Evaluation method

Abstract

To provide a corrugated cardboard that makes it possible to simply and easily evaluate whether it has been coated with a proper amount of antibacterial-antiviral agent, and a method for processing the same.SOLUTION: A corrugated cardboard has a liner with its outermost layer provided with a layer containing an antibacterial-antiviral agent, the layer having a surface gloss of 3.0-15.0.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to corrugated board and a method for processing antibacterial and antiviral corrugated board. [Background technology]

[0002] Conventionally, cardboard whose surface is coated with an antibacterial agent has been known to inhibit bacterial and viral contamination.

[0003] For example, Patent Document 1 discloses a cardboard box whose surface is coated with an antibacterial agent containing an antibacterial metal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 08-151037 Summary of the Invention [Problem to be solved by the invention]

[0005] However, antibacterial and antiviral agents are very expensive, and the invention described in Patent Document 1 does not fully consider both cost and antibacterial properties. Furthermore, for quality control purposes, it is necessary to evaluate whether the appropriate amount of agent has been applied to the cardboard, but Patent Document 1 does not mention this either. Therefore, with a configuration such as the invention described in Patent Document 1, the antibacterial properties of the cardboard may not be fully guaranteed, and costs may be higher than necessary.

[0006] Therefore, an object of the present invention is to provide cardboard and a processing method thereof that can easily evaluate whether an appropriate amount of antibacterial and antiviral agent has been applied. [Means for solving the problem]

[0007] The corrugated board according to the present invention is a corrugated board having a liner in which a layer containing an antibacterial and / or antiviral agent is formed as the outermost layer, and is characterized in that the layer containing the antibacterial and / or antiviral agent has a surface gloss of 3.0 to 15.0.

[0008] The antibacterial and antiviral cardboard processing method according to the present invention is characterized in that a layer containing an antibacterial and antiviral agent is formed as the outermost layer on the liner of the cardboard using a printing device in a box-making machine so that the surface gloss is 3.0 to 15.0.

[0009] In this specification and claims, "antibacterial agent (antibacterial drug)" refers to a substance that inhibits the growth of bacteria, "antiviral agent (antiviral drug)" refers to a substance that inactivates viruses, and "antibacterial / antiviral agent" refers to a substance that has antibacterial and / or antiviral functions. Furthermore, "layer containing antibacterial / antiviral agent" and "antibacterial / antiviral layer" refer to a layer formed by directly applying the "antibacterial / antiviral agent" to the surface of an object, as well as a layer composed of a printed ink layer on the object and an antibacterial / antiviral layer formed by covering the printed ink layer. In this invention, "antibacterial / antiviral agent" refers to both an active ingredient alone that has antibacterial and / or antiviral functions, and also to paints and inks with antibacterial and / or antiviral functions that contain the active ingredient in a vehicle (such as an alkali-soluble resin, emulsion resin, alkaline component, water, etc.) and various auxiliary agents (such as a dispersant, crosslinking agent, or defoaming agent). [Effects of the Invention]

[0010] According to the present invention, by forming a layer containing the antibacterial and antiviral agent on the liner so that the surface gloss, which is linked to the coating amount of the antibacterial and antiviral agent, falls within the above range, the appropriate coating amount of the antibacterial and antiviral agent is applied to the liner, making it possible to optimize the costs involved in antibacterial and antiviral treatment of corrugated board. Furthermore, simply measuring the surface gloss during the box-making process makes it possible to check whether the appropriate amount of antibacterial and antiviral agent has been applied, facilitating quality control of antibacterial and antiviral treated corrugated board. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view showing a cardboard box making device according to an embodiment of the present invention. [Figure 2] 2 is an explanatory diagram illustrating the process of forming a folding box from the cardboard of FIG. 1. FIG. [Figure 3] 1 is a schematic cross-sectional view of a printing process for cardboard according to one embodiment of the present invention. [Figure 4] FIG. 1 is a perspective view showing a printing process on a cardboard according to an embodiment of the present invention. [Figure 5] 1 is a schematic cross-sectional view of a cut sheet of corrugated cardboard according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to Figures 1 to 5. However, the present invention is not limited to this embodiment.

