Patent Description:
For example, a conventional wax paper cup is made using a paper web that includes a printed graphic on one side and a wax coating that is not applied until after the cup is formed. The paper web is supplied to a cup forming machine where the sleeve blanks are cut from the paper web and a liquid glue is applied along two edges. The sleeve blank is then wrapped around a forming mandrel and a side seam clamp is used to apply pressure to seal the overlapping edges of the wrapped blank with the liquid glue to form the sleeve. Typically the same adhesive is used to then attach the bottom end of the sleeve to a bottom blank to form the cup. Once fully formed, a wax coating is applied to the cup.

Paper cups made using a paper web that includes a polyethylene-based coating, rather than a wax, do not require the step of applying a liquid glue at the cup forming machine. The polyethylene-based coating can provide sufficient adhesion for forming the side seam and sealing with the bottom blank without the application of an additional glue. Removal of the glue application station from the cup forming machine can allow the cups to be formed at a higher rate. However, in some cases, the use of a polyethylene-based coating on the paper web is not desirable. For example, cups made from paper that includes a polyethylene-based coating can be challenging to recycle.

<CIT> discloses a dripless, easily cleaned glue applicator for a machine for making two-piece paper cups comprising an outer body member in which there is a cavity that opens to a slot in a flat bottom surface of the member. The slot has a shape and size conforming to an area of glue to be applied. An inner member in the body member forces the longitudinally central portion of a resilient foam pad to bulge down through the slot and clamps the pad to the outer body member. The inner member also provides a glue chamber that is communicated with a pressurized source of glue and from which numerous bores, spaced along the length of the inner member, open downwardly to the pad. A top plate on the outer body member closes its cavity, holds the inner member in clamping relation to the outer body member, and provides for mounting the applicator.

Aspects of the present invention are recited by the independent claim, with the dependent claims reciting optional features. Aspects of the present disclosure relate to an assembly and process for forming a container from a sleeve blank and a bottom blank that includes at least one adhesive printing station for printing an adhesive on a web, a blank cutting station for cutting the sleeve blank from the web, and a container forming station for wrapping the sleeve blank around the bottom blank, wherein the at least one adhesive printing station is provided upstream of the container forming station.

An aspect provides an assembly for forming a container from a sleeve blank and a bottom blank, the sleeve blank defined by a pair of opposing side edges and opposing top and bottom edges and the bottom blank including a bottom wall for closing one end of the container, the assembly comprising: at least one adhesive printing station for printing an adhesive on a web in register with portions of the web forming at least one of the opposing side edges of the sleeve blank and the bottom edge of the sleeve blank; a blank cutting station for cutting the sleeve blank from the web; and a container forming station for wrapping the sleeve blank around the bottom blank, wherein the printed adhesive in register with the at least one of the side edges forms a seam seal between overlapping side edges of the wrapped sleeve blank and the printed adhesive in register with the bottom edge of the sleeve blank forms a bottom seal between overlapping portions of the sleeve blank and the bottom blank; wherein the at least one adhesive printing station is provided upstream of the container forming station such that the adhesive is printed on portions of the web forming the sleeve blank prior to the sleeve blank being provided to the container forming station.

The assembly may comprise at least one of: at least one ink printing station for printing at least one graphic on the web in register with portions of the web forming the sleeve blank, wherein the at least one ink printing station is provided at least one of upstream of the at least one adhesive printing station or in-line with the at least one adhesive printing station; or at least one ink printing station for printing at least one graphic on the web in register with portions of the web forming the sleeve blank provided upstream of the at least one adhesive printing station and a turn-bar station for flipping the web after one of the at least one ink printing stations and prior to one of the at least one adhesive printing stations.

A cavity of the container defined by the wrapped sleeve blank and bottom blank may be free of the printed adhesive.

The at least one adhesive printing station may comprise flexography or gravure printing.

The at least one adhesive printing station may comprise one of: a single adhesive printing station configured to print the adhesive in register with the at least one of the side edges and the bottom edge of the sleeve blank; or multiple adhesive printing stations configured to separately print one or more portions of the adhesive in register with the at least one of the side edges and one or more portions of the adhesive in register with the bottom edge of the sleeve blank.

The at least one adhesive printing station may be configured to at least one of: print the adhesive in register with the at least one side edge such that when the sleeve blank is wrapped to form the seam seal, the printed adhesive does not extend beyond the at least one side edge into a cavity of the container; or print the adhesive in register with the bottom edge such that when the sleeve blank is wrapped around the bottom blank to form the bottom seal, the printed adhesive does not extend beyond the bottom wall into the cavity of the container.

An amount of the printed adhesive forming the seam seal and the bottom seal may be in the range of about <NUM> to <NUM> wt. % of the container.

The at least one adhesive printing station may be configured such that a rate at which the sleeve blank is wrapped around the bottom blank at the container forming station is not limited by a rate at which the adhesive is printed.

Another aspect provides a process for forming a container from a sleeve blank and a bottom blank, the sleeve blank defined by a pair of opposing side edges and opposing top and bottom edges and the bottom blank including a bottom wall for closing one end of the container, the process comprising: passing a web through at least one adhesive printing station; printing an adhesive on the web in register with portions of the web forming at least one of the opposing side edges of the sleeve blank and the bottom edge of the sleeve blank; cutting the sleeve blank from the web; and wrapping the sleeve blank around the bottom blank at a container forming station, wherein the printed adhesive in register with the at least one of the side edges forms a seam seal between overlapping side edges of the wrapped sleeve blank and the printed adhesive in register with the bottom edge of the sleeve blank forms a bottom seal between overlapping portions of the sleeve blank and the bottom blank; wherein the at least one adhesive printing station is provided upstream of the container forming station such that the adhesive is printed on portions of the web forming the sleeve blank prior to the sleeve blank being provided to the container forming station.

