How the veil is made

Abstract

To provide a method for producing a bale, which reduces the number of bacteria attached to waste paper contained in the bale and also excels in the disintegration property of the waste paper contained in the bale. The method includes a washing step of washing waste paper having at least a resin layer and a paper base layer with acidic washing water, and a molding step of compressing and molding the waste paper to obtain a bale, and the waste paper has a basis weight of 100 g / m 2 or more, and the median area of ​​the waste paper is 20 cm 2 More than 150cm 2 The following is a method for manufacturing a veil.

Description

[Technical field]

[0001] The present invention relates to a method for producing a veil. [Background technology]

[0002] In recent years, efforts to reduce the use of plastic have been accelerating worldwide due to growing interest in waste reduction and environmental issues. As a result, in order to reduce the amount of plastic used in various products, efforts are being made to change raw materials that were previously made only from plastic to laminated paper, which is a paper base material laminated with a resin layer, etc. This laminated recycled paper is particularly used for food packaging materials such as food containers. Conventionally, laminated paper was considered taboo and was not recycled, but due to growing interest in reducing waste and environmental issues, there is now a demand to reuse laminated paper as recycled paper. Generally, waste paper is temporarily stored in bales for recycling.

[0003] Patent Document 1 discloses an apparatus for forming a bale from compressible waste materials such as waste paper and discarded cartons, the apparatus comprising a press housing having a substantially rectangular parallelepiped shape and including at least one compression chamber and a press plate that can be reciprocated in the press direction within the compression chamber by a drive means. Furthermore, Patent Document 2 discloses a bale press for compressing paper, cardboard, etc., which has a load chamber that receives material to be compressed and baled by a piston mechanism that reciprocates within the chamber, and a choke chamber that is formed at the outlet of the load chamber, holds the compressed material by frictional force, and presses new material against the held material by the piston mechanism. Patent Document 3 discloses a crushing and washing device for recycling both used paper containers and unused paper containers that are full of contents, which is characterized by being composed of a receiving hopper (14) for receiving used paper containers (16) and unused paper containers that are full of contents in the initial process of recycling paper containers, an input conveyor (15) for carrying these paper containers to a crusher (1), the crusher (1) for crushing these paper containers into scraps (2), a screw conveyor (3) that is sealed in a housing and installed at an angle for transporting the scraps (2) while cleaning them, and a scrap receiver (10) for receiving the scraps (7) after cleaning. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2010-521312 [Patent Document 2] International Publication No. 1998 / 33643 [Patent Document 3] JP 2001-314825 A Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, waste paper is formed into a bale by a bale forming device as disclosed in Patent Documents 1 and 2, and then it is recycled. However, waste paper used as food packaging material in particular may become difficult to recycle because bacteria increase due to food and other contaminants remaining on the waste paper, which may cause the waste paper to decay. In addition, a method of washing the waste paper with tap water is disclosed in an apparatus for crushing and washing the waste paper as disclosed in Patent Document 3, but these washing methods may not be able to fully remove food and other contaminants remaining on the waste paper. In addition, depending on the state of the formed bale, the disaggregation of the waste paper contained in the bale may be insufficient, which may reduce the recyclability. An object of the present invention is to provide a method for producing a bale in which the number of bacteria adhering to the waste paper contained in the bale is reduced and the disintegration properties of the waste paper contained in the bale are also excellent. [Means for solving the problem]

[0006] The present inventors have discovered that in a bale manufacturing method having a washing step for washing waste paper and a molding step for compressing and molding the waste paper to obtain a bale, the above-mentioned problems can be solved by using an acidic washing solution as the washing water in the washing step. The present invention relates to the following [1] to

[11] . [1] A method for producing a bale from waste paper having at least a resin layer and a paper base layer, comprising: a washing step of washing the waste paper having at least a resin layer and a paper base layer with acidic washing water; and a molding step of compressing and molding the waste paper to obtain a bale, wherein the basis weight of the waste paper is 100 g / m 2 or more, and the median area of ​​the waste paper is 20 cm 2 More than 150cm 2 The following is a method for manufacturing a veil. [2] The method for producing a veil according to [1], wherein the pH of the washing water in the washing step is 2.5 or more and 6.5 or less. [3] The method for producing a veil according to [1] or [2], wherein the washing water in the washing step is hypochlorous acid water. [4] 1 cm of wastepaper stored in a bale for 3 days 2 The number of bacteria adhering to the surface per unit area is 10 CFU / cm 2 The method for producing a veil according to any one of [1] to [3], wherein the veil is less than [5] The median density of the waste paper is 0.70 g / cm 3 The method for producing a veil according to any one of [1] to [4] above. [6] The method for manufacturing a bale according to any one of [1] to [5], wherein the water absorbency of the waste paper is 25% or more and 85% or less. [7] The method for manufacturing a bale according to any one of [1] to [6], wherein the content of sizing agent in the paper base layer of the recycled paper is 0.2% by mass or more and 2.1% by mass or less. [8] The method for producing a bale according to any one of [1] to [7], wherein the waste paper further has a metal layer. [9] The forming pressure during the forming process is 500 kN / m 2 More than 2500kN / m 2 The method for producing a veil according to any one of [1] to [8] below.

[10] The density of the bale is 0.3 t / m 3 More than 1.0t / m 3 The method for producing a veil according to any one of [1] to [9] below.

