JP6947706B2 - Paper straw - Google Patents

Description

The present invention relates to a paper straw, particularly a paper straw that can be crushed into a flat plate and housed compactly.

Generally, straws used for drinking beverages and the like are made of plastic. Since plastic straws are rigid, they cannot be crushed, and most of their capacity is occupied by air, so that they are required to be compactly accommodated during storage, transportation, and the like.

As a plastic straw that can be stored compactly, there is a telescopic plastic straw that is a combination of two or more cylinders having different diameters. Further, Patent Document 1 proposes a straw made of synthetic resin provided with a foldable portion in the length direction of the straw.
Although these straws are somewhat compact, there is a limit in reducing the capacity as long as they are made of rigid plastic, and there is a problem that the manufacturing cost increases due to the complicated structure.

Furthermore, in recent years, movements to prevent environmental destruction caused by plastic waste have begun, and it is required to replace plastic disposable products with materials having a small environmental load. Among them, 500 million plastic straws are consumed daily in the United States and more than 1 billion in the world, but deaths due to accidental ingestion of sea birds and sea turtles have been reported, and environmental protection groups etc. , Has begun a campaign to avoid using plastic straws.

Japanese Unexamined Patent Publication No. 2001-54457

An object of the present invention is to provide a paper straw that can be housed compactly and has a small burden on the environment.

The means for solving the problem of the present invention is as follows.
1. 1. It is a polygonal cylinder shape with four or more faces made of water resistant paper.
A paper straw that can be crushed into a flat plate consisting of a first main surface composed of two or more adjacent surfaces and a second main surface composed of the remaining surfaces.
2. 1. The cross section in the direction perpendicular to the length direction is a quadrangle, a pentagon, or a hexagon. The paper straw described in.
3. 3. 1. At least one surface of the polygonal cylinder is a reinforcing surface having a plurality of paper layers. Or 2. The paper straw described in.
4. The polygonal cylinder is characterized by having two or more sheets of water-resistant paper. ~ 3. The paper straw described in any of.
5. 1. The water-resistant paper is provided with a thermoplastic resin layer at least on the outer surface side of the polygonal cylinder. ~ 4. The paper straw described in any of.
6. 5. The water resistant paper is provided with a water resistant coating layer on the inner surface side of the polygonal cylinder. The paper straw described in.
7. 5. The water resistant paper is provided with a high melting point thermoplastic resin layer on the inner surface side of the polygonal cylinder. The paper straw described in.
8. 1. It is characterized in that the tip is cut so as to form an acute angle in a state of being crushed into a flat plate. ~ 7. The paper straw described in any of.
9. 1. It is characterized in that one long side is cut so as to protrude from the other long side in a state of being crushed into a flat plate. ~ 8. The paper straw described in any of.
10. It is characterized by being able to be folded in the length direction. ~ 9. The paper straw described in any of.

The paper straw of the present invention has a polygonal tubular shape and can be crushed into a flat plate shape composed of a first main surface composed of two or more adjacent surfaces and a second main surface composed of the remaining surfaces. .. Since the paper straw crushed into a flat plate has a small proportion of air, it can be stored very compactly, and the space required for storage, transportation, etc. can be reduced. The paper straw of the present invention, which can be folded in the length direction, can be compactly attached to a beverage paper pack container or the like without protruding from the outer frame of the container.
Since the paper straw of the present invention uses water-resistant paper, it has excellent water resistance and retains sufficient strength for about the time of drinking a beverage or the like.
The paper straw of the present invention is mainly made of paper and has a small impact on the environment.

