Paper tool manufacturing apparatus

Abstract

To manufacture a paper tool that is higher in water resistance, strength, and safety.SOLUTION: A device 2 for manufacturing a paper tool comprises: a spoon press cutting part 4 that forms a spoon-shaped notch in a cardboard P1 for generating a paper spoon and a separation part 5 that punches a spoon-shaped cardboard P2; and a crushing part 6 that compresses the spoon-shaped cardboard P2 punched by the separation part 5. By compressing the punched spoon-shaped cardboard P2 and crushing the cut surface of the spoon-shaped cardboard P2, a shape of the cut surface can be made smooth and hardness can be increased by compression. Thus, by further compressing the spoon-shaped cardboard P2 punched from the cardboard P1 for generating the paper spoon to obtain a paper spoon 1, there can be provided the paper spoon 1 that is higher in hardness and water absorbance than the spoon-shaped cardboard P2.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a paper-made tool manufacturing apparatus Place .

Background Art

[0002] Conventionally, as disposable cutlery such as spoons and forks, wooden, paper, plastic, etc. have been proposed. In addition, since plastic products affect marine pollution and the ecosystem of marine organisms, in recent years, from the perspective of environmental protection, paper stirring sticks, spoons, and knives with improved water resistance and hot water resistance have been proposed as alternatives to plastic cutlery (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in paper-made cutlery, further improvement is required in terms of water resistance and strength. In addition, paper-made cutlery made by cutting paper may have a sharp end face, that is, a cut surface, which may cause injury or discomfort in the oral cavity during use, and improvement has been desired.

[0005] The present invention has been made by paying attention to the above unsolved problems, and provides a paper-made tool manufacturing apparatus capable of manufacturing a paper-made tool with more excellent water resistance, strength, and safety. Place The purpose is to provide.

Means for Solving the Problems

[0006] To achieve the above objective, according to one aspect of the present invention, a paper tool manufacturing apparatus for manufacturing paper cutlery as a paper tool comprises a cutter device for punching out tool-shaped cardboard from cardboard, and a compression device for compressing the tool-shaped cardboard punched out by the cutter device, wherein the compressed tool-shaped cardboard is used as a paper tool, and the cutter device is of the push-cut type. Dyroll The cutter is such that the blades of the cutting device are arranged in a frame shape similar to the tool-shaped cardboard in a plan view, and the end face obtained by cutting the blades with a plane perpendicular to the direction in which the blades are connected is mountain-shaped, and the inner angle between the side of the two sides of the mountain shape that is closer to the inside of the frame and the line segment extending in the height direction of the mountain shape is smaller than the outer angle between the side of the two sides that is closer to the outside of the frame and the line segment extending in the height direction of the mountain shape, the inner angle is between 12 degrees and 18 degrees, and the outer angle is between 17 degrees and 23 degrees. The blade section is frame-shaped with two sides parallel to the rotation axis of the die roll cutter, and multiple blade sections are arranged on the circumferential surface of the die roll cutter such that the two parallel sides become the front and rear ends in the direction of rotation of the die roll cutter. All of the multiple blade sections are the same shape, arranged in multiple rows along the direction of rotation of the die roll cutter, and the number of blade sections in each row is the same, the spacing between adjacent blade sections in the direction of rotation is the same for all blade sections, and all blade sections are offset in the direction of rotation from the front and rear ends of one blade section to the front and rear ends of all other blade sections. It is characterized by the following. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to manufacture paper tools that have superior water resistance and strength, as well as superior safety. [Brief explanation of the drawing]

[0009] [Figure 1] This diagram shows a schematic configuration of an example of a paper spoon. [Figure 2] This is a diagram showing an example of a paper tool manufacturing apparatus according to the first embodiment of the present invention. [Figure 3] This is an example of layout for spoon-shaped cardboard. [Figure 4] This is an explanatory diagram illustrating an example of the shape of the cross-section of a spoon-shaped piece of cardboard. [Figure 5] This figure shows an example of the main part of the spoon-cutting mechanism. [Figure 6] This is an end view of a cross-section showing an example of the blade portion of a spoon-cutting section. [Figure 7] This is an explanatory diagram illustrating the placement of the elastic members. [Figure 8]This is a diagram showing the schematic configuration of an example of a paper toothpick. [Figure 9] This is a configuration diagram showing an example of a paper product manufacturing apparatus according to a second embodiment of the present invention. [Figure 10] This is an example of the surface attachment of a toothpick-shaped cardboard. [Figure 11] This is a diagram showing an example of the main part of a toothpick cutting section. [Figure 12] This is an end view of a cross-sectional view showing an example of the blade part of a toothpick cutting section. [Figure 13] This is a diagram showing the schematic configuration of an example of a measuring apparatus used for buckling load measurement.

Embodiments for Carrying out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, the drawings are schematic, and the relationship between thickness and planar dimensions, the ratio of each thickness, etc. are different from the actual ones. Further, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, etc. of the components as the following ones. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[0011] <First Embodiment> First, the first embodiment of the present invention will be described.

[0012] <Paper Products> Paper products include cutlery such as spoons, forks, knives, ladles, chopsticks, toothpicks, skewers, etc., medical devices such as tongue depressors, swabs, etc., and tools that a person holds in their hand and uses on objects or acts on the human body and are made of paper. Here, the case of manufacturing a paper spoon (hereinafter also referred to as a paper spoon) as a paper product will be described.

[0013] <Shape of Paper Spoon> FIG. 1 shows a schematic configuration of an example of a paper spoon 1, where (a) is a plan view and (b) is a right side view. As shown in FIG. 1, the paper spoon 1 has a plate-shaped, tapered, elongated rectangular shape in plan view, with a length in the longitudinal direction of slightly less than 8 cm, a maximum width of slightly less than 3 cm, and a thickness of about 2 mm. The paper spoon 1 has a shape that is line symmetric about a line segment passing through the center in the width direction, and the four corners are chamfered. And the narrower end side is used as the handle 1a and is grasped by sandwiching it from the thickness direction with the index finger and the thumb, and at the other end side where the width is wider, it is designed to scoop objects such as ice cream and mochi.

[0014] Here, as shown in FIG. 1, the paper spoon 1 is a plate-shaped, tapered rectangular paper spoon, but the shape of the paper spoon 1 is not limited to the shape shown in FIG. 1. For example, it may be rectangular in plan view or the like, as long as it can scoop objects and has a shape that can exhibit the function of a spoon.

[0015] <Cardboard for generating paper spoons> The cardboard for generating paper spoons is formed of a three-layered hard cardboard made by laminating three sheets of water-resistant paper. Note that the cardboard for generating paper spoons is not limited to a three-layer structure, and it may be a cardboard formed by laminating single-layer, two-layer, four-layer or more water-resistant papers, as long as it is a cardboard having water resistance and high strength and can be applied.

[0016] <Configuration of a paper tool manufacturing apparatus> FIG. 2 is a configuration diagram showing an example of a paper tool manufacturing apparatus 2 according to an embodiment of the present invention. As shown in FIG. 2, the paper tool manufacturing apparatus 2 includes, for example, an embossing section 3, a spoon cutting section (cutter device) 4, a separating section 5, a crushing section (compression device) 6, and a paper spoon stacker 7. In terms of the process, in FIG. 2, the processing steps at each section are performed from right to left, and between each section, the transfer of the processing object is performed by, for example, a transfer belt (not shown).