[11] The method for producing a bale according to any one of [1] to

[10] , further comprising a crushing step of crushing waste paper prior to the molding step. Effect of the Invention

[0007] According to the present invention, a method for producing a bale is provided which reduces the number of bacteria adhering to the waste paper contained in the bale and further improves the disintegration properties of the waste paper contained in the bale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [How the veil is manufactured] The method for producing a bale in this embodiment includes, in this order, a washing step of washing waste paper having at least a resin layer and a paper base layer with acidic washing water, and a molding step of compressing and molding the waste paper to obtain a bale, and the basis weight of the waste paper is 100 g / m 2 or more, and the median area of ​​the waste paper is 20 cm 2 More than 150cm 2 The following is the result. According to the bale manufacturing method of the present embodiment, the number of bacteria attached to the waste paper contained in the bale is reduced, and furthermore, the disintegration property of the waste paper contained in the bale is excellent. Although the reason for this is not clear, it is thought to be as follows. Generally, it has at least a resin layer and a paper base layer, and has a basis weight of 100 g / m 2The laminated paper described above is often used as food packaging material. Therefore, when used as waste paper, bacteria grow due to food residue and other contaminants on the waste paper, causing it to decay and making it impossible to recycle. In addition, when the laminated paper is subjected to a disintegration process for recycling, the resin layer and the like prevent water from penetrating into the paper base layer, so that disintegration tends to decrease. In contrast, the bale manufacturing method of this embodiment includes a washing step in which the waste paper is washed with acidic washing water, which removes bacteria that cause spoilage, and is therefore thought to suppress the growth of bacteria in the waste paper during bale storage. Furthermore, the median area of ​​waste paper is 20 cm 2 This creates a suitable amount of space between the wastepaper in the bale, allowing air to pass through the bale and drying the wastepaper appropriately, which is thought to inhibit the growth of bacteria that cause spoilage. 2 If the temperature is below this range, it is believed that water will sufficiently penetrate into the waste paper when the paper is subjected to a defibration step for recycling, thereby improving the defibration properties.

[0009] The basis weight of the waste paper is set at 100 g / m2 in order to improve the disintegration property of the waste paper contained in the bale. 2 or more, preferably 120 g / m 2 More than 600g / m 2 Less than 140g / m 2 More than 500g / m 2 More preferably, 160 g / m 2 More than 400g / m 2 More preferably, 180 g / m 2 More than 300g / m 2 The following is the result. The basis weight of the waste paper is measured by the method described in the Examples.

[0010] The median area of ​​waste paper is set at 20 cm2 from the viewpoint of reducing the number of bacteria attached to the waste paper contained in the bale and improving the disintegration property of the waste paper contained in the bale. 2 More than 150cm 2 Less than or equal to 50 cm, preferably 2More than 120cm 2 Less than or equal to 70cm, preferably 2 More than 100cm 2 The following is the result. The median area of ​​the waste paper is measured by the method described in the Examples.

[0011] (Waste paper) In this embodiment, the waste paper has at least a resin layer and a paper base layer. [Resin Layer] The resin constituting the resin layer in waste paper is not particularly limited, but examples thereof include polyolefins such as high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and polypropylene (PP), polyesters such as polyethylene terephthalate (PET), polyamides such as ethylene-vinyl alcohol copolymer (EVOH), nylon, ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), styrene-acrylic copolymer, and ethylene-α-olefin copolymer. In addition, when waste paper has multiple resin layers, the resins constituting each resin layer may be the same or different. Among these, from the viewpoint of recyclability, the resin constituting the resin layer is preferably one or more selected from polyolefin, ethylene-vinyl alcohol copolymer (EVOH), and ethylene-methyl methacrylate copolymer (EMMA), more preferably one or more selected from low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and ethylene-methyl methacrylate copolymer (EMMA), and even more preferably one or more selected from low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE).

[0012] The basis weight of the resin layer in the waste paper is preferably 5 g / m from the viewpoint of improving the disintegration property of the waste paper contained in the bale. 2 More than 120g / m 2 Less than 10 g / m 2 More than 100g / m2 More preferably, 15 g / m or less 2 More than 80g / m 2 More preferably, 20 g / m or less 2 More than 60g / m 2 In addition, when the waste paper has a plurality of resin layers, the basis weight of the resin layers in the waste paper indicates the total basis weight of the respective resin layers.

[0013] From the viewpoint of improving the disintegrability of the waste paper contained in the bale, the thickness of the resin layer in the waste paper is preferably 5 μm to 130 μm, more preferably 10 μm to 110 μm, even more preferably 15 μm to 90 μm, and even more preferably 20 μm to 70 μm. When the waste paper has multiple resin layers, the thickness of the resin layer in the waste paper refers to the total thickness of the respective resin layers.

[0014] [Paper base layer] The paper base layer is not particularly limited as long as it is a paper that is generally used with plant-derived wood pulp as the main component. The wood pulp is not particularly limited, but examples thereof include chemical pulps such as hardwood kraft pulp (LKP), softwood kraft pulp (NKP), sulfite pulp (SP), dissolving pulp (DP), soda pulp (AP), bleached kraft pulp (BKP), unbleached kraft pulp (UKP), and oxygen bleached kraft pulp (OKP), semi-chemical pulps such as semi-chemical pulp (SCP) and chemi-groundwood pulp (CGP), and mechanical pulps such as groundwood pulp (GP), thermomechanical pulp (TMP), and chemi-thermomechanical pulp (CTMP). Among these, from the viewpoint of recyclability, the paper base layer preferably contains one or more selected from hardwood kraft pulp and softwood kraft pulp, more preferably one or more selected from hardwood unbleached kraft pulp (LUKP), hardwood bleached kraft pulp (LBKP), softwood unbleached kraft pulp (NUKP) and softwood bleached kraft pulp (NBKP), and even more preferably one or more selected from hardwood bleached kraft pulp (LBKP) and softwood bleached kraft pulp (NBKP).

[0015] The paper base layer may also have a pigment coating layer. The pigment coating layer may be one layer or two or more layers. The pigment coating layer preferably contains a pigment and a binder. Examples of the pigment include, but are not limited to, heavy calcium carbonate, kaolin, plastic pigment, etc. Examples of the binder include, but are not limited to, starch, styrene-acrylic copolymer latex, styrene-butadiene copolymer latex, olefin-carboxylic acid emulsion copolymer latex, etc.

