JP2023114287A5 - - Google Patents

Description

The present invention relates to cutlery such as spoons, forks, and knives.

Discarding after using it once or several times in various food and beverage locations such as food courts in commercial facilities, fast food shops, take-out bento shops, food and beverage services such as on airplanes, food delivery, and catering events. Disposable cutlery that is expected to be used is used. Such disposable cutlery is required to be convenient and low-cost since most of it is assumed to be provided free of charge.

For this reason, plastic cutlery is often used because it is easy to mold into the same shape as high-quality metal cutlery that is not disposable, and is inexpensive and lightweight (see Patent Document 1).

On the other hand, in recent years, problems such as marine pollution caused by microplastics have been attracting attention, and the shift away from plastics is progressing worldwide from the standpoint of environmental protection. In Japan as well, the ``Act on Promotion of Plastic Resource Recycling'' has been enacted, making it mandatory for certain businesses to reduce the use of single-use plastic products, for example. The Act on the Promotion of Plastic Resource Recycling defines forks, spoons, Cutlery such as knives is designated, and there is a growing demand for plastic-free cutlery.

Techniques for using natural materials other than plastic for cutlery instead of plastic are disclosed in Patent Document 2, Patent Document 3, and Patent Document 4 listed below.

Special table 2017-524498 publication Japanese Patent Application Publication No. 2012-249963 JP2021-29926A JP2021-29924A

Since the technology of Patent Document 2 forms a container portion for storing food by folding and gluing sheet-shaped materials, it can be manufactured by procuring and processing sheet-shaped materials in advance. There is an advantage. However, molded plastic cutlery does not have a curved design like non-disposable metal cutlery, so it does not feel like plastic cutlery when placed in the mouth. It is very different from manufactured cutlery.

On the other hand, in the technologies of Patent Documents 3 and 4, the part that is placed in the mouth has a curved design similar to metal cutlery due to pulp molding technology, and the surface is smooth and does not fit inside the oral cavity. The feeling of use is similar to that of plastic cutlery, such as when you put it in.

However, the pulp molding technology of Patent Document 3 and Patent Document 4 is a technology that directly molds slurry-like wet pulp, so it requires equipment to handle wet pulp in order to manufacture it, and the pulp molding technology disclosed in Patent Documents 3 and 4 requires equipment to handle wet pulp. The manufacturing process and management are more complicated than the technology of Document 2. In addition, since pulp molding technology molds wet pulp, it is difficult to increase the density and water resistance of molded products.

Therefore, the main objective of the present invention is to be able to achieve the same design and usability as conventional plastic disposable cutlery while using natural materials as the main raw material, and also to be easy to manufacture as it can be manufactured from sheet material. The objective is to provide cutlery that is also sufficiently water resistant.

The first means to solve the above problem is
Disposable cutlery,
It has a head part that comes into contact with the food, a neck part connected to the head part, and a handle part connected to the neck part for gripping,
Formed from sheet material made from pulp fibers,
and part or all of the sheet material is compression molded by press processing,
This is disposable cutlery that is characterized by:

The second means is
The disposable cutlery according to the first means contains a siloxane compound.

The third means is
The above-mentioned first or second means contains a total of 90 to 100% by mass of softwood kraft pulp and hardwood kraft pulp as pulp fibers, and the blending ratio of softwood kraft pulp and hardwood kraft pulp is 5:95 to 30:70. This is disposable cutlery.

The fourth means is
The disposable cutlery according to the first to third means has a density of 1.0 g/cm ³ or more in the pressed part.

The fifth means is
It has a head portion having a dish shape or at least a curved portion toward the tip side, a neck portion connected to the head portion and narrower than the head portion, and a handle portion having the same width as the neck portion or wider than the neck portion. ,
At least the head part and neck part are formed by press working,
The neck portion is formed to have a curved cross section, and the ratio of the radius of curvature of the cross section to the width is 1:0.4 to 1:0.8.
This is a disposable cutlery according to the first to fourth means above.

The sixth means is
It has a head portion having a blade portion that tapers toward one edge, a neck portion connected to the head portion, and a handle portion connected to the neck portion,
The head part, neck part and handle part are formed by laminating multiple sheet materials,
and at least the blade portion is formed by press working to be tapered toward one edge;
This is a disposable cutlery according to the first to fourth means above.

According to the present invention, while using natural materials as the main raw material, it is possible to achieve the same design and usability as conventional plastic disposable cutlery, and furthermore, it is possible to manufacture from sheet material and is easy to manufacture. Furthermore, the objective is to provide cutlery that is sufficiently water resistant.

It is a front view for explaining cutlery concerning this embodiment. FIG. 1 is a schematic cross-sectional view of multilayer paper according to the present embodiment. It is a front view, a side view, and a cross-sectional view of a spoon according to the present embodiment. FIG. 3 is a front view, a side view, and a cross-sectional view of a fork according to the present embodiment. FIG. 3 is a front view, a side view, and a cross-sectional view of a knife according to the present embodiment. It is a figure for explaining the locking structure concerning this embodiment. It is a figure for explaining the measuring method of the bending strength of cutlery concerning this embodiment. It is a figure for explaining the result of bending strength measurement of cutlery concerning this embodiment. It is a figure for explaining the result of other bending strength measurement of cutlery concerning this embodiment.

Next, embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 9. However, the present invention is not limited to these embodiments.

The disposable cutlery 1 according to the present embodiment can be provided in various food and beverage provision locations such as food courts in commercial facilities, fast food shops, take-out bento shops, in-flight food and beverage services, food delivery, and catering events. Therefore, it is assumed that the product will be discarded after being used once or several times. The disposable cutlery 1 according to the present embodiment has a head portion 11 that mainly comes into contact with food, a neck portion 12 that is connected to the head portion 11, and a handle portion 13 that is connected to the neck portion 12 and is mainly used for handles and operations. In particular, as shown in FIG. 1, a spoon 10, a fork 20, and a knife 30 are included. Others may include lotuses, stirrers, slotted spoons, and the like.