The process may comprise at least one of: passing the web through at least one ink printing station and printing at least one graphic on the web in register with portions of the web forming the sleeve blank, wherein the at least one ink printing station is provided at least one of upstream of the at least one adhesive printing station or in-line with the at least one adhesive printing station; or passing the web through at least one ink printing station upstream of the at least one adhesive printing station and printing at least one graphic on the web in register with portions of the web forming the sleeve blank and further comprising passing the web through a turn-bar station for flipping the web after one of the at least one ink printing stations and prior to one of the at least one adhesive printing stations.

The passing a web through at least one adhesive printing station may comprise one of: passing a web through a single adhesive printing station configured to print the adhesive in register with the at least one of the side edges and the bottom edge of the sleeve blank; or passing a web through multiple adhesive printing stations configured to separately print one or more portions of the adhesive in register with the at least one of the side edges and one or more portions of the adhesive in register with the bottom edge of the sleeve blank.

The printing an adhesive on the web may comprise at least one of: printing the adhesive in register with the at least one side edge such that when the sleeve blank is wrapped to form the seam seal, the printed adhesive does not extend beyond the at least one side edge into a cavity of the container; or printing the adhesive in register with the bottom edge such that when the sleeve blank is wrapped around the bottom blank to form the bottom seal, the printed adhesive does not extend beyond the bottom wall into the cavity of the container.

An amount of the printed adhesive forming the seam seal and the bottom seal may be in the range of about <NUM> to <NUM> wt. % of the container (<NUM>); and/or the at least one adhesive printing station may be configured such that a rate at which the sleeve blank is wrapped around the bottom blank at the container forming station is not limited by a rate of printing the adhesive.

Embodiments are described, by way of example only, with reference to the accompanying drawings, in which:.

Aspects of the present disclosure relate to processes for forming a two-piece paper container made by wrapping a paper sleeve blank around a paper bottom blank that can take advantage of the high container forming rates available with current container forming machines. While aspects of the present disclosure are discussed in the context of a cup, additional container types, such as bowls and storage containers, including those suitable for use in food service, are also contemplated.

Conventional two-piece paper containers are made by cutting a sleeve blank and a bottom blank from suitable paper substrates (also referred to as a paper web). The sleeve blank and bottom blank are assembled by a container forming machine to form the container defining a cavity for holding material. The container forming machine generally includes a mandrel about which the sleeve blank is wrapped and overlapping side edges of the sleeve blank are adhered together to form a sleeve. A bottom edge of the sleeve is adhered to the bottom blank to seal the sleeve with the bottom blank and thus form the container. Thus, the process of forming the two-piece paper container involves the use of an adhesive both in forming the sleeve and in sealing the sleeve with the bottom blank.

These conventional two-piece paper containers are typically made from paper stock that has been coated with a polyethylene-based coating. The polyethylene-based coating acts as a barrier coating that provides protection to the paper from the contents of the container (e.g. liquids, grease). The polyethylene-based coating is also heat-sealable and thus can also function as the adhesive for securing the overlapping side edges of the sleeve blank and sealing the sleeve with the bottom blank at the container forming machine. The container forming machine is configured to apply heat and/or pressure at specific locations of the sleeve and bottom blanks to form an adhesive seal with the polyethylene-based coating that provides an adhesive sidewall seam (also referred to as a seam seal or a sidewall seal) where the side edges of the sleeve blank overlap and to form a bottom seal between the sleeve and the bottom blank.

Containers that are made using paper stock that does not include a polyethylene-based coating can require the use of an adhesive to form a suitable sidewall seam and bottom seal. For example, wax containers (i.e., containers that include a wax barrier coating on the paper that is typically applied to the paper stock after forming the container), generally include the additional step of adding an adhesive to the paper blanks on the container forming machine to form the sidewall seam and the bottom seal. This additional adhesive applying step limits the rate at which the container forming machine can form the waxed containers compared to the polyethylene-based coated containers discussed above, which do not require the additional adhesive applying step. Other types of coatings, such as aqueous-based barrier coatings may also require the additional adhesive applying step to provide an adhesive that can form a suitable sidewall seam and bottom seal, thus limiting the rate at which containers can be formed using these types of barrier coatings.

Aspects of the present disclosure relate to printing an adhesive on the sleeve blank while it is still in the web prior to sending the sleeve blank to the container forming machine where the sleeve blank is wrapped around a mandrel to form the sleeve, which is then sealed with the bottom blank to form the container. In one aspect, the paper web containing the sleeve blanks with the pre-printed adhesive can be stored as a pre-printed adhesive roll for supplying to the container forming machine. In another aspect, the pre-printed adhesive sleeve blanks can be cut from the web and supplied to the container forming machine as pre-cut, pre-printed adhesive sleeve blanks.

In this manner, the rate of application of the adhesive is not a rate limiting step in the container forming process. Because the adhesive has been printed onto the sleeve blank prior to the sleeve blank being provided to the container forming machine, the container forming machine does not have to include an additional adhesive applying step, which would limit the rate at which the containers are formed on the machine. In this manner, polyethylene-based coating-free containers (for example, waxed containers or aqueous-based coated containers), can be formed on a container forming machine at production rates comparable to that of a polyethylene-based coated container. As used herein, comparable rates are within about plus/minus <NUM> %, optionally about plus/minus <NUM> %, further optionally about plus/minus <NUM> %.

According to another aspect of the present disclosure, the adhesive is printed on the sleeve blank in-line with the printing of graphics on the sleeve blank prior to supplying the sleeve blank to the container forming machine. In one aspect, the adhesive is printed using flexography or gravure printing to apply the adhesive to defined portions of the sleeve blank such that the cavity of the formed container is free of the adhesive.