[0017] The cardboard used to produce the paper spoons is in sheet form and is first introduced into the embossing section 3. There, the area of ​​the cardboard that will become the handle 1a of the finished paper spoon 1 is embossed or foil-stamped. The embossing section 3 is not strictly necessary, but the design of the paper spoon 1 can be improved by embossing marks or patterns or by foil-stamping. Furthermore, by embossing the part that will become the handle 1a, the paper spoon 1 can be made less slippery when the user holds it, improving the affordances when using the paper spoon 1, such as holding, cutting, stabbing, and pinching. The cardboard used to produce the paper spoons, which has been processed in the embossing section 3, is then transported to the spoon pressing and cutting section 4.

[0018] Furthermore, embossing or foil stamping can be applied not only to the area that forms the handle 1a of the finished paper spoon 1, but also to the entire surface of the finished paper spoon 1. By applying embossing or similar processing to the entire surface of the paper spoon 1 in this way, the friction with food or the friction with the inside of the mouth can be adjusted.

[0019] The spoon-cutting section 4 is composed of, for example, a known die-roll cutter of the push-cutting type. The spoon-cutting section 4 applies a push-cutting process to the cardboard for producing paper spoons, thereby making cuts in the cardboard for producing paper spoons to punch out spoon-shaped cardboard (tool-shaped cardboard) that will later become the paper spoon 1 shown in Figure 1, and which will have substantially the same shape as the paper spoon 1 in a plan view. The cardboard for producing paper spoons with the cuts made in it is conveyed to the separation section 5.

[0020] In this description, the spoon-shaped cardboard is punched out by using a die-roll cutter with a push-cutting method to cut the cardboard for making paper spoons in the spoon-cutting section 4. However, this is not the only method, and spoon-shaped cardboard may be obtained from the cardboard for making paper spoons by other cutting methods.

[0021] The separation unit 5 separates the cardboard for producing paper spoons into spoon-shaped cardboard and the remaining portion from which the spoon-shaped cardboard has been removed. The separation unit 5 is composed of, for example, a metal template and a punching device equipped with punching pins. The template is a rectangular plate shape having a size roughly equivalent to that of the cardboard sheet for producing paper spoons, and when the cardboard for producing paper spoons, which has been cut and has notches for punching out the spoon-shaped cardboard, is placed on top of the template, a roughly similar shape, slightly smaller than the spoon-shaped cardboard, is formed in a plan view at a position that overlaps with each of the cut spoon-shaped cardboard portions. The punching pins are plate-shaped, smaller than the through holes in the template, and have a shape that presses near the center of the spoon-shaped cardboard portion rather than near the edges, for example, slightly smaller than the through holes and roughly similar in shape to the through holes. Furthermore, the punching pins are provided protruding from the lower side of the plate-shaped support member, and are formed to correspond to each through-hole so that, when the template and the support member for the punching pins are superimposed, the punching pins are positioned inside the through-holes of the template in a plan view.

[0022] The template is supported from below by a frame-like member that supports the template at its edges, and cardboard for producing paper spoons is sandwiched between the template and the frame-like member. In addition, the support member for the punching pin is formed to be movable in the vertical direction by the punching device body.

[0023] Then, the cardboard for generating paper spoons is sandwiched between the frame-shaped member and the template, maintaining the up and down orientation it had when it was transported from the spoon-cutting section 4. With the template's through-hole positioned inside the spoon-shaped cardboard portion in a plan view, and the punching pin positioned inside the through-hole, the punching pin is lowered. This causes the punching pin to pass through the template's through-hole and press the spoon-shaped cardboard portion downwards, separating it from the cardboard for generating paper spoons. Only the punched-out spoon-shaped cardboard remains on the transport belt, maintaining its position on the cardboard for generating paper spoons. The spoon-shaped cardboard on the transport belt is transported to the crushing section 6, and the remaining portion of the cardboard for generating paper spoons is stocked in the remaining sheet stacker 8.

[0024] In the separation section 5, a template is placed on top of the cardboard for generating paper spoons, and the spoon-shaped cardboard portion is pressed and punched out through through holes formed in the template with punching pins. This suppresses changes in the shape and density of the edges of the spoon-shaped cardboard due to force being applied to the edges during punching. In other words, when punching out the spoon-shaped cardboard from the cardboard for generating paper spoons, if force is applied to the edges of the spoon-shaped cardboard, the density and shape of the edges that have been cut by the press-cutting process may change. For example, if the positional relationship between the spoon-shaped cardboard portion and the punching pin in a plan view is misaligned, the punching pin may press near the edges of the spoon-shaped cardboard. Even if the relative positions of the spoon-shaped cardboard portion and the punching pins are misaligned in a plan view, pressing the spoon-shaped cardboard portion through the template's through-holes will adjust the position of the punching pins so that they press approximately in the center of the spoon-shaped cardboard portion. This prevents the edges of the spoon-shaped cardboard portion from being pressed by the punching pins, thus avoiding changes in the density and shape of the edges that have been cut by the cut-out process. In other words, the separation process can suppress changes in the shape and density of the edges of the spoon-shaped cardboard.

[0025] In addition, the separation unit 5 described above may be configured so that the positions of the template and the cardboard for generating paper spoons are reversed. That is, the template is placed on the conveyor belt, and the cardboard for generating paper spoons is placed on top of the template. At this time, the cuts formed in the cardboard for generating paper spoons, the through holes in the template, and the punching pins are positioned so that they overlap in a plan view. In this state, the punching pins are lowered and pressed against the spoon-shaped cardboard portion, thereby separating the spoon-shaped cardboard from the cardboard for generating paper spoons on the template and moving to the lower end of the through holes in the template, i.e., onto the conveyor belt. In this state, by raising the template, the spoon-shaped cardboard is aligned on the conveyor belt, maintaining the arrangement of the spoon-shaped cardboard with the cuts made in the cardboard for generating paper spoons. In this case, the spoon-shaped cardboard pressed by the punching pins moves from the position on the top surface of the template to the position on the conveyor belt where the template is placed, and the amount of movement is equivalent to the thickness of the template. Therefore, the spoon-shaped cardboard can be cut out onto a conveyor belt while maintaining its position on the cardboard used for producing paper spoons. For example, the template can be equipped with a vertical movement device to move the template up and down. First, the template is lowered and placed on the conveyor belt. After the spoon-shaped cardboard is cut out, the template is raised to make the spoon-shaped cardboard movable.

[0026] The crushing section 6 includes, for example, two upper and lower rolls of the same diameter, and compresses the spoon-shaped cardboard by passing it between the two rolls. The compressed spoon-shaped cardboard is then stored as a paper spoon 1 in the paper spoon stacker 7.

[0027] The two rolls in the crushing section 6 may be metal rolls made of, for example, steel, copper, alloys, chrome-plated materials, aluminum, etc., or hard rubber rolls made of, for example, chloroprene rubber, etc., or a combination of one metal roll and the other hard rubber roll. The material of the rolls and the degree of compression should be set considering the hardness required for the paper spoon.

[0028] <Layout of spoon-shaped cardboard pieces> Figure 3 shows the layout of spoon-shaped cardboard pieces P2 on cardboard P1 for producing paper spoons. Spoon-shaped cardboard pieces P2 are the parts that become paper spoons 1 after being punched out from cardboard P1 for producing paper spoons. That is, in plan view, spoon-shaped cardboard pieces P2 have approximately the same shape as paper spoons 1, and have a tapered, elongated rectangular shape with one end in the longitudinal direction being shorter than the other end. Furthermore, spoon-shaped cardboard pieces P2 have a shape that is symmetrical with respect to a line segment passing through the center in the width direction, and the four corners are rounded.