Paper straws having a quadrangular, pentagonal, or hexagonal cross-sectional shape in the direction perpendicular to the length direction require a small number of bending processes, are easy to manufacture, and can increase the yield.
The polygonal cylinder whose at least one surface is a reinforcing surface can maintain the polygonal cylinder shape by holding the reinforcing surface so as to be sandwiched between fingers, and can prevent the cylinder from being crushed when drinking a beverage or the like. can.
By forming a polygonal cylinder from two or more sheets of water-resistant paper, the number of times of bending per sheet of water-resistant paper can be reduced. In addition, by forming a polygonal cylinder from two or more sheets of water-resistant paper, two or more bonding points are created, but by using these bonding points as reinforcing surfaces, the paper is stronger and less likely to be crushed during suction. It can be made of straw.

Water-resistant paper having a thermoplastic resin layer on the outer surface side of the polygonal cylinder can be easily bonded by heat laminating. Further, in a water-resistant paper having a water-resistant coating layer on the inner surface side of the polygonal cylinder, the inner surfaces do not heat-fuse to each other, so even if the inner surfaces are formed into a cylinder by heat laminating, the inner surfaces do not heat-fuse to each other. .. Further, the water-resistant paper having a high-melting point thermoplastic resin layer on the inner surface side of the polygonal cylinder can be heat-sealed between the inner surfaces when the cylinder is formed by thermal lamination by adjusting the heat seal temperature. Can be prevented. Since the base paper and the thermoplastic resin layer can be easily separated, they can be recycled in the same system as a milk carton or the like.

A paper straw whose tip is cut so as to form an acute angle in a state of being crushed into a flat plate can be easily pierced into a straw hole. Further, by having the tip having two or more layers of paper, the strength of the tip can be further increased.
Further, a paper straw in which one long side is cut so as to protrude from the other long side in a state of being crushed into a flat plate can be used as a spoon because the area of the protruding portion is large. .. Further, by using at least one surface forming the protruding portion as a reinforcing surface, a heavier object can be scooped.

The schematic diagram of the paper straw which is the 1st Embodiment of this invention. The figure which shows the state which crushed the paper straw which is 1st Embodiment of this invention into a flat plate shape. The schematic diagram of the tip of the paper straw which is the 2nd Embodiment of this invention. The schematic diagram of the tip of the paper straw which is the 3rd Embodiment of this invention. FIG. 6 is a schematic view of a tip of a paper straw in a state of being crushed into a flat plate, which is a third embodiment of the present invention. The schematic diagram of the tip of the paper straw which is the 4th Embodiment of this invention. The schematic diagram of the tip of the paper straw which is the 5th Embodiment of this invention. The schematic diagram of the tip of the paper straw which is the 6th Embodiment of this invention. The figure which shows the manufacturing method of the paper straw in Example 1. FIG. The figure which shows the manufacturing method of the paper straw in Example 4. FIG.

<Water resistant paper>
In the present invention, the water-resistant paper means a paper having a ^{water absorption value of 15 g / m 2} or less obtained by the Cobb method (contact time: 30 seconds) specified in JIS P8140. For water resistant paper, this value is ^{more preferably 12 g / m 2} or less, and further preferably 10 g / m ² or less.
The water-resistant paper used in the present invention is not particularly limited as long as it has the above-mentioned water resistance, and a paper having a water-resistant layer such as a thermoplastic resin layer or a water-resistant coating layer formed on the base paper should be used. Can be done.

-Base paper The base paper consists of pulp, fillers, various auxiliaries, etc.
Since the paper straw of the present invention can be held in the mouth, it is preferable to use a straw that conforms to food safety, such as being approved as a food additive or having obtained FDA certification, as a raw material. ..

As the pulp, chemical pulp of wood such as bleached kraft pulp of coniferous tree (NBKP), unbleached kraft pulp (NUKP), bleached kraft pulp of broadleaf tree (LBKP), unbleached kraft pulp (LUKP), sulfite pulp (SP) , Grand pulp (GP), refiner ground pulp (RGP), stone ground pulp (SGP), chemi-grand pulp (CGP), semi-chemical pulp (SCP), thermomechanical pulp (TMP), chemi-thermomechanical pulp (CTMP) Known pulp such as mechanical pulp of wood such as Kenaf, bagas, non-wood pulp obtained from bamboo, hemp, straw, etc. Can be appropriately blended and used. Among these, chemical pulps such as LBKP and NBKP, which are less likely to be mixed with foreign substances, are preferable, and the amount of used paper pulp is preferably small. Specifically, the blending amount of the chemical pulp is preferably 80% or more, and the blending amount of the chemical pulp is particularly preferably 100%.

