Field of Invention

[0001] The present invention relates to dispensers for web materials, such as plastic film. In particular, the invention relates to containers having a cutting device for cutting across the material as it is dispensed.

Background of Invention

[0002] Various containers are known for dispensing web material. Many of these containers use an exposed serrated edge as the means for cutting the web material once dispensed from the container. These serrated edges have several disadvantages. For example, the sharp, exposed serrated edge can inadvertently cut the user or other material that it contacts. Also, the user must engage the web material with the serrated edge by holding the web material in one hand and the container in the other. This awkward arrangement can lead to adverse results such as ineffective cutting, the web material doubling over itself, and so on.

[0003] Some known containers include a track-guided cutting assembly to overcome the problems associated with the use of a serrated edge. An example of such a container is described in commonly assigned U.S. Pat. App. No. 10/641 ,958, filed August 15, 2003 in the name of Keith E. Antal. This application describes a box for a roll of web material, with a molded plastic track extending along the box, parallel to the axis of the roll. A cutter is captive in the track. The web material is led out of the box and across the track. The cutter is slid along the track, cutting across the material. This and similar devices have been very successful. However, the separate plastic track, and the need to install that track in the box, increases the cost and complexity of the product. A problem that is experienced with some sliding cutters is that the web material may bunch in front of the cutter, instead of being cut cleanly.

[0004] U.S. Pat. No. 4,787,284 (Chen) proposed a cardboard box for a roll of plastic wrap film with a cutter that ran in a slot formed in a double-thickness part of the cardboard box.

[0005] An important consideration with cutters of the sort shown by Antal and Chen is to hold the web material steady across the path of the cutter while it is cut so that the web material does not bunch in front of the cutting blade. A plastic track such as that described by Antal can be co-extruded from different grades of polyvinyl chloride (PVC), so that the parts that guide the cutter are of hard PVC while the exposed parts on which the web material rests while it is being cut are of soft, highly plasticized PVC. Dioctyl phthalate may be used as a plasticizer. When a web of PVC film is placed in contact with the highly plasticized PVC surface, the phenomenon known as "cling" is observed. This phenomenon causes a substantial resistance to movement of the film across the surface, but little or no resistance to lifting the film off the surface. Cling is dependent on the pair of materials forming the web and the underlying surface, so that a particular surface material may exhibit cling with one web material, but not with another web material.

[0006] The applicants have found that unplasticized web materials including polyethylene (PE) do not cling reliably to highly plasticized PVC. Without being limited to a specific theory, the applicants believe that the plasticizer from the PVC migrates into the unplasticized web material, leaving the surface of the PVC unplasticized and therefore without cling. Cling is distinguished from adhesive tackiness, which causes a resistance to lifting off. Cling is distinguished from "static cling" because cling requires direct contact between the two surfaces that are clinging together. Static cling is an electrostatic effect, and can produce an attraction even if there is an intervening layer of some other material. Cling and static cling sometimes occur on the same materials, but they can be separated out either by comparative measurements with a thin intervening layer of non-cling material or by measurements at very high humidity that allows the electrostatic charge to leak away.

[0007] The cling between the film web and the highly plasticized PVC surfaces of the track can hold the film in place over the entire width of the film, on both sides of the cutter, as it is being cut. This facilitates a clean cut across the entire width of the film without the film bunching in front of the cutter blade. Because the cling creates

substantially no resistance to lifting the film off the track, the cut length can be easily removed and used, while the remaining end of the roll can be easily lifted and advanced for the next cut. These advantages are not available in Chen's apparatus, because in Chen the plastic wrap film rests directly on the cardboard surface, to which the plastic wrap film does not cling. The plastic wrap film must then be held in place in some other way, most commonly by pulling the web material taut in front of the cutter blade.