[0029] As shown in Figure 3, when the direction perpendicular to the conveying direction of the cardboard P1 for generating paper spoons by a conveyor belt is defined as the width direction of the cardboard P1 for generating paper spoons, the spoon-shaped cardboard P2 is arranged so that its longitudinal direction is parallel to the conveying direction, and is positioned in three rows in the width direction of the cardboard P1 for generating paper spoons, with a constant interval in the conveying direction. Furthermore, each of the three rows of spoon-shaped cardboard P2 arranged in the width direction is positioned such that the leading and trailing ends of each of the three rows of spoon-shaped cardboard P2 do not coincide in the longitudinal direction with the leading and trailing ends of any other spoon-shaped cardboard P2 on the cardboard P1 for generating paper spoons.

[0030] Furthermore, in the cardboard P1 for generating paper spoons, the spoon-shaped cardboard P2 is positioned such that the shorter side of the spoon-shaped cardboard P2, that is, the side that will later become the handle 1a of the paper spoon 1, is located towards the front end in the transport direction. Here, as will be described later, the spoon-shaped cutting section 4 is designed to make a spoon-shaped cut by pressing the blade section 4a against the cardboard P1 for making paper spoons.

[0031] On the other hand, the longitudinal ends of the spoon-shaped cardboard P2 are parallel to each other. Therefore, if the longitudinal positions of the tips of the three rows of spoon-shaped cardboard P2 are aligned and arranged on the cardboard P1 for making paper spoons, and the blade 4a of the spoon cutting section 4 makes a cut in the cardboard P1 for making paper spoons, the length of the widthwise portion of the cardboard P1 that is in contact with the blade 4a will be the sum of the widths of the tips of each of the three rows of spoon-shaped cardboard P2 in the portion corresponding to the tip of the spoon-shaped cardboard P2. Similarly, in the portion corresponding to the rear end of the spoon-shaped cardboard P2, it will be the sum of the widths of the rear ends of each of the three rows of spoon-shaped cardboard P2. In contrast, in the portion of the cardboard P1 used for making paper spoons, excluding the parts corresponding to the front and rear ends of the spoon-shaped cardboard P2, the length is the sum of the lengths of the parts where the two longitudinal sides of each of the three spoon-shaped cardboard P2 intersect with the blade portion 4a. In other words, the force applied from the blade 4a to the cardboard P1 for making paper spoons differs depending on which part of the spoon-shaped cardboard P2 the blade 4a cuts into, that is, whether the cut corresponds to the tip or the rear end of the spoon-shaped cardboard P2. In particular, when the cut is made at the tip or the rear end, the force applied from the blade 4a to the cardboard P1 for making paper spoons is dispersed in the width direction, resulting in a change in the cutting performance of the blade 4a. Consequently, when the spoon-shaped cardboard P2 is punched out, variations occur in the shape of the cut surface of the spoon-shaped cardboard P2, resulting in splinters, whisker-like pieces of scrap material, or burrs on the cut surface, which may lead to a decrease in water resistance, strength, or safety.

[0032] In this embodiment, when the spoon-shaped cardboard sheets P2 are positioned on the cardboard P1 for making paper spoons, the positions of the leading edge of each spoon-shaped cardboard sheet P2 and the leading edge or trailing edge of other spoon-shaped cardboard sheets P2 in the longitudinal direction of the cardboard P1 for making paper spoons, and the positions of the trailing edge of each spoon-shaped cardboard sheet P2 and the leading edge or trailing edge of other spoon-shaped cardboard sheets P2 in the longitudinal direction of the cardboard P1 for making paper spoons, are not made to be the same. As a result, when the cutting process is performed by the spoon cutting section 4, the force transmitted to the cardboard P1 for making paper spoons is distributed in the width direction, thereby suppressing the generation of burrs or other rough edges on the cut surface of the spoon-shaped cardboard sheets P2.

[0033] Furthermore, as will be described later, the blade portion 4a of the spoon-cutting section 4, as shown in Figure 6 below, has a mountain-shaped end face when cut by a plane perpendicular to the direction in which the blade portions 4a are connected. Therefore, the spoon-shaped cardboard P2 punched out from the cardboard P1 for producing paper spoons has a roughly frustum shape where the top surface is smaller than the bottom surface, and as shown in Figure 4, the cut surface (end) of the spoon-shaped cardboard P2 is not a roughly vertical surface, but a surface that is inclined towards the center of the spoon-shaped cardboard P2. In addition, the angle between the bottom surface and the cut surface of the spoon-shaped cardboard P2 tends to be acute at the rear end in the transport direction than at the front end in the transport direction (angle θ2). In Figure 4, (a) is a plan view of the spoon-shaped cardboard P2, and (b) is an end view of the surface cut by plane AA' of (a).

[0034] Considering the function of paper spoon 1, it is preferable that the angle between the bottom surface and the cutting surface of paper spoon 1 be acute, especially when scooping or scraping off sticky foods such as mochi. Therefore, the wider side of paper spoon 1, which is the scooping side, is positioned so that it is at the rear end in the direction of transport.

[0035] Although not shown in the diagram, the conveying line that transports multiple spoon-shaped cardboard pieces P2 punched out from cardboard P1 for producing paper spoons is equipped with various devices such as guides, which are generally installed to align and transport the spoon-shaped cardboard pieces P2. For example, the widthwise position of each spoon-shaped cardboard piece P2 is adjusted by the guides. In this case, if the widthwise misalignment of the spoon-shaped cardboard pieces P2 is large, they are more likely to get caught in the guides. Therefore, the side of the spoon-shaped cardboard piece P2 that is narrower and less likely to create resistance is positioned towards the leading edge in the transport direction, thereby suppressing the punched-out spoon-shaped cardboard pieces P2 from getting caught in the guides or other devices.

[0036] Furthermore, as shown in Figure 4, the spoon-shaped cardboard P2 has a roughly frustum shape, with its top surface being smaller than its bottom surface. When transporting the spoon-shaped cardboard P2 with a roughly frustum shape, if the bottom surface of the frustum is facing downwards and the top surface is facing upwards, the spoon-shaped cardboard P2 is more likely to get caught on guides or other equipment. Therefore, when transporting multiple spoon-shaped cardboard pieces P2 punched out from cardboard P1 for paper spoon production, the cut-out spoon-shaped cardboard P2 is transported with the narrower, less resistant top surface of the frustum facing upwards to suppress the chance of it getting caught on guides or other equipment.

[0037] <Blade portion of the spoon-cutting part> The blade portion 4a of the spoon-shaped cutting section 4 is formed on the circumferential surface of a cylindrical die roll cutter, and as shown in Figure 5, multiple blade portions are formed in the same pattern as the layout pattern of the spoon-shaped cardboard P2 shown in Figure 3. In addition, each blade portion 4a is formed in a frame shape that is similar in shape to the outer shape of the spoon-shaped cardboard P2 when viewed from above. In Figure 5, (a) is a side view showing the blade portion 4a of the spoon-shaped cutting section 4, and (b) is an unfolded view of the circumferential surface of the roll on which the blade portion 4a of the spoon-shaped cutting section 4 is provided.

[0038] As shown in Figure 6, the blade portion 4a is formed such that the end face obtained by cutting the blade portion 4a with a plane perpendicular to the direction in which the blade portions 4a are connected is mountain-shaped. The inner angle θin between the side of the frame-shaped blade portion 4a located closer to the inside of the frame and the line segment extending in the height direction of the mountain shape is smaller than the outer angle θout between the side of the frame-shaped blade portion 4a located closer to the outside of the frame and the line segment extending in the height direction of the mountain shape. The inner angle θin is set to a value within the range of, for example, 12 degrees or more and 18 degrees or less, and the outer angle θout is set to a value within the range of, for example, 17 degrees or more and 23 degrees or less. From the viewpoint of ensuring the strength of the blade portion 4a, it is preferable that the sum of the inner angle θin and the outer angle θout is greater than or equal to a certain angle (for example, 30 degrees or more). Figure 6 shows only the outer shape of the blade portion 4a at the end face obtained by cutting the blade portion 4a shown in Figure 5(b) with the BB' plane.