Fillers include talc, kaolin, calcined kaolin, clay, heavy calcium carbonate, light calcium carbonate, white carbon, zeolite, magnesium carbonate, barium carbonate, titanium dioxide, zinc oxide, silicon oxide, amorphous silica, and aluminum hydroxide. , Calcium hydroxide, magnesium hydroxide, zinc hydroxide, barium sulfate, calcium sulfate and other inorganic fillers, urea-formalin resin, polystyrene resin, phenolic resin, organic fillers such as fine hollow particles, etc. Can be done. The filler is not an essential material and does not have to be used.

Examples of various auxiliary agents include sizing agents such as rosin, alkyl ketene dimer (AKD), alkenyl succinic acid anhydride (ASA), polyacrylamide-based polymers, polyvinyl alcohol-based polymers, cationized starch, various modified starches, urea, etc. Dry paper strength enhancer such as formalin resin, melamine / formalin resin, wet paper strength enhancer such as polyamide polyamine epichlorohydrin resin, polyamine epichlorohydrin resin, polyamide epichlorohydrin resin, polyvinylamine resin, polyethyleneimine resin, retention agent, drainage improvement Agents, coagulants, sulfate bands, bulking agents, dyes, fluorescent whitening agents, pH adjusters, defoaming agents, UV inhibitors, anti-fading agents, pitch control agents, slime control agents, etc. can be exemplified and required. It can be selected and used as appropriate.

<Paper machine>
The manufacturing (paper making) method of the base paper and the model of the paper making machine are not particularly limited, and are a long net paper making machine, a twin wire paper making machine, a circular net paper making machine, a gap former, and a hybrid former (on-top former). A known manufacturing (paper making) method such as, and a paper making machine can be selected.
The pH at the time of papermaking may be any of an acidic region (acidic papermaking), a pseudo-neutral region (pseudo-neutral papermaking), a neutral region (neutral papermaking), and an alkaline region (alkaline papermaking). Later, an alkaline agent may be applied to the surface of the paper layer.
The basis weight of the base paper is preferably 80 g / m ² or more and 200 g / m ² or less from the viewpoint of forming a rigid paper straw.

-Water resistant layer The water resistant layer is not particularly limited as long as it can obtain the water resistant surface having the above water resistant performance.
Polyolefin-based, polyester-based, ethylene vinegar copolymer, paraffin-based thermoplastic resin, polyolefin-based, silicone-based, acrylic-based, epoxy-based, cellulose-based, urethane-based, vinyl acetate-based copolymer, vinyl chloride-based Water-resistant paints containing resins such as polymers, vinylidene chloride-based, synthetic rubber-based, rosin-based, alkylketen dimer-based, and styrene / acrylic copolymer-based resins can be used.

Among these, water-resistant paper having excellent water resistance and having a thermoplastic resin layer on at least the outer surface side of the polygonal cylinder because the cylinder can be formed by firmly laminating the water-resistant paper by heat laminating. Is preferable. Furthermore, it prevents heat fusion between the inner surfaces of the paper straws when molding the cylinder by thermal lamination, and prevents the inner surfaces of the paper straws from sticking (blocking) when stored in a flat plate shape. From the point of view, it is preferable to use a water-resistant coating layer or a water-resistant paper provided with a high-melting point thermoplastic resin layer as the inner surface side of the polygonal cylinder. In the present specification, the high melting point thermoplastic resin layer has a melting point of 10 ° C. or more higher than that of the thermoplastic resin layer formed on the other surface (the outer surface of the polygonal cylinder) of the water-resistant paper. It means a layer made of a thermoplastic resin. The melting point of the high melting point thermoplastic resin layer is preferably 15 ° C. or higher, more preferably 20 ° C. or higher, and 25 ° C. or higher, higher than the melting point of the thermoplastic resin layer formed on the other surface of the water-resistant paper. Higher is more preferred.