<FIG> illustrates an exemplary container <NUM> according to an aspect of the present disclosure in the form of a cup. While aspects of the present disclosure are discussed in the context of the cup, the container <NUM> can have any desired shape and size and can optionally be suitable for food service. Container <NUM> can be in the form of a two-piece cup that includes a sleeve <NUM> and a bottom <NUM>. The sleeve <NUM> includes a portion defining a sidewall <NUM> of the container <NUM>. A rim <NUM> defines an open end <NUM> of the sleeve <NUM> at an upper end of the sleeve <NUM>. The rim <NUM> may optionally be rolled, bent, curled, or crimped in a conventional manner. A sidewall seam <NUM> is formed where overlapping side edges <NUM>, <NUM> of the sleeve <NUM> are adhered together to form a sidewall seam, also referred to as a sidewall seal.

A bottom portion of the sleeve <NUM>, opposite the rim <NUM>, is sealed with the bottom <NUM> by an adhesive. The bottom <NUM> includes a bottom wall <NUM> and a depending skirt <NUM>. The sleeve <NUM> includes a portion defining a flange <NUM> that is wrapped around the skirt <NUM> of the bottom <NUM> such that the skirt <NUM> is sandwiched between an inner flange portion <NUM> and an outer flange portion <NUM>. The wrapped skirt <NUM> defines a foot <NUM>, opposite the rim <NUM>, which supports the container <NUM> on a surface. An adhesive forms a seal between the flange <NUM> on both sides of the skirt <NUM> to form a bottom seal <NUM> between the sleeve <NUM> and the bottom <NUM>.

The bottom wall <NUM> includes an outer surface <NUM> facing the foot <NUM> and an opposing inner surface <NUM>. The inner surface <NUM> of the bottom wall <NUM> together with an inner surface <NUM> of the sidewall <NUM>, above the bottom wall <NUM>, together define a container cavity <NUM>. The inner surfaces <NUM> and <NUM> define the surfaces of the container <NUM> that are exposed within the container cavity <NUM> and may come into contact with material contained within the container cavity <NUM>.

Optionally, the container <NUM> can be a flat-bottom type container, rather than the illustrated raised bottom (also referred to as a pot-type container), in which the bottom <NUM> does not include a skirt and the flange <NUM> is wrapped and sealed under the bottom wall <NUM>. The flat-bottom type container can have a bottom wall that is generally flat or has a curved portion.

Referring now to <FIG>, the sleeve <NUM> is formed from a sleeve blank <NUM> that can be cut from a sheet or web of paper stock <NUM>. The sleeve blank <NUM> includes the opposing first and second side edges <NUM> and <NUM>, a top edge <NUM> extending between the side edges <NUM> and <NUM> at an upper portion of the sleeve blank <NUM>, and a bottom edge <NUM> extending between the side edges <NUM> and <NUM> at a lower portion of the sleeve blank <NUM>, opposite the top edge <NUM>.

The sleeve blank <NUM> can be considered as having multiple portions that each form a different portion of the assembled container <NUM>. The sleeve blank <NUM> includes a cavity portion <NUM> that corresponds to the inner surface <NUM> of the sidewall <NUM> that defines the cavity <NUM> of the container <NUM>, a bottom portion <NUM> corresponding to the portion that defines the flange <NUM> that wraps around the skirt <NUM>, and a top portion <NUM> corresponding to the rim <NUM>. The sleeve blank <NUM> also includes a seam portion <NUM> that extends along at least a portion of the side edge <NUM> between the top and bottom edges <NUM> and <NUM>. The relative dimensions of the cavity portion <NUM>, the bottom portion <NUM>, the top portion <NUM>, and the seam portion <NUM> can vary based on the dimensions and structure of the container <NUM> that is to be formed. The cavity portion <NUM> can be defined as extending between the bottom portion <NUM>, the top portion <NUM>, and the seam portion <NUM>.

The sleeve blank <NUM> also includes a first surface <NUM> and an opposing second surface <NUM>. The sleeve blank <NUM> can be wrapped to form the sleeve <NUM> such that the first surface <NUM> forms an interior surface which faces a central axis of the formed container <NUM> and the opposing second surface <NUM> forms an exterior surface which faces outward, away from the central axis of the formed container <NUM>. Optionally, the sleeve blank <NUM> can be wrapped to form the sleeve <NUM> such that the first surface <NUM> forms the exterior surface and the second surface <NUM> forms the interior surface.

According to an aspect of the present disclosure, the sleeve blank <NUM> includes a first printed adhesive applied to the bottom portion <NUM> corresponding to the flange <NUM> to form a printed adhesive bottom flange portion <NUM> and a second printed adhesive applied to the seam portion <NUM> to form a printed adhesive seam portion <NUM>. The printed adhesive bottom flange portion <NUM> is configured to adhesively seal to the skirt <NUM> in the formed container <NUM> to form the bottom seal <NUM> between the sleeve <NUM> and the bottom <NUM>. The printed adhesive seam portion <NUM> is configured to adhesively seal the overlapping side edges <NUM>, <NUM> to form the sidewall seam <NUM>. Optionally, when the container <NUM> is in the form of a flat-bottom type cup which does not include a skirt <NUM>, the adhesive flange portion <NUM> is configured to adhesively seal to the bottom wall <NUM>.

The first and second printed adhesives are applied along two, intersecting edges of the sleeve blank <NUM>. The second printed adhesive is applied along whichever of the side edges <NUM>, <NUM> overlaps the other on the second surface <NUM> of the sleeve blank <NUM>. The first printed adhesive can be applied along the bottom portion <NUM> along the entire distance between the side edges <NUM>, <NUM> or only a portion of the distance between the side edges <NUM>, <NUM>. The first printed adhesive can extend all the way to one or both of the side edges <NUM>, <NUM> or be offset from one or both of the side edges <NUM>, <NUM>. The first printed adhesive can be printed as a strip having a length extending between the side edges <NUM>, <NUM> and a width defined as the dimension extending between the top and bottom edges <NUM>, <NUM>. The first printed adhesive can extend all the way to the bottom edge <NUM> or be offset from the bottom edge <NUM>.