[0039] The inner angle θin and outer angle θout of the blade portion 4a are values ​​set according to the shape of the edge of the paper spoon 1, the characteristics of the paper spoon 1, the material and thickness of the cardboard P1 used to manufacture the paper spoon, etc. In other words, since the paper spoon 1 is used in the oral cavity, it is required to have a highly safe shape that will not injure the inside of the mouth, and also a shape that does not cause discomfort when the paper spoon 1 is touched in the oral cavity.

[0040] Furthermore, the shape of the edge of the paper spoon 1 is required to facilitate handling of food, depending on the type of food the paper spoon is intended for (viscous, solid, or liquid), including its ability to pierce and cut. In particular, for viscous foods such as mochi (rice cakes) that are difficult to peel off containers, a sharper angle between the tip of the paper spoon and the cut surface (the surface that faces downwards when the cutting process is performed by the spoon's cutting mechanism 4) makes peeling easier. In addition, the edge of the paper spoon 1 is required to have particular water resistance and strength.

[0041] Here, the shape of the edge, or cut surface, of the spoon-shaped template also changes depending on the shape of the blade portion 4a. That is, as shown in Figure 6, the end surface of the plane that cuts the blade portion 4a with a plane perpendicular to the direction in which the blade portions 4a are connected has a mountain-like shape. Therefore, when an incision is made in the cardboard P1 for making paper spoons with the blade portion 4a, the cardboard P1 is crushed by the blade portion 4a as the incision is made, and the deeper the incision, the more it is crushed. As a result of being crushed, the density of the crushed part increases, and as a result the hardness increases, the hardness of the cut surface and the vicinity of the edges of the spoon-shaped cardboard P2 increases.

[0042] Furthermore, as the cutting edge 4a crushes and cuts the cardboard P2, the cut surface of the punched-out spoon-shaped cardboard P2 becomes inclined towards the center, as shown in Figure 4(b). The top surface is crushed more, so in plan view, the top surface is smaller than the bottom surface. As a result, the angles θ1 and θ2 between the bottom surface and the cut surface of the spoon-shaped cardboard P2 become acute angles, making it easier to scrape off viscous foods and the like.

[0043] Furthermore, a change in the inner angle θin of the blade portion 4a alters the degree of deformation of the cut surface of the spoon-shaped cardboard P2, thereby changing the shape of the edge of the paper spoon 1, as well as its water resistance and strength. Therefore, the inner angle θin of the blade portion 4a is set considering the required edge shape, water resistance, and strength for the paper spoon 1. Also, a change in the inner angle θin of the blade portion 4a alters the pressure applied to the blade portion 4a during the cutting process. For example, a larger inner angle θin increases the pressure on the blade portion 4a, so it is necessary to ensure the strength of the blade portion 4a. Therefore, the outer angle θout of the blade portion 4a is set to an angle that allows the blade portion 4a to maintain its strength, in accordance with the inner angle θin. Note that if the strength of the blade portion 4a can be ensured, the outer angle θout does not need to be a large angle.

[0044] The height of the blade 4a is set according to the usage conditions of the blade 4a during the cutting process, such as the thickness of the cardboard P1 used for making paper spoons and the pressure applied to the blade 4a during the cutting process. The height of the blade 4a is also set taking into account changes in the shape of the blade 4a. That is, the blade 4a wears down with use and needs to be sharpened, and repeated sharpening changes the shape of the blade 4a, so the blade 4a itself needs to be replaced. When sharpening, the area near the tip of the blade 4a is usually sharpened, so the shape of the tip of the blade 4a changes. Specifically, the height of the blade 4a becomes shorter and the thickness of the blade 4a becomes thinner. In the case of a blade 4a in its initial stages of use, the height of the blade 4a is sufficient, and even if sharpening is performed, the part of the blade 4a closer to the base is hardly sharpened compared to the tip, so the shape of the part of the blade 4a closer to the base hardly changes compared to before sharpening. As mentioned above, the shape of the blade portion 4a, especially the shape of the part near the base, is one of the factors that determine the density of the edge of the spoon-shaped cardboard P2 and the inclination of the cut surface of the spoon-shaped cardboard P2, that is, the angles θ1 and θ2 in Figure 4. However, in the case of the blade portion 4a in its initial use, even if it is sharpened, the shape of the part of the blade portion 4a near the base does not change much before and after sharpening. Therefore, even if a push-cutting process is performed using this sharpened initial blade portion 4a, the density of the edge of the spoon-shaped cardboard P2 and the inclination of the cut surface of the spoon-shaped cardboard P2 will be approximately the same before and after sharpening.

[0045] On the other hand, if the blade is sharpened multiple times, the height of the blade portion 4a will decrease, and even if the area near the tip of the blade portion 4a is sharpened, the height of the blade portion 4a itself will be lower, resulting in a change in the shape of the part of the blade portion 4a closer to the base compared to when the blade portion 4a was sharpened initially. Therefore, when a push-cutting process is performed using a blade portion 4a that has been sharpened multiple times in this manner, the density of the edges of the spoon-shaped cardboard P2 and the inclination of the cut surface of the spoon-shaped cardboard P2 may differ significantly compared to when using a blade portion 4a that has been sharpened initially.

[0046] Thus, the shape of the blade 4a changes through sharpening, and this change in the shape of the blade 4a changes the density of the edges of the spoon-shaped cardboard P2 and the inclination of the cut surface of the spoon-shaped cardboard P2. Therefore, the height of the blade 4a is set considering the range of possible heights for the blade 4a when the density of the edges of the spoon-shaped cardboard P2 and the inclination of the cut surface of the spoon-shaped cardboard P2 are within an acceptable range, as well as the replacement interval for the blade 4a. For example, if the thickness of the cardboard P1 for making paper spoons is 2.1 mm, the initial height of the blade 4a is set to 4 mm ± 0.2 mm.

[0047] <Elastic material for the spoon-cut section> Figure 7 is an enlarged view showing the blade portion 4a of the spoon-cutting section 4. As shown in Figure 7, a sheet-like elastic member 4b is provided in the area inside the frame-shaped blade portion 4a. The elastic member 4b is made of, for example, rubber or synthetic resin sponge. The elastic member 4b is formed in a similar or nearly similar shape to the frame shape of the blade portion 4a in a plan view, and is positioned with a gap of several millimeters between the blade portion 4a and the elastic member 4b. The elastic member 4b is also detachably attached to the inside of the frame-shaped blade portion 4a with adhesive or the like, and is designed to be replaced when the elasticity of the elastic member 4b decreases due to deterioration over time, etc.

[0048] In this way, by providing the elastic member 4b, when the die roll cutter rotates and the blade portion 4a formed on the circumferential surface of the die roll cutter makes an incision in the cardboard P1 for making paper spoons, it holds down the cardboard P1 for making paper spoons, and after the incision is made, it prevents the spoon-shaped cardboard P2 from being separated from the cardboard P1 for making paper spoons and getting stuck inside the frame-shaped blade portion 4a.

