DISPOSABLE INSULATED DRINKING VESSEL AND METHOD OF MAKING THE SAME

An insulating disposable vessel for holding a liquid and method of making it. The vessel is made up of a paper cup and a laminated wrap. The cup has a sidewall and a bottom wall. The laminated wrap has opposed marginal side edges and is wrapped about the sidewall with the marginal edges overlapping each other in an overlapped joint. The laminated wrap is formed from a strip having an outer layer formed of paper, and an inner layer formed of embossed paper towel material. The strip is wrapped around the sidewall with the inner layer interposed between the sidewall and the outer layer resulting in a plurality of thermally insulating air pockets providing thermal insulation for the cup.

FIELD OF THE INVENTION

This invention relates generally to disposable vessels for holding beverages and more specifically to disposable beverage cups formed of paper whose sidewalls include a thermally insulating paper-based wrap and methods of making the same.

SPECIFICATION

BACKGROUND OF THE INVENTION

Disposable cups for hot beverages, such as coffee, tea, soup, etc., are available in various configurations. Some such cups are formed entirely of a foamed plastic, e.g., polystyrene, so that the cup is heat insulating and can be readily held in a user's hand when filled with a hot beverage. Other commercially available cups are composed of paper with at least one layer of a plastic foam thermally insulating material at the sidewall of the cup so that the heat from the liquid in the cup can't readily penetrate through the sidewall to the hand of a person holding the cup. While such disposable cups may provide good heat-insulating properties, their plastic content renders them non-biodegradable. A variety of all-paper cups have been proposed and many are available commercially as environmentally acceptable alternatives to cups including plastic material insulation. However, such all-paper cups leave something to be desired from one or more standpoints of: complexity, cost, ease of manufacture, insulating ability. Thus, a need exists for a cup that is essentially all paper and which overcomes the disadvantages of the prior art. The subject invention addresses that need.

BRIEF SUMMARY OF THE INVENTION

One aspect of this invention is a disposable insulating vessel, e.g., beverage cup, for holding a liquid therein. The insulating vessel comprises a cup-shaped body and a laminated wrap. The cup-shaped body has a circumferential sidewall and a bottom wall. The circumferential sidewall is formed of paper, and has an outer surface, a top end and a bottom end. The laminated wrap extends about the circumferential sidewall of the cup-shaped body between the top end and the bottom end. The laminated wrap has a top edge, a bottom edge, and opposed marginal side edges. The opposed marginal edges overlap and are secured to each other by an overlapped joint. The laminated wrap comprises an outer layer and an inner layer. The outer layer is formed of paper and has an inner surface. The inner layer is formed of an embossed paper towel material. The inner layer has an inner surface and an outer surface. The inner surface of the outer layer is secured to the outer surface of the inner layer. The inner surface of the inner layer is secured to the outer surface of the circumferential sidewall, whereupon a plurality of thermally insulating air pockets are located between the outer surface of the circumferential sidewall and the outer layer of the laminated wrap.

In accordance with one preferred aspect of the disposable insulating vessel of this invention, the inner layer has a basis weight within the range of range of approximately 12 pounds to approximately 50 pounds per 3000 square feet.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the inner layer has a caliper within the range of approximately 0.005 inch to approximately 0.02 inch.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the outer layer has a basis weight of approximately 90 pounds to approximately 215 pounds per 3000 square feet.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the outer layer has a caliper within the range of approximately 0.015 inch to approximately 0.035 inch.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the inner surface of the outer layer and the outer surface of the inner layer are secured together by an adhesive.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the inner surface of the inner layer is secured to the outer surface of the circumferential sidewall by frictional engagement.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the circumferential sidewall tapers downward in diameter from the top edge to the bottom edge.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the top edge of the laminated wrap is disposed immediately adjacent to the top edge of the circumferential sidewall.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the bottom edge of the laminated wrap is disposed immediately adjacent to the bottom edge of the circumferential sidewall.

In accordance with another preferred aspect of the disposable insulating vessel of this invention, the bottom edge of the laminated wrap is disposed spaced from the bottom edge of the circumferential sidewall.

