Glass interleaf paper and manufacturing method of glass interleaf paper

Abstract

To provide glass interleaf paper and a manufacturing method of glass interleaf paper that can be provided continuously and can reduce a production cost.SOLUTION: Glass interleaf paper 15e includes, as a raw material, waste corrugated board or waste kraft paper. As handling amount of waste corrugated board will not decrease due to increase of physical distribution along with IT development, a supply amount of waste corrugated board for recycling will not decrease and will be stably supplied, so that glass interleaf paper with suppressed production cost can be supplied stably.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a glass interleaving paper and a method for manufacturing the glass interleaving paper. More specifically, the present invention relates to a glass interleaving paper containing a specific material and a method for manufacturing the glass interleaving paper. [Background technology]

[0002] Among recycled items, the recycling rate of paper is said to be relatively higher than that of other recycled items. By carrying out this recycling, it is possible to reduce the amount of virgin pulp used and the amount of carbon dioxide emitted in the production of virgin pulp, and it is also possible to reduce the cost of recycled paper products. Patent Document 1 discloses an invention related to glass interleaving paper, etc., and also discloses that recycled paper is used in the glass interleaving paper.

[0003] Paper recycling can be divided into horizontal recycling and cascade recycling. Horizontal recycling refers to recycling into a product equivalent to the original product, while cascade recycling refers to recycling into a product of lower value than the original product. For example, cascade recycling is the recycling of high-quality products with a high pulp content, such as newspapers, into low-quality toilet paper or cardboard, which have a low pulp content. Cardboard is a low-quality product made of unbleached pulp, and is cascade recycled from other high-quality waste paper products with a high pulp content, or horizontally recycled from low-quality cardboard products into cardboard. Considering such industry standards, the statement that waste paper is used as the raw material for glass interleaving paper means that high-quality products such as newspapers are used as waste paper, just like glass interleaving paper. In other words, it was previously impossible to use low-quality products with unbleached pulp as raw materials rather than glass interleaving paper, considering costs, etc. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-226479 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the advancement of IT, the number of newspapers published continues to decline, and as the term ``publishing recession'' suggests, the number of paper books published also continues to decline, resulting in a decrease in the amount of high-quality waste paper that can be recycled.This means that there is less high-quality waste paper to be used for glass interleaving paper, and the cost of producing glass interleaving paper is rising.

[0006] In view of the above circumstances, an object of the present invention is to provide glass interleaving paper and a method for manufacturing glass interleaving paper that can be continuously provided and that can reduce manufacturing costs. [Means for solving the problem]

[0007] The glass interleaving paper of the first invention is characterized in that it contains recycled corrugated cardboard or recycled kraft paper as a raw material. The glass interleaving paper of the second invention is the same as that of the first invention, except that the basis weight is 30 g / m 2 More than 55g / m 2 The material is characterized in that it has a thickness of 150 μm or less, and in a stiffness test that measures the length of sagging from a horizontal plane when a square sample with sides of 30 cm is extended 10 cm, the sagging is less than 80 mm. The manufacturing method of the glass interleaving paper of the third invention uses a raw material containing waste paper including waