SAME

FIELD OF INVENTION

The present invention generally relates to a drinking straw, and more particularly to a flexible paper drinking straw and a method of producing thereof.

BACKGROUND OF INVENTION

Drinking straw is a common consumer product that utilizes the principle of a change in air pressure to cause a fluid to rise above a settled level in a container. It is widely used because of its convenience to reach the beverage and assists people to consume a beverage out of the container especially when driving or for people with mobility impairments.

Modern drinking straws are mostly made of plastics material due to a number of advantages. Plastics drinking straw is generally very light in weight. The material as well as manufacturing costs for plastic drinking straws are also much economical. Plastics drinking straw can withstand long exposure to fluid and can handle hot fluid well. It is fairly rigid and resilient, even after accidental bending, and can be easily formed into various shape and size.

Over the years, plastics drinking straw is not only in its basic form, which is straight for its full length. They can be customized to various forms that cater for different purposes or uses. One common example is the flexible drinking straw where the drinking straw is capable of bending at a flexible portion of the drinking straw to a desired angle. The flexible drinking straw further provides convenience to its user in that the user can consume the drink without the need of tilting the container, leaning forward or bending his head to contact the drinking straw with his mouth. Global plastics pollution is increasingly alarming and part of it is contributed by these used plastics drinking straws when discarded, mostly after a single use. As such, many countries have imposed bans of plastics drinking straws as part of numerous campaigns to reduce plastics waste being released to the environment. Alternatives to plastics drinking straw are readily available, such as those made of metal, glass, silicone or paper. Single use paper drinking straws are however more acceptable to the public as they are biodegradable, cheaper and hygienic.

Despite there exist numerous alternatives to plastics drinking straw, they are not as well-received as the plastics drinking straw. There are critics that these alternatives, especially paper drinking straws, are non-durable and inflexible, apart from potential risks of allergy. In light of the current pushes by the governments and environmental bodies to reduce usage of plastics drinking straws, there is a need to have an improved paper drinking straw which solves the abovementioned drawbacks and a method of producing the same.

SUMMARY OF INVENTION

Accordingly, it is an object of the present invention to provide a solution to the above problems.

The present invention describes a method of producing a flexible drinking straw comprising: an elongated hollow tube of a paper material; and at least one flexible segment on the tube having a plurality of annular corrugations such that the tube can extend, retract or bend along the flexible segment, the method comprising the steps of: (a) providing the tube of a desired length; (b) forming the plurality of annular corrugations on a segment of the tube; and (c) compressing the tube lengthwise to form the flexible segment, wherein the moisture content of the tube is maintained at 16% or above so that the tube is sufficiently soft to undergo step (b).

The invention advantageously provides a biodegradable flexible paper drinking straw having a flexible segment which provides flexibility to the drinking straw to extend, retract or bend at the flexible segment. The flexible paper drinking straw, unlike currently available paper drinking straw, is strong, durable and highly resistant to tearing, particularly when bending the drinking straw repeatedly. These characteristics are made possible by the disclosed method of producing. With the present invention, the current issues of plastics pollution could be addressed.

The preferred embodiment of the invention consists of novel features and a combination of parts hereinafter fully described and illustrated in the accompanying drawings and particularly pointed out in the appended claims; it being understood that various changes in the details may be effected by those skilled in the arts but without departing from the scope of the invention or sacrificing any of the advantages of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawing the preferred embodiments from an inspection of which when considered in connection with the following description, the invention, its construction and operation and many of its advantages would be readily understood and appreciated.

FIGURE 1 is a perspective view of a flexible paper drinking straw in (a) straight and (b) bent configurations.

FIGURE 2 shows an illustration of an enlarged cross-sectional view of a paper drinking straw, with a mandrel being inserted thereto, adjacent to a die roller during corrugations formation.

FIGURE 3 is an enlarged elevation view of a paper drinking straw (a) after formation of corrugations and (b) after compressing the paper drinking straw following formation of corrugations. DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the invention shall be described according to the preferred embodiments of the present invention and by referring to the accompanying description and drawings. However, it is to be understood that limiting the description to the preferred embodiments of the invention and to the drawings is merely to facilitate discussion of the present invention and it is envisioned that those skilled in the art may devise various modifications without departing from the scope of the appended claims.

The present invention generally relates to a drinking straw, and more particularly to a flexible paper drinking straw and a method of producing thereof.

The invention discloses a method of producing a flexible drinking straw (10) comprising: an elongated hollow tube (12) of a paper material; and at least one flexible segment (18) on the tube (12) having a plurality of annular corrugations (18A) such that the tube (12) can extend, retract or bend along the flexible segment (18), the method comprising the steps of: (a) providing the tube (12) of a desired length; (b) forming the plurality of annular corrugations (18A) on a segment of the tube (12); and (c) compressing the tube (12) lengthwise to form the flexible segment (18), wherein the moisture content of the tube (12) is maintained at 16% or above so that the tube (12) is sufficiently soft to undergo step (b).

FIG. 1 illustrates a flexible drinking straw (10) predominantly made of a paper material. The flexible drinking straw (10) is formed with an elongated hollow tube (12) having a generally cylindrical sidewall extending between two open ends (14, 16), such that when in use, one of which serves as a top (14) and the other bottom (16). The use of the ends (14, 16) as a top and bottom of the drinking straw (10), although not necessarily always the case, may be similarly defined in a similar fashion as for a conventional plastics drinking straw when in use. The elongated tube (12) has a generally constant outer diameter throughout its length with circular openings defining the two ends (14, 16) of the drinking straw (10). Similar to a conventional plastics drinking straw, when in use, a user draws a liquid from one bottom end (16) of the drinking straw (10), through an interior of the flexible drinking straw (10), to an opposed top end (14) and into the user’s mouth for consumption.

The flexible drinking straw (10) can be made of a paper material of any types and qualities, and preferably of weight between 30 g/m ² (gsm) to 250 g/m ² (gsm). To further enhance resistance of the paper drinking straw (10) to sogginess and degradation from prolonged exposure to fluids, the paper material may be impregnated with a fluid impermeable material. Non-limiting example of this paper material includes paper material coated with wax or paraffin. Such coating may be pre-applied to the paper material prior to using or forming the drinking straw (10). However, such coating may also be similarly applied after forming the drinking straw (10) without impinging the performance of the flexible drinking straw (10).

The elongated hollow tube (12) is constructed from multiple spirally wound plies of paper strip, preferably pre-coated fluid impermeable paper strip. The hollow tube (12) has a preferred cylindrical sidewall thickness of approximately 0.3 mm to 1 mm. This construction provides the hollow tube (12) sufficient rigidity to maintain its shape and form and to prevent deformation of its cylindrical sidewall. In this regard, it is preferable to wind at least 2 plies of paper strip and more preferably, not more than 4 plies of paper strip, considering the desired thickness and the type of paper used. An exemplary methods of producing the elongated hollow tube (12) of a desired length is described in the following. A jumbo roll of paper is first slit into reels of narrower paper strips. The paper strip is then spirally wound on mandrel to a desired sidewall thickness, secured with an adhesive and subsequently cut into elongated hollow tubes (12) of desired length.

The drinking straw (10) is flexible in that the drinking straw (10) can extend, retract or bend with a construction to endure repeated bending and flexing, which may be used in a straight or bent configurations, as shown in FIG. 1, according to the preference of the user. The flexibility is provided by a flexible segments (18), constructed from a plurality of annular corrugations (18A), that preferably be provided at a region near one end (14) of the flexible drinking straw (10), which may conventionally be used as the top (14) of the drinking straw (10). The annular corrugations (18A) are defined by circular inward connecting folds in the sidewall of the hollow tube (12). Outside of the region of the flexible segment, the drinking straw (10) is rigid and inflexible. The constructions of the flexible segment (18) will not be described in details as they are in close similarity to that of conventional flexible plastics drinking straw.

To form the flexible segment (18) on the elongated hollow tube (12), a mandrel (22) having a plurality of corrugations (24) on its surface is first inserted within the hollow space of the hollow tube (12) and the resultant is placed on a die roller (20) having a plurality of corresponding corrugations (26) in such fashion that a trough of the corrugations (24) of the mandrel (22) corresponds to a ridge of the corrugations (26) of the die roller (20), as exemplified in FIG. 2. Upon rotation and compression of both the mandrel (22) and the die roller (20), annular corrugations (18A) are formed on the hollow tube (12). To ensure the hollow tube (12) not be damaged by these mechanical actions, it is necessary to maintain the moisture content of the hollow tube (12) at above 16%, so that the hollow tube (12) is sufficiently soft to receive deforming force from the die roller (20). With reference to FIG. 3, the mandrel (22) is then removed from the hollow tube (12) immediately after formation of the annular corrugations (18A), and the hollow tube (12) is then subject to an axial compressive force to contract the hollow tube (12) lengthwise, thereby forming the flexible segment (18). While the configuration of the apparatus or means of forming the annular corrugations (18A) is described herein, this is not to be taken by way of limitation and other readily available apparatuses of forming the annular corrugations (18A) shall possibly be adopted without departing from the scope of the invention.

One or more flexible segments (18) can be similarly formed on the hollow tube (12) to cater different needs, utilizing the above-described method. Although it is not shown in any of the accompanying drawings, the present flexible paper drinking straw (10) can similarly be formed into twisted or spiral drinking straws that are conventionally used in parties or special events, using the method as described in the preceding description. Although the invention has been described and illustrated in detail, it is to be understood that the same is by the way of illustration and example, and is not to be taken by way of limitation. The spirit and scope of the present invention are to be limited only by the terms of the appended claims.