[0013] <Overall structure and operation of this box making device> FIG. 1 is a schematic cross-sectional view showing a cardboard box-making apparatus 100 according to one embodiment of the present invention. The box-making apparatus 100 of this embodiment includes a printing device 10 that performs flexographic printing on cut sheets S of cardboard; a blank-forming device 20 that includes a rotary creaser that creates vertical creases for folding the printed cut sheets S and a rotary slotter that performs vertical cuts, such as groove cutting, to form blank sheets in the unfolded shape of a cardboard case from the cut sheets S; and a processing device 30 that performs processes such as hand holes and H-cuts using a punching die. The box-making apparatus 100 also includes a folding device 40 that forms sleeves S' from blank sheets supplied from the processing device 30, and a stacking device 50 that stacks the sleeves S' transported from the folding device 40. The stacking device 50 is located downstream of the folding device 40, and multiple conveyors that transport the sleeves S' are located between the folding device 40 and the stacking device 50.

[0014] A cut sheet S of corrugated cardboard consists of a fluted corrugating medium and two front and back liners sandwiching the medium. The cut sheet S of corrugated cardboard is pre-lined with creases for horizontal folding, as shown in FIG. 2. Hereinafter, the liner to be flexographically printed is the front liner, and for convenience of explanation, it will be referred to simply as the "liner." However, the present invention does not exclude the possibility of flexographically printing on the back liner. After the printing process by the printing device 10, the cut sheet S is transported to the processing device 30, where processing is performed, such as adding creases for vertical folding, adding a glue tab for forming a corrugated cardboard case, and adding hand holes and H-cuts. After processing, the cut sheet S is transported to the folding device 40. The folding device 40 folds the cut sheet S to create a sleeve S'. The sleeve S' is then transported to the stacking device 50, where a predetermined number of sleeves S' are stacked. A predetermined number of stacked sleeves S' are distributed to the market.

[0015] The liners used on the outer surface of cut cardboard sheets S have a multi-layer structure of about 3 to 5 layers, and are classified as "white liners" or "brown liners" depending on the color of the raw material used in the outermost layer on the surface side. "Brown liners" are strong and made from unbleached raw materials. "White liners" are made from bleached pulp (or coated with white pigment). "White liners" can be used when aesthetics are important.

[0016] <Printing device structure> Fig. 3 is a schematic cross-sectional view of a printing process on a corrugated board according to one embodiment of the present invention. Fig. 4 is a perspective view showing a printing process on a corrugated board according to this embodiment. Fig. 5 is a schematic cross-sectional view of a cut sheet of corrugated board according to one embodiment of the present invention.

[0017] The printing apparatus 10 of this embodiment is equipped with three printing devices 10a, 10b, and 10c for using three types of ink (see FIG. 1). Specifically, the printing devices 10a and 10b print characters, figures, and the like (designs) on the liner of the cut sheet S using quick-drying, water-resistant printing ink. Hereinafter, the printing ink used for printing designs will be abbreviated to "printing ink." Meanwhile, the printing device 10c applies (or prints) an antibacterial agent onto the liner printed by the printing devices 10a and 10b. In other words, the printing layer formed on the liner is composed of a printing ink layer Ia, a printing ink layer Ib, and an antibacterial / antiviral layer Ic, in which the surfaces of the printing ink layer Ia and the cut sheet S are coated with an antibacterial / antiviral agent, as shown in FIG. 5. This allows the antibacterial and antiviral agent to be printed on the cut sheet S while printing characters, graphics, etc.; that is, in a single printing process, it is possible to display characters, graphics, etc. on the cut sheet S while inhibiting bacterial growth and inactivating viruses. Alternatively, the printing ink layer may be multi-layered, and the antibacterial and antiviral agent may be applied on top of the multi-layered ink layer. In this embodiment, printing was performed using three printing devices, but the present invention is not limited to this number as long as the effects of the present invention are achieved.

[0018] The antibacterial agent used in the present invention is preferably an inorganic antibacterial agent, and examples thereof include those in which silver or silver ions used in this embodiment are supported on an inorganic substance, and those containing copper, copper ions, zinc, zinc ions, or the like as an active ingredient.