[0016] The basis weight of the paper base layer in the waste paper is preferably 80 g / m from the viewpoint of improving the disintegration property of the waste paper contained in the bale. 2 More than 400g / m 2 Less than 100 g / m 2 More than 350g / m 2 More preferably, 120 g / m 2 More than 300g / m 2 or less, even more preferably 150 g / m 2 More than 250g / m 2 The following is the result. In addition, when the waste paper has a plurality of paper base layers, the basis weight of the paper base layers in the waste paper indicates the total basis weight of the respective paper base layers.

[0017] From the viewpoint of improving the disintegrability of the waste paper contained in the bale, the thickness of the paper base layer in the waste paper is preferably 100 μm or more and 600 μm or less, more preferably 120 μm or more and 550 μm or less, even more preferably 150 μm or more and 500 μm or less, and even more preferably 200 μm or more and 450 μm or less. In addition, when the waste paper has a plurality of paper base layers, the thickness of the paper base layer in the waste paper refers to the total thickness of each of the paper base layers.

[0018] In this embodiment, the content of sizing agent in the paper base layer in the waste paper is preferably 0.2% by mass or more and 2.1% by mass or less, more preferably 0.4% by mass or more and 1.8% by mass or less, even more preferably 0.6% by mass or more and 1.6% by mass or less, and even more preferably 0.8% by mass or more and 1.4% by mass or less. When the content of sizing agent in the paper base layer of wastepaper is 0.2% by mass or more, the moisture remaining in the wastepaper contained in the bale is reduced when the wastepaper is washed before bale formation, etc., thereby further reducing the number of bacteria attached to the wastepaper contained in the bale. Also, when the content of sizing agent in the paper base layer of wastepaper is 2.1% by mass or less, sufficient water is likely to penetrate into the wastepaper in the maceration process when the bale is recycled, thereby further improving the maceration property of the wastepaper contained in the bale. The content of the sizing agent in the paper base layer of the waste paper is measured by the method described in the Examples.

[0019] In this embodiment, examples of the sizing agent in the paper base layer of the waste paper include rosin sizing agents, synthetic sizing agents, and petroleum resin-based sizing agents.

[0020] In this embodiment, the total content of dry strength agent and wet strength agent in the paper base layer of the waste paper is, from the viewpoint of reducing the number of bacteria attached to the waste paper contained in the bale and improving the disintegrability of the waste paper contained in the bale, preferably 0.05% by mass or more and 2.00% by mass or less, more preferably 0.10% by mass or more and 1.50% by mass or less, and even more preferably 0.12% by mass or more and 1.20% by mass or less.

[0021] In this embodiment, the content of the dry paper strength agent in the paper base layer in the waste paper is preferably 0.50% by mass or more and 2.00% by mass or less, more preferably 0.65% by mass or more and 1.60% by mass or less, and even more preferably 0.80% by mass or more and 1.20% by mass or less, from the viewpoints of reducing the number of bacteria attached to the waste paper contained in the bale and improving the disintegrability of the waste paper contained in the bale. Furthermore, in this embodiment, the content of the wet strength agent in the paper base layer of the waste paper is preferably 0.05% by mass or more and 0.25% by mass or less, more preferably 0.07% by mass or more and 0.20% by mass or less, and even more preferably 0.10% by mass or more and 0.15% by mass or less, from the viewpoints of reducing the number of bacteria attached to the waste paper contained in the bale and improving the disintegrability of the waste paper contained in the bale. The content of the paper strength agent in the paper base layer of the recycled paper is measured by the method described in the Examples.

[0022] In this embodiment, the paper strength enhancer in the paper base layer of the waste paper includes a dry strength enhancer and a wet strength enhancer. Examples of the dry strength enhancer include polyacrylamide, cationic starch, and carboxymethyl cellulose. Examples of the wet strength enhancer include polyamide polyamine epichlorohydrin, polyamide epichlorohydrin, urea formaldehyde resin, and melamine formaldehyde resin.

[0023] In this embodiment, the waste paper may have other layers in addition to the resin layer and the paper base layer, such as a metal layer, a printed layer, and an adhesive layer.

[0024] [Metal layer] In this embodiment, the waste paper may further have a metal layer. In this embodiment, the metal layer of the waste paper preferably contains aluminum. In addition, in this embodiment, the metal layer of the waste paper is more preferably aluminum foil.

[0025] When the waste paper contains a metal layer, the basis weight of the metal layer in the waste paper is preferably 8 g / m2 from the viewpoint of suppressing the disintegration of the metal layer during the disintegration process of the waste paper and improving the disintegration property of the waste paper contained in the bale. 2 More than 30g / m 2 Less than 10 g / m 2 More than 27g / m 2 More preferably, 12 g / m or less 2 More than 24g / m 2More preferably, 14 g / m 2 More than 22g / m 2 The following is the result. In addition, when waste paper has a plurality of metal layers, the basis weight of the metal layers in the waste paper indicates the basis weight of each metal layer.

[0026] When the waste paper contains a metal layer, the thickness of the metal layer in the waste paper is preferably 1 μm or more and 50 μm or less, more preferably 3 μm or more and 40 μm or less, even more preferably 5 μm or more and 30 μm or less, and even more preferably 6 μm or more and 20 μm or less. In addition, when waste paper has multiple metal layers, the thickness of the metal layers in the waste paper refers to the thickness of each metal layer. If the thickness of the metal layer is 1 μm or more, the metal layer is prevented from becoming finer during the defibration process of the waste paper when the bale is recycled, making the defibration process more efficient. Also, if the thickness of the metal layer is 50 μm or less, the penetration of moisture into the waste paper contained in the bale is less likely to be hindered, making the defibration process more efficient.

[0027] [Printing layer] In this embodiment, the waste paper may further have a printed layer. An example of the printed layer is a printed layer provided on a paper substrate layer. The printed layer may be formed using a known ink such as an oil-based ink, a water-based ink, or a biomass ink. The printed content may be a pattern, a design, or information (ingredients, expiration date, QR code (registered trademark), etc.). The printed layer may be formed on one surface or on a part of the layer on which the printed layer is applied.