-Method of forming the water resistant layer The method of forming the water resistant layer is not particularly limited, and depending on the composition, viscosity, presence or absence of solvent, etc. of the composition forming the water resistant layer, a blade coater, a curtain coater, a spray coater, etc. It can be formed by a coating method using a gravure coater or the like, a known laminating method such as extrusion laminating, wet laminating, dry laminating, or the like.
The coating amount (dry weight) of the water resistant layer is not particularly limited as long as it can obtain the water resistant surface having the above water resistant performance, ^{but is preferably 1 g / m 2} or more and 25 g / m 2 or less, and is preferably 3 ^{g / m 2.} It is more preferably m ² or more and 20 g / m ² or less from the viewpoint of water resistance.

<Paper straw>
The paper straw of the present invention has a polygonal tubular shape having four or more faces made of water-resistant paper, and has a first main surface composed of two or more adjacent surfaces and a second main surface composed of the remaining surfaces. It is characterized in that it can be crushed into a flat plate consisting of a surface.
Here, the fact that the first main surface composed of two or more adjacent surfaces and the second main surface composed of the remaining surfaces can be crushed into a flat plate shape is the direction of the length of the paper straw of the present invention. In a polygon having a first side to an nth side (4 ≦ n), which is a cross-sectional shape in the vertical direction, the sum of the lengths of the sides from the first side to the p side (p <n-1) is It means that it is equal to the sum of the lengths of the sides from the p + 1 side to the n side. When the polygon which is the cross section of the paper straw satisfies the above conditions, the first main surface composed of the surfaces including the first side to the p side (p <n-1) and the first main surface composed of the surfaces including the first side to the p + 1 side to n. It has the same width as the second main surface composed of surfaces including sides, and can be crushed into a flat plate.

The paper straw of the present invention is not particularly limited as long as it is a polygonal cylinder having four or more faces, but the cross-sectional shape is quadrangular, pentagonal, or hexagonal in terms of simplification of the manufacturing process, reduction of yield, and cost reduction. It is preferable that it is a quadrangle, and it is more preferable that it is a quadrangle. In the case of an even polygonal cylinder, its cross-sectional shape is not limited to a regular polygon.
The paper straw of the present invention can be formed by winding one sheet of water-resistant paper into a cylinder, or can be formed by laminating two or more sheets of water-resistant paper to form a cylinder. In this case, it is preferable to form a cylinder by laminating a plurality of paper members having the same shape. From the viewpoint of simplifying the manufacturing process such as bending and bonding, it is preferable to form a polygonal cylinder from one or two sheets of paper members.

In the paper straw of the present invention, one or more sheets of water-resistant paper are bonded together along the length direction to form a cylinder. The method of laminating the water-resistant paper is not particularly limited, and examples thereof include a method of using a heat seal and a water-resistant adhesive. The paper straw of the present invention can be crushed and deformed, and the diameter of the polygonal cylinder changes. The widths of the first main surface and the second main surface when the paper straw is crushed into a flat plate are not particularly limited, and may be, for example, 3 mm or more and 15 mm or less.

In the paper straw of the present invention, the number of places where the water-resistant paper is attached is not particularly limited, but one or two places is preferable from the viewpoint of simplification of the manufacturing process. Further, the number of paper layers to be bonded is not particularly limited and may be three or more layers by folding back or the like, but two or three layers are preferable from the viewpoint of simplification of the manufacturing process. When folding back the paper layer, it is preferable to fold it back to the outer surface side of the paper straw because the inner surface becomes flat and it is easy to crush it into a flat plate.