Optionally, the first printed adhesive can be printed as multiple strips rather than a single strip. The multiple strips can be printed along the bottom portion <NUM> such that the first printed adhesive comes into contact with portions of the skirt <NUM> on both sides of the skirt <NUM>, but the adhesive does not wrap around the entire skirt <NUM>. For example, the first printed adhesive can be applied as two strips such that an adhesive seal is formed between the flange <NUM> and the skirt <NUM> on both sides of the skirt <NUM>, but no adhesive is printed on the portion of the sleeve blank <NUM> that is adjacent the distal end of the skirt <NUM>. Applying the first printed adhesive as multiple strips, rather than a single strip can reduce the amount of adhesive used while still providing adhesive where it is needed in order to form the desired seal between the flange <NUM> and the skirt <NUM>.

The second printed adhesive is applied along the seam portion <NUM> along the entire distance between the top and bottom edges <NUM>, <NUM>. The second printed adhesive can extend all the way to one or both of the top and bottom edges <NUM>, <NUM> or be offset from one or both of the top and bottom edges <NUM>, <NUM>. The second printed adhesive can be printed as a strip having a length extending between the top and bottom edges <NUM>, <NUM> and a width defined as the dimension extending between the side edges <NUM>, <NUM>. The second printed adhesive can extend all the way to the side edge <NUM> or can be offset from the side edge <NUM>. Optionally, the second printed adhesive can be applied to the side edge <NUM> in a similar manner.

The first and second printed adhesives can be the same or different and can be heat and/or pressure activated. As used herein, a heat activated adhesive refers to an adhesive that requires exposure to temperatures above ambient to form an adhesive bond. Heat activated adhesives are generally in a non-tacky state until heat is applied and the adhesive is transformed into a tacky state capable of forming an adhesive bond with a suitable substrate. A pressure activated adhesive, also referred to as a pressure sensitive adhesive, can be in a tacky state without the addition of heat and forms an adhesive bond with a suitable substrate when pressed together with the substrate. Non-limiting examples of suitable adhesives for printing along the bottom portion <NUM> and the seam portion <NUM> include CK-<NUM> and CK57CP, both commercially available from Cork Industries, Inc. Other example adhesives include acrylic co-polymer dispersion based adhesives, such as NeoCryl® FL-<NUM> XP and NeoCryl® FL-<NUM>, both commercially available from DSM, U. Additional suitable adhesives include aqueous polyethylenimine based adhesives, examples of which include MICA H-<NUM>, available from MICA Corporation, U. , Polymin® P, available from BASF Corporation, U. The first and second printed adhesives can be selected based on the paper stock used for the sleeve blank <NUM>, the intended material to be held by the container (e.g. cold cup or hot cup), and/or the paper stock treatment or coatings.

In one aspect of the present disclosure, the sleeve blank <NUM> can be made from a solid bleached sulfate (SBS) paperboard paper stock or other paper stock suitable for forming containers. An example of a suitable paper stock is the TruServ™ brand of cupstock grades, available from WestRock, U. Table <NUM> lists examples of suitable paper stock for different cup sizes according to an aspect of the disclosure.

According to one aspect of the present disclosure, the side of the paper stock that forms the interior surface of the sleeve blank <NUM> is provided with a polyethylene-free barrier coating before or after cutting the sleeve blanks <NUM>. Examples of suitable polyethylene-free barrier coatings include wax-based barrier coatings, such as natural and/or biodegradable wax coatings, polylactic acid (PLA) based barrier coatings, and aqueous-based barrier coatings that are suitable for food service. Optionally, the barrier coating can be applied after the container <NUM> is formed. For example, some wax containers are formed in a process that includes applying the wax coating to the formed container. The paper stock can include the same or different coatings on both sides of the paper.

According to one aspect of the present disclosure, the first and second printed adhesives are applied to the bottom and seam portions <NUM> and <NUM> of the sleeve blank <NUM>, respectively, using flexography (also referred to as flexographic printing) or gravure printing prior to cutting the sleeve blank <NUM> from the paper web <NUM>. Flexography and gravure printing allow the adhesive to be printed onto the sleeve blank <NUM> with a high degree of precision and consistency. According to one aspect, printing the adhesive onto the first surface <NUM> of the sleeve blank <NUM> occurs in-line with printing graphics on the second surface <NUM> of the sleeve blank <NUM>. As used herein, graphics includes a blank registration or index mark that is used for alignment of the web during cutting of the sleeve blank and/or text, symbols, images, pictures, and/or artwork.

The first and second printed adhesive portions <NUM>, <NUM> can be printed together as a single pattern or as two separate strips, which optionally intersect or overlap. According to one aspect, the first and second printed adhesive portions <NUM>, <NUM> are printed such that the first and second adhesives do not extend into the cavity portion <NUM> of the sleeve blank, i.e. the cavity portion <NUM> is free of the first and second printed adhesives. For example, the second printed adhesive portion <NUM> can be printed in register with at least one of the side edges <NUM>, <NUM>, such that when the sleeve blank <NUM> is wrapped to form the seam seal, the printed adhesive does not extend beyond the at least one side edge <NUM>, <NUM> into the container cavity <NUM>. Optionally, the first printed adhesive portion <NUM> can be printed in register with the bottom edge <NUM> such that when the sleeve blank <NUM> is wrapped around the bottom <NUM> to form the bottom seal, the printed adhesive does not extend beyond the bottom wall <NUM> in to the container cavity <NUM>. In this manner, the cavity <NUM> of the formed container <NUM> is free of adhesive. While the cavity <NUM> is free of adhesive, the contents of the cavity <NUM> may come into contact with the first and/or second adhesives if the contents seep in-between the overlapping side edges <NUM>, <NUM> and/or the overlapping flange <NUM> and skirt <NUM>.