The disposable cutlery 1 of this embodiment is characterized by being formed of a sheet material made from pulp fibers, and a part or all of the sheet material made from pulp fibers is pressed in the thickness direction to be formed. ing. That is, the whole is made of a sheet material made from pulp fibers, and a mold preformed in the partial or entire shape of the cutlery 1 such as the spoon 10, fork 20, knife 30, etc. is inserted into the sheet material. Compression molding is performed so that the shape of the mold is transferred to the sheet material by pressing against a part or all of it from the thickness direction. Of course, it may be shaped into a desired shape by appropriately punching, cutting, etc. after press working. In addition, the thickness of a part or all of a press-formed item is increased by laminating other sheet materials that have not been press-processed in the thickness direction. You can. Preferably, the whole part is press-formed in the thickness direction because it can be molded with high press pressure. In the cutlery 1 having the above-mentioned head portion 11, neck 12 portion, and handle portion 13, when the cutlery 1 is a spoon 10 or a fork 20, at least the head portion 11 and the neck portion 12 are pressed. It is desirable that it be molded, and in particular, it is desirable that the entire body including the head portion 11, neck portion 12, and handle portion 13 be molded by press working. Further, when the cutlery 1 is a knife 30, it is desirable that at least the edge portion of the head portion 11, which is to be a blade, is press-formed. Furthermore, the disposable cutlery 1 of this embodiment may be formed by pressing a plurality of sheet materials in a laminated state, but since there is no risk of peeling between the layers, a single sheet can be used. It is preferable to use only the material that is pressed into shape.

Conventional pulp molding technology, like casting technology in metal molding, molds fluid raw materials containing pulp fibers by pressing them and making them stick together through compression, making it easy to mold molded products into complex shapes. Densification is difficult, and since the molded product does not have fiber orientation, there are problems in that it is rigid and has weak stiffness and is prone to bending and cracking. The cutlery of this embodiment is not made by stamping a fluid raw material such as pulp molding technology, but by forming a sheet that is dried once to form hydrogen bonds and has a fixed fiber orientation, similar to forging technology in metal forming. Because it is formed by further pressing the material in the thickness direction, it is highly compacted, and although it is thin, it has the appropriate stickiness and flexibility of plastic, and is strong enough for use. Furthermore, compared to conventional pulp molding techniques, it is possible to increase the strength while reducing the thickness, and it is also possible to make the surface smoother. Therefore, it can be molded into a shape similar to high-grade metal cutlery with smooth curves and curved surfaces, and has an excellent mouthfeel when used. Furthermore, it does not require fluid pulp slurry during production and has the advantage of being easy to produce.

Moreover, since the cutlery 1 of this embodiment is formed not from plastic but from a sheet material made from pulp fibers, it is possible to eliminate plastics. From the viewpoint of achieving plastic-free use, it is preferable that the cutlery 1 according to the present embodiment is not laminated with plastic made of non-biodegradable resin, and it is particularly preferable that the cutlery 1 is not laminated with plastic using a non-biodegradable resin. Moreover, since the cutlery 1 of this embodiment is an aggregate of pulp fibers, it will not be crushed in the oral cavity even if it is chewed with the teeth during use, so that the cutlery 1 can be used with sufficient safety.

Here, the bending strength of the cutlery 1 of the present embodiment is measured using a composite material testing machine (10kN) type 5966 model or equivalent machine, although it is not necessarily limited since the necessary bending strength varies depending on its shape and the use of the cutlery. It is desirable that the strength in a two-point bending load test is such that the bending load at a bending deflection of 15 mm is 0.5 N or more. In addition, in this two-point bending test, as shown in FIG. 7, the handle part 13 of the cutlery 1 is fixed to the support stand 80A, and the center part of the head part 11 of the cutlery 1 is measured as the pushing position. For example, if the cutlery 1 is a spoon 10 as shown in FIG. 7, the bottom position of the bowl shape is the push-in position. The holding length L20 from the rear end of the cutlery to the end of the support base is not limited by the type or shape of the cutlery 1, but may be 25 to 30% of the total length of the cutlery. However, at least the neck portion 12 is set so that the narrowest position is beyond the line end 80t of the support base 80A. The measurement was performed using a small load of 500 N, a pushing speed of 40 mm/min, and an indenter 81 with a semicircular tip. If the measurement sample is a spoon 10 or a fork 20, it is set with the front side facing upward, and if it is a knife 30, it is set with the side side facing upward. Generally, a curry spoon or one tablespoon weighs about 15 to 30 g, and when operating the cutlery 1 such as the spoon 10 or fork 20, the neck 12 or the vicinity thereof should be supported with fingers or the like. . Therefore, if the bending load is 0.5 N or more when the bending deflection is 15 mm using this measurement method that does not support the neck part, the cutlery 1 has a particularly preferable strength sufficient to be used with the general operating method. It can be said. Furthermore, it is desirable that the cutlery of this embodiment has a bending deflection of 2N or more when the bending deflection is 30 mm. Even though it is shaped like a relatively large table spoon, it has a high degree of flexibility and is much less likely to break or break during use, making it highly safe.

On the other hand, it is desirable that the cutlery 1 of this embodiment has a water resistance of 3 minutes or more, more preferably 5 minutes or more, although this is not necessarily limited. Here, the water resistance is determined as long as the layers do not separate even when completely immersed in water, and as long as they do not decompose in water. However, it is particularly desirable that the strength in the above two-point bending load test, that is, the bending load at a bending deflection of 15 mm, be maintained at 0.5 N or more even after immersion for 5 minutes.