[0019] Furthermore, examples of the antiviral agent used in the present invention include linear alkylbenzenesulfonate sodium, alkylglycoside, alkylamine oxide, benzalkonium chloride, benzethonium chloride, dialkyldimethylammonium chloride, and polyoxyethylene alkyl ether.

[0020] Flexographic inks used on corrugated board consist of colorants, vehicles (used to fix the ink to the surface), additives, etc. The vehicles consist of resins and solvents. Water-resistant printing inks mainly use emulsion-based resins or contain polymerization accelerators, which increases their resistance to water after fixing. Quick-drying printing inks are made with solvents with high vapor pressures or low-viscosity resins to increase their concentration, which reduces the drying load.

[0021] A feature of the corrugated board of this embodiment, which will be described in detail later, is that the layer containing the antibacterial and antiviral agent formed as the outermost layer on the liner has a surface gloss of 3.0 to 15.0. The inventors discovered that there is a correlation between the surface gloss value and the coating amount of the antibacterial and antiviral agent applied to the liner. Therefore, by forming a layer containing the antibacterial and antiviral agent on the liner so that the surface gloss, linked to the coating amount of the agent, falls within the above range, it is possible to apply an appropriate coating amount of the antibacterial and antiviral agent to the liner. Furthermore, by measuring the surface gloss during the box-making process, it is possible to inspect whether the appropriate amount of the antibacterial and antiviral agent has been applied, thereby facilitating quality control of antibacterial and antiviral treated corrugated board.

[0022] Another feature of the cardboard of this embodiment is that the average application amount of printing ink in the printed areas of the printing ink layers Ia and Ib is less than the average application amount of the antibacterial agent in the antibacterial / antiviral layer Ic that coats the printing ink layers Ia and Ib with the antibacterial agent.

[0023] The reason for applying less printing ink than the amount of antibacterial and antiviral agent is that in order for the antibacterial and antiviral properties to be exerted, the active ingredients of the antibacterial and antiviral agents need to be exposed on the surface; however, if the amount of printing ink applied in the layer below is too great, the active ingredients in the antibacterial and antiviral layer will penetrate into the printing ink layer.

[0024] The upper limit for the ratio of antibacterial / antiviral agent to printing ink application amount is 3.0. The reason for this is that applying more than a certain amount of antibacterial / antiviral agent not only limits the effectiveness and is cost-effective, but also takes a long time for the antibacterial / antiviral layer to dry, causing the active ingredients to sink in and actually reducing the antibacterial / antiviral effect. A more preferable application amount ratio range is 1.0 to 1.6.

[0025] Antibacterial and antiviral agents are more expensive than the printing inks used to print characters, graphics, and the like. Therefore, by using quick-drying, water-resistant printing inks, printing devices 10a and 10b can prevent the antibacterial agent applied by subsequent printing device 10c from penetrating the quick-drying, water-resistant printing ink. In the present invention, the antibacterial agent may be replaced with an antibacterial and antiviral agent, and the average application amount of the printing ink in the printed areas of printed ink layers Ia and Ib may be less than the average application amount of the antibacterial and antiviral agent in antibacterial and antiviral layer Ic, which coats printed ink layers Ia and Ib with the antibacterial and antiviral agent.

[0026] The printing apparatus 10 includes an ink reservoir 11 that contains ink I as printing ink, an ink supply port 11a that supplies ink I from the ink reservoir 11 through a passage 11b, an anilox roll 12 with minute recesses formed therein for obtaining a desired printing pattern, etc., a doctor roll 13 that adjusts the amount of ink I supplied from the ink supply port 11a to an appropriate amount, a plate cylinder 14 having a printing plate 14a, a receiving roll 15 that, together with the plate cylinder 14, conveys a cut sheet S, and a pair of conveying rolls 16 that convey the cut sheet S to a subsequent process. Covers 18 are arranged around the anilox roll 12 and the doctor roll 13 to prevent ink from scattering. The printing device 10 adjusts the amount of ink I supplied from the ink supply port 11a that adheres to the anilox roll 12 by bringing the doctor roll 13 into contact with the anilox roll 12. Then, the ink I transferred from the anilox roll 12 to the printing plate 14a is transferred between the plate cylinder 14 and the backing roll 15 onto the liner of the cut sheet S, which is fed from upstream to downstream in the conveyance direction T, for printing. The printing speed for corrugated board is typically 150 to 350 sheets per minute. The printed cut sheet S is transported downstream by a pair of transport rolls 16, which are located downstream of the plate cylinder 14 and the backing roll 15.