[0049] The height of the elastic member 4b can be set according to the thickness of the cardboard P1 used to make the paper spoon, the pressure applied to the cardboard P1 when the blade 4a makes an incision, and the elasticity of the elastic member 4b. For example, if the height of the elastic member 4b is set so that its upper end is higher than the upper end of the blade 4a, the repulsive force of the elastic member 4b will fix the cardboard P1 used to make the paper spoon between the elastic member 4b and the blade 4a, making it easier to make an incision. Conversely, if the height of the elastic member 4b is set so that its upper end is lower than the upper end of the blade 4a, the elastic member 4b will not get in the way and prevent the blade 4a from cutting through the cardboard P1 sufficiently, thereby suppressing a decrease in the cutting performance of the blade 4a.

[0050] Furthermore, by providing a gap between the blade portion 4a and the elastic member 4b, the elastic member 4b is prevented from actually hindering the blade portion 4a when it is cutting through the cardboard P1 used to make paper spoons.

[0051] The shape and position of the elastic member 4b are determined in accordance with the elasticity and other properties of the elastic member 4b, the relative positional relationship between the elastic member 4b and the blade portion 4a, the thickness, hardness, and other properties of the cardboard P1 used for making paper spoons, and the peripheral speed of the die roll cutter's roll, so as to ensure sufficient cutting performance of the blade portion 4a.

[0052] Furthermore, the elastic member 4b is not limited to sponge, but may also be cork, rubber, etc. Depending on the specifications of the cardboard P1 for making paper spoons and the shape of the blade portion 4a, any member with elasticity that can prevent the spoon-shaped template from becoming stuck in the inner region of the blade portion 4a can be used.

[0053] Furthermore, although the shape of the elastic member 4b is similar to that of the blade portion 4a in this example, it does not necessarily have to be similar in shape. For example, it could be a rectangle sized to fit inside the blade portion 4a. The point is that it should have a gap between it and the blade portion 4a and exert an elastic force that prevents the spoon-shaped template from becoming trapped inside the inner region of the blade portion 4a.

[0054] <Effects> (1) In this embodiment, the paper spoon 1 is obtained by pressing and cutting a water-resistant cardboard P1 for making paper spoons to punch out a spoon-shaped cardboard P2, and then further compressing the spoon-shaped cardboard P2. Therefore, by compressing the spoon-shaped cardboard P2, whose edges have hardened to some extent by the pressing and cutting process, the density is further improved, and consequently the hardness is improved, improving water resistance and strength. As a result, the water resistance and strength of the paper spoon 1 can be further improved, and the function as a spoon can be further enhanced.

[0055] As a result, even when used with water-containing foods, the strength of the paper spoon 1 can be more effectively maintained, and buckling or interlayer cracking of the paper spoon 1 in a short time can be suppressed.

[0056] Furthermore, by adjusting the shape of the blade portion 4a, the shape of the cut surface of the spoon-shaped cardboard P2 during the push-cutting process is adjusted. This allows the end face of the paper spoon 1 to be shaped appropriately for functioning as a spoon, thereby preventing injuries to the inside of the mouth caused by the end face of the paper spoon 1, and resulting in a safer paper spoon.

[0057] Furthermore, by punching out spoon-shaped cardboard P2 from cardboard P1 for making paper spoons and then compressing it, the strength can be increased. This allows relatively thin cutlery, such as toothpicks or skewers, to be manufactured as paper tools and perform better as toothpicks or skewers.

[0058] Furthermore, the hardness of the paper spoon 1 can be improved simply by compressing the spoon-shaped cardboard P2, which is punched out from the cardboard P1 used for producing paper spoons. Therefore, the hardness of the paper spoon 1 can be easily improved without involving any special processes.

[0059] Furthermore, when spoon-shaped cardboard P2 is punched out from cardboard P1 used for making paper spoons, burrs may form on the edges of the spoon-shaped cardboard P2. If spoon-shaped cardboard P2 with burrs is used as is, the edges of the spoon (spoon-shaped cardboard P2) may cause injury or discomfort in the mouth. Also, if spoon-shaped cardboard P2 with burrs is laminated, the burrs may prevent the spoon-shaped cardboard P2 from being stacked tightly together, potentially making handling difficult.

[0060] However, by compressing the spoon-shaped cardboard P2 after punching it out, the burrs can be crushed. Therefore, compared to using the spoon-shaped cardboard P2 as a spoon as is, it is possible to avoid injuries to the inside of the mouth caused by the burrs, thereby improving the safety of the paper spoon 1. In addition, because the burrs can be crushed, when stacking paper spoons 1, they can be stacked tightly together, making them easy to handle.

[0061] Furthermore, when punching out spoon-shaped cardboard P2 from cardboard P1 for producing paper spoons, there is a possibility that the spoon-shaped cardboard P2 may warp. However, since compression processing is performed after punching out the spoon-shaped cardboard P2, the warping that occurs in the paper spoon 1 can also be suppressed.

[0062] Furthermore, because paper spoon 1 is made of paper, embossing and foil stamping can be easily applied to it. By embossing or foil stamping paper spoon 1, it is possible to harden or increase the rigidity of paper spoon 1. Therefore, the properties such as hardness and rigidity of paper spoon 1 can be easily adjusted, and by applying embossing or foil stamping according to the intended use and method of use, a more user-friendly paper spoon can be realized. In addition, by applying embossing or foil stamping, the frictional force when holding paper spoon 1 can be improved, resulting in a paper spoon 1 that is less slippery, easier to hold, and easier to handle.

[0063] (2) The blade portion 4a of the spoon-cutting portion 4 is not flat but has a mountain-shaped cut surface, and the angle of the apex of the blade portion 4a is adjusted so that the shape of the cut surface is the desired shape. As a result, the cut surface of the spoon-shaped cardboard P2 punched out by the press-cutting process can be punched out in a shape that is safer in the mouth. As a result, the safety of the paper spoon 1 can be further improved. In other words, by adjusting the inner angle θin and outer angle θout of the blade portion 4a, the cut surface of the press-cut spoon-shaped cardboard P2 can be compressed. As a result, the hardness of the edge of the paper spoon 1 can be improved, and safety in the mouth can also be improved.

[0064] (3) The spoon-cutting section 4 is provided with an elastic member 4b such as a sponge in the area inside the frame-shaped blade section 4a. Therefore, when the cardboard P1 for making paper spoons is cut using a die roll cutter or the like, it is possible to prevent the spoon-shaped cardboard P2 punched out by the cutting process from getting stuck inside the frame-shaped blade section 4a, thereby preventing a decrease in the processing efficiency of the cutting process.

[0065] (4) When impositioning spoon-shaped cardboard sheets P2 on cardboard P1 for making paper spoons, the positions of each spoon-shaped cardboard sheet P2 arranged in three rows in the width direction of cardboard P1 for making paper spoons are such that the position of the tip of each spoon-shaped cardboard sheet P2 does not coincide with the position of the tip and rear end of other spoon-shaped cardboard sheets P2, and the position of the rear end of each spoon-shaped cardboard sheet P2 does not coincide with the position of the tip and rear end of other spoon-shaped cardboard sheets P2.

[0066] Therefore, it is possible to avoid simultaneous cutting of the leading or trailing ends of the spoon-shaped cardboard P2, or the leading end of one spoon-shaped cardboard P2 with the trailing end of another spoon-shaped cardboard. As a result, the pressure applied to the blade 4a is distributed in the width direction, reducing the cutting performance and suppressing the generation of splinters or whisker-like scraps on the cut surface.

[0067] (5) For the cardboard P1 used to make the paper spoon, laminated paper made by layering three layers of water-resistant paper is used. Therefore, greater rigidity can be obtained compared to when a single layer of cardboard is used. In particular, when using the paper spoon 1 to scrape off viscous foods, higher rigidity makes it easier to handle. Therefore, a user-friendly paper spoon 1 can be realized.