In the paper straw of the present invention, the surface having two or more layers of paper due to bonding, folding, etc. is thicker and superior in strength to the surface composed of one layer of paper. Here, in the present specification, among the surfaces of the polygonal cylinder, a surface having two or more paper layers at 50% or more of the width of the surface is referred to as a reinforcing surface.
In the paper straw of the present invention, since one or more surfaces of the polygonal cylinder are formed of reinforcing surfaces, the strength is improved and it becomes easy to maintain the tubular shape. In the paper cylinder of the present invention, the number of reinforcing surfaces is not particularly limited, but one or two surfaces is preferable for simplification of the manufacturing process. The width of the reinforcing surface to which the plurality of layers of water-resistant paper are bonded is preferably wide from the viewpoint of strength and ease of holding, and specifically, it is 70% or more of the width of the reinforcing surface. It is preferably 80% or more, more preferably 90% or more, and most preferably the full width.

The shape of the tip of the paper straw of the present invention is not limited, and the straw can be cut in a direction perpendicular to the length direction while being crushed into a flat plate, and can be cut in a diagonal direction with respect to the length direction. It can also be cut. Further, the cut surface is not limited to a straight line, and can be cut into a curved line, or can be cut into a plurality of straight lines or a combination of curved lines.
By cutting the tip of the paper straw so as to form a sharp angle in the state of being crushed into a flat plate, the paper straw of the present invention can be easily pierced into the straw hole formed in the paper pack or the like. At this time, since the tip has two or more layers of paper, the strength of the tip can be further increased.

Further, by cutting the tip of the paper straw so that one long side protrudes from the other long side in a state of being crushed into a flat plate, the protruding portion is formed at the tip when expanded into a polygonal cylinder. It can be provided, and the protruding portion can be used as a spoon for scooping frozen desserts such as shaved ice. For use as a spoon, one long side of the paper straw preferably protrudes 8 mm or more from the other long side, and the protruding length is more preferably 10 mm or more, more preferably 12 mm or more. More preferably, it is more preferably 15 mm or more. Further, it is preferable that one of the two surfaces sandwiching the protruding long side is a reinforcing surface, and it is more preferable that both of the two surfaces sandwiching the protruding long side are reinforcing surfaces, and all the surfaces forming the protruding portion. Is most preferably a reinforcing surface.

The paper straw of the present invention is preferably folded in the length direction. By folding it in the length direction and storing it short, it can be attached without protruding from the outer frame of a container such as a paper carton.

<Manufacturing method of paper straws>
The paper straw of the present invention can be produced by combining known methods. Specifically, according to a predetermined straw development drawing, water-resistant paper is cut out, fold lines are made, and then (1) crushed into a flat plate and bonded by heat sealing, (2) to the portion to be bonded. The paper straw of the present invention can be produced by a method of applying a water-resistant adhesive and crushing it into a flat plate.

To cut out and make fold lines, you can use a technique called Thomson processing, which uses a wooden pattern with a built-in blade to cut paper into complex shapes and make fold lines. To fold the paper, you can fold it evenly by sandwiching it between two hard metal plates along the fold lines. At this time, by sandwiching it between heated metal plates, it can be bonded by heat sealing. Further, when applying the water resistant adhesive, the water resistant adhesive can be uniformly applied by using a roller suitable for the coating width or a discharge port having a flat tip.

The above is the production method using the developed single-wafer sheet, but it is preferable to continuously produce a paper straw from the strip-shaped water-resistant paper from the viewpoint of production speed, production cost, and the like.
A long polygonal cylinder can be manufactured by continuously forming fold lines on a strip-shaped water-resistant paper by pressing a rotating disk or the like. After that, the straw is cut into a desired length and tip shape, and further folded in the length direction as needed to obtain a paper straw crushed into a flat plate.

