Patent Publication Number: US-2007095693-A1

Title: Compressed layered roll package and associated method

Description:
BACKGROUND OF THE INVENTION  
      1) Field of the Invention  
      The present invention relates to compressed rolls of wound material and, more particularly, to a package for storing compressed rolls in a compressed form.  
      2) Description of Related Art  
      The distribution of rolled paper products represents a multibillion dollar industry in the United States with one of the largest segments represented by the toilet or tissue paper segment, as well as the paper towel or kitchen towel market. The process by which both tissue and towels are made can be broken-up into two general steps. The first step involves the creation of the paper base sheet from pulp, while the second step involves converting the base sheet (from a large jumbo roll) to finished smaller roll products. While tissue is designed to be soft and degrade in septic tanks, kitchen towels are designed to be much stronger for use in absorbing spills, for use as placemats, and for cleaning.  
      Tissue and towels are generally made using multiple layers of base sheet. Tissue tends to have minimal glue between the layers, and generally at selected spots, while the individual plies in paper towels are generally adhered across their entire surface area. Both tissue and paper towels are embossed to create patterns which also help in strengthening the paper. The pulp drying process plays a significant role in the creation of the end product, with through air drying (TAD) producing the softest paper. Papers made using the TAD process are used to form the highest quality tissue and towel papers.  
      The converting machines used in the second step of the process for making both tissue and towels incorporate unwinders, embossers, rewinders, core handlers, gluers, accumulators, and log saws. Currently, these machines can produce as many as 1000 rolls of toilet paper or 400 rolls of paper towels per minute. Additional steps of wrapping, packing, and case packing are done after the log saw and are generally connected to the converting operation via conveyors.  
      The sales of rolled paper products occur through retail stores, bulk discount stores, and more industrial “away from home” markets. One of the major difficulties for retailers involves the disposal of boxes and other packaging used to ship the finished rolls. The inherent bulkiness of rolled paper products also requires stores to order on-demand, with the overall cycle from production to sale occurring over several days (e.g., a 45 day period). Bulkiness also limits the ability of manufacturers to set-up production facilities far from end-users, as transportation of the finished goods can be cost-prohibitive. For end-users, the purchase, transport, and storage of tissue and towels also prove difficult because of the large inherent volume.  
      Furthermore, tissue and towels typically include an inner core for dispensing individual rolls. The central core of tissue and towels is generally made of paper and is difficult to collapse without causing significant distortion and separation from the sheet. This is due to the amount of adhesive applied to the paper when attached to the core, as well as the type of adhesive used in forming the core. Additional innovations in the resiliency and fabrication of the core is needed.  
      It would therefore be advantageous to provide a package that is capable of storing compressed rolls of material. In addition, it would be advantageous to provide a package that is economical and effectively stores the rolls of material in a compressed form, as well as a package that facilitates individual dispensing of individual rolls. Furthermore, it would be advantageous to provide a core for the compressed roll of material that is capable of collapsing and expanding without significant distortion of the core and/or compressed roll.  
     BRIEF SUMMARY OF THE INVENTION  
      Embodiments of the invention address the above needs and achieve other advantages by providing a package for storing compressed rolls of material. The compressed rolls of material are stored within a tray and sealed under vacuum with a lid, such as a film. Thus, the package reduces the inherent bulkiness associated with conventional packages, which facilitates the storage and transport of the package. Furthermore, a method for forming the package may be employed that includes compressing the rolls of material and sealing the rolls within respective cavities defined in a tray. The compressed rolls may be sealed under vacuum such that the rolls are maintained in their compressed state.  
      In one embodiment of the present invention a package is provided and includes a tray defining at least one cavity, as well as at least one compressed roll of material (e.g., a paper roll) positioned within a respective cavity. The package also includes a lid attached to a surface of the tray covering the cavity to define an enclosed volume and to enclose the at least one compressed roll within the enclosed volume.  
      In various aspects of the package, the package includes a core positioned within the compressed roll. The core could be paper, foam, metallic, elastomeric, and/or thermoplastic materials, or the core could be a polymer core having a strain relief area. In addition, the core may include a plurality of layers of paper, and an elastomeric adhesive may be applied between respective layers of paper. The package could include a supplemental core attached to the tray.  