Furthermore, it is desirable that the cutlery 1 according to this embodiment contains a siloxane compound. It is more desirable that at least the pressed part contains a siloxane compound, and it is particularly desirable that the entire part contains a siloxane compound. When a siloxane compound is contained, the siloxane bond provides high stiffness, strength, water resistance, and surface smoothness. At least a range that includes the head portion 11 that is likely to come into contact with food or moisture in the oral cavity, and that is likely to come into contact with the inside of the oral cavity or lips, and the neck portion 12 that is likely to be twisted or subjected to force during operation. It is desirable that a siloxane compound be contained in the siloxane compound. It is easy to feel the effects of improving stiffness, strength, water resistance, and surface smoothness due to the inclusion of siloxane compounds. Preferably, the entire cutlery contains a siloxane compound.

The siloxane compound is not necessarily limited as long as it has a siloxane bond, but the cutlery 1 is one that has no or low toxicity to living organisms because it may come into contact with food or be put into the oral cavity. is desirable. In order to make the cutlery 1 contain a siloxane compound, in addition to coating the cutlery 1 with a siloxane compound, it is also possible to apply an appropriate alkoxysilane solution or alkoxysilane solution processed product to the sheet material before molding. After the impregnation, heating or pressing while heating may be performed. In this way, the siloxane compound is contained in such a manner that it binds to the pulp fiber itself or coats the pulp fiber.

Here, the cutlery 1 of this embodiment is formed by pressing a sheet material, but the pressing pressure and pressing speed may be changed as appropriate depending on the type and shape of the sheet material and cutlery. Yes, but not necessarily limited. However, in order to consolidate the sheet material in the thickness direction and develop sufficient strength, a press pressure of 60 tons or more, more preferably 80 tons or more, particularly preferably 100 tons or more is used. It is preferable to compress the sheet material using pressure. The upper limit may be designed within a range that does not cause breakage of the sheet material, but considering that the sheet material is made from pulp fibers, the upper limit is about 200 tons. In addition, in the cutlery 1 of the present embodiment, when such a high pressing pressure is applied, it is easier to manufacture and mold the entire cutlery than to press and mold a part of the cutlery 1. This is desirable in terms of strength. Therefore, the cutlery 1 of this embodiment is made by pressing and compression molding the entirety of a single sheet material, and by partially gluing or pressing unpressed sheet materials into one piece. You can also use it as Note that when performing press working, heating may be performed together with press working, and the sheet material may be moistened to make it easier to deform. A solution containing the above-mentioned siloxane compound or a solution containing a substance serving as a precursor of the siloxane compound may be used as the wetting agent. Furthermore, the heating temperature and the like during heating are not necessarily limited.

The preferred basis weight of the cutlery 1 of this embodiment is 700 g/m ² or more, more preferably 850 g/m ² or more, particularly preferably 950 g/m ² or more. The basis weight is a value measured in accordance with "Paper and Paperboard - Basis Weight Measuring Method" described in JIS P 8124 (2011). A preferable density of the cutlery 1 of this embodiment is 0.70 g/cm ³ or more, preferably 0.98 g/cm ³ or more, particularly preferably 1.1 g/cm ³ . In particular, the density in the pressed portion is preferably 1.0 g/cm ³ or more, particularly preferably 1.2 g/cm ³ . Density is calculated by (grammage)/(paper thickness). The cutlery 1 of this embodiment can be said to have a sufficiently high density if it has this density. In particular, with the above basis weight and this density, it is compacted with an appropriate mass, has the appropriate stickiness and flexibility like plastic even though it is thin, and has high enough strength for use. Become. Although the thickness is not necessarily limited, the thickness of the pressed portion is 1.5 mm or less per sheet layer, preferably 1.35 m or less, particularly preferably 1.0 mm or less. The paper thickness is a value measured in accordance with "Paper and paperboard - Test method for thickness and density" described in JIS-P8118 (2014).

Although the pulp fibers constituting the cutlery 1 are not necessarily limited, preferred constituent pulp fibers are softwood kraft pulps such as softwood unbleached kraft pulp (NUKP), softwood semi-bleached kraft pulp (NSBKP), and softwood bleached kraft pulp (NBKP). and hardwood kraft pulps such as hardwood unbleached kraft pulp (LUKP), hardwood semi-bleached kraft pulp (LSBKP), and hardwood bleached kraft pulp (LBKP). Other pulps include chemical pulps such as waste paper pulp, hardwood sulfite pulp, softwood sulfite pulp, and various known pulps such as chemically or mechanically produced pulps from non-wood fibers such as kenaf, hemp, and reeds. A suitable combination of pulps may be used. However, since the cutlery 1 is used for purposes such as coming into contact with food or being placed in the oral cavity, it is preferable that the cutlery 1 is made of 100% virgin pulp and does not contain waste paper pulp. Furthermore, it is desirable that the content of softwood kraft pulp and hardwood kraft pulp be 90 to 100% by mass since it is a virgin pulp and it is easy to achieve both the appearance and strength of the product after processing. In this case, the blending ratio of softwood kraft pulp and hardwood kraft pulp is preferably 5:95 to 30:70. By increasing the blending ratio of hardwood kraft pulp with short fiber length, it is easier to consolidate through press processing and develop strength, and it is also easier to improve the surface texture. Further, it is particularly preferable to use bleached softwood kraft pulp and bleached hardwood kraft pulp because the cutlery 1 is bleached pulp and has a high degree of whiteness and has a clean and hard design.

Examples of the sheet material made from pulp fibers according to this embodiment include paper made by dry papermaking and paper made by wet papermaking. Preferably, the paper has a machine direction (MD direction) and a width direction (CD direction), which are produced by wet papermaking from pulp slurry. Since such paper has fiber orientation, it is easy to increase the strength. In particular, in the cutlery 1 which is formed by pressing a sheet material having such fiber orientation, the longitudinal direction from the head part 11 side to the handle part 13 side is the longitudinal direction of the paper (MD direction). ) is desirable. By matching the longitudinal direction (MD direction) of the paper with the longitudinal direction, the cutlery 1 becomes less likely to break and easily bends when the head section 11 is operated using the handle section 13.