Another aspect of this invention is a method of making a disposable insulated vessel for holding a liquid. The method comprises providing a cup-shaped body having a circumferential sidewall and a bottom wall. The circumferential sidewall is formed of paper, having an outer surface, a top end and a bottom end. A laminated strip is provided. The laminated strip has a top edge, a bottom edge, and opposed marginal side edges. The laminated strip comprises an outer layer and an inner layer. The outer layer is formed of a paper and has an inner surface. The inner layer is formed of an embossed paper towel material. The inner layer has an inner surface and an outer surface. The inner surface of the outer layer is secured to the outer surface of the inner layer. The laminated strip is wrapped around the circumferential sidewall to form a laminated wrap. The marginal edges of the laminated wrap are caused to overlap each other, with the inner surface of the inner layer engaging the outer surface of the circumferential sidewall, whereupon a plurality of insulating air pockets are located between the outer layer of the laminated wrap and the outer surface of the circumferential sidewall. Those overlapping marginal edges are secured together, whereupon said the surface of the inner layer of the laminated wrap is secured to the outer surface of the circumferential sidewall.

In accordance with one preferred aspect of the method of this invention, the inner surface of the inner layer is secured to the outer surface of said circumferential sidewall by frictional engagement.

In accordance with another preferred aspect of the method of this invention, the inner surface of said outer layer and the outer surface of said inner layer are secured together by an adhesive.

In accordance with another preferred aspect of the method of this invention, the inner layer has a basis weight within the range of range of approximately 12 pounds to approximately 50 pounds per 3000 square feet.

In accordance with another preferred aspect of the method of this invention, the outer layer has a basis weight in the range of approximately 90 pounds to approximately 215 pounds per 3000 square feet.

In accordance with another preferred aspect of the method of this invention, the inner layer has a caliper within the range of approximately 0.005 inch to approximately 0.02 inch.

In accordance with another preferred aspect of the method of this invention, the outer layer has a caliper within the range of approximately 0.015 inch to approximately 0.035 inch.

In accordance with another preferred aspect of the method of this invention, the circumferential sidewall tapers downward in diameter from said top edge to said bottom edge.

In accordance with another preferred aspect of the method of this invention, the top edge of the laminated wrap is disposed immediately adjacent to the top edge of the circumferential sidewall.

In accordance with another preferred aspect of the method of this invention, the bottom edge of the laminated wrap is disposed immediately adjacent to the bottom edge of the circumferential sidewall.

In accordance with another preferred aspect of the method of this invention, the bottom edge of said laminated wrap is disposed spaced from said bottom edge of said circumferential sidewall.

Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown at20inFIG. 1one exemplary embodiment of a disposable insulated vessel constructed in accordance with this invention. The vessel20basically comprises a cup22and a thermally insulating wrap24. The cup and the wrap are formed essentially of paper. The cup is of conventional construction and includes a peripheral sidewall26and a bottom wall28. The sidewall26has a top edge30and a bottom edge32and tapers down in diameter from the top edge to the bottom edge at a slight acute angle, e.g., approximately 5.6 degrees. The top edge30is rolled to form the drinking lip of the cup as is conventional.

The bottom wall28of the cup is planar and circular in profile. The outer periphery of the bottom wall is in the form of a downwardly directed peripheral flange34, which is fixedly secured to the inner surface of the cup's sidewall just above the cup's bottom edge32, as best seen inFIG. 4. As is conventional the inner surface of the sidewall of the cup and the inner surface of the bottom wall of the cup include a thermoplastic, e.g., polyethylene, coating36. The coating36renders the sidewall and bottom of the cup resistant to liquid absorption and also serves as the means for securing the flange34of bottom wall to the sidewall26of the cup.

The thermally insulating wrap24is in the form of a lamination that is cut into a strip and tightly wrapped about the cup's sidewall26to secure it to the sidewall by friction, as will be described later. The lamination making up the wrap basically comprises an outer layer38and an inner layer40which are coextensive is size and secured together by an interposed adhesive42, e.g., a water based adhesive. The outer layer38is formed of paper which has a basis weight in the range of approximately 90 pounds to approximately 215 pounds per 3000 square feet, with the most preferred basis weight of approximately 90 pounds per 3000 square feet. The caliper of the outer layer36is in the range of approximately 0.015 inch to approximately 0.035 inch, with the most preferred caliper being 0.015 inch. The inner layer40is formed of an embossed low density paper, such as used for conventional paper hand towels. In accordance with one preferred aspect of this invention the paper towel material inner layer has a basis weight within the range of approximately 12 pounds to approximately 50 pounds per 3000 square feet, with the most preferred basis weight being approximately 12 pounds per 3000 square feet. The caliper of the paper towel material inner layer is in the range of approximately 0.005 inch to approximately 0.02 inch, with the most preferred caliper being 0.005 inch.