"Paper straw, the first embodiment"
FIG. 1 shows a schematic view of a paper straw according to the first embodiment of the present invention, and FIG. 2 shows a cross-sectional view when the paper straw according to the first embodiment is crushed.
The paper straw 1 according to the first embodiment is a square cylinder, the cross-sectional shape thereof is a kite shape (a quadrangle that is line-symmetrical with respect to one diagonal line), and the tip is in a direction perpendicular to the length direction. It has been cut into. The paper straw 1 according to the first embodiment is crushed in the direction of the kite-shaped symmetry axis having a cross-sectional shape, and the first main surface 11 composed of the adjacent wide surface 11A and the narrow surface 11B and the rest. It can be in the shape of a flat plate composed of a wide surface 12A which is a surface and a second main surface 12 composed of a narrow surface 12B.
The paper straw 1 according to the first embodiment is a reinforcing surface 13 made of one sheet of water resistant paper and having a wide surface 12A having two layers of paper. The paper straw 1 according to the first embodiment is less likely to buckle because the reinforcing surface 13 has a total width of two layers of paper. Further, the paper straw 1 according to the first embodiment is easily held by a finger by sandwiching the reinforcing surface 13, and is not easily crushed during suction by being held by a finger or a lip so as to sandwich the reinforcing surface 13.

"Paper straw according to the second embodiment"
FIG. 3 shows a schematic view of a paper straw 2 according to a second embodiment of the present invention.
The paper straw 2 according to the second embodiment is a square cylinder, the cross-sectional shape thereof is square, and the tip thereof is cut in a direction perpendicular to the length direction. Since the paper straw according to the second embodiment has a square cross-sectional shape, it can be crushed in any direction of the two axes of symmetry to form a flat plate.
The paper straw according to the second embodiment is composed of two sheets of water-resistant paper, and the water-resistant papers are bonded to each other over the entire width of the opposite surfaces to provide two reinforcing surfaces 23A and 23B. ing. Since the paper straw according to the second embodiment can be held so as to sandwich the two reinforcing surfaces 23A and 23B, the tubular shape can be stably maintained at the time of suction.

"Paper straw according to the third embodiment"
FIG. 4 is a schematic view of the paper straw 3 according to the third embodiment of the present invention, and FIG. 5 is a schematic view of the tip of the paper straw 3 according to the third embodiment in a flat plate shape. Is shown.
The paper straw 3 according to the third embodiment is a square cylinder, the cross-sectional shape thereof is square, and the tip 34 forms an acute angle in a state of being crushed into a flat plate, and the length of one of the straws 3 is formed. The side 35A is cut so as to protrude from the other long side 35B. The paper straw according to the third embodiment has two reinforcing surfaces 33A and 33B, and the two reinforcing surfaces 33A and 33B are adjacent to each other to form a protruding portion 36. In the paper straw 3 according to the third embodiment, since the tip 34 has two layers of paper, the protruding portion 36 is formed of reinforcing surfaces 33A and 33B which are easy to pierce into a straw hole or the like and have excellent strength. Since it can scoop something heavy to some extent, it can be suitably used as a spoon.

"Another embodiment of a paper straw"
6 to 8 show schematic views of the fourth to sixth embodiments of the paper straw of the present invention. The paper straws shown in FIGS. 1 to 8 are merely examples of embodiments of the present invention, and the paper straws of the present invention are not limited thereto.
The paper straw 4, which is the fourth embodiment shown in FIG. 6, has a regular quadrangular cross-sectional shape, is made of a single sheet of water-resistant paper, and has two layers of paper in less than 50% of the width of the surface. It is affixed to and has no reinforcing surface.

The paper straw 5, which is the fifth embodiment shown in FIG. 7, has a regular quadrangular cross-sectional shape, is made of a single sheet of water-resistant paper, and is bonded so as to form two layers of paper on the entire surface. It has a reinforcing surface 53. The paper straw 5 according to the fifth embodiment has a reinforcing surface 53, so that it is superior in strength to the paper straw 4 according to the fourth embodiment shown in FIG. Hard to yield. Further, the paper straw 5 according to the fifth embodiment has a small number of processing steps and is easy to manufacture.