[0028] [Adhesive layer] In this embodiment, the waste paper may further have an adhesive layer. The adhesive layer is formed mainly for adhering the metal layer and the paper base layer when the waste paper has a metal layer, and / or for adhering the metal layer and the resin layer. Examples of resins that constitute the adhesive layer include ethylene-methacrylic acid copolymer resin (EMAA), ethylene-acrylic acid copolymer resin (EAA), ethylene-vinyl acetate copolymer resin (EVA), ethylene-ethyl acrylate copolymer resin (EEA), ethylene-butyl acrylate copolymer resin (EBA), and the like.

[0029] In this embodiment, the median density of waste paper is preferably 0.70 g / cm 3 More preferably, it is 0.73 g / cm 3 More than 1.00g / cm 3 More preferably, 0.76 g / cm 3 More than 0.90g / cm 3 The following is the result. The median density of recycled paper is 0.70 g / cm 3 If the median density of the wastepaper is within the above upper limit range, sufficient water can easily penetrate into the wastepaper contained in the bale in the disintegration step when the bale is recycled, thereby improving the disintegration property of the wastepaper contained in the bale. The density of the waste paper can be adjusted by the press line pressure during dehydration when making the paper base layer of the waste paper.

[0030] In this embodiment, the 24-hour water absorbency of waste paper is preferably 25% or more and 85% or less, more preferably 30% or more and 80% or less, even more preferably 40% or more and 75% or less, and even more preferably 50% or more and 65% or less. When the 24-hour water absorbency of wastepaper is 25% or more, sufficient water can easily penetrate into the wastepaper contained in the bale during the disintegration process when the bale is recycled, improving the disintegration of the wastepaper contained in the bale. Also, when the 24-hour water absorbency of wastepaper is 85% or less, the amount of moisture remaining in the wastepaper contained in the bale is reduced when the wastepaper is washed before bale formation, and the number of bacteria attached to the wastepaper contained in the bale is further reduced. The 24-hour water absorbency of wastepaper is adjusted, for example, by the content of a sizing agent in the paper base layer of the wastepaper. The 24-hour water absorbency of wastepaper is determined from the rate of increase in the mass of the wastepaper when the wastepaper is immersed in water for 24 hours, and is specifically determined by the method described in the Examples.

[0031] Examples of the waste paper include waste paper from food and beverage containers, paper bags, and paper cutlery. Examples of food and beverage containers include liquid containers and food containers, and more specifically, paper trays, aseptic containers, paper cups, milk cartons, etc. Among these, the waste paper is preferably at least one selected from aseptic container waste paper and paper cup waste paper. The aseptic container waste paper has, for example, the following configurations (a1) to (a2). In the following configurations, the layer on the right side indicates the layer that was in contact with the contents when used as an aseptic container. In the following configurations, the "(printed layer)" and "(adhesive layer)" are optional layers, and may or may not be present as necessary. In the following configurations, the paper base layer may have the above-mentioned pigment coating layer, and a printed layer may be provided on the pigment coating layer. In the following configurations, the "resin layer" may be one layer or two or more layers. (a1): Resin layer / (printing layer) / paper base layer / resin layer / metal layer / (adhesive layer) / resin layer (a2): Resin layer / (printing layer) / paper base layer / resin layer / resin layer (barrier layer) / (adhesive layer) / resin layer

[0032] The recycled paper for paper cups preferably has the following structures (b1) to (b5), for example. In the structures below, the layer on the right side indicates the layer that was in contact with the contents when used as a paper cup. In the structures below, the "printed layer" and "adhesive layer" are optional layers, and may or may not be present as necessary. In the structures below, the paper base layer may have the above-mentioned pigment coating layer, and a printed layer may be provided on the pigment coating layer. In the structures below, the "resin layer" may be one layer, or two or more layers. (b1): (Printing layer) / Paper base layer / Resin layer / (Adhesive layer) / Metal layer / (Adhesive layer) / Resin layer (b2): (Printing layer) / Paper base layer / Resin layer / (Adhesive layer) / Resin layer (b3): ​​Resin layer / (Printing layer) / Paper base layer / Resin layer (b4): (printing layer) / resin layer / paper base layer / resin layer (b5): (printing layer) / paper base layer / resin layer

[0033] (Cleaning process) In this embodiment, the washing step is a step of washing the waste paper with an acidic washing solution. By washing the waste paper with the acidic washing solution, bacteria that cause spoilage are removed, and the proliferation of bacteria attached to the waste paper during storage in a bale is suppressed.

[0034] In the washing step, the pH of the washing water is preferably 2.5 or more and 6.5 or less, more preferably 3.0 or more and 6.0 or less, and further preferably 3.5 or more and 5.5 or less. If the pH of the washing water is 6.5 or less, bacteria that cause spoilage are removed, and the proliferation of bacteria adhering to the waste paper during storage in a bale is inhibited, and the number of bacteria adhering to the waste paper contained in the bale is further reduced. In addition, if the pH of the washing water is 2.5 or more, corrosion of processing equipment such as a washing device is further inhibited, which is preferable.

[0035] In addition, in the washing step, the washing water is more preferably hypochlorous acid water from the viewpoint of reducing the number of bacteria attached to the waste paper contained in the bale. When the cleaning water is hypochlorous acid water, the effective chlorine concentration in the cleaning solution is preferably 0.0001% (1 ppm) or more and 1% or less, more preferably 0.0005% (5 ppm) or more and 0.5% or less, even more preferably 0.001% (10 ppm) or more and 0.1% or less, and even more preferably 0.002% (20 ppm) or more and 0.05% (500 ppm) or less, from the viewpoint of reducing the number of bacteria attached to the waste paper contained in the bale and from the viewpoint of the integrity of processing equipment such as the cleaning equipment.