Summary of Invention

[0008] The present invention generally comprises a container for dispensing selected portions of a web material retained in a roll within the container. The container has an elongated opening in a wall thereof, through which the web material can be led out of the container. The container includes a slot in the surface of the container across which the web material from the elongated opening can be laid, and a cutter guided in the slot. A strip of a substance to which a web material clings is applied to the surface of the container along at least one side of the slot.

[0009] In an embodiment, strips of a substance to which a web material clings are applied to the surface of the container along both sides of the slot.

Brief Description of the Drawings

[0010] For the purpose of illustrating the invention, there is shown in the drawings various forms which are presently disclosed; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities particularly shown.

[0011] Figure 1 is a perspective view of a first embodiment of a dispenser as contemplated by the invention.

[0012] Figure 2 is a perspective view of a cutter forming part of the dispenser shown in Figure 1.

[0013] Figure 3 is a perspective view of a second embodiment of a dispenser as contemplated by the invention.

[0014] Figure 4 is a flat view of a sheet of material that can be folded to form the major part of the dispenser shown in Figure 3.

[0015] Figure 5 is a perspective view of a cutter rail forming part of a third embodiment of a dispenser as contemplated by the invention.

[0016] Figure 6 is an enlarged detail of Figure 6.

Detailed Description of the Drawings

[0017] In the drawings where like elements are identified by like numerals, there are shown various embodiments of a container for storing and dispensing rolled web material, for example, plastic wrap. Referring initially to Figures 1 and 2, a first form of container, identified generally by the numeral 10, comprises a cardboard box 12 that is long and thin and is approximately square in cross section. The box 12 has a body with two ends 14, two full sides 16, 18 and a partial third side 20. One edge of each of the sides 16 and 20 joins the long edges of the side 18. The box 12 also has a lid 22, hinged to the other edge of the side 16. The lid 22 has a full side 24 adjacent to the hinge, a partial side 26 adjacent to the side 24, and partial ends 28 When the lid 22 is closed, as shown in Figure 1, The partial side 26 of the lid overlaps the partial side 20 of the body, creating a narrow opening 29, parallel to the overlapping sides, extending the length of the box 12.

[0018] In use, plastic film or other web material 30 is retained on a hollow roll 32 positioned within the box 12. The web material 30 may be, for example, polyethylene film, polyvinyl chloride film, gift-wrap paper, freezer wrap paper, foil, or the like. The hollow roll 32 may be supported for easy rotation on roll supports (not shown) formed on the insides of the ends 14. For shipping, the material 30 and the roll 32 may be contained entirely within the closed box 12. For use, a free end 34 of the film material 30 is led off the roll 32 and through the opening 29 to the exterior of the box. The free end 34 may be positioned by opening the box 12, placing the film material 30 over the partial side 20, and closing the partial side 26 of the lid over the film material.

[0019] A slot 36 is formed in the side 18 of the box 12, near the edge 37 with the partial side 20, parallel to the length of the box 12. The slot 36 is positioned so that plastic film material 30 led out of the opening 29 can be led over the edge 37 and laid across the slot 36. The slot 36 then extends beyond the film material 30 at both ends of the box. A cutter 38, best seen in Figure 2, is captive in the slot 36. The cutter comprises a foot 40 that is inside the box 12, a pillar 42 that extends through the slot 36, a head 44 that is outside the box 12, and a pair of cutter blades 46 that are between the head 44 and the foot 40 on either side of the pillar 42. The cutter blades 46 may be the two ends of a single piece of metal or other hard material embedded in or attached to the pillar 42.

[0020] The foot 40 is substantially longer and broader than the width of the slot 36. The foot 40 slides over the inside surface of the box side 18. The foot 40 prevents the cutter 38 from lifting away from the box 12, and guides the cutter against tipping either endways or sideways. The foot 40 may be a snap fit onto the pillar 42, so that the cutter 36 is assembled in the slot 36 and becomes captive when the foot is snapped onto the pillar. Alternatively, a wider opening may be provided at one end of the slot through which the foot 40 can be inserted when already attached to the pillar 42 and the head 44. Because the slot 36 is near to one corner of the box 12, it does not foul the film material 30 on the roll 32. However, to minimize the risk of fouling and damaging the film material 30 if the film material does not remain tightly rolled, the exposed edges and corners of the foot 40 are rounded.