      Further variations of the package provide a tray having a handle defined therein. The tray may be a thermoformable material and may include a plurality of cavities defined therein. At least one compressed roll of material could be positioned within each of the cavities. Furthermore, the tray may include lines of weakening between respective cavities such that each cavity is capable of being separated from the tray along respective lines of weakening. Similarly, the lid may include lines of weakening such that at least a portion of the lid may be removed from the tray to expose at least one of the cavities. The lid could include lines of weakening proximate to each cavity such that each roll may be removed from a respective cavity without affecting the compression and pressure of the rolls within the remaining cavities. The bond between the lid and the tray may have a peel strength to the tray of less than about 0.5 to 4 pounds/inch such that the lid is peelable from the tray. The tray may include a greater bending stiffness than the lid. The pressure within the enclosed volume may be less than the pressure outside of the enclosed volume, and one or more cavities may be partially evacuated such that the pressure within the package is sub-atmospheric.  
      The present invention also provides a method for packaging one or more rolls of material. The method includes providing a tray defining at least one cavity and compressing at least one roll of wound material. The method further includes positioning the compressed roll of material within a respective cavity, and sealing the compressed roll of material within the cavity by attaching a lid to a surface of the tray covering the at least one cavity.  
      In various aspects of the method, the method includes cutting a log of rolled material into a plurality of rolls. The positioning step may include positioning each of the compressed rolls of material within a respective cavity. The method may also include providing a tray defining a plurality of cavities, as well as forming lines of weakening in the tray between respective cavities such that each cavity is capable of being separated from the tray along respective lines of weakening. The method could further include forming a sheet of material into a tray defining at least one cavity. The providing step could also include providing a tray having a handle. Moreover, the method may include forming lines of weakening in a portion of the lid such that at least a portion of the lid is removable to expose a compressed roll of wound material positioned within a respective cavity. In addition, the method could include forming lines of weakening in the lid proximate to each cavity such that each roll may be removed from a respective cavity without affecting the compression of the rolls within the remaining cavities.  
      Additional aspects of the method include compressing the roll of wound material with a platen. The method may include compressing the roll of wound material radially, while the compressing and positioning steps may occur approximately simultaneously. The method may further include the step of reducing the pressure within the at least one cavity before sealing the lid to the tray, and/or compressing the roll below the surface of the tray prior to sealing the lid to the surface of the tray. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)  
      Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:  
       FIGS. 1   a ,  1   b , and  1   c  are isometric views generally illustrating the sequence of packaging rolls of material with a tray and a lid according to one embodiment of the present invention;  
       FIG. 2  is an isometric view of a compressible core according to one embodiment of the present invention;  
       FIG. 3  is an isometric view of a compressible core attached to the package of  FIG. 1   c  according to an additional embodiment of the present invention;  
       FIG. 4  is an isometric view of the process for manufacturing the package of  FIG. 1   a ,  1   b , and  1   c  according to one embodiment of the present invention;  
       FIG. 5  is an enlarged isometric view of the compression process shown in  FIG. 4 ; and  
       FIG. 6  is an enlarged isometric view of  FIG. 4  illustrating the conveyors moving rolls of material from a cutoff saw to a vacuum packing area. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.  
      Referring now to the drawings and, in particular to  FIGS. 1   a - 1   c , there is shown a package  10  including a plurality of rolls of material  11  disposed therein. In particular, the package  10  includes a tray  12  having a plurality of cavities  13 . As shown in  FIG. 1   b , the rolls  11  may be compressed and are capable of being positioned within a respective cavity  13 . The tray  12  may be sealed with a lid  15  such that the rolls  11  are maintained in a compressed configuration while positioned within the cavities  13 .  
      As used herein, the term “package” is not meant to be limiting as the package could be any enclosure capable of storing compressed rolls therein. Thus, the package could be any suitable tray and lid combination that is capable of storing one or more compressed rolls of material. Furthermore, the term “roll” is not meant to be limiting, as the rolls may include various wound materials that are capable of being compressed. For example, the roll could be a paper, tissue, towel, or foam material wound about a core. The roll of material may be compressed into various shapes, but would typically be compressed radially (i.e., perpendicular to the longitudinal axis of the core), as will be explained in further detail below.  