[0027] The anilox roll 12 is a cylindrical roll body coated with ceramic or chrome plating and rotatably supported in parallel with the doctor roll 13. The anilox roll 12 is connected to a drive motor (not shown) and can rotate during printing. The outer circumferential surface of the anilox roll 12 has uniformly arranged microscopic cells as recesses for accommodating ink I. The anilox roll 12 and the doctor roll 13 receive a supply of ink I, adjust the amount of ink I, and transfer the ink I to the plate cylinder 14 by rotating the anilox roll 12 in the direction of arrow A. An ink receiver Ir is provided at one end of the anilox roll 12 and the doctor roll 13, and excess ink I is collected in the ink receiver Ir. The ink receiver Ir and the ink reservoir 11 are connected via a passage 11c, and ink I accumulated in the ink receiver Ir is returned to the ink reservoir 11 via the passage 11c. In this way, the anilox roll 12, together with the doctor roll 13, can transfer an appropriate amount of ink I to the plate cylinder 14.

[0028] The doctor roll 13 is a roll body made of laminated cylindrical rubber members, and is rotatably supported. The outer peripheral surface of the cylindrical rubber member is formed to be a smooth surface. The doctor roll 13 is connected to a drive motor (not shown) and can rotate during printing. The outer diameter of the doctor roll 13 is formed to be approximately the same as the outer diameter of the anilox roll 12.

[0029] The plate cylinder 14 is a cylindrical body with a printing plate 14a fixed to its periphery and is disposed below and parallel to the anilox roll 12. The plate cylinder 14 is rotatably supported with the anilox roll 12 and the printing plate 14a in contact with each other. The plate cylinder 14 is connected to a drive motor (not shown) and can rotate in the direction of arrow B. As the plate cylinder 14 rotates, ink I is transferred from the anilox roll 12 to the printing plate 14a on the plate cylinder 14. The outer diameter of the plate cylinder 14 is larger than that of the anilox roll 12. The plate cylinder 14 is configured to be paired with a backing roll 15. As a cut sheet S is transported between the plate cylinder 14 and the backing roll 15 in the transport direction T, the ink I is transferred to the liner of the cut sheet S as a print. The printed cut sheet S is then transported to a subsequent process by a pair of transport rolls 16.

[0030] The printing process of printing devices 10a and 10b of printing device 10 is as described above, and the printing process of printing device 10c is the same as the printing process of printing devices 10a and 10b, except that ink I is replaced with an antibacterial agent, and is as described above.

[0031] In this embodiment, printing is performed on the liner of the cut sheet S using a flexographic printing apparatus having the configuration described above, but the present invention is not limited to this, and printing may be performed on the liner of the cut sheet S using a flexographic printing apparatus having a configuration other than that described above. Furthermore, other printing methods (gravure printing, inkjet printing, offset printing, etc.) are also acceptable as long as they achieve the effects of the present invention.

[0032] <Surface gloss of cardboard liner> In the present invention, the surface gloss of the outermost surface of a layer containing an antibacterial and antiviral agent formed as the outermost layer on a corrugated cardboard liner (for example, a layer composed of a printed ink layer formed on the corrugated cardboard liner with a printing ink and an antibacterial and antiviral layer in which the printed ink layer is coated with an antibacterial and antiviral agent, such as in the above-described embodiment and the evaluation targets in Tables 1 and 2 below) is preferably 3.0 to 15.0. For an incident angle of 85°, the surface gloss is more preferably 4.5 to 7.0 when the corrugated cardboard liner is a brown liner, and even more preferably 7.0 to 10.0 when the corrugated cardboard liner is a white liner. Furthermore, for an incident angle of 60°, the surface gloss is more preferably 3.0 to 5.0 when the corrugated cardboard liner is a brown liner, and even more preferably 4.5 to 6.0 when the corrugated cardboard liner is a white liner. As described above, the present inventors have discovered that there is a correlation between surface gloss and the coating amount of the antibacterial and antiviral agent. Therefore, in the inspection after the application of antibacterial and antiviral agents, by measuring the surface gloss of the outermost surface of the cardboard and determining whether the measurement result falls within the above numerical range, it is possible to determine the amount of coating required for the cardboard without chemically analyzing the amount of coating on the cardboard case, making quality control easier.