A particularly preferable sheet material according to this embodiment is a multilayer paper 50 having three or more paper layers. It is particularly preferable that the cutlery 1 of this embodiment is constructed using the multilayer paper 50 as a sheet material and containing a siloxane compound. Here, as shown in FIG. 2, since the multilayer paper 50 has a plurality of paper layers 51 and 52 laminated, it is easier to increase the strength when compacted in the thickness direction than a single layer paper. Moreover, the multilayer paper 50 can change the characteristics of each layer, and can easily ensure elasticity despite its high density, and can easily provide water resistance. For example, by combining a flexible middle layer 52 with a pair of surface layers 51 that are hard but tend to break easily, which have excellent water resistance, excellent water resistance, toughness, and durability can be achieved. In the disposable cutlery 1 according to the present embodiment, since the sheet material is compression-molded by press working in the thickness direction, that is, in the layer stacking direction of the multilayer paper 50, the characteristics of each layer in the multilayer paper 50 are easily maintained. Therefore, the head part 11 and the handle part 13 are connected via the narrow neck part 12 in a shape similar to the plastic disposable cutlery 1, for example, like a spoon shown in FIG. 3 or a fork shown in FIG. Even if it has an elongated shape that is thin as a whole, it is easy to develop sufficient strength. In particular, the neck portion 12 is likely to be bent, and the cutlery 1 is likely to have a feeling of use similar to that of the disposable cutlery 1 made of plastic. Note that the multilayer paper 50 can be manufactured by multilayer papermaking. Moreover, the multilayer paper 50 may be one that is commercially available, such as ELIPLA paper manufactured by Dainichi Paper Industries Co., Ltd., for example.

It is desirable that the multilayer paper 50, which is a preferable sheet material according to this embodiment, has a tensile strength in both the longitudinal and transverse directions of 50 kN/m or more, as measured in accordance with JIS P 8113 (2006). With this tensile strength, it is easy to ensure sufficient strength even in the non-press portion and after forming by press processing.

Furthermore, the multilayer paper 50, which is a preferable sheet material according to the present embodiment, has a Taber stiffness of 125 mN·m or more in the longitudinal direction, preferably 150 mN·m or more, as measured in accordance with JIS P 8125 (2000). , 40 mN·m or more in the lateral direction, preferably 60 mN·m or more. This multilayer paper 50 can have sufficient rigidity and strength, and it is easy to ensure sufficient strength even in the non-press portion and after forming by press processing.

Furthermore, the multilayer paper 50 was tested according to JAPAN TAPPI Paper Pulp Test Method No. 18-1:2000 is preferably 400 kN/m ² or more, preferably 450 kN/m ² or more. It has excellent formability through press processing, and is easy to manufacture by punching such as Thomson processing before and after press processing, and cutting with a cutting plotter.

The number of layers of the multilayer paper 50, which is a preferable sheet material according to this embodiment, is not limited, but it is preferably five to nine layers, and the number of layers of the middle layer 52 is preferably three or more layers, particularly five layers. In particular, the configuration shown in FIG. 2 has a three-layer intermediate layer 52. It is said that when the total number of middle layers 52 is three or more layers, the toughness and durability of the multilayer paper 50 are more likely to be exhibited. The upper limit of the total number of middle layers 52 is preferably seven layers or less from the viewpoint of maintaining interlayer strength. In addition, three to seven layers are easy to operate while maintaining interlayer strength when using a circular mesh multi-tube type paper machine.

Here, the basis weight of the multilayer paper 50, which is a preferable sheet material according to this embodiment, is preferably 700 g/m ² or more, more preferably 850 g/m ² or more, particularly preferably It is 950 g/m ² or more. With the multilayer paper 50 having this basis weight, it is easy to obtain sufficient rigidity and strength by compacting it in the thickness direction, and it is easy to obtain a feeling of use similar to that of plastic disposable cutlery. The upper limit of the basis weight of the multilayer paper 50 is not limited, but there is a risk that wrinkles may easily occur due to calender rolls during paper making, and from this point of view, the upper limit is preferably 1400 g/ ^m2 , and 1240 g/m2. ² is more preferred. Moreover, the paper thickness of the multilayer paper is preferably 900 μm or more and 1,500 μm or less, more preferably 1000 μm or more and 1,350 μm or less. When the multilayer paper 50 having this paper thickness is pressed to a thickness of 1.5 mm or less, preferably 1.35 mm or less, particularly preferably 1.0 mm or less, the strength of the cutlery 1 of this embodiment can be easily obtained. Note that the basis weight is a value measured in accordance with "Paper and paperboard - basis weight measurement method" described in JIS P 8124 (2011), and paper thickness is a value measured in accordance with "Paper and paperboard - basis weight measurement method" described in JIS P 8118 (2014). This is a value measured in accordance with the "Thickness and Density Test Method for Paperboard and Paperboard".

Note that the basis weights of the surface layer 51 and middle layer 52 in the multilayer paper 50, which is a preferable sheet material according to this embodiment, can be adjusted within the range of the basis weight of the entire sheet material, and are not particularly limited, but preferably The basis weight of the surface layer 51 is preferably 60.0 g/m ² or more and 250.0 g/m ² or less, particularly 130 to 150 g/m ² per layer. The basis weight of the entire middle layer 52 is preferably 500 g/m ² or more and 900 g/m ² or less, particularly 650 g/m ² or more and 800 g/m ^{2 or} less. Further, the multilayer paper 50 preferably has a ratio of the total basis weight of the pair of surface layers 51, 51 to the basis weight of the entire multilayer paper 50 of 20.0% or more and 35.0% or less. This is because the pair of surface layers 51 have high rigidity and the middle layer 52 has excellent flexibility. Further, in the multilayer paper 50, if the ratio of the total basis weight of the pair of surface layers 51 is within the above range, it has a characteristic that it is difficult to bend. The preferred multilayer paper 50 has a density of preferably 0.65 to 1.50 g/cm ³ , more preferably 0.73 to 1.00 g/cm ³ , particularly preferably 0.76 before compression molding by press working. ~0.96g/ ^cm3 . When the density of the multilayer paper 50 is within this range, it has a high basis weight and excellent rigidity, is hard to break, and tends to have more hardness and high stiffness when molded by press processing.