      The distortion of the roll  11  once the package is opened and the roll is uncompressed can be appreciable. Through Air Dried tissue with an approximate density of 0.02 lbs/in 3  compressed by 30% of its original volume, performs well and can be easily reshaped. However, the rolls  11  may be various materials and densities if desired. For example, the roll  11  could be compressed between 20-70% of its original volume.  
      The tray  12  may comprise one or more thermoformable materials such as one or more thermoplastic (e.g., one or more of polyethylene homo- or co-polymers and polypropylene homo- or co-polymers. The tray  12  may define one or more cavities  13  defined therein. Each cavity  13  is sized and configured to receive a respective roll of material  11 , and each cavity is separated from adjacent cavities by a divider or boundary  14  for separating individual rolls. As shown in  FIGS. 1   a  and  1   b , each cavity  13  includes a rectangular cross section such that a roll of material  11  that is compressed may be positioned therein. Furthermore, the tray  12  may also include a handle  16  that is formed in one end of the tray. Thus, the handle  16  may be integrally formed in the tray  12  or separately attached thereto and be used to carry the package  10 . The handle  16  could be an aperture extending completely through a portion of the tray  12 , or a recess or the like formed in the tray, and could be formed at various locations on the tray. In addition, the tray  12  could include a hanging rack hole (not shown) formed therein such that the package  10  may be placed on hanging racks, such as for retail.  
      The lid  15  may comprise a film that is sealed to the tray  12 . The lid  15  may be sealed at least about the outer periphery of the tray  12  and may also be sealed along boundaries  14  defining individual cavities  13 . Thus, the lid  15  could be a single sheet of material that seals all of the cavities  13 . Alternatively, individual lids  15  could be sealed to respective cavities  13  if desired. Various techniques may be employed to seal the lid  15  to the tray  12 , such as with an adhesive or by heat sealing. The lid  15  may be permanently affixed or peelable from the tray  12 . For example, the peel strength between the lid  15  and tray  12  may be about 0.5 to 4.5 pounds/inch such that at least a portion of the lid is peelable from the tray. The peel strength is measured in accordance with ASTM F88-94. For further discussion of peel strength, see U.S. Pat. No. 6,630,237 to Rivett et al., entitled “Peelably Sealed Packaging, which is incorporated herein by reference.  
      The lid  15  may be sealed to the tray  12  to not only maintain individual rolls  11  within respective cavities  13 , but also to help maintain a vacuum that is provided within the cavities. Although the seal between the lid  15  and tray  12  may be airtight, generally the seal between the lid and tray is capable of maintaining the pressure within the cavities  13  below atmospheric pressure. For example, the air pressure inside the package  10  may be at least about, and/or at most about any of the following: 14, 13, 12, 10, 8, 6, and 5 psia. In addition, the pressure differential between the external pressure and the internal pressure within the closed chamber may be at most about, and/or at least about any of the following, for example: 0.5, 1, 2, 3, 4, 5, 6, 8, and 10 psia. Furthermore, the pressure inside of the of the enclosed cavities  13  may be less than the pressure outside of the cavities (e.g., 14.7 psia) for at least about any of the following number of days: 30, 40, 50, 60, 90, 120, and 180 days. In an additional embodiment of the present invention, the pressure inside of the package  10  may less than the pressure outside of the package at least momentarily. Additionally, the volume of the cavities  13  may at least partially collapse over time (e.g., 1, 2, 12, and 24 hours) as the inherent counterforce of the rolls  11  against the lid  15  and tray  12  equilibrates.  
      The lid  15  may include one or more lines of weakening  17  (e.g., lines of a plurality of perforations or lines of scoring) such that individual cavities  13  can be opened along the lines of weakening without opening adjacent cavities. Thus, individual rolls  11  may be removed without affecting the compression of adjacent rolls. In other words, the remaining unopened cavities  13  remain closed, compressed, and under vacuum such that the rolls are also remain protected from contaminants. The lines of weakening  17  may be located along one or more edges or boundaries  14  about the periphery of the tray  12  or between each cavity  13 , or at any other desired location such that a roll  11  is capable of being accessed and removed via the lines of weakening. In addition or alternatively, the package  10  may include lines of weakening extending between each cavity  13 . Lines of weakening between cavities  13  allows for the separation of individual cavities from adjacent cavities.  