[0068] <Variation> In the manufacturing line of the paper tool manufacturing apparatus 2 shown in Figure 2, a dust collection unit may be provided downstream of the separation unit 5 to remove paper fragments and the like that scattered on the conveyor belt when the spoon-shaped cardboard P2 is separated from the cardboard P1 for making paper spoons. Alternatively, a cleaner unit may be provided downstream of the crushing unit 6 to remove burrs from the paper spoon 1 by, for example, brushing it, or to remove paper dust and the like adhering to the paper spoon 1 using an adhesive roll, thereby scraping off paper fragments and paper dust adhering to the paper spoon 1. Furthermore, a metal detection unit equipped with a metal detector may be provided downstream of the cleaner unit to detect metal fragments and the like adhering to, for example, the conveyor belt or the spoon-shaped cardboard P2.

[0069] <Second Embodiment> Next, a second embodiment of the present invention will be described. This second embodiment further manufactures paper toothpicks 11 using the cardboard P1 for producing paper spoons after punching out the spoon-shaped cardboard P2 in the first embodiment, that is, the remaining sheets stocked in the remaining sheet stacker 8.

[0070] <Shape of a paper toothpick> Figure 8 shows a schematic configuration of an example of a paper toothpick 11, where (a) is a plan view and (b) is a right side view. As shown in Figure 8, the paper toothpick 11 has a rod shape with one end tapered when viewed from above, with a length of approximately 9 cm, a maximum width of approximately 7 mm, and a thickness of approximately 2 mm. The paper toothpick 11 has a shape that is symmetrical with respect to a line segment passing through the center in the width direction. The non-tapered end is held between the index finger and thumb as a handle 11a, and the tapered end is used to pierce an object.

[0071] <Configuration of a paper tool manufacturing apparatus> Figure 9 shows an example of a paper tool manufacturing apparatus 2a according to the second embodiment of the present invention. As shown in Figure 9, the paper tool manufacturing apparatus 2a according to the second embodiment is identical to the paper tool manufacturing apparatus 2 according to the first embodiment shown in Figure 2, except that it is further provided with a toothpick cutting unit (cutter device) 9, a residual sheet stacker 10a, and a paper toothpick stacker 10b. That is, the paper tool manufacturing apparatus 2a according to the second embodiment comprises a spoon cutting unit 4 and a toothpick cutting unit 9. The toothpick cutting unit 9 is composed of a known cutting-type die roll cutter, similar to the spoon cutting unit 4, and cuts toothpick-shaped cardboard P4 from the residual sheet P3 (Figure 10), which is cardboard P1 for producing paper spoons after the spoon-shaped cardboard P2 has been punched out and is stocked in the residual sheet stacker 8. The residual sheet P3 with the toothpick-shaped cardboard P4 cut is conveyed to the separation unit 5. In other words, the separation unit 5 receives the cardboard P1 for making paper spoons after the spoon-shaped cardboard P2 has been cut in the spoon-cutting unit 4, and the remaining sheet P3 after the toothpick-shaped cardboard P4 has been cut in the toothpick-cutting unit 9.

[0072] In the separation unit 5, similar to the separation unit 5 in the paper tool manufacturing apparatus 2 of the first embodiment, spoon-shaped cardboard P2 is separated from the cardboard P1 for producing paper spoons, and the spoon-shaped cardboard P2 is conveyed to the crushing unit 6. The remaining sheet P3 after separating the spoon-shaped cardboard P2 from the cardboard P1 for producing paper spoons is stocked in the remaining sheet stacker 8. In addition, the separation unit 5 separates toothpick-shaped cardboard P4 from the remaining sheet P3, and the toothpick-shaped cardboard P4 is conveyed to the crushing unit 6. The remaining sheet after separating the toothpick-shaped cardboard P4 from the remaining sheet P3 is stocked in the remaining sheet stacker 10a.

[0073] In Figure 9, the toothpick-shaped cardboard P4 is transported to the crushing section 6 and compressed; however, the toothpick-shaped cardboard P4 does not necessarily have to be compressed. Compared to the spoon-shaped cardboard P2, the toothpick-shaped cardboard P4 is longer and thinner and has a rod shape. Therefore, during the push-cutting process, it is easier to press the remaining sheet P3 around the entire circumference of the blade 9a of the toothpick push-cutting section 9 (described later), and because the pressing force is relatively even, burrs are less likely to form. For this reason, considering the thickness of the remaining sheet P3 (i.e., the cardboard P1 for making paper spoons) and the pressing force of the blade 9a, if it is possible to generate sufficient pressing force on the blade 9a to make an incision in the remaining sheet P3, and it is predicted that the possibility of burrs forming is low, compression is not necessary.

[0074] Furthermore, while Figure 9 illustrates a case where the spoon-cutting section 4 and the toothpick-cutting section 9 are provided separately, the invention is not limited to this. For example, in a push-cut type die roll cutter, a roll for spoons and a roll for toothpicks may be prepared, and the main parts other than the rolls may be common to a single die roll cutter. The die roll cutter with the spoon roll attached may be used as the spoon-cutting section 4, and the die roll cutter with the toothpick roll attached may be used as the toothpick-cutting section 9. In this way, by switching between the spoon-cutting section 4 and the toothpick-cutting section 9 by changing the rolls in a single die roll cutter, the equipment can be used effectively, the installation area can be reduced, and costs can be lowered.

[0075] <Paper toothpick layout> Figure 10 shows the layout of the toothpick-shaped cardboard P4 on the remaining sheet P3. The remaining sheet P3 has three rows of spoon-shaped cardboard holes P2' formed in the width direction and at regular intervals in the transport direction, which are the parts where the spoon-shaped cardboard P2 has been punched out.

[0076] As shown in Figure 10, the toothpick-shaped cardboard pieces P4 are positioned at regular intervals in the transport direction between the rows of spoon-shaped cardboard holes P2', which are formed in two rows, i.e., three rows, in the width direction of the remaining sheet P3. Furthermore, each toothpick-shaped cardboard piece P4 is positioned such that the position of each of its longitudinal ends on the remaining sheet P3 is not the same as the position of each of its longitudinal ends on the remaining sheet P3. In addition, each toothpick-shaped cardboard piece P4 is positioned such that the position of each of its longitudinal ends on the remaining sheet P3 is not the same as the position of each of the spoon-shaped cardboard holes P2' on the remaining sheet P3. In other words, similar to the first embodiment, the positions of the leading and trailing ends of each toothpick-shaped cardboard P4 in the longitudinal direction of the remaining sheet P3 are arranged so that they do not coincide with the positions of the leading and trailing ends of other toothpick-shaped cardboard P4s, nor with the positions of the leading and trailing ends of the spoon-shaped cardboard holes P2'. This suppresses the generation of burrs or other rough edges on the cut surface of the toothpick-shaped cardboard P4 due to pressure distribution in the width direction during the cutting process by the toothpick-cutting section 9.

[0077] Furthermore, similar to the first embodiment, when punching out toothpick-shaped cardboard P4, if the narrower end of the toothpick-shaped cardboard P4 is positioned towards the front in the transport direction, it is less likely that the toothpick-shaped cardboard P4 will get caught on guides or other equipment during transport. For this reason, the toothpick-shaped cardboard P4 is positioned so that the tapered end is at the front in the transport direction.