Preferred pulp fibers constituting each layer of the multilayer paper 50 are the same as the pulp fibers constituting the cutlery 1 described above, and are preferably, but not necessarily limited to, softwood unbleached kraft pulp (NUKP), softwood semi-bleached kraft pulp, etc. pulp (NSBKP), softwood kraft pulp such as softwood bleached kraft pulp (NBKP), and hardwood kraft pulp such as hardwood unbleached kraft pulp (LUKP), hardwood semi-bleached kraft pulp (LSBKP), and hardwood bleached kraft pulp (LBKP). . Other pulps include chemical pulps such as waste paper pulp, hardwood sulfite pulp, softwood sulfite pulp, and various known pulps such as chemically or mechanically produced pulps from non-wood fibers such as kenaf, hemp, and reeds. A suitable combination of pulps may be used. However, since the cutlery is used for purposes such as coming into contact with food or being placed in the oral cavity, it is preferable that the cutlery be made of 100% virgin pulp and contain no waste paper pulp. Furthermore, it is desirable that the content of softwood kraft pulp and hardwood kraft pulp be 90 to 100% by mass since it is a virgin pulp and it is easy to achieve both the appearance and strength of the product after processing. In this case, the blending ratio of softwood kraft pulp and hardwood kraft pulp is preferably 5:95 to 30:70. By increasing the blending ratio of hardwood kraft pulp with short fiber length, it is easier to consolidate through press processing and develop strength, and it is also easier to improve the surface texture. Further, it is particularly preferable to use bleached softwood kraft pulp and bleached hardwood kraft pulp because the cutlery 1 is bleached pulp and has a high degree of whiteness and has a clean and hard design.

Note that, from the viewpoint of eliminating plastics, it is desirable that the multilayer paper 50, which is a preferable sheet material according to this embodiment, be a paper made only of fibers derived from natural materials and not containing synthetic fibers including plastics. Preferably, paper is made of only pulp fibers.

Regarding the blend of pulp fibers in each layer of this multilayer paper 50, it is preferable that the mass ratio (%) of the softwood kraft pulp and the hardwood kraft pulp in the surface layer 51 is 0/100 or more and 15/85 or less. The cutlery 1 contains a large amount of hardwood kraft pulp, which is rigid and easy to increase density, and the surface layer has high density and rigid characteristics, resulting in cutlery 1 with excellent strength. In addition to the surface layer 51 having this composition, the middle layer 52 preferably has a mass ratio (%) of softwood kraft pulp and hardwood kraft pulp of 15/85 or more and 35/65 or less. When the softwood kraft pulp, which is more flexible than the surface layer, is contained in a larger amount, the cutlery 1 can be firmly compression-molded in the thickness direction during press processing, and the cutlery 1 can easily be formed into a desired shape.

Further, it is desirable that the multilayer paper 50, which is a preferable sheet material according to this embodiment, has at least one of a sizing agent and a paper strength enhancer added thereto as a paper manufacturing additive. Easy to adjust to desired strength. Note that the multilayer paper 50 may contain various other additives within a range that does not impair the intended effects of the present invention. For example, polyvinyl alcohol, wax, etc. can be applied.

Examples of the sizing agent include styrene sizing agents, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), neutral rosin sizing agents, rosin sizing agents, and modified rosin emulsion sizing agents. Among these, rosin sizing agents and modified rosin emulsion sizing agents are preferred. The rosin sizing agent is not particularly limited. Rosin-based substances include, for example, reinforced rosins such as gum rosin, wood rosin, tall oil rosin, etc., modified with α,β-unsaturated carboxylic acids such as fumaric acid, maleic acid, and acrylic acid or their anhydrides; Examples include rosin esters obtained by reacting polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and diglycerin. Further, rosin sizing agents include those obtained by emulsifying these alone or a mixture thereof, and those obtained by emulsifying them alone and then mixing them. Furthermore, it also includes emulsified products to which various polymers are added in order to further improve size development.

Various known paper strength enhancers can be used, such as polyacrylamide resins, polyamide resins, polyamine resins, acrylic resins, melamine resins, urea resins, and polyamide epichlorohydrin resins. Among these, it is preferable to use an amphoteric paper strength enhancer. Examples of the amphoteric polyacrylamide include copolymers of acrylamide and anionic monomers and cationic monomers, Mannich-modified copolymers of acrylamide and anionic monomers, and Hoffmann decomposition products. In particular, amphoteric polyacrylamide has a self-fixing function, so even if it is added to improve interpaper strength, it will not become excessively cationic, and by including it together with the modified rosin emulsion sizing agent, it will stabilize. It can be fixed in.

The amount of the sizing agent added is preferably 0.5 kg/t or more and 5.0 kg/t or less in terms of solid content. The amount of the paper strength enhancer added is preferably 12 kg/t or more and 30 kg/t or less in terms of solid content. Note that "kg/t" indicates the mass (kg) per 1 ton of pulp. When the amount of the sizing agent added is within this range, water resistance can be sufficiently improved, resulting in a multilayer paper particularly suitable for cutlery applications.