      The tray  12  and lid  15  can be various sizes, configurations, and materials in various aspects of the present invention. For instance, the tray  12  and lid  15  could be a thin flexible film or a thick and substantially inflexible material, but are generally capable of withstanding a vacuum that is drawn from the tray. For example, the tray  12  and lid  15  could be any of the following thicknesses: 0.25, 0.5, 1, 2, 4, 5, 8, 10, 12, 15, and 20 mils. Generally, the tray  12  includes a greater bending stiffness than the lid  15  to provide support and facilitate transport and storage of the packages  10 . Moreover, although  FIGS. 1   a - 1   c  illustrate a tray  12  having four cavities  13 , the tray may include one or more cavities. In addition, although the tray  12  and cavities  13  are illustrated as having a rectangular cross section, the tray and/or cavities could be various cross sections, such as a square or circle, and could be capable of receiving compressed rolls  11 .  
      Furthermore, each of the tray  12  and lid  15  can include one or more barrier resins to reduce the air (i.e., oxygen) permeation rate through the tray and lid. For example, the tray  12  and lid  15  could include ethylene/vinyl alcohol copolymer (“EVOH”), polyvinyl alcohol (“PVOH”), vinylidene chloride polymers (“PVdC”), polyalkylene carbonate, polyester (e.g., PET, PEN), polyacrylonitrile (“PAN”), and polyamide. The tray  12  and lid  15  may include various amounts of barrier resins such as, for example, 50%. For a more detailed discussion of barrier resins, see U.S. Pat. No. 6,769,227 to Mumpower et al., entitled “Package Including a Lidstock Laminate,” which is incorporated herein by reference. The tray  12  and lid  15  could also be metallized or include a foil laminate to decrease the air permeation rate.  
      Each roll of material  11  is wound about a respective core  19 . The core  19  is typically cylindrical having a hole defined along its longitudinal axis, where the hole may receive a spindle of a dispenser or other mechanism for facilitating unrolling of the roll  11 . The core  19  could be various materials such as a paper, foam, metallic, elastomeric, or thermoplastic material. The core  19  is capable of being compressed, as well as expanding when the lid  15  is removed from the tray  12 . An external force, such as pushing radially on the roll  11 , may be required to aid in expanding the core  19  to its original shape or near original shape. However, the core  19  may experience some distortion during the compression and expansion of the roll  11 .  
       FIG. 2  illustrates a modified extruded plastic core  19  with a strain relief area  28  designed to store the energy during collapse of the tissue core in direction  29 . The strain relief area  28  extends parallel to the longitudinal axis of the core  19  and provides a flexible hinge for facilitating compression of the core. For example, the strain relief area  28  could be made by extruding a hinge along the inner wall of the core, where the hinge comprises a small flexible section of plastic with a “V” notch located at its bending point such that the hinge may bend about the “V” notch. In addition, paper cores including a plurality of layers of paper secured together with elastomeric adhesives may be employed to prevent disintegration or peeling when compressing the rolls  11  and cores  19 . Moreover, the core  19  could be configured to self-expand to its original shape or near original shape without any external force.  
      While replacement of the core  19  with a more compressible energy-storing core is possible, it is typically not practical to do so. Instead, a modified insertion core can be provided as an adjunct to the package. For example,  FIG. 3  shows the attachment of an extra core  19 ′ to the package  10  to form a package  30 . The extra core  19 ′ is provided to allow consumers to either replace the core currently positioned within the roll  11 , or position the core within the existing core to maintain consistent rolling characteristics in a dispenser. In one embodiment of the present invention, an additional cavity may be formed in the tray  12  for accommodating the core  19 ′. Furthermore, although the core  19  and extra core  19 ′ are typically hollow, the core could be solid in order to achieve a desired resiliency and/or to provide additional support for a particular material.  