[0078] <Blade portion of the toothpick cutting mechanism> The blade portion 9a of the toothpick cutting section 9 is formed on the circumferential surface of a cylindrical die roll cutter, and as shown in Figure 11, multiple blade portions are formed in the same pattern as the arrangement pattern of the toothpick-shaped cardboard P4 shown in Figure 10. In addition, each blade portion 9a is formed in a frame shape that is similar in shape to the outer shape of the toothpick-shaped cardboard P4 when viewed from above. In Figure 11, (a) is a side view showing the blade portion 9a of the toothpick cutting section 9, and (b) is an unfolded view of the circumferential surface of the roll on which the blade portion 9a of the toothpick cutting section 9 is provided.

[0079] As shown in Figure 12, the blade portion 9a is formed such that the end face obtained by cutting the blade portion 9a with a plane perpendicular to the direction in which the blade portions 9a are connected has a mountain-shaped form. The inner angle θ1in between the side of the frame-shaped blade portion 9a located closer to the inside of the frame and the line segment extending in the height direction of the mountain shape is smaller than the outer angle θ1out between the side of the frame-shaped blade portion 9a located closer to the outside of the frame and the line segment extending in the height direction of the mountain shape. The inner angle θ1in is set to a value within the range of, for example, 12 degrees or more and 18 degrees or less, and the outer angle θ1out is set to a value within the range of, for example, 17 degrees or more and 23 degrees or less. From the viewpoint of ensuring the strength of the blade portion 9a, it is preferable that the sum of the inner angle θ1in and the outer angle θ1out is greater than or equal to a certain angle (for example, 30 degrees or more). Figure 12 shows only the outer shape of the blade portion 9a at the end face obtained by cutting the blade portion 9a shown in Figure 11(b) with the CC' plane.

[0080] The inner angle θ1in and outer angle θ1out of the blade portion 9a are set according to the shape of the edge of the paper toothpick 11 and the characteristics of the paper toothpick 11, similar to the blade portion 4a. Here, we have described the case in which the blade portion 9a is formed so that it has the same shape as the blade portion 4a, but the shape of the blade portion 9a of the toothpick cutting portion 9 does not necessarily have to be the same as the shape of the blade portion 4a of the spoon cutting portion 4, and the shape of the blade portion 9a may be set according to the shape of the edge required for the paper toothpick 11.

[0081] <Effects> The paper toothpick 11 according to the second embodiment can achieve the same effects and advantages as the paper spoon 1 in the first embodiment. Furthermore, in the second embodiment, since the toothpick-shaped cardboard P4 is punched out from the remaining sheet P3 after the spoon-shaped cardboard P2 has been punched out, the cardboard P1 for producing paper spoons can be utilized efficiently.

[0082] In the second embodiment, the case in which a spoon-shaped cardboard P2 and a toothpick-shaped cardboard P4 are punched out from cardboard P1 for making paper spoons was described, but the invention is not limited to this, and other combinations of cardboard that will become different tools are also possible, such as a combination of spoon-shaped cardboard P2 and a stirrer-shaped cardboard that will become a stirrer, or combinations of cardboard that will become the same tool. Furthermore, the same cardboard P1 for making paper spoons may be subjected to a press-cutting process three or more times to cut out three types of cardboard that will become paper tools.

[0083] <Variation> When using the toothpick-cutting section 9 to cut the remaining sheet P3 after punching out the spoon-shaped cardboard P2, it is also possible to pre-curve the remaining sheet P3 before performing the cutting process. In other words, when punching out cardboard with a particularly long and narrow shape, such as toothpick-shaped cardboard P4, after punching out the spoon-shaped cardboard P2, there is a possibility that the punched-out toothpick-shaped cardboard P4 will be warped. Therefore, before punching out the toothpick-shaped cardboard P4, specifically before performing the cutting process on the remaining sheet P3, a warp is pre-applied to the remaining sheet P3, and then an incision is made to punch out the toothpick-shaped cardboard P4. Since the remaining sheet P3 is pre-curved, it is possible to suppress the occurrence of warping in the toothpick-shaped cardboard P4 after punching.

[0084] Specifically, a curvature-applying section (not shown) is provided upstream of the toothpick-cutting section 9 to impart curvature to the remaining sheet P3. The curvature-applying section is composed of a known roll device that performs curvature forcing, for example, three rollers. The direction of the curvature applied by the curvature-applying section is the opposite direction to the curvature that occurs when the toothpick-shaped cardboard P4 is punched out. Then, the remaining sheet P3 stocked in the remaining sheet stacker 8 is introduced into the curvature-applying section to impart curvature, and the curved remaining sheet P3 is then transported to the toothpick-cutting section 9, where the remaining sheet P3 is subjected to a cut-out process. When the cut-out process is performed in the toothpick-cutting section 9, a force that causes curvature is applied to the toothpick-shaped cardboard P4, i.e., the remaining sheet P3. However, since the remaining sheet P3 has already been given curvature, the remaining sheet P3 becomes approximately flat after being cut in the toothpick-cutting section 9, and the occurrence of curvature in the remaining sheet P3 is suppressed. The amount of curvature applied by the curvature-applying section should be adjusted according to the curvature that occurs in the toothpick-shaped cardboard P4. The amount of curvature that occurs in the toothpick-shaped cardboard P4 will vary depending on the relative sizes of the remaining portion of the remaining sheet P3 and the toothpick-shaped cardboard P4, as well as the specifications of the cardboard and the shapes of the blades 4a and 9a. Therefore, the amount of curvature applied in advance should be adjusted according to the actual curvature that occurs in the toothpick-shaped cardboard P4. [Examples]

[0085] The water absorption and strength of the following were evaluated: cardboard P1 for making paper spoons, spoon-shaped cardboard P2 obtained by punching out cardboard P1 with a spoon-cutting section 4, paper spoon 1 obtained by further compressing spoon-shaped cardboard P2 with a crushing section 6, and a wooden spoon. Specifically, the water absorption and strength of the base paper 1A for cardboard P1 for making paper spoons, the paper spoon 1B in the state after punching out cardboard P1 but before compression, the paper spoon 1C after punching out cardboard P1 and then compressing it, and the wooden spoon 1D.

[0086] Using a commercially available handheld cutter knife with a thin blade, a piece of cardboard identical in shape to the spoon-shaped cardboard P2 was cut from the base paper 1A, and this was used as a test piece of base paper 1A.

[0087] Furthermore, a wooden spoon of approximately the same thickness and shape as the spoon-shaped cardboard P2 was prepared and used as a test specimen for wooden spoon 1D.

[0088] Furthermore, a spoon-shaped piece of cardboard P2 was used as the test piece for paper spoon (before compression) 1B, and a paper spoon 1 was used as the test piece for paper spoon (after compression) 1C.

[0089] Eight test pieces (No. 1 to No. 8) were prepared for both the base paper 1A and the paper spoon (before compression) 1B, while five test pieces (No. 1 to No. 5) were prepared for both the paper spoon (after compression) 1C and the wooden spoon 1D.

[0090] <Water absorption evaluation> For each of the original paper (1A), paper spoon (before compression) (1B), paper spoon (after compression) (1C), and wooden spoon (1D), each test piece was immersed in tap water for 10 minutes, ensuring that the entire piece was submerged. Then, the weight of each test piece of base paper 1A was measured before and after water absorption, and the water absorption rate was calculated from the difference in weight before and after water absorption. At this time, after removing each test piece from the tap water, any moisture adhering to the surface was wiped off with tissue paper or the like. The average value of the weight before and after water absorption was calculated, and the water absorption rate (average water absorption rate) of cardboard A1 was calculated from the obtained average value.