Further, in the multilayer paper 50, it is preferable that at least one of the above-mentioned sizing agent and paper strength enhancer is added as a papermaking additive to each layer of the surface layer 51 and the middle layer 52. In this case, the amount of the sizing agent added to the surface layer 51 is preferably 0.5 kg/t or more and 5.0 kg/t or less in terms of solid content. Further, the amount of the sizing agent added to the middle layer 52 is preferably 2.0 kg/t or more and 5.0 kg/t or less in terms of solid content. Further, the amount of the paper strength enhancer added to each layer is preferably 12 kg/t or more and 30 kg/t or less in terms of solid content. By setting it within this range, it is easy to achieve various paper strengths such as the interlayer strength of multilayer paper suitable for cutlery.

Furthermore, a more preferable specific shape of the disposable cutlery 1 according to the present embodiment will be further explained using the spoon 10 as an example. FIG. 3 shows a table spoon 10 which is a disposable cutlery according to this embodiment. In FIG. 3, (A) is a diagram showing a front view, (B) is a diagram showing a side view, and (C) is a diagram showing the curvature of the front side at positions (1) to (7) in (A). It is a figure showing a shape in cross section.

The spoon 10 of this illustrated embodiment is formed by compression molding the entire portion from the head portion 11 to the handle portion 13 by pressing a sheet material. The head part 11 that comes into contact with the food is a bowl that opens on the front side, similar to a general metal spoon or a conventional plastic disposable spoon, so that it can scoop out food in various shapes such as solid, powder, or liquid. The situation is as follows.

In addition, in the spoon 10 according to the present embodiment, the neck portion 12 connected to the head portion 11 is formed to be narrow and smoothly continuous from the head portion 11 in a curved line when viewed from the front, and the handle portion 13 connected to the neck portion 12 is formed to have a narrow width. is the same width as the neck portion 12 or wider than the neck portion 12. Furthermore, the edges from the head part 11 to the handle part 13 are curved in front and side views, and the front and back surfaces are curved. It has a similar shape and has an excellent design. However, the spoon 10 according to this embodiment is not limited to this shape.

On the other hand, in the spoon 10 according to the present embodiment, the neck portion 12 connected to the head portion 11 is formed to be narrow and smoothly continuous from the head portion 11 in a curved line when viewed from the front. As shown in FIG. 3, the cross section is curved with the front side open, and the ratio of the radius of curvature R1 of the cross section to the width L1 is 1:0.4 to 1:0.8. Particularly preferred is 1:0.4 to 1:0.75. By setting the ratio of the radius of curvature of the cross section to the width of the neck portion from 1:0.4 to 1:0.8, it is possible to improve the strength while being able to come out of the compression mold. In addition, in general metal molding, if the ratio of the radius of curvature of the cross section to the width is less than 1:0.5, it will not come out of the mold, but in the cutlery of this embodiment, the sheet material is a sheet material made of paper made of lupus fibers. The ratio can be less than 1:0.5 since the curved surface is bent to open. If the neck part 12 is formed to have a curved cross section, the bending strength will be improved when the head part 11 is pressed from the front side or the back side, compared to a case where the neck part 12 is not formed with a curved cross section. In particular, if the ratio of the radius of curvature of the cross section to the width is 1:0.4 to 1:0.8, there is a risk that the neck will break during use, for example during general operations such as scooping food with a spoon. It gets progressively lower.

Although the specific size of the spoon of this embodiment is not limited, in particular, in the case of the table spoon 10 shown in FIG. 3, the overall length L2 is 180 to 200 mm, and the length L3 of the head portion 11 is 45 mm. 0 to 60.0 mm, the maximum width L4 of the head part 11 is 35.0 to 45.0 mm,

The length L5 of the neck portion 12 can be 40.0 to 50.0 mm, and the minimum width L6 of the neck portion 12 can be 8.5 to 22.0 mm. With this shape, the spoon 10 can have a feeling of use similar to that of a commonly used disposable table spoon 10 made of plastic.

In addition, in the illustrated form, the shape and size of the table spoon 10 have been explained as an example, but when the cutlery of this embodiment is used as a spoon, it is not limited to this, and may be used as appropriate within the range that does not impede the effects of the present invention. For example, it can be of a size and shape suitable for use as a service spoon, dessert spoon, soup spoon, fish spoon, teaspoon, coffee spoon, demitasse spoon, or ice cream spoon. I can do it. Alternatively, a spoon with a bifurcated or trifurcated tip called a melon spoon, strawberry spoon, etc. may also be used.

Furthermore, a more preferable specific shape of the disposable cutlery 1 according to the present embodiment will be further explained using the fork 20 as an example. FIG. 4 shows a table fork 20, which is the disposable cutlery 1 according to this embodiment. In FIG. 4 , (A) is a diagram showing a front view, (B) is a diagram showing a side view, and (C) is a diagram showing the front side curvature at positions (1) to (7) in (A). It is a figure showing a shape in cross section.

Like the spoon 10 described above, the fork 20 of this illustrated embodiment is formed by compression molding the entire portion from the head portion 11 to the handle portion 13 by pressing a sheet material. The head part 11 that comes into contact with the food has a shallow bowl shape with a shallow opening on the front side so that it can scoop up food in various shapes such as solid, powder, or liquid, and has a tip with a shallow opening so that it can hold the food by stabbing it. It is shaped like a four-pronged comb.

Further, in the fork 20 according to the present embodiment, the neck portion 12 connected to the head portion 11 is formed narrowly and smoothly in a curved line from the head portion 11 when viewed from the front, as in the spoon 10 described above. A handle portion 13 connected to the handle portion 13 has the same width as the neck portion 12 or is wider than the neck portion 12. Furthermore, from the head part 11 to the handle part 13, the edges are curved in front and side views, and the surface is composed of curved surfaces. The shape is excellent in design. However, the fork 20 according to this embodiment is not limited to this shape.