The paper straw 6 according to the sixth embodiment shown in FIG. 8 has a regular quadrangular cross-sectional shape, is made of a single piece of water-resistant paper, and is formed by bending a reinforcing surface 63A to which the water-resistant paper is bonded. It is provided with a reinforced surface 63B. The paper straw shown in FIG. 8 includes two reinforcing surfaces 63A and 63B, and a plurality of layers of paper are bonded to each other over the entire width of the reinforcing surfaces 63A and 63B. Therefore, the paper according to the second embodiment. It has the same strength as the straw 2.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to the following Examples.

The method for producing a paper straw in Example 1 is shown in FIG.
A water resistant paint (polyolefin-based water resistant varnish) was applied to both sides of a cup base paper having a basis weight of 110 g / m ^{2 to obtain a water resistant paper.}
A sheet of paper with a width of 32 mm and a length of 200 mm is cut out from this water-resistant paper to make a square cylinder having a kite-shaped cross section and a two-layer paper layer on the entire surface of the reinforcing surface (8 mm width). Folded streaks that divide the direction into 8 mm, 8 mm, 4 mm, 4 mm, and 8 mm widths were drawn in the length direction, respectively (FIG. 9A).

This single-wafer sheet is bent 180 degrees so that it has an upper surface of 20 mm width (8 + 8 + 4) and a lower surface of 12 mm width (4 + 8) (FIG. 9B), and a water-resistant adhesive is uniformly applied to an 8 mm wide surface that does not overlap the lower surface of the upper surface. (Fig. 9C), this 8 mm wide surface was bent 180 ° downward according to the folding streaks, overlapped with the 8 mm wide surface on the lower surface, and crimped to produce a paper straw crushed into a 12 mm wide (8 + 4) flat plate. (Fig. 9D). The structure of this paper straw is the same as that of the paper straw according to the first embodiment of the present invention.

When both ends of this flat-crushed paper straw were sandwiched between fingers and pushed inward, the cross section became a kite shape, and the kite shape further became a substantially equilateral triangular cross section with a side of 8 mm (Fig. 9E). .. By holding the paper straw so as to sandwich the reinforcing surface, it was possible to maintain the cross-sectional shape. Further, since the entire surface of the reinforcing surface (8 mm width) has two layers of paper, it is resistant to buckling in the length direction and can be suitably used as a straw.

Using a cup base paper with a basis weight of 110 g / m ² , the outer surface of the polygonal cylinder was laminated with polyethylene and bonded with a heat seal instead of a water-resistant adhesive, in the same manner as in Example 1. , Manufactured paper straws.

The paper straw produced in Example 2 had the same strength as the paper straw produced in Example 1, and could be suitably used as a straw. Further, the heat-sealing process can be performed at the same time as crimping, and unlike the water-soluble adhesive, the excess amount does not squeeze out, so that the production was easier than in Example 1.

In the same manner as in Example 1, a single-wafer sheet having a width of 28 mm and a length of 200 mm is divided into 4 mm, 8 mm, 4 mm, 4 mm, and 8 mm widths in the width direction, and the cross-sectional shape is kite-shaped (line-symmetric with respect to one diagonal line). A paper straw made of a square cylinder having a width of 4 mm and two layers of paper, which is half of an 8 mm width surface, was manufactured.

The paper straw produced in Example 3 could be used as a straw, but as compared with the paper straw produced in Examples 1 and 2, the reinforcing surface was easily bent and the stability when held was inferior. In addition, the strength of the reinforcing surface was inferior, and it was easy to buckle.

