intention to limit the claims to the precise 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 cardboard product comprising: A first medium is formed from a first sheet of paper having a machine orientation and a cross orientation. The first medium has one or more grooves aligned with the machine orientation of the first sheet, wherein the width of the first medium in the cross orientation after the grooves are formed is equal to the width of the first medium in the cross orientation before the grooves are formed. A second medium, formed from a second sheet having a machine orientation and a cross orientation, the second medium being fixed relative to the first medium and having one or more grooves aligned with the cross orientation of the second sheet; and A third medium is fixed to the first medium. 2. The cardboard product according to claim 1, further comprising a surface layer adhered to the first medium. 3. The cardboard product according to claim 1, further comprising a surface layer bonded to the second medium. 4. The cardboard product according to claim 1, wherein the first medium is directly bonded to the second medium. 5. The cardboard product according to claim 1, further comprising a surface layer bonded to the first medium and bonded to the second medium, such that the surface layer is fixed between the first medium and the second medium. 6. The paperboard product according to claim 1, wherein the first medium further comprises grooves formed by embossing. 7. The paperboard product of claim 1, wherein the second medium further comprises grooves created by corrugation. 8. The paperboard product of claim 1, wherein the third medium is formed of a third sheet having a machine orientation and a cross orientation, the third medium being fixed relative to the first medium and having one or more grooves aligned with the cross orientation of the third sheet, wherein the third medium further includes grooves created by corrugation. 9. The paperboard product of claim 1, wherein the first medium further comprises a groove having dimensions corresponding to the profile of an E-shaped groove. 10. The paperboard product of claim 1, wherein the second medium further comprises a groove having dimensions corresponding to the profile of a C-shaped groove. 11. The paperboard product according to claim 1, wherein the groove in the first medium is not the same as the groove in the second medium. 12. A method for producing a cardboard product with an improved structure, the method comprising: A printing medium that embosses a first sheet of paper in the machine direction, the embossing causing a groove to be formed in the machine direction, wherein the width of the first sheet of paper after the groove is formed in the intersecting direction is equal to the width of the first sheet of paper before the groove is formed in the intersecting direction. The second paper is corrugated in the intersecting direction, the corrugation resulting in a corrugated medium with grooves in the intersecting direction; The embossed medium is fixed relative to the corrugated medium; and A fixed third medium relative to either the embossed medium or the corrugated medium. 13. The method of claim 12, further comprising directly bonding the embossed medium to the corrugated medium. 14. The method of claim 12, further comprising bonding the corrugated medium to a first side of a first surface layer and bonding the third medium to a first side of a second surface layer. 15. The method of claim 12, further comprising corrugating a third sheet in the intersecting direction, the corrugation causing the third medium to form grooves in the intersecting direction. 16. The method of claim 12, further comprising bonding a surface layer to the corrugated medium such that the surface layer is positioned spaced apart from the embossed medium. 17. The method of claim 12, wherein the embossed medium includes a groove having an E-shaped groove profile and the corrugated medium includes a groove having a C-shaped groove profile. 18. A machine comprising: The first paper feed roller is configured to feed paper to the corrugated table; The second paper feed roller is configured to feed paper to the printing table; The third paper feed roller is configured to feed paper to the media forming stage; At least one pair of corrugating rollers are configured to cross-corrugate the paper fed to the corrugating table to generate a cross-corrugated medium. At least one pair of letterpress rollers configured to linearly letterpress feed the paper to the letterpress table to generate a linear letterpress medium, wherein the width of the paper in the intersecting direction after the grooves are formed is equal to the width of the paper in the intersecting direction before the grooves are formed. At least one pair of media forming rollers configured to create grooves in the paper fed to the media forming stage to generate a third medium; A platform for combining the cross-corrugated medium and the third medium with the linear embossed medium. 19. The machine of claim 18, further comprising: A fourth paper feed roller, configured to feed the first surface layer to the assembly stage, such that the first surface layer is bonded to one of the cross-corrugated medium and the third medium; and A fifth paper feed roller is configured to feed the second surface layer to the stage for assembly, such that the second surface layer is bonded to another of the cross-corrugated medium and the third medium. 20. The machine of claim 18, further comprising a fourth paper feed roller configured to feed the surface layer to the table for assembly, such that the surface layer adheres to the cross-corrugated medium and to the linear letterpress medium.