<FIG> illustrates a printing assembly process <NUM> according to an aspect of the disclosure by which the sleeve blank <NUM> having the first and second printed adhesive portions <NUM>, <NUM> are formed. The process <NUM> is provided for illustrative purposes and may proceed in a different logical order or additional or intervening steps may be included, unless otherwise noted. While the process <NUM> is described in the context of forming the container <NUM>, the process <NUM> may be used in a similar manner to form other types of two-piece paper containers.

The process <NUM> begins with a roll <NUM> of paper stock suitable for forming the sleeve blank <NUM>. The roll <NUM> is unwound to provide a web <NUM> having a second side <NUM> that ultimately forms the second surface <NUM> of the sleeve blank <NUM> and a first side <NUM> that ultimately forms the first surface <NUM> of the sleeve blank <NUM>. The process <NUM> is described within the context of the second surface <NUM> forming the exterior surface of the container <NUM> and the first surface <NUM> forming the interior surface of the container <NUM>, although it is within the scope of the present disclosure for the process <NUM> to be used in a similar manner if the first and second surfaces <NUM>, <NUM> are reversed, depending on how the sleeve blank <NUM> is to be folded.

According to one aspect, the paper stock is made on a traditional Fourdrinier paper machine that produces a web having a felt side and a wire side. The felt side is generally smoother than the wire side, which can have a more textured surface. The felt side can form the second side <NUM> to provide a smoother surface for printing graphics whereas the wire side can form the first side <NUM> on which the adhesives are printed.

At <NUM>, the web <NUM> passes through a first ink printing station <NUM> which applies a first ink application to the second side <NUM> of the web <NUM>. Optionally, at <NUM>, the web <NUM> can pass through a second ink printing station <NUM> which applies a second ink application to the second side <NUM> of the web <NUM>. The ink can be applied on the web <NUM> in register with the portions of the web <NUM> in which the sleeve blank <NUM> is to be cut from. Ink can be printed on the web adjacent to and/or on the portions of the web <NUM> that will form the sleeve blank <NUM>.

The number of ink printing stations <NUM>, <NUM> utilized may depend on the complexity of the graphic, the type of ink used, the number of different color(s) of ink used, etc. to provide the container <NUM> with the desired final graphic. Each ink printing station <NUM>, <NUM> is configured to provide ink to the web <NUM> such that the desired graphic is displayed on each sleeve blank <NUM> cut from the web <NUM>. While two ink printing stations <NUM>, <NUM> are illustrated, according to an aspect of the present disclosure, the process <NUM> can include fewer or greater ink printing stations. For example, if the cup graphic includes <NUM> different colors, each color can be applied in a separate ink printing station.

According to one aspect, the web <NUM> has a width such that a single column of sleeve blanks <NUM> is formed in the web <NUM> (shown). Optionally, the web <NUM> can have a width such that multiple, side-by-side columns of sleeve blanks <NUM> are formed in the web <NUM>.

Subsequent to the final ink printing station <NUM>, the web <NUM> can be passed through a turn-bar station <NUM> at <NUM>. The turn-bar station <NUM> flips the web <NUM> to expose the first side <NUM> of the web <NUM>. The web <NUM> then passes through an adhesive printing station <NUM> at <NUM> to print adhesive on the first surface <NUM> of the sleeve blanks <NUM> in register with the graphics printed on the second surface <NUM>. The adhesive can be printed on the first surface <NUM> of the sleeve blanks <NUM> along the bottom portion <NUM> to form the first printed adhesive bottom flange portion <NUM> and along the seam portion <NUM> to form the second printed adhesive seam portion <NUM> along the bottom portion <NUM>.

The thus formed printed web <NUM> including the ink printed graphic on the second side <NUM> and the printed adhesive on the first side <NUM> can then be wound on a roll <NUM> for storage prior to cutting the sleeve blanks <NUM> from the printed web <NUM>. Optionally, the printed web <NUM> can be passed through a cutting station (not shown) to cut the sleeve blanks <NUM> from the printed web <NUM> and the pre-cut sleeve blanks <NUM> can be stored for later use by a container forming machine to form the container <NUM>.

While the process <NUM> is illustrated as including a single adhesive printing station <NUM> for printing the adhesive along the bottom portion <NUM> and the seam portion <NUM> of the sleeve blank <NUM>, the process optionally includes two or more adhesive printing stations for printing an adhesive along each of the bottom portion <NUM> and the seam portion <NUM> in separate stages. According to one aspect of the present disclosure, multiple adhesive printing stations <NUM> may be used to print an adhesive such that the final amount of printed adhesive has a greater thickness. Water-based adhesives require adequate drying time prior to reaching the next printing station and prior to the web being wound onto a roll. If the adhesive is not dry enough, the adhesive may build-up on subsequent printing plates and/or offsetting (unintended transfer of the adhesive from the surface it was printed on to a subsequent surface it comes in contact with) may occur if the web is wound before the adhesive has sufficiently dried. This may result in unwanted adhesive on the interior surfaces of the container <NUM> that could flake off into the material contained by the container <NUM>. Printing multiple layers of adhesive to provide the desired total thickness of adhesive rather than printing a single layer having the desired thickness can minimize/avoid these challenges without significantly impacting overall printing speed. The use of flexographic printing allows the location and the amount of each of the multiple layers of adhesive to be printed accurately, precisely, and consistently.

Optionally, multiple adhesive stations can be used to print different adhesives along the bottom portion <NUM> and the seam portion <NUM>.