[0021] The pillar 42 joins together the foot 40 and the head 44 and, together with the cutter blades 46, prevents the cutter 38 from turning about an axis perpendicular to the box side 18. The length of the cutter blades and pillar, measured along the slot 36 at the level where the cutter blades and pillar pass through the slot 36, is therefore considerably longer than the width of the slot 36. The pillar 42 and the slot 46 are preferably narrow. In an alternative embodiment, the pillar 42 and cutter blades 46 may be made integrally from one or two thicknesses of plastic sheet with sharpened edges. The cutter blades may be similar to those described in the above-mentioned U.S. Pat. App. No. 10/641 ,958 to Antal, the disclosure of which is herein incorporated by reference in its entirety.

[0022] The head 44 forms a sled that slides over the film material 30 when the film material is laid across the slot 36. The underside 48 of the head 44 is generally broad and flat, to co-operate with the foot 40 in preventing tipping of the cutter 38, but the ends of the underside 48, facing along the slot 36, may be slightly raised so that the head 44 is less likely to catch on the edge of the film material 30.

[0023] The head 44 and the foot 40 can be manufactured from plastic or some other rigid material. The head 44 can be contoured to accept a human finger so as to facilitate movement of the cutter 38 along the slot 36.

[0024] The amount by which the slot 36 is longer than the film material 30 is wide is sufficient for the cutter 38 to be parked at either end of the slot 36 without obstructing the laying of the film material 30 across the slot 36.

[0025] At each side of the slot 36, there is a strip of cling material 50 applied directly to the surface of the box side 18. If the strips 50 have appreciable thickness, they are preferably spaced sufficiently far from the slot 36 that they do not obstruct the head 44 of the cutter 38. The strips 50 are preferably applied in a liquid or semi-liquid form, and caused or permitted to dry or harden on the box 12. As shown in Figure 1 , the strips extend over the whole width of the film material 30. The strips 50 may alternatively form dashed lines or otherwise be patterned. To ensure that the edges of the film material 30 contact the cling strips 50, while avoiding the need for very precise deposition, the cling strips may extend beyond the points where the edges of the film material are expected to lie.

[0026] The material chosen for the strips 50 may depend on the composition of the film material with which the dispenser 10 is intended to be used, and must exhibit cling with the film material in question. Satisfactory results have been achieved with Lexel all purpose sealant, obtainable from Colorado Steel Sash Co., Inc., of Brighton, CO, or Vulkem sealant, obtainable from Tremco Incorporated. The Lexel and Vulkem coatings were dried with a hot air gun. A thin layer of highly plasticized PVC material, either extruded directly onto the cardboard or dissolved in a solvent and coated on has produced satisfactory results with PVC film. Urethane dissolved in methyl ethyl ketone and coated

onto cardboard has produced satisfactory results with PVC film and is believed also to produce satisfactory results with PE film. An energy curable coating, for example, an ultra-violet curable coating, may be used instead of a solvent-based coating. An ultraviolet-cured coating of a polyurethane acrylate copolymer has been found to produce good results with both PVC and PE films.

[0027] Holes 52 are formed in the side 18 of the box 12, positioned so that when the free end 34 of the film material 30 is clinging to the cling strips 50 the side edges of the film material 30 lie across the holes 52. The holes 52 are large enough for a user to inserted a finger into one of the holes 52 and under the film material 30.