[0036] The washing step may be carried out before the crushing step described below, may be carried out after the crushing step described below, or may be carried out simultaneously with the crushing step described below. Among these, from the viewpoint of washing efficiency, it is preferable to carry out the washing step after the crushing step and before the molding step, or to carry out the crushing step and the washing step simultaneously, and it is more preferable to carry out the crushing step and the washing step simultaneously. As the apparatus used in the washing step, a known apparatus can be appropriately used. When the crushing step and the washing step are carried out simultaneously, it is preferable to appropriately use a crushing / washing machine or the like.

[0037] (Crushing process) In this embodiment, it is preferable to have a crushing step of crushing the waste paper before the molding step. By having the crushing step, the waste paper to be subjected to the molding step is aligned to an appropriate size, so that, for example, when a bale is subjected to recycling, the disintegration process becomes more efficient and the disintegration property of the waste paper contained in the bale is improved. As the crusher used in the crushing step, it is preferable to use a single-shaft crusher, a double-shaft crusher, etc., depending on the size of the waste paper after crushing. In addition, when the crushing step is performed and a washing step described below is performed at the same time, it is preferable to use a crushing and washing machine, etc.

[0038] (molding process) The bale manufacturing method of the present embodiment includes a molding step of compressing and molding waste paper having at least a resin layer and a paper base layer to obtain a bale. As a bale forming device in the molding step, a known bale forming device may be appropriately used.

[0039] In the forming step, the bale forming pressure is preferably 500 kN / m 2 More than 2500kN / m 2 Less than or equal to 750 kN / m 2 More than 2250kN / m 2 Less than 1000 kN / m, more preferably 1000 kN / m 2 More than 2000kN / m 2 The following is the result. By keeping the bale forming pressure within the above range, the density of the bale falls within the desired bale density range described below, thereby further reducing the number of bacteria adhering to the waste paper contained in the bale and further improving the disintegrability of the waste paper contained in the bale.

[0040] [Veil] In this embodiment, the bale can be obtained by the above-mentioned bale manufacturing method. Therefore, the bale in this embodiment has a reduced number of bacteria attached to the waste paper contained in the bale, and further has excellent disintegration properties of the waste paper contained in the bale.

[0041] In this embodiment, the waste paper contained in the bale has a thickness of 1 cm after storage for 3 days. 2 The number of bacteria adhering to the surface per unit area should preferably be 10 CFU / cm 2 Less than 8 CFU / cm, more preferably 2 less than 5 CFU / cm 2 less than 1 CFU / cm, even more preferably 2 The lower limit is not particularly limited, but is preferably less than 0.01 CFU / cm 2 More specifically, after storing the bale under conditions of a temperature of 30° C. and a humidity of 70 RH% for 3 days, the waste paper taken from the bale is 2 The number of bacteria adhering to the surface per unit area should preferably be 10 CFU / cm 2 less than 5 CFU / cm 2 less than 5 CFU / cm 2 less than 1 CFU / cm, even more preferably 2 The lower limit is not particularly limited, but is preferably less than 0.01 CFU / cm 2 It may be more than that. 1 cm of waste paper in a bale after storage for 3 days 2 When the number of bacteria adhering to the surface of the bales is within the above range, spoilage of the bales due to bacteria and the accompanying generation of unpleasant odors can be suppressed, thereby further improving recyclability. 1 cm of waste paper in a bale after storage for 3 days 2The number of bacteria adhering to the surface of the container can be measured by the method described in the Examples.

[0042] In this embodiment, the density of the bale is preferably 0.3 t / m 3 More than 1.0t / m 3 Less than or equal to 0.4t / m 3 More than 0.8t / m 3 Less than 0.5t / m, more preferably 0.5t / m 3 More than 0.7t / m 3 The following is the result. Bale density is 0.3t / m 3 If the density of the bale is 1.0 t / m or more, the waste paper inside the bale will be in close contact with each other, making the bale less likely to crumble and improving the handling of the bale. 3 At or below this, the waste paper is not compressed more than necessary inside the bale, creating appropriate gaps between the waste paper inside the bale, allowing moisture inside the bale to escape easily, suppressing the spoilage of the bale due to bacterial growth and the accompanying generation of foul odors, thereby improving recyclability. In addition, when the bale is recycled, it becomes easier to loosen, and the disintegration of the waste paper contained in the bale is improved.

[0043] In this embodiment, the bale is made from the above-mentioned waste paper. The composition and other physical properties of the waste paper do not change before and after bale formation. In other words, in this embodiment, the form of the waste paper contained in the bale is the same as that of the waste paper exemplified in the above-mentioned bale manufacturing method. The bale in this embodiment may contain waste paper other than the waste paper as long as the effects of the present invention are not impaired. The bale in this embodiment may also contain foreign matter other than the waste paper as long as the effects of the present invention are not impaired. Examples of foreign matter include straws, caps for food and beverage containers, and lids for food and beverage containers. In this embodiment, the content of the waste paper in the bale is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 100% by mass.

[0044] (Application) Since the bale in this embodiment has the above characteristics, it can be preferably used for recycling waste paper and can be suitably used as a raw material for waste paper pulp. Waste paper pulp made from the bale in this embodiment is preferably used as a raw material for various papers. The type of paper to be made is not particularly limited, and examples include printing paper, packaging paper, sanitary paper, and cardboard. It is also possible to process the made paper to manufacture packaging containers (for example, tissue boxes, paper cup sleeves, etc.). In addition, the bale in this embodiment can recover resin components derived from the resin layer and metal components derived from the metal layer contained in the waste paper, and these can be recycled. EXAMPLES

[0045] The features of the present invention will be described in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, processing contents, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the specific examples shown below. In the examples and comparative examples, "parts" and "%" refer to "parts by mass" and "% by mass", respectively, unless otherwise specified. In addition, the operations of the examples and comparative examples were carried out under conditions of 23±1°C and 50±2% RH, unless otherwise specified.