On the other hand, in the fork 20 according to the present embodiment, similarly to the spoon 10 described above, the neck portion 12 connected to the head portion 11 is formed to be narrow and smoothly continuous in a curved line from the head portion 11 when viewed from the front. In particular, as shown in FIG. 4, the neck portion 12 is formed to have a curved cross section with an open front side, and the ratio of the radius of curvature R2 of the cross section to the width L7 is 1:0.4 to 1:0.8. It becomes. Particularly preferred is 1:0.4 to 1:0.75. If the neck part 12 is formed to have a curved cross section, the bending strength will be improved when the head part 11 is pressed from the front side or the back side, compared to a case where the neck part 12 is not formed with a curved cross section. In particular, by setting the ratio of the radius of curvature of the cross section to the width to be 1:0.4 to 1:0.8, there is no risk that the neck portion 12 will break during use, for example, during the general operation of stabbing food with a fork. Each level gets lower.

Although the specific size of the fork 20 of this embodiment is not limited, in particular, if it is the table fork 20 shown in FIG. 0 to 60.0 mm, the maximum width L10 of the head part 11 is 35.0 to 45.0 mm, the length L11 of the neck part is 40.0 to 50.0 mm, and the minimum width L12 of the neck part is 8.5 to 22 It can be set to .0mm. With this shape, the table fork 20 can have a usability similar to that of a commonly used disposable table fork 20 made of plastic.

In addition, in the illustrated form, the shape and size of the table fork have been explained as an example, but when the cutlery of this embodiment is used as a fork, the shape and size are not limited to this, and may be used as appropriate within the range that does not impede the effects of the present invention. For example, it can have a size and shape suitable for use as a service fork, dessert fork, fish fork, salad fork, fruit fork, cake fork, or Hime fork.

Furthermore, a more preferable specific shape of the disposable cutlery 1 according to the present embodiment will be further explained using the knife 30 as an example. FIG. 5 shows a table knife 30, which is the disposable cutlery 1 according to this embodiment. In FIG. 5, (A) is a rear view, (B) is a side view, and (C) is a cross-sectional view at positions (1) to (7) in (A). It is a diagram.

The knife 30 of this illustrated embodiment has a blade portion 11B in which one edge of the head portion 11 is tapered toward the one edge by press working. Further, in the knife 30 according to the present embodiment, one edge constituting the blade portion 11B is formed in a curved shape with a slight bulge when viewed from the side, and the neck portion 12 connected to this edge is curved when viewed from the side. It continues smoothly and continuously to the handle part 13, and the edge on the blade part 11B side has a streamlined shape similar to that of high-quality cutlery made of metal or the like, which is not disposable, and has an excellent design. There is. However, the knife 30 according to this embodiment is not limited to this shape.

Further, the knife 30 of this embodiment is characterized in that the portions extending to the head portion 11, neck portion 12, and handle portion 13 are formed by laminating two sheet materials 30A and 30B. Particularly, the sheet material is not pressed, except for the pressed one edge, and is thicker than the blade portion 11B. The thickness of the non-press processed portion is not necessarily limited, but is 1800 μm or more and 3000 μm or less. Although the number of sheet materials to be laminated is not necessarily limited, it is preferably 2 to 3 sheets. One edge of the head part 11 is made into a blade part 11B which tapers toward the one edge by press working, and sheet materials are further laminated in other parts, so that food can be cut into pieces with a knife when in use, for example. The risk of the knife breaking during normal operation is significantly reduced. Although not shown, the edge of the blade portion 11B may be formed into a sawtooth shape. This makes it easier to cut fibrous materials such as meat.

Although the specific size of the knife of this embodiment is not limited, in particular, in the case of the table knife 30 shown in FIG. 4, the overall length L13 is 180 to 200 mm, and the length L14 of the head portion 11 is 90 mm. 0 to 110.0 mm, the maximum width L15 of the head part 11 is 12.0 to 20.0 mm, the length L16 of the handle part is 90.0 to 100.0 mm, and the width L17 of the handle part is 15.0 to 25.0 mm. It can be done. With this shape, it can have a feeling of use similar to that of a commonly available disposable table knife made of plastic.

In addition, in the illustrated form, the shape and size are explained using a table knife as an example, but when the cutlery of this embodiment is used as a fork, the cutlery is not limited to this, and may be used as appropriate within the range that does not impede the effects of the present invention. For example, it can have a size and shape suitable for use as a dessert knife, fish knife, fruit knife, or butter knife.

Here, in the cutlery of this embodiment, there may be a portion in which unpressed portions of the sheet material are laminated and integrated, like the knife 30 shown in FIG. 4. Furthermore, there may be a pressed portion of the sheet material and a portion formed by laminating and integrating sheet materials that are not pressed. The method of joining sheet materials is not necessarily limited. To the extent that the effects of the present invention are not impaired, joining may be performed by joining means such as joining using a locking structure also referred to as adhesive, crimping means, caulking means, eyelet means, wedge means, stapling means, coreless staples, etc. can. Further, as the joining means, a plurality of types of joining means may be used in combination. As adhesives for bonding, starch, various modified starches, modified celluloses such as carboxymethylcellulose, water-soluble polymer adhesives such as polyvinyl alcohol, water-based emulsion resins such as acrylic esters, vinyl acetate, etc. may be used. good. Materials derived from natural materials such as starch and cellulose are preferable in terms of environmental impact. Rivets and staples constituting caulks and grommets for joining should be made of wood or metal other than plastic, and should preferably be made of a material other than plastic.

As a preferable joining means, as shown in FIG. 5(A) and FIG. 5(B) showing the cross section B-B thereof, the locking structure is shown in FIG. An example of this is a locking structure in which the respective layers are mechanically joined to each other by forming the top portions 70t and pushing the tip portions 70t into at least the adjacent layers. In this locking structure, a half-cut line may be inserted at the same position in plan view as the edge 70e of the cut-and-raised piece 70 in at least the adjacent layer so that the tip portion 70t can be easily inserted. Specifically, this locking structure can be formed at a plurality of appropriate locations to integrate the sheet materials, like the locking portion 40 of the knife 30 shown in FIG. In the cutlery 1 of this embodiment, since the sheet material is a paper material having stiffness, each layer can be joined by joining using such a locking structure. This locking structure is desirable because it does not require the use of other parts. However, as described above, a mechanical locking structure including this locking structure and an adhesive may be used together. In this case as well, there is an advantage that the amount of adhesive used can be reduced.