[0028] In use, the cutter 38 is positioned at one end of the slot 36. The film material 30 is led out of the opening 29, round the edge 37 and across the slot 36. The film material 30 is positioned with a desired length at the free end 34 beyond the slot 36, and laid down onto the box side 18 so that the material 30 clings to the cling strips 50. Then, the cutter 38 is slid across the film material 30 to the other end of the slot 36. Because the cling strips 50 hold the film material 30 on both sides of the slot 36 over the whole width of the web of film material, a clean, straight cut is easy to achieve. The cut length of film material 30 is lifted off the cling strip 50 and removed. The new end of the film material on the roll 32 is held by the cling strip 50 until another cut length is needed, when the end is lifted off the cling strip 50 by a finger in one or each of the holes 52 and moved forward across the slot 36. In the embodiment shown in Figure 2, the cutter 38 has cutter blades 46 at both ends, so it is not necessary to return the cutter 38 to the starting position between cuts.

[0029] Referring now to Figures 3 and 4, a second embodiment of a container for film material, indicated generally by the reference numeral 60, best seen in Figure 3, comprises a box 62 formed by folding up a cardboard blank 63 best seen in Figure 4. The box 62 has two triangular ends 64, and three sides 68, 70, 72. In the interests of clarity, distinct fold lines are shown between the ends and sides 64, 66, 68, 70 of the blank in Figure 4. Preferably, however, the edges between the sides 66, 68, 70 are rounded, as shown in Figure 3. One side 68 has a cut 79 and a slot 86. The slot 86 extends along the side 68, and is closed at both ends. The cut 79 is parallel to the slot 86, near to the edge 87

between the sides 68 and 70, and turns away from the slot 86 at both ends, so as to define a flap. If the edge 87 is rounded, the ends of the cut 79 may extend slightly into the rounded part, so that the flap 72 tends to gape away from the side 68, opening the cut 79 slightly. The open cut 79 then faces towards the slot 86. Two strips of cling material 100, 102, similar in composition to the cling strips 50 described above, are applied to the blank 63. One cling strip 100 is between the cut 79 and the slot 86. The other cling strip 102 is on the side of the slot 86 further from the cut 86. A cutter 88, which may be similar to the cutter 38 described above, slides along the slot 86. A roll of a web of film material 80, which may be similar to the film material 30 described above, is enclosed within the box 62.

[0030] In use, a free end 84 of the film material 80 is led out through the cut 79, and across the slot 68. The film material 80 is laid down onto surface of the box side 68, and is held by the cling strips 100. The cutter 86 is slid across the film material 80, cutting free the end portion 84. The cut length is then lifted off the cling strip 102 and removed for use. The newly cut end of the web is retained on the cling strip 100.

[0031] Referring now to Figures 5 and 6, a second embodiment of a container for film material, indicated generally by the reference numeral 120 comprises a box 122 with a hollow roll 32 of film material 30 inside the box. The box 122 may have a lid 22 creating a narrow opening 29 through which the film material 30 can be led out of the box, as shown in Figure 1. A rail 124 attached to a corner of the box. The rail 124 may be supplied to the user inside the hollow the roll 32. The user then removes the rail 124 from inside the roll 32 and attaches it to the outside of the box 122. For this purpose the rail 124 is provided with a strip of pressure-sensitive adhesive 126, which is protected by a strip of release paper that the user removes in order to attach the rail to the box 122. The rail 124 has a pair of upper flanges 128 separated by a slot 130. A cutter 38 runs in the slot 130 as in the slot 36 shown in Figure 1. The upper flanges 128 of the rail 124 are coated with strips of cling material 132 similar to the strips 50, 100, 102.

[0032] In use, a free end 34 of the film material 30 is led out through the narrow slot 29, and across the flanges 124 and the slot 130. The film material 30 is laid down onto the upper surface of the flanges 124, and is held by the cling strips 132. The cutter 38 is slid

across the film material 30, cutting free the end portion 34. The cut length is then lifted off the cling strip 132 and removed for use. The newly cut end of the web is retained on the other cling strip 132.