In accordance with one preferred aspect of this invention the material making up the paper towel layer28of the laminated wrap24is preferably embossed, as is commonly found in conventional paper hand towels. The embossing of the paper towel layer28enhances its thermal insulating properties when it is combined with the outer paper layer to form the lamination. In particular the securement of the inner and outer layers together forms a plurality of thermally insulating air pockets therebetween, as will be described shortly. The particular shape and configuration of the embossments can take numerous forms so that the embossed paper towel layer has a multitude of peaks and/or valleys. In the exemplary embodiment shown inFIGS. 5 and 6the paper towel layer28has a multitude of embossments in the form of elongated rounded end peaks44and a multitude of correspondingly shaped and sized elongated rounded end valleys46interposed between adjacent peaks. The embossments shown inFIGS. 5 and 6are merely exemplary, and thus can take other various shapes and be of other sizes and layouts than shown inFIGS. 5 and 6. In fact, it is contemplated that the embossed paper towel layer28can be made so that it only includes either plural peak embossments44or plural valley embossments46, and not plural peak and valley embossments.

The making of the laminated wrap is accomplished as follows. A web of un-embossed paper (which will be used to form the outer layer38of the laminated wrap) is superimposed over a web of embossed paper towel material (which will be used to form the inner layer40of the laminated wrap), with the adhesive42applied at their interface. The two webs are then brought into engagement so that the interposed adhesive42fixedly secures the top surface of the peaks44of the embossed towel material web to the undersurface of the paper web thereby laminating the two webs together and forming the plurality of insulating air pockets48therebetween like shown inFIG. 6(the interposed adhesive42not being shown in this figure). The resulting laminated web is then cut into a laminated strip, like shown inFIG. 5, having a desired shape, e.g., a trapezoid, which is sized and shaped to enable it to be wrapped about and secured the outer surface of the sidewall of the cup. In particular, the strip to which the laminated web is cut has a top edge50, a bottom edge50, a first slightly angled side edge52and a second and opposite slightly angled side edge54. The laminated strip is then tightly wrapped around the outer surface of the sidewall26of the cup22so that the undersurface of the inner layer (the paper towel layer40) is in engagement with the outer surface of the sidewall26of the cup, with the portions of the laminated strip contiguous with the marginal angled edges side edges52and54overlapping each other as best seen inFIG. 3. The overlapping edges are fixedly secured together by an interposed layer of adhesive58to form an overlapped joint thereat. Any suitable adhesive, e.g., a water based adhesive, may be used to secure the overlapped edge portions together to form the joint.

In any case the tight wrapping of the laminated strip about the sidewall of the cup secures the wrap to the cup by frictional engagement sufficient to prevent the wrap from sliding off of the cup. Moreover, the frictional engagement of the undersurface of the wrap with the outer surface of the sidewall of the cup also results in the formation of other insulating air pockets between the embossed towel layer and the outer surface of the sidewall of the cup. Those other air pockets, along with the air pockets48located between the lower layer40and the upper layer38provide additional thermally insulating properties to the vessel20.

As best seen inFIGS. 1 and 6the thermally insulating wrap of the embodiment20extends virtually the entire height of the sidewall of the cup, i.e., from immediately below the rolled top edge30to the bottom edge32. In another exemplary embodiment of a disposable beverage vessel constructed in accordance with this invention, which is shown inFIG. 7, the bottom edge of the thermally insulating wrap is located above the bottom edge of the cup.

It must be pointed out at this juncture that various changes can be made to disposable thermally insulating vessels from the exemplary embodiments shown and described above. For example, other paper-based low density materials can be used in lieu of the embossed paper towel material so long as such materials provide sufficient thermal insulation and a low cost in view of the fact that the vessels of the subject invention are disposable and normally for one-time use. Moreover, the embossed paper towel layer need not have embossments that are in the form of peaks and valleys like discussed above, so long as the embossment results in the formation of insulating air pockets when the laminated strip making up the wrap25is wrapped about the cup22. Furthermore, the strip that is cut to form the wrap need not be a trapezoid, so long as the marginal side edges can be overlapped and secured to each other to frictionally hold the wrap in place on the cup. In fact, while it is preferred that the insulating wrap be secured to the outer surface of the sidewall of the cup by frictional engagement, other means for securing the wrap can be used, if desired. Such other means can be in the form of an adhesive or can be in the form of an interposed thermoplastic coating which is melted to secure the insulating wrap to the outer surface of the sidewall of the cup. Further still, the dimension and proportions of the vessel can be changed from that shown and described above.

Without further elaboration the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service.