Each of the ink printing stations <NUM>, <NUM> and the adhesive printing station <NUM> utilize flexography or gravure printing to print the ink and the adhesive in register on each side of the printed web <NUM>. When the sleeve blanks <NUM> are cut from the printed web <NUM>, each sleeve blank <NUM> includes printed graphics on the second surface <NUM> and printed adhesive on the first surface <NUM> in desired alignment with the edges <NUM>, <NUM>, <NUM>, and <NUM> of each sleeve blank <NUM>. Providing the adhesive printing station <NUM> in-line with the ink printing stations <NUM>, <NUM> facilitates rapidly creating the printed web <NUM> and printing the adhesive in the desired positions on the sleeve blank <NUM>.

Optionally, the adhesive printing station <NUM> can be configured to print the adhesive onto the underside of the web <NUM> without flipping the web <NUM>. In this configuration, the turn-bar station <NUM> would not be necessary. Optionally, other systems may be utilized to flip the web <NUM> for printing on both sides.

Separate steps for printing the graphic and applying an adhesive can present opportunities for misalignment as the paper web is transferred to different machine stations. Providing a turn-bar station <NUM> to flip the paper web between the ink printing station <NUM> and the adhesive printing station <NUM> removes the need to transfer the paper web to separate machines for applying the adhesive. Printing the graphics and the adhesive in-line minimizes opportunities for mis-alignment and damage to the paper web that can occur when the paper web is removed from one machine station and then transferred and set-up on a different machine station. Printing the graphics and the adhesive on printing stations in-line can also increase the rate at which the sleeve blank <NUM> with graphics and printed adhesive can be formed compared to a process in which the ink printing and the adhesive are applied at different machine stations.

In addition, application of the adhesive using flexography or gravure printing is more precise and consistent than traditional methods of applying adhesives on the container forming machine. For example, a conventional glue wheel used to apply a glue at the container forming machine can transfer from the paper to the forming mandrels and build-up of glue on parts of the container forming machine (e.g., the forming mandrels and clamps) can require frequent cleaning. Conventional glue wheels can apply glue unevenly or even skip areas, resulting in an unacceptable seal. Printing the adhesive using flexography or gravure printing to apply the adhesive to the desired location on each sleeve blank prior to the container forming machine according to the present disclosure can avoid or mitigate many of these challenges associated with conventional glue application at the container forming machine.

The accuracy and precision of flexography or gravure printing for printing the adhesive facilitates applying the desired amount of adhesive where it is needed to form an acceptable sidewall seam and bottom seal while decreasing waste as a result of applying adhesive where it is not needed or at a higher amount than is needed. This level of control for applying the adhesive can contribute to higher production rates and lower production costs.

According to one aspect of the present disclosure, flexography or gravure printing is utilized to print the printed adhesive bottom flange portion <NUM> and the printed adhesive seam portion <NUM> in a predetermined amount on each sleeve blank <NUM> in the desired location in register with the graphic printed on the second surface <NUM> of the sleeve blank <NUM>. An exemplary paper sleeve blank for a <NUM> (<NUM> ounce) hot cup having a sleeve height of about <NUM> (about <NUM> inches) and a maximum sleeve width of about <NUM> (about <NUM> inches) can have a total printed adhesive amount of about <NUM> % by weight (wt. %) of the formed cup. According to one aspect, the adhesive weight used in the example <NUM> (<NUM> ounce) hot cup is about <NUM>/<NUM><NUM> (<NUM> lb/<NUM> ft<NUM>), which corresponds to <NUM>/<NUM><NUM> (<NUM> lb/<NUM> ft<NUM>) applied twice. In another example, <NUM>/<NUM><NUM> (<NUM> lb/<NUM> ft<NUM>) may be applied once to the sleeve blank <NUM>.

In one aspect, the amount of adhesive applied to the sleeve blank can be in the range of about <NUM> to about <NUM> wt. % of the finished container (i.e., sleeve plus bottom). According to one aspect, the range of about <NUM> to about <NUM> wt. % corresponds to cup sizes ranging from <NUM> to <NUM> (<NUM> to <NUM> ounce) hot cups having a barrier coating applied to only the interior side of the sleeve and <NUM> to <NUM> (<NUM> to <NUM> ounce) cold cups having a barrier coating applied both sides of the sleeve.

The second printed adhesive seam portion <NUM> can have a width corresponding to the amount of overlap of the side edges <NUM>, <NUM>, and the first printed adhesive bottom flange portion <NUM> can have a width corresponding to the amount of the flange <NUM> required to wrap around the skirt <NUM>. For example, for the <NUM> (<NUM> ounce) hot cup sleeve, the second printed adhesive seam portion <NUM> can have a width of about <NUM> (about <NUM> inches) and the first printed adhesive bottom flange portion <NUM> can have a width of about <NUM> (about <NUM> inches).

<FIG> illustrates a container assembly process <NUM> according to an aspect of the disclosure for forming a container using the sleeve blank <NUM> produced according to the process <NUM> of <FIG>. The process <NUM> is provided for illustrative purposes and may proceed in a different logical order or additional or intervening steps may be included, unless otherwise noted. While the process <NUM> is described in the context of forming the container <NUM>, the process <NUM> may be used in a similar manner to form other types of two-piece paper containers.

The process <NUM> can be implemented at a container forming station <NUM> that includes a container forming machine including multiple forming stations <NUM>-<NUM> for assembling the sleeve blank <NUM> and the bottom blank for forming the container <NUM>. The container forming machine can include a forming turret <NUM> having a plurality of forming mandrels <NUM> that can be indexed by the forming turret <NUM> to each of the forming stations <NUM>-<NUM>.