[0033] Table 1 shows the surface gloss of the corrugated cardboard liner measured at an incidence angle of 85° (based on JIS Z 8741) after antibacterial treatment, the coating weight of the antibacterial / antiviral agent corresponding to the surface gloss measurement, the coating weight evaluation for antibacterial performance, the antibacterial activity value against Escherichia coli and Staphylococcus aureus (based on JIS Z 2801), and the antibacterial performance evaluation, for both brown and white cardboard liners. Table 2 also shows the surface gloss of the corrugated cardboard liner measured at an incidence angle of 60° after antibacterial treatment, evaluated in the same way. Regarding antibacterial performance, an antibacterial activity value of 2.0 or higher indicates antibacterial effectiveness and is marked "Good." An antibacterial activity value of less than 2.0 indicates ineffectiveness and is marked "Poor." The gloss values listed in Tables 1 and 2 below were measured using a Nippon Denshoku PG-2M handheld gloss meter. The antibacterial and antiviral agent used was a paint with antibacterial and antiviral properties, made by adding silver ions supported on an inorganic substance as a substance with antibacterial and antiviral properties to a vehicle (alkali-soluble resin, emulsion resin, alkaline component, water, etc.) and various auxiliary agents (dispersants, crosslinking agents, antifoaming agents, etc.). The viscosity of the antibacterial and antiviral agent was adjusted to a #4 Zahn cup viscosity of 10 to 13 seconds.

[0034] [Table 1]

[0035] [Table 2]

[0036] As shown in Table 1, when the surface gloss is 4.5 to 7.0 at an incident angle of 85°, if the liner of the corrugated board is brown, the coating weight is 6.2 to 9.2 g / m 2 This shows that the coating amount is appropriate for antibacterial performance. Also, as shown in Table 1, when the surface gloss is 6.0 to 10.0 at an incident angle of 85°, if the cardboard liner is white, the coating amount is 3.5 to 6.4 g / m2 This shows that the coating amount is appropriate for antibacterial performance.

[0037] As shown in Table 2, when the surface gloss is 3.0 to 5.0 at an incident angle of 60°, if the cardboard liner is brown, the coating weight is 5.9 to 9.5 g / m 2 This shows that the coating amount is appropriate for antibacterial performance. Also, as shown in Table 2, when the surface gloss is 4.0 to 6.0 at an incident angle of 60°, if the cardboard liner is white, the coating amount is 3.7 to 6.7 g / m 2 This shows that the coating amount is appropriate for antibacterial performance.

[0038] In addition, the coating amount in Tables 1 and 2 being "high" simply means that it is high compared to the appropriate amount in the vicinity, and does not mean that it is too high and therefore costly.

[0039] In this way, by measuring surface gloss, it is possible to determine the amount of antibacterial and antiviral agent applied, making it easy to determine whether that amount is appropriate for antibacterial performance.

[0040] Traditionally, antibacterial and antiviral agents are expensive, so it has been necessary to ensure the amount of coating necessary to achieve antibacterial and antiviral effects, while at the same time avoiding excessive amounts. To meet this requirement, at corrugated board production sites, the amount of coating required for ink paints and other materials has been calculated by dividing the amount of paint used by the amount of production. However, when an accurate amount of coating is required, such as with antibacterial and antiviral agents, it must be determined by chemical analysis, which takes time to obtain results, making this method unsuitable for quality control at production sites. Therefore, corrugated board production sites needed a management method to replace chemical analysis.