[0033] Although specific embodiments have been described, various modifications may be made without departing from the scope and spirit of the invention as defined by the appended claims. For example, the box 12, 62, 92 has been described as being made of cardboard. The box can alternatively be made from another substantially rigid material, for example, layered paper stock or plastic. The box 12, 62, 92 could be made from two plies of 12 pt or thinner material. It is contemplated that a thicker box construction would be more expensive to manufacture but would allow for the container 10, 60, 90 to be reusable, whereas a thinner box construction would be less expensive to manufacture but would be more suitable for merely a one-time-use (or disposable) container. A reusable container 10, 60, 90 may require more durable cutter blades 46 than a disposable container. A metal cutter blade may be used instead of the plastic blade 46 described, especially for a reusable container 10, 60, 90.

[0034] Although a box 12, 62 of uniform wall thickness has been shown, the part in which the slot 36, 86 is formed may be thicker than the remainder. The thicker part may extend to, and may extend round, a corner between the side 18, 68 and an adjacent side of the box. In the case of a cardboard or similar box, the extra thickness may be formed by adding one or more extra layers of cardboard. The extra layer may be formed by doubling back the cardboard at a free edge. For example, in the box 12 shown in Figure 1, the cardboard at the free edge of the partial side 20 may be doubled back over the partial side 20 and over the adjacent part of the side 18 to a point beyond the slot 36. The doubled back part is then preferably on the inside of the box, because boxes are commonly made of cardboard that is finished and printed on one side only, and if the doubled back part were on the outside it would have its wrong side exposed to view.

[0035] Although elongate square and triangular dispensers 10, 60, 90 have been described, the dispenser may be of any shape, provided that is capable of accepting a hollow roll 32 of web material 30, 80 and has surfaces on which the opening 29 or cut 79, the slot 36, 86 with the cutter 38, 88, and the cling strips 50, 100, 102 or the rail 124 can

be arranged. Thus, at a minimum, the dispenser must include a space capable of housing the web material 30, 80. The dispenser may be circular in cross section. The dispenser can also be semi-cylindrical, rectangular, oval or some other geometrical or non- geometrical shape. As is shown for the triangular dispenser 60 in Figure 3, terms such as "square" and "triangular" are not limited to the strict geometric shape, but include approximations thereto, whether arising from manufacturing tolerances and imprecision or from deliberate design choices such as the rounded corners shown in Figure 3. The web of material 30, 80 could be in some form other than a roll 32. For example, the web of material 30, 80 may be folded back and forth on itself. If the web of material is in a form other than a roll, then the shape of the dispenser is not constrained to shapes that can efficiently contain a roll.

[0036] Although the slot 36, 86 has been shown as closed at both ends, the slot may instead open out through one or both ends of the box side 18, 68, and be closed off by the box end 14, 64 or by a separate plug or end cap. The open end of the slot enables the cutter 38, 88 to be slid into the slot from the end. However, an open-ended slot 16, 86 may weaken the box side 18, 68, and may require greater attention to securing the end of the box side 18, 68, on both sides of the slot, to the box end 14, 64.

[0037] Although in the embodiments the cling strips 50, 100, 102 have been shown as fairly narrow strips, broader strips may be used. For thick webs, and/or for web materials that do not cling strongly to the cling strips, the entire side 18, 68 of the container 10, 60 may be coated with cling material. The strip of the surface over which the underside 48 of the head 44 of the cutter 38, 88 actually passes may be left uncoated.

[0038] Although in the embodiment shown in Figures 5 and 6 the cling strips 132 are applied to the surfaces of the cutter rail, the dispenser could be provided with a cutter rail with one or both of the cling strips applied to the box side alongside the cutter rail. If the cutter rail is embedded in the adjacent surface of the box, a thick coating of cling material 50, 100, 102 may be applied to the surface of the box alongside the cutter rail. The exposed surface of the coating of cling material is then preferably flush with or slightly proud of the cutter rail.

[0039J It will be appreciated by those skilled in the art, that the present invention may be practiced in various alternate forms and configurations. The previously detailed description of the disclosed embodiments is presented for purposes of clarity of understanding only, and no unnecessary limitations should be implied therefrom.