The container assembly process <NUM> begins at <NUM> with providing the bottom <NUM> to an end section <NUM> of the mandrel <NUM>. The bottom <NUM> can be held in place on the end section <NUM> by a vacuum. The bottom <NUM> can be a blank cut and formed from a paper web prior to providing the bottom <NUM> to the container forming station <NUM>. Optionally, the container forming station <NUM> includes a bottom forming station <NUM> in which a pre-cut bottom blank is bent to form or re-form the bottom <NUM> having a bottom wall <NUM> and the depending skirt <NUM>. Optionally, the container forming station <NUM> includes a bottom blank cutting station (not shown), in which the bottom blank is cut from a paper web prior to station <NUM> or <NUM>.

At station <NUM> a transfer turret <NUM> provides a sleeve blank <NUM> to a wrapping apparatus (not shown) that wraps the sleeve blank <NUM> around the mandrel <NUM> and the bottom <NUM>. The sleeve blank <NUM> is provided to the mandrel <NUM> with the printed adhesive bottom flange portion <NUM> and the printed adhesive seam portion <NUM> facing toward the mandrel <NUM>. The wrapping apparatus wraps the sleeve blank <NUM> around the mandrel <NUM>, including the bottom <NUM> carried by the mandrel <NUM>, such that the printed adhesive seam portion <NUM> overlaps the opposing side edge and the printed adhesive bottom flange portion <NUM> overlaps the bottom <NUM>.

At station <NUM> the printed adhesive bottom flange portion <NUM> and the printed adhesive seam portion <NUM> can be heated in one or more stages simultaneously or sequentially. In the process <NUM> illustrated, a bottom heater <NUM> is moved into position in the open bottom end of the wrapped sleeve blank <NUM> to heat the printed adhesive bottom flange portion <NUM>. A seam clamp <NUM> can be moved into position relative to the overlapped printed adhesive seam portion <NUM> to apply heat and/or pressure to heat-seal the overlapped side edges of the sleeve blank <NUM> with the printed adhesive seam portion <NUM>. The seam clamp <NUM> can provide heat and/or pressure to the printed adhesive seam portion <NUM>. Optionally, the seam clamp <NUM> applies only pressure and an optional separate heating device is provided for heating the printed adhesive seam portion <NUM>. Heating of the printed adhesive bottom flange portion <NUM> and the printed adhesive seam portion <NUM> can be obtained using any suitable heating device or combination of heating devices including radiant heat and heated air diffusers. Optionally, the printed adhesive in the bottom flange and seam portions <NUM>, <NUM> can be heated while the sleeve blank <NUM> is on the transfer turret <NUM>, prior to wrapping the sleeve blank <NUM> onto the mandrel <NUM> at station <NUM>. Optionally, if heat is not necessary to achieve the desired seal, then only pressure is applied to the seams.

The mandrel <NUM> is next indexed to station <NUM> where a bottom curl forming tool <NUM> is moved into position to fold the flange <NUM> including the printed adhesive bottom flange portion <NUM> around the skirt <NUM> of the bottom <NUM>. Heat from the bottom heater <NUM> applied at station <NUM> can soften the adhesive on the printed adhesive bottom flange portion <NUM> to facilitate adhesion of the flange <NUM> to the skirt <NUM>. At station <NUM>, bottom clamp <NUM> is utilized to apply pressure to the folded flange <NUM> to facilitate heat-sealing the printed adhesive bottom flange portion <NUM> to the skirt <NUM> to form the bottom seal <NUM> between the sleeve <NUM> and the bottom <NUM>.

The mandrel <NUM> is then indexed to station <NUM> where the formed container <NUM> is ejected. The free mandrel <NUM> is indexed to station <NUM> where it is in position to receive the next bottom <NUM> at station <NUM>. Optionally, the formed container <NUM> is sent to a waxing station to apply a wax barrier coating to at least the interior of the container <NUM> to form a waxed paper cup.

According to one aspect, the formed container <NUM> may be ejected to a rimming station (not shown) that curls or folds the top edge <NUM> to form the rim <NUM>. The portion of the sidewall seam <NUM> near the top edge <NUM> that forms the rim <NUM> can be stretched during the rimming process, which can decrease the strength of the seal of the sidewall seam <NUM> in the rim <NUM> if an adhesive is not used. Printing the adhesive on the seam portion <NUM> according to the present disclosure addresses these challenges in maintaining the strength of the sidewall seam seal in the area of the rim <NUM> while allowing the cup forming process to proceed at acceptable rates.

The forming turret <NUM> rapidly indexes the sleeve blank <NUM> and the bottom <NUM> through the various stations <NUM>-<NUM> to form the container <NUM>. A delay or pause at any of the stations <NUM>-<NUM> can result in a decrease in the rate of formation of the container <NUM>. Decreases in the rate of formation decrease the number of containers <NUM> formed, which can increase production times and costs.

<FIG> illustrates a process <NUM> for forming a two-piece paper container according to an aspect of the disclosure using a paper sleeve blank and paper bottom blank. The process <NUM> is provided for illustrative purposes and may proceed in a different logical order or additional or intervening steps may be included, unless otherwise noted. While the process <NUM> is described in the context of forming the container <NUM> from sleeve blank <NUM>, the process <NUM> may be used in a similar manner to form other types of two-piece paper containers using other suitable sleeve blanks.

The process <NUM> begins at <NUM> with providing a paper web to a printing assembly. The printing assembly can include one or more ink printing stations for printing graphic on the paper web and one or more adhesive printing stations for printing an adhesive on the paper web. An example of a suitable printing assembly is shown in <FIG> with respect to the printing assembly process <NUM>.