[0046] [How the veil is manufactured] <Example 1> (Waste paper) The waste paper used was aseptic packaging waste paper that had been collected after using the paper of composition 1 in Table 1 as paper containers for beverages. The contents of the paper containers when used as paper containers for beverages included milk, soy milk, and fruit juices. The paper base layer of the waste paper of the composition 1 of Example 1 was obtained from a paper stock (pulp slurry) to which 1.0 part by mass of a rosin sizing agent (Sizepine N-881, manufactured by Arakawa Chemical Industries Co., Ltd.) was added as a sizing agent, 1.0 part by mass of a polyacrylamide-based paper strength agent (PS117, manufactured by Arakawa Chemical Industries Co., Ltd.) as a dry paper strength agent, and 1.0 part by mass of aluminum sulfate were added to 100 parts by mass of raw pulp (pulp blend (mass ratio): softwood bleached kraft pulp (NBKP) / hardwood bleached kraft pulp (LBKP) = 40 / 60, redisintegrated freeness (CSF): 550 mL). The press line pressure during dehydration when making the paper base layer was 800 kN / m. (Crushing process / Washing process) The waste paper was placed into a crushing and washing machine (A-tech Corporation, paper container recycling device PPRS), crushed using a blade with six hooks, and washed with washing water (aqueous hypochlorous acid solution, effective chlorine concentration: 50 ppm, pH: 5.4, new water usage: 24 L / min). (Bale forming process) Approximately 60 kg of waste paper was fed into a bale compressor (Yuken Kogyo Co., Ltd., YB-32M-PA-10, bale size: 640 x 430 x 350 mm) and the bale was formed under a pressure of 1800 kN / m 2 The mixture was compressed at a bale forming pressure of 1000 g to obtain a bale.

[0047] <Example 2> The number of blade hooks in the crushing process was set to 3, and the bale forming pressure in the bale forming process was set to 1900 kN / m 2 A veil was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0048] <Example 3> The number of blade hooks in the crushing process was set to 9, and the bale forming pressure in the bale forming process was set to 1700 kN / m 2 A veil was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0049] <Example 4> A veil was obtained in the same manner as in Example 1, except that the washing water in the washing step was changed to an aqueous hypochlorous acid solution (available chlorine concentration: 0.5%, pH: 3.5).

[0050] <Example 5> A bale was obtained in the same manner as in Example 1, except that the waste paper used was the waste paper of Configuration 1 obtained by setting the press line pressure during dewatering when making the paper base layer at 750 kN / m.

[0051] <Example 6> A bale was obtained in the same manner as in Example 1, except that the waste paper used was the waste paper of Configuration 1 obtained by setting the press line pressure during dewatering when making the paper base layer at 850 kN / m.

[0052] <Example 7> A veil was obtained in the same manner as in Example 1, except that the waste paper used was of configuration 1, in which the amount of sizing agent added to the paper material (pulp slurry) when producing the paper base layer was 0.5 parts by mass per 100 parts by mass of raw pulp.

[0053] <Example 8> A veil was obtained in the same manner as in Example 1, except that the waste paper used was of configuration 1, in which the amount of sizing agent added to the paper material (pulp slurry) when producing the paper base layer was 0.8 parts by mass per 100 parts by mass of raw pulp.

[0054] <Example 9> A veil was obtained in the same manner as in Example 1, except that the waste paper used was of configuration 1, in which the amount of sizing agent added to the paper material (pulp slurry) when producing the paper base layer was 1.2 parts by mass per 100 parts by mass of raw pulp.

[0055] <Example 10> A veil was obtained in the same manner as in Example 1, except that the waste paper used was of configuration 1, in which the amount of sizing agent added to the paper material (pulp slurry) when producing the paper base layer was 1.5 parts by mass per 100 parts by mass of raw pulp.

[0056] <Example 11> The bale forming pressure during the bale forming process is 1400kN / m 2A veil was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0057] <Example 12> The bale forming pressure during the bale forming process is 2200 kN / m 2 A veil was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0058] <Example 13> Bales were obtained in the same manner as in Example 1, except that the waste paper used was waste paper (used paper cups) that had been collected after using the paper of configuration 2 in Table 1 as paper containers for beverages. The contents when used as paper containers for beverages included iced coffee, soft drinks, ice cream, etc. The paper base layer of the waste paper of the composition 2 of Example 13 was obtained from a paper material (pulp slurry) to which 1.0 part by mass of rosin sizing agent (Size Pine N-881, manufactured by Arakawa Chemical Industries Co., Ltd.) was added as a sizing agent, 1.0 part by mass of polyacrylamide-based paper strength agent (PS117, manufactured by Arakawa Chemical Industries Co., Ltd.) as a dry paper strength agent, 0.15 part by mass of polyamide epichlorohydrin (WS4024, wet paper strength agent, manufactured by Seiko PMC Co., Ltd.) as a wet paper strength agent, and 1.0 part by mass of aluminum sulfate were added to 100 parts by mass of raw pulp (pulp blend (mass ratio): softwood bleached kraft pulp (NBKP) / hardwood bleached kraft pulp (LBKP) = 40 / 60, redisintegrated freeness (CSF): 440 mL). In addition, the press line pressure during dehydration when making the paper base layer was 700 kN / m.

[0059] <Example 14> Bales were obtained in the same manner as in Example 1, except that the waste paper used was waste paper (used paper cups) that had been collected after using the paper of configuration 3 in Table 1 as paper containers for beverages. The contents when used as paper containers for beverages included hot coffee, cocoa, green tea, corn soup, etc. The paper base layer of the waste paper of the composition 3 of Example 14 was obtained from a paper material (pulp slurry) to which 1.0 part by mass of rosin sizing agent (Size Pine N-881, manufactured by Arakawa Chemical Industries Co., Ltd.) was added as a sizing agent, 1.0 part by mass of polyacrylamide-based paper strength agent (PS117, manufactured by Arakawa Chemical Industries Co., Ltd.) as a dry paper strength agent, 0.15 part by mass of polyamide epichlorohydrin (WS4024, wet paper strength agent, manufactured by Seiko PMC Co., Ltd.) as a wet paper strength agent, and 1.0 part by mass of aluminum sulfate were added to 100 parts by mass of raw pulp (pulp blend (mass ratio): softwood bleached kraft pulp (NBKP) / hardwood bleached kraft pulp (LBKP) = 40 / 60, redisintegrated freeness (CSF): 440 mL). In addition, the press line pressure during dehydration when making the paper base layer was 700 kN / m.