Next, spoons (Examples 1 to 7) were produced as cutlery according to the present invention, and their bending strengths were measured. Examples 1 to 7 all had the shape shown in FIG. 3. Note that the total length is 190 mm. The sheet material used was a multilayer paper (Ellipura paper manufactured by Dainichi Paper Industries, Ltd., basis weight 1000 g/m ² ) whose fiber raw material was 100% pulp fiber. Pressing was performed as a whole, and Example 1 was processed with a press pressure of 60 tons, Example 2 was processed with a press pressure of 80 tons, and Example 3 was processed with a press pressure of 110 tons. The processing pressure was varied. Further, Examples 4 and 5 were processed under a press pressure of 110 tons and contained a siloxane compound. In Examples 4 and 5, the content of the siloxane compound in Example 4 was increased by twice. Examples 6 and 7 were processed under a press pressure of 60 tons and contained a siloxane compound. In Examples 6 and 7, the content of the siloxane compound in Example 6 was increased by twice.

The test method was a two-point bending load test using a composite material testing machine (10 kN) type 5966, and the sample was placed at a position where the tip position 80t of the support stand 80A was 70 mm from the rear end of the cutlery, as shown in Figure 7. That's how I fixed it. Note that the narrowest portion of the neck portion 12 is located forward of the tip position 80t. The push-in position was the bottom of the bowl shape. The measurement was carried out under a small load of 500 N, the pushing speed was 40 mm/min, and the radius R1 of the indenter 81 was 5 mm.

The measurement results of each example are shown in FIGS. 8 and 9. As shown in FIG. 8, although the press working pressures of Examples 1 to 3 are different, the bending load is 0.5 N or more when the bending deflection is 15 mm, and it is 2 N or more when the bending deflection is 30 mm. It has been shown that it is strong enough to be used as cutlery. Furthermore, as shown in FIG. 9, it was confirmed that the strength was further increased by containing a siloxane compound.

Next, a spoon (Example 8) and a fork (Example 9), which are cutlery according to the present invention, and cutlery-shaped sheet materials (Comparative Examples 1 and 2) before press processing were produced, and the test subjects were A sensory test was conducted on actual use. The spoon according to Example 8 was similar to that of Example 3. The fork according to Example 9 had the shape shown in FIG. It was molded using Elipura paper (basis weight 1000 g/m ² ) manufactured by Paper Seizai Co., Ltd. under a press pressure of 110 tons. In Comparative Examples 1 and 2, the shapes were the same as those of Examples 8 and 9 before press processing, and the sheet material was made of multilayer paper (manufactured by Dainichi Paper Corporation) whose fiber raw material was 100% pulp fiber. Ellipura paper with a basis weight of 1000 g/m ² ) was used.

The sensory test was conducted using the curry roux, white rice, and fried chicken of the take-out "Crispy Chicken Curry" sold by the curry specialty store "Curry House CoCo Ichibanya" (operated by Ichibanya Co., Ltd.) using the spoons and forks according to Examples 8 and 9. and the spoons and forks according to Comparative Example 1 and Comparative Example 2 were used to eat freely, and the feeling of use was evaluated. The evaluation criteria were free, with particular emphasis on strength, mouthfeel, and operational feel, and easy to use was evaluated as ○, while difficult to use was evaluated as ×. The number of subjects was N=5. As a result of the test, all five subjects rated Example 8 and Example 9 as easy to use ○, and Comparative Example 1 and Comparative Example 2 as difficult to use ×. From this result, it can be said that the cutlery according to the present invention can be used satisfactorily.

As described above, according to the present invention, while using natural pulp fiber as the main raw material, it is possible to achieve the same design and usability as conventional plastic disposable cutlery, and furthermore, it is possible to manufacture from sheet material. Cutlery that is easy to manufacture and has sufficient water resistance is provided.

DESCRIPTION OF SYMBOLS 1... Cutlery, 10... Spoon, 20... Fork, 30... Knife, 30A, 30B... Sheet material, 11... Head part, 12... Neck part, 13... Handle part, 50... Multilayer paper, 51... Surface layer, 52... Middle layer .

Claims (6)

Disposable cutlery,
It has a head part that comes into contact with the food, a neck part connected to the head part, and a handle part connected to the neck part for gripping,
Formed from sheet material made from pulp fibers,
and part or all of the sheet material is compacted and compression molded by press working,
Disposable cutlery characterized by: Disposable cutlery according to claim 1, which contains a siloxane compound. The disposable according to claim 1 or 2, which contains a total of 90 to 100% by mass of softwood kraft pulp and hardwood kraft pulp as pulp fibers, and the blending ratio of softwood kraft pulp and hardwood kraft pulp is 5:95 to 30:70. cutlery. The disposable cutlery according to any one of claims 1 to 3, wherein the density of the pressed part is 1.0 g/cm ³ or more. It has a head portion having a dish shape or at least a curved portion toward the tip side, a neck portion connected to the head portion and narrower than the head portion, and a handle portion having the same width as the neck portion or wider than the neck portion. ,
At least the head part and neck part are formed by press working,
The neck portion is formed to have a curved cross section, and the ratio of the radius of curvature of the cross section to the width is 1:0.4 to 1:0.8.
Disposable cutlery according to any one of claims 1 to 4. It has a head portion having a blade portion that tapers toward one edge, a neck portion connected to the head portion, and a handle portion connected to the neck portion,
The head part, neck part and handle part are formed by laminating multiple sheet materials,
and at least the blade portion is formed by press working to be tapered toward one edge;
Disposable cutlery according to any one of claims 1 to 4.