The method for producing a paper straw in Example 4 is shown in FIG.
Using a cup base paper with a basis weight of 110 g / m ² , the inner surface of the polygonal cylinder is laminated with polyethylene with a melting point of 118 ° C, and the outer surface of the polygonal cylinder is laminated with polyethylene with a melting point of 96 ° C, and the outer surface of the straw is laminated. A water-resistant paper having a thermoplastic resin layer on the side surface and a high melting point thermoplastic resin layer on the inner surface was obtained.
From this water-resistant paper, the width is 40 mm to make a square cylinder with a kite-shaped cross section (a quadrangle that is line-symmetrical with respect to one diagonal line) and the entire surface of the reinforcing surface (8 mm width) having three layers of paper. A 200 mm long single-wafer sheet was cut out and divided into 8 mm, 8 mm, 4 mm, 4 mm, 8 mm, and 8 mm widths in the width direction (FIG. 10A).

This sheet-fed sheet is bent 180 degrees at the center (FIG. 10B), further bent 180 degrees so as to have an upper surface of 12 mm width (8 + 4) and a lower surface of 8 mm width, and a portion where four layers of paper are laminated. A paper straw crushed into a flat plate having a width of 12 mm (8 + 4) was produced by crimping while heating from below and bonding with a heat seal (FIG. 10C).
This paper straw has a paper layer having three reinforcing surfaces, and the high melting point thermoplastic resin layers are bonded to each other by heat sealing. On the reinforcing surface, the high melting point thermoplastic resin layer is bent so that the portion where the high melting point thermoplastic resin layers are bonded to each other is located on the outer side, and is heated from the high melting point thermoplastic resin layer side to heat the high melting point thermoplastic resin layer on the inner surface of the paper straw. The high melting point thermoplastic resin layer to be bonded as a reinforcing surface could be heat-sealed without heat-sealing.

When both ends of the paper straw crushed into a flat plate were sandwiched between fingers and pushed inward, the cross section became a kite shape, and the kite shape further became a substantially equilateral triangular cross section with a side of 8 mm (FIG. 10D). Since the entire surface of the reinforcing surface (8 mm width) of this paper straw has three layers of paper and is excellent in strength, it is easy to maintain the cross-sectional shape and it is also very strong in buckling.

1 Paper straw 11 First main surface 11A Wide surface 11B Narrow surface 12 Second main surface 12A Wide surface 12B Narrow surface 13 Reinforcing surface

2, 3, 4, 5, 6 Paper straws 23, 33, 53, 63 Reinforcing surface 34 Tip 35 Long side 36 Protruding part

Claims (9)

It is a polygonal cylinder shape with four or more faces made of water resistant paper.
At least one surface of the polygonal cylinder is a reinforcing surface having a plurality of paper layers.
A paper straw that can be crushed into a flat plate consisting of a first main surface composed of two or more adjacent surfaces and a second main surface composed of the remaining surfaces. The paper straw according to claim 1, wherein the cross section in the direction perpendicular to the length direction is a quadrangle, a pentagon, or a hexagon. The paper straw according to claim 1 or 2 , wherein the polygonal cylinder has two or more sheets of water-resistant paper. The paper straw according to any one of claims 1 to 3 , wherein the water-resistant paper is provided with a thermoplastic resin layer at least on the outer surface side of the polygonal cylinder. The paper straw according to claim 4 , wherein the water-resistant paper is provided with a water-resistant coating layer on the inner surface side of the polygonal cylinder. The paper straw according to claim 4 , wherein the water-resistant paper is provided with a high-melting point thermoplastic resin layer on the inner surface side of the polygonal cylinder. The paper straw according to any one of claims 1 to 6 , wherein the tip is cut so as to form an acute angle in a state of being crushed into a flat plate. The paper straw according to any one of claims 1 to 7 , wherein one long side is cut so as to protrude from the other long side in a state of being crushed into a flat plate. The paper straw according to any one of claims 1 to 8 , wherein the straw can be folded in the length direction.

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