At <NUM> graphics are printed on an exterior side of the paper web by passing the paper web through one or more ink printing stations. The exterior side of the paper web is defined herein as the side of the paper web that will form the exterior of the container formed using the sleeve blanks cut from the paper web. At <NUM> an adhesive is printed on the other side of the paper web corresponding to the side that will form the interior of the formed container. The adhesive is printed at <NUM> in register with the graphic printed at <NUM> such that each sleeve blank cut from the printed web includes the graphic on one side and the printed adhesive on the other side in the desired locations on the sleeve blank for forming the container. The adhesive is printed on the interior of the paper web in areas corresponding to portions of the sleeve blank that will form the sidewall seam and the bottom seal in the formed container, such as described with respect to the sleeve blank <NUM> of <FIG>.

An exemplary process for printing the graphic and the adhesive on the paper web is shown with respect to the printing assembly process <NUM> of <FIG>. As illustrated in <FIG>, a turn-bar roller, for example, can be used at the turn bar station <NUM> to flip the paper web to allow for in-line printing of the graphic on one side and the adhesive on the other side. Optionally, alternative methods for flipping the paper web in-line or for printing the adhesive without flipping the paper web can be used.

The graphic printing and adhesive printing at <NUM> and <NUM> produce a printed paper web that is optionally supplied to a blank cutter at <NUM> for cutting the sleeve blanks from the printed paper web. The pre-cut sleeve blanks can then by supplied to a two-piece container forming machine at <NUM>, such as the two-piece container forming station <NUM> of <FIG>. Optionally, the printed paper web can be supplied to the two-piece container forming machine at <NUM> and the container forming machine can include a blank cutting station to cut the sleeve blanks from printed paper web.

At <NUM>, the two-piece container forming machine can form the container using the sleeve blank according to the present disclosure and a bottom blank. The sleeve blank can be wrapped around a bottom blank such that the printed adhesive forms a sidewall seam and a bottom seal to form the two-piece paper container. An exemplary process <NUM> for assembling a container according to the present disclosure is illustrated in <FIG>.

Commercial two-piece container forming machines are capable of forming upwards of <NUM> containers per minute. However, this high rate of container forming can be challenging to realize for containers made from paper that does not include a polyethylene-based coating, such as waxed containers. Aspects of the present disclosure provide a container forming assembly, process, and sleeve blank which can be used to form containers using paper that is free of polyethylene-based coatings on a container forming machine at rates comparable to containers made from polyethylene-based coated paper.

Earlier two-piece paper container forming machines had much slower production rates than the <NUM> containers per minute rate of current machines. As polyethylene-based coated containers came into the market, the rate at which the container forming machines can form a container has also increased. The polyethylene-based coating acts as a barrier coating to protect the paper substrate, but is also heat sealable and thus acts as an adhesive for forming the container, thus removing the need to have an adhesive applying station as part of the container forming machine. Removing the adhesive applying station from the container forming machine increases the rate at which the machine can be operated and thus contributes to increasing the rate at which polyethylene-based coated containers are formed.

There is a desire in some markets to move away from polyethylene-based coated containers and utilize containers that include an aqueous-based barrier coating or are wax coated. Polyethylene-based coated containers can be challenging to recycle, whereas certain wax and aqueous-based barrier coatings may be more amenable to recycling and/or biodegrading. However, it has been challenging to identify aqueous-based barrier coatings that are heat-sealable for forming the sidewall seam and bottom seal in the containers at rates comparable to traditional polyethylene-based coatings.

Aspects of the present disclosure relate to printing an adhesive on a sleeve blank prior to providing the sleeve blank to the container forming machine. The adhesive can be printed using flexography or gravure printing on the sleeve blank, in-line with the ink printing process that prints graphics on the container. In this manner, application of the adhesive is not a rate limiting step in the container forming process. In addition, the use of flexography or gravure printing allows for more uniform, consistent, and precise printing of the adhesive on the sleeve blank compared to other traditional styles of applying adhesive. By printing the adhesive offline of the container forming machine using flexography or gravure printing, the adhesive can be applied such that the formed container cavity is free of adhesive.

To the extent not already described, the different features and structures of the various embodiments of the present disclosure may be used in combination with each other as desired. For example, one or more of the features illustrated and/or described with respect to one of the container <NUM>, sleeve blank <NUM>, or processes <NUM>, <NUM>, and <NUM> can be used with or combined with one or more features illustrated and/or described with respect to the other of the container <NUM>, sleeve blank <NUM>, or processes <NUM>, <NUM>, and <NUM>. That one feature may not be illustrated in all of the embodiments is not meant to be construed that it cannot be, but is done for brevity of description. Thus, the various features of the different embodiments may be mixed and matched as desired to form new embodiments, whether or not the new embodiments are expressly described.

While aspects of the present disclosure have been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation. The claims are to be construed literally, purposively, and/or to encompass equivalents.

Claim 1:
A method of forming a container (<NUM>) from a sleeve blank (<NUM>) and a bottom blank, the sleeve blank (<NUM>) including a pair of opposing side edges (<NUM>, <NUM>), the method comprising:
providing the sleeve blank (<NUM>), having a first layer of adhesive printed thereon by a first adhesive printing station (<NUM>), to a second adhesive printing station (<NUM>);
printing, using the second adhesive printing station (<NUM>), a second layer of adhesive on the sleeve blank (<NUM>) such that the final amount of printed adhesive has a greater thickness than the first layer of adhesive and forms a printed adhesive seam portion (<NUM>) configured to adhesively seal the side edges (<NUM>, <NUM>) to form a sidewall seal (<NUM>); and
wrapping the sleeve blank (<NUM>) around the bottom blank at a container forming station (<NUM>) to adhesively seal the side edges (<NUM>, <NUM>) to form the sidewall seal (<NUM>),
wherein the sleeve blank (<NUM>) includes a top edge (<NUM>) and a bottom edge (<NUM>).
characterised in that
the first and second layers of adhesive are applied along a seam portion (<NUM>) along the entire distance between the top and bottom edges (<NUM>, <NUM>) to form the printed adhesive seam portion (<NUM>).