       FIG. 1   a  illustrates rolls of material  11  placed above a thermoformed tray  12  with corresponding cavities  13  and an integrated handle  16 . The rolls  11  are compressed into the form shown in  FIG. 1   b  and positioned into cavities  13 . The rolls  11  are shown as having a rectangular cross section; however, the rolls could be compressed to various cross sections (e.g., oval) depending on the type of material or the amount and/or direction of the compressive force on the roll. The process of compressing the rolls  11  can be done outside or inside of the cavity  13  and, in some cases, may be used to create the shape of the cavity  13 . A lid  15  is secured to the outer edges  18  of the tray  12  forming the completed package  10 . Upon removal of the lid  15 , the roll  11  may expand outwardly to its original shape or to a shape that includes some distortion due to the compression of the roll and core  19 .  
      Moreover, sequential cavities  13  can be formed, filled, and sealed to produce a completed cluster of compressed rolls  11  stored within the package  10 . Filling of the cavity  13  with a compressed roll  11  may be performed in such a manner to prevent the roll from expanding past the open top end of the cavity. The roll  11  may be compressed to a greater degree than required due to the fact that the roll may expand towards its original shape before the roll is sealed within a cavity  13 . Therefore, during the time the roll  11  expands to the open top end, the top end may be sealed with the lid  15  while the pressure is reduced.  
       FIGS. 4, 5 , and  6  illustrate one embodiment of the present invention, which provides a production system for forming and filling the package in the sequence described in  FIGS. 1   a ,  1   b , and  1   c . The production of the package  10  is typically situated immediately after a log cutter  50  that slices tissue logs  24  into individual rolls, and the rolls  11  are transported in groups  31  via a conveyor  25  to a station  22  for compressing the rolls within respective packages. Base tray material  60  is unwound from roll  61  and formed at station  21  into trays  12 . Individual cavities  13  are formed within each tray, and a handle  16  may also be formed therein if desired. The rolls  11  are compressed in group  31  at station  22  by a platen  40  and forced into cavities  13 . A top layer  26  (i.e., lid  15 ) is sealed to the tray  12  at station  23  while the rolls  11  are compressed and air is evacuated from the cavities  13 . Station  23  may also print, cut, and perforate both the top layer  26 , as well as the tray base material  60  between cavities  13 . In some cases, station  27  applies a supplementary core  41  to the package  10  to form the package  30 . The package  10  or  30  exits at area  70 . Transport of the finished packages  10  or  30  can be done directly on a pallet without the need for additional boxes or cartons and further avoiding additional wrapping. Multiple assemblies of packages  10  or  30  can also be bundled into groups and shrink wrapped. The production system may comprise a thermoforming machine that may produce at least about 500 cavities/minute, or the production system may comprise a plurality of thermoforming machines to meet the desired production rate.  
      Various processes or techniques may be employed to form the packages  10  and  30 . For example, the rolls  11  could be compressed with the platen  40  before positioning the rolls within respective cavities  13  ( FIG. 5 ), or stations  21  and  22  ( FIGS. 4 and 5 ) could be combined into a single operation such that compressing the rolls while positioned on the tray base material  60  also forms individual cavities. Furthermore, rolls  11  may be cut, compressed, and/or sealed individually rather than as a group  31 . Trays  12  may be formed using various processes such as thermoforming or injection molding. Moreover, additional processes may be employed such as a converting process for making rolls of tissue or towels.  
      The present invention may provide one or more advantages. For example, the package  10  stores compressed rolls of wound material, such as rolled tissue and towels, which significantly reduces the inherent bulk of these products and facilitates the purchase, transport, and storage of the rolls. Thus, packages are aesthetically pleasing, and the amount of packaging required to ship the rolls of material from a manufacturing facility to a retailer is reduced. The packages may be formed consistently into regular shapes such that handling and storage of the packages, such as by stacking multiple packages, is improved. In addition, the process for packaging the compressed rolls of material may be integrated with current manufacturing processes generally used to make rolls of material. Moreover, the package can maintain the compressed rolls in a compressed state without bulging, and each compressed roll may be stored within individual cavities defined in the tray. The package may provide for individual opening of sequential cavities of the package, as well as the separation of a cavity from the tray itself. When removed from the tray, the compressed rolls of material and/or core may expand to a usable form. The core may be specifically configured to collapse and expand between compressed and uncompressed positions, which reduces the incidence of damage to the core and/or roll of material.  
      Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.