[0091] Similarly, for each test piece—paper spoon (before compression) 1B, paper spoon (after compression) 1C, and wooden spoon 1D—the weight was measured before and after water absorption. The average of the weights before and after water absorption was calculated, and the water absorption rate was calculated from the obtained average value. The water absorption rates of paper spoon (before compression) 1B, paper spoon (after compression) 1C, and wooden spoon 1D were then calculated. In this case as well, after removing each test piece from the tap water, any moisture adhering to the surface was wiped off with a tissue or similar material. Table 1 shows the calculation results for the water absorption rate (average water absorption rate).

[0092] As shown in Table 1, the paper spoon (before compression) 1B, obtained by cutting with the blade 4a, which has a mountain-shaped edge, has a lower water absorption rate than the base paper 1A. Furthermore, the paper spoon (after compression) 1C, obtained by further compressing the paper spoon (before compression) 1B, has a lower water absorption rate than the paper spoon (before compression) 1B without compression. In addition, the base paper 1A, the paper spoon (before compression) 1B, and the paper spoon (after compression) 1C all have lower water absorption rates than a wooden spoon. [Table 1]

[0093] <Strength Evaluation> In the same manner as used for the water absorption evaluation, three test pieces (No. 1 to No. 3) of base paper 2A, three test pieces (No. 1 to No. 3) of paper spoon (before compression) 2B, five test pieces (No. 1 to No. 5) of paper spoon (after compression) 2C, and five test pieces (No. 1 to No. 5) of wooden spoon 2D were prepared for strength evaluation. Furthermore, of the test pieces used for water absorption evaluation, three test pieces (No. 1 to No. 3) of the base paper 1A after water absorption, three test pieces (No. 1 to No. 3) of the paper spoon (before compression) 1B after water absorption, five test pieces (No. 1 to No. 5) of the paper spoon (after compression) 1C after water absorption, and five test pieces (No. 1 to No. 5) of the wooden spoon 1D after water absorption were used as test pieces for strength evaluation.

[0094] The strength was then evaluated using test pieces of the base paper (after water absorption) 1A, paper spoon (before compression) (after water absorption) 1B, paper spoon (after compression) (after water absorption) 1C and wooden spoon (after water absorption) 1D, and the base paper 2A, paper spoon (before compression) 2B, paper spoon (after compression) 2C and wooden spoon 2D.

[0095] Specifically, buckling loads were measured using test specimens of base paper 1A, paper spoon (before compression) 1B, paper spoon (after compression) 1C, and wooden spoon 1D, and base paper 2A, paper spoon (before compression) 2B, paper spoon (after compression) 2C, and wooden spoon 2D. The buckling load was measured using, for example, the test apparatus 12 shown in Figure 13. That is, the test specimen S1 was placed between two rectangular parallelepiped bases 12a placed at a distance from each other. A 1 kg roll 12c was placed between a support plate 12b, which was supported to be movable in the vertical direction relative to the test specimen S1, and the longitudinal center of the test specimen S1, with its curved surface in contact with the test specimen S1. The roll 12c was then sandwiched between the support plate 12b and the test specimen S1, and the buckling load was measured by increasing the load on the test specimen S1 by placing a weight on the support plate 12b.

[0096] Buckling load was measured for each test specimen. From the measured buckling loads of each test specimen (base paper 2A, 1A, paper spoon (before compression) 2B, 1B, paper spoon (after compression) 2C, 1C, and wooden spoon 2D, 1D), the average value of the buckling load before water absorption and the average value of the buckling load after water absorption were calculated for each type of test specimen. The strength reduction rate before and after water absorption was calculated from the calculated average values. The results of the calculation of the strength reduction rate before and after water absorption are shown in Table 2.

[0097] As shown in Table 2, in the state before water absorption, the buckling load of the paper spoon (after compression) 2C was greater than that of the base paper 2A and the paper spoon (before compression) 2B. It was confirmed that the strength of the paper spoon (before compression) 2B was improved by cutting while compressing it with the blade portion 4a, which has a mountain-shaped end face, and that the strength of the paper spoon (after compression) 2C was further improved by compression. Furthermore, it was confirmed that the paper spoons (before compression) 2B and 1B had a larger buckling load, meaning they were stronger, and had a smaller rate of strength reduction than the base papers 2A and 1A, both before and after water absorption. In addition, although the rate of strength reduction was greater for the paper spoons (after compression) 2C and 1C than for the paper spoons (before compression) 2B and 1B, the buckling load itself was greater for paper spoons (after compression) 2C and 1C than for paper spoons (before compression) 2B and 1B in both cases, confirming that a high level of strength was maintained even after water absorption. [Table 2]

[0098] <Rating> Tables 1 and 2 show that the spoon-shaped cardboard P2 obtained by cutting cardboard P1 for making paper spoons while crushing it with a blade 4a having a mountain-shaped end face is superior in terms of water absorption and strength. Furthermore, it was confirmed that the paper spoon 1 obtained by compressing the spoon-shaped cardboard P2 is even superior in terms of water absorption and strength. [Explanation of Symbols]

[0099] 1 paper spoon 2, 2a Paper tool manufacturing equipment 3 Embossed area 4. Spoon-cutting section 4a Blade part 4b Elastic member 5 Separation part 6. Crushing section 7 Paper spoon stacker 8. Remaining Sheet Stacker 9. Toothpick cutting section 9a Blade part 10a Remaining Sheet Stacker 10b Paper toothpick stacker 11. Paper toothpicks 12 Test equipment P1 Cardboard for making paper spoons P2 Spoon-shaped cardboard P3 Remaining Sheet P4 Toothpick-shaped cardboard

Claims

1. A paper tool manufacturing apparatus for manufacturing paper cutlery as paper tools, A cutter device for punching out tool-shaped cardboard from cardboard, The device comprises a compression device for compressing the tool-shaped cardboard punched out by the cutter device, The compressed tool-shaped cardboard is used as the paper tool. The cutter device is a push-cutting type die roll cutter, The blade portion of the cutter device is arranged in a frame shape similar to the tool-shaped cardboard in a plan view. The end face obtained by cutting the blade portion with a plane perpendicular to the direction in which the blade portions are connected is mountain-shaped. The inner angle formed by the side of the two sides forming the mountain shape that is located closer to the inside of the frame and the line segment extending in the height direction of the mountain shape is smaller than the outer angle formed by the side of the two sides that is located closer to the outside of the frame and the line segment extending in the height direction of the mountain shape. The aforementioned inner angle is 12 degrees or more and 18 degrees or less, and the aforementioned outer angle is 17 degrees or more and 23 degrees or less. The blade portion is frame-shaped with two sides parallel to the rotation axis of the die roll cutter, and multiple blade portions are arranged on the circumferential surface of the die roll cutter such that the two parallel sides become the front and rear ends in the rotation direction of the die roll cutter. The multiple blade portions are all the same shape, are arranged in multiple rows along the rotation direction of the die roll cutter, and the number of blade portions included in each of the multiple rows is the same. The spacing between adjacent blade portions in the rotational direction is the same for all blade portions. A paper tool manufacturing apparatus characterized in that all of the blades are offset in the rotational direction between the tip and rear end of one blade and the tips and rear ends of all other blades.

2. The paper tool manufacturing apparatus according to claim 1, characterized in that the inner angle is 15 degrees and the outer angle is 20 degrees.

3. A sheet-like elastic member is provided in the region inside the frame of the blade portion arranged in the frame shape, The paper tool manufacturing apparatus according to claim 1 or 2, characterized in that the elastic member is arranged with a gap between it and the blade portion in a plan view.

4. The paper tool manufacturing apparatus according to any one of claims 1 to 3, characterized in that the cardboard is a rigid paper with a three-layer structure formed by laminating three sheets of water-resistant paper.

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