[0060] <Comparative Example 1> The washing process was not carried out (the crushing process was carried out), and the bale forming pressure in the bale forming process was 1900 kN / m 2 A veil was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0061] <Comparative Example 2> A veil was obtained in the same manner as in Example 1, except that the washing water in the washing step was changed to water (without addition of hypochlorous acid, pH: 7.0).

[0062] <Comparative Example 3> A bale was obtained in the same manner as in Example 1, except that the washing water in the washing step was changed to an aqueous sodium hydroxide solution (concentration: 5 ppm by mass, pH: 9.0).

[0063] <Comparative Example 4> The crushing process was not carried out (the washing process was carried out), and the bale forming pressure in the bale forming process was 1900 kN / m 2 A veil was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0064] <Comparative Example 5> The number of blade hooks in the crushing process was set to 12, and the bale forming pressure in the bale forming process was set to 1700 kN / m 2 A veil was obtained in the same manner as in Example 1, except that the above-mentioned was used.

[0065] The composition of the waste paper used in the examples and comparative examples is shown in Table 1.

[0066] [Table 1]

[0067] [Evaluation and measurement methods] <Median area of ​​recycled paper> Approximately 100 g of waste paper randomly taken from the bales of the Examples and Comparative Examples was sieved (φ: 20 mm) to remove small amounts of waste paper, and the remaining waste paper was scanned using EPSON Scan to obtain an image. The scanned image was analyzed using ImageJ, and the area of ​​each piece of waste paper was obtained to calculate the median area. The median area refers to the value that is in the middle when the area values ​​of the obtained waste paper pieces are arranged in ascending order.

[0068] <Median density of recycled paper> Wastepaper randomly collected from the bales of the Examples and Comparative Examples was dried completely and then conditioned for 96 hours in a humidity-conditioned environment as specified in JIS P 8111: 1998. Approximately 100 g of the conditioned wastepaper was passed through a sieve (φ: 20 mm) to remove minute wastepaper particles, and the density of the remaining wastepaper was measured in accordance with JIS P 8118: 2014 to calculate the median density of the wastepaper. The median density value refers to the value that is in the middle when the density values ​​of the obtained waste paper are arranged in ascending order.

[0069] <Water absorption over 24 hours> Waste paper randomly taken from the bales of the examples and comparative examples was dried completely, and then conditioned for 96 hours in a humidity-conditioned environment as specified in JIS P 8111:1998. After conditioned, about 10 g of the waste paper was immersed in 1 L of water (water temperature: 23±1°C) for 24 hours, and the waste paper was collected. Each of the collected waste paper sheets was placed on absorbent paper (manufactured by ADVANTEC, No. 26, 190 mm x 190 mm) and sandwiched between them, and then a metal roller (width 18 cm, diameter 10 cm, 10 kg) was rolled back and forth without applying pressure to remove excess moisture, and this was used as waste paper after immersion in water. The mass of the waste paper before and after immersion in water was measured (measured to the nearest 1 mg), and the water absorbency was calculated using the following formula, which was used as the water absorbency of the waste paper for 24 hours. [Water absorption rate (%)] = ([Mass of wastepaper after immersion in water (g)] - [Mass of wastepaper before immersion in water (g)]) / [Mass of wastepaper before immersion in water (g)] × 100

[0070] <Content of dry strength agent in sizing agent and content of wet strength agent> Randomly collected waste paper from the bales of the examples and comparative examples was dried. After drying, layers other than the paper base layer, such as the resin layer, were removed by grinding using a grinding device (manufactured by Sagawa Corporation, grinding wheel dimensions φ50.8×12.7 mm) while checking the layer boundaries under a microscope, and the paper base layer was recovered. The contents of sizing agent, dry strength agent and wet strength agent in the recovered paper base layer were each quantified using pyrolysis gas chromatography (GCMS) under the following measurement conditions. (Measurement conditions for sizing agent content) ·Pyrolysis furnace temperature: 450℃ Temperature conditions during measurement: 100 to 325°C, heated at 15°C / min. Column used: HP-5MS (Agilent Technologies) Calibration curve: A calibration curve was created using a rosin sizing agent of known concentration (Sizepine N-881, manufactured by Arakawa Chemical Industries, Ltd.) as a standard. (Conditions for measuring dry strength agent content) ·Pyrolysis furnace temperature: 500℃ Temperature conditions during measurement: 40 to 270°C, heated at 10°C / min. Column used: HP-INNOWax (Agilent Technologies) Calibration curve: A calibration curve was created using polyacrylamide (PS117, dry paper strength agent, manufactured by Arakawa Chemical Industries, Ltd.) of known concentration as a standard. (Conditions for measuring wet strength agent content) ·Pyrolysis furnace temperature: 500℃ Temperature conditions during measurement: 40 to 270°C, heated at 10°C / min. Column used: HP-INNOWax (Agilent Technologies) Calibration curve: A calibration curve was created using polyamide epichlorohydrin (WS4024, wet strength agent, manufactured by Seiko PMC Corporation) of known concentration as a standard.

[0071] <Bale density> The bale density was calculated from the weight of waste paper input during the bale forming process and the volume of the resulting bale.