[0041] According to the present invention, by measuring surface gloss as an alternative indicator of coating amount, it is possible to ensure the coating amount necessary to exhibit antibacterial and antiviral properties and avoid excessive coating amount, thereby facilitating quality control at cardboard production sites.

[0042] <Hand hole in cardboard> In a cardboard case assembled from the cardboard of the present invention, a hand hole may be formed in a surface portion, and an antibacterial area may be provided in the hand hole, to which an antibacterial or antiviral agent has been applied (or printed). In one embodiment of the present invention, for example, hand holes are formed in a pair of side portions of the cardboard case, and the antibacterial area is formed in an area a distance L from the outer periphery of the handle flaps that constitute the hand hole, which are formed into a rounded rectangular shape by score lines. Distance L may be within a range of 20 to 100 mm. Distance L is preferably at least 150 mm. In one embodiment of the present invention, the antibacterial area is formed in a rectangular area at least distance L from the outer periphery of the handle flaps. Distance L is set to 150 mm, but is not limited to this, and may be any distance that covers the hand hole.

[0043] The hand hole has a rounded rectangular shape, but is not limited to this and may be an oval or ellipse, or may be an isosceles triangle with a base slit formed along the base to allow opening. The hand hole may also be shaped as finger holes for three fingers, or a handle hole may be formed by cutting a score and pressing a tongue inward, or by cutting four score lines and pressing the tongue inward.

[0044] In this way, in this embodiment, an antibacterial area is formed on the surface of the cardboard case, and even if a worker's hands are contaminated with bacteria, infection can be prevented by holding the hand holes in the cardboard case. In addition, by limiting the range of the antibacterial area where the antibacterial and antiviral agents are printed, it is possible to provide an inexpensive antibacterial and antiviral cardboard case.

[0045] In order to express the contents of the present invention, the preferred embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and includes modifications and improvements that are obvious to those skilled in the art based on the matters described in this specification. [Explanation of symbols]

[0046] 10a Printing device 10b Printing device 10c printing device Ia Printing ink layer Ib Printing ink layer Ic Antibacterial and antiviral layer

Claims

1. An evaluation method for evaluating whether an appropriate amount of antibacterial / antiviral agent has been applied to the outermost layer of a cardboard liner to which the antibacterial / antiviral agent has been applied, based on surface glossiness, comprising: The antibacterial and antiviral agent is an inorganic substance carrying silver ions, The surface glossiness evaluated as being an appropriate amount of coating is 4.5 to 7.0 when the liner is a brown liner and 7.0 to 10.0 when the liner is a white liner, at an incident angle of 85°; The evaluation method is characterized in that the surface gloss is measured in accordance with JIS Z 8741.

2. An evaluation method for evaluating whether an appropriate amount of antibacterial / antiviral agent has been applied to the outermost layer of a cardboard liner to which the antibacterial / antiviral agent has been applied, based on surface glossiness, comprising: The antibacterial and antiviral agent is an inorganic substance carrying silver ions, The surface glossiness evaluated as being an appropriate amount of coating is 3.0 to 5.0 when the liner is a brown liner and 4.5 to 6.0 when the liner is a white liner, at an incident angle of 60°; The evaluation method is characterized in that the surface gloss is measured in accordance with JIS Z 8741.

3. the layer containing the antibacterial and antiviral agent is composed of a printed ink layer formed with printing ink and an antibacterial and antiviral layer formed by coating the printed ink layer with the antibacterial and antiviral agent, 3. The evaluation method according to claim 1, wherein an average coating amount of the printing ink layer in a printed portion is less than an average coating amount of the antibacterial and antiviral layer.

4. A single printing process has multiple printing devices, (a) printing the liner of the corrugated board with printing ink by the printing device; (b) a step of printing the antibacterial and antiviral agent on the liner of the cardboard using the printing device; and step (b) is performed after step (a), 3. The evaluation method according to claim 1, wherein a layer containing the antibacterial and antiviral agent is formed on the liner by steps (a) and (b).

5. 5. The evaluation method according to claim 4, wherein the average application amount of the printing ink in the step (a) is less than the average application amount of the antibacterial and antiviral agent in the step (b).

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