[0072] <1cm of waste paper after 3 days of storage 2 Number of bacteria attached to each surface> The bales of the examples and comparative examples were wrapped with five PP bands (manufactured by Moriya Sangyo Co., Ltd., model number: 12 J-S1) at equal intervals on the sides only using a cordless handy packaging machine (manufactured by Strapak Co., Ltd., STB73, tightening strength 900N), and stored for three days under conditions of a temperature of 30°C and a humidity of 70% RH. After the storage, 3 cm squares (9 cm 2 Waste paper large enough to make a square sample was collected. Using a wipe test kit (Sato Kasei Kogyo Co., Ltd., Wipe Check TE-302), both sides of the waste paper were wiped over a 3 cm square area to collect a sample. 1 mL of the obtained sample was applied to a general viable bacteria drop test medium (JNC Corporation, MC-Media Pad), and after culturing for 48 hours in an incubator at 35°C, the number of colonies formed was counted. The number of colonies counted was multiplied by the size (area) of the waste paper when the specimen was taken (9 cm 2 ) and divide by 1 cm2 Colony count per surface (CFU / cm 2 The number of colonies (CFU / cm) was calculated from 10 pieces of waste paper. 2 ) was calculated based on the average value of 1 cm 2 of bacteria per surface (CFU / cm 2 ) and evaluated according to the following evaluation criteria. (Evaluation Criteria) A: The number of bacteria is 1 CFU / cm 2 less than B: The number of bacteria is 1 CFU / cm 2 More than 5 CFU / cm 2 less than C: The number of bacteria is 5 CFU / cm 2 More than 10CFU / cm 2 less than D: The number of bacteria is 10 CFU / cm 2 End

[0073] <Disintegrability> From the bales of the Examples and Comparative Examples, 60 g of waste paper was collected in bone dry weight and disintegrated for 15 minutes using a disintegrator (Kumagaya Riki Kogyo Co., Ltd., No. 2532) to obtain a pulp slurry with a solid concentration of 3% by mass. The obtained pulp slurry was then fed into a flat screen (Kumagaya Riki Kogyo Co., Ltd., No. 230703, slit: 6 cuts) at a flow rate of 10 L / min for 15 minutes. The residue rate was calculated from the bone dry weight of the residue that did not pass through the flat screen, and the fiber recovery rate was calculated using the following formula, which was used as an index of disintegration property. Fiber recovery rate (%) = {1-([residue rate (%)] / 100)} / proportion of the basis weight of the paper base layer in the basis weight of the waste paper × 100 Residue rate (%) = [Bone dry mass (g) of residue that did not pass through the flat screen] / [Solid mass (g) of pulp slurry fed into the flat screen] × 100 (Evaluation Results) A: Fiber recovery rate is 90% or more B: Fiber recovery rate is 70% or more but less than 90% C: Fiber recovery rate is 50% or more but less than 70% D: Fiber recovery rate is less than 50%

[0074] Table 2 shows the measurement and evaluation results for the examples and comparative examples.

[0075] [Table 2]

[0076] From Table 2, the manufacturing methods of the bales in Examples 1 to 14 include a washing step in which washing is performed with acidic washing water, and the median area of ​​the waste paper is 20 cm 2 More than 150cm 2 Since the temperature was below 100°C, it was confirmed that the number of bacteria adhering to the waste paper contained in the bale was reduced, and furthermore, the disintegration property of the waste paper contained in the bale was excellent. On the other hand, in the bale manufacturing methods of Comparative Examples 1 to 3, Comparative Example 1 did not include a washing step, and Comparative Examples 2 and 3 used non-acidic washing water, so the number of bacteria attached to the waste paper contained in the bales was high. In addition, the manufacturing method of the bale in Comparative Example 4 is such that the median area of ​​the waste paper is 150 cm 2 In addition, in the manufacturing method of the bale of Comparative Example 5, the median area of ​​the waste paper was 20 cm2, which resulted in poor disintegration of the waste paper contained in the bale. 2 This resulted in a high number of bacteria adhering to the waste paper contained in the bale. [Industrial Applicability]

[0077] Since the bale manufacturing method of the present invention has the above-mentioned characteristics, the number of bacteria adhering to the waste paper contained in the bale is reduced, and furthermore, the waste paper contained in the bale has excellent disintegration properties.

Claims

1. A washing step of washing waste paper having at least a resin layer and a paper base layer with acidic washing water; and a molding step of compressing and molding the waste paper to obtain a bale. The basis weight of the waste paper is 100 g / m ２ That's all. The median area of ​​the waste paper is 20 cm ２ More than 150cm ２ Below is the How the veil is manufactured.

2. 2. The method for producing a veil according to claim 1, wherein the pH of the washing water in the washing step is 2.5 or more and 6.5 or less.

3. The method for producing a veil according to claim 1 or 2, wherein the washing water in the washing step is hypochlorous acid water.

4. The thickness of 1 cm of waste paper in a bale after storage for 3 days ２ The number of bacteria adhering to the surface per unit area is 10 CFU / cm ２ The method for producing a veil according to claim 1 or 2, wherein the veil is less than 100% by mass.

5. The median density of the waste paper is 0.70 g / cm ３ The method for producing a veil according to claim 1 or 2,

6. The method for manufacturing a bale according to claim 1 or 2, wherein the water absorbency of the waste paper is 25% or more and 85% or less.

7. The method for producing a bale according to claim 1 or 2, wherein the content of the sizing agent in the paper base layer of the waste paper is 0.2% by mass or more and 2.1% by mass or less.

8. The method for producing a bale according to claim 1 or 2, wherein the waste paper further comprises a metal layer.

9. The molding pressure in the molding process is 500 kN / m ２ More than 2500kN / m ２ 3. The method for producing a veil according to claim 1 or 2, wherein:

10. Bale density is 0.3t / m ３ 1.0t / m or more ３ 3. The method for producing a veil according to claim 1 or 2, wherein:

11. The method for producing a bale according to claim 1 or 2, further comprising a crushing step of crushing the waste paper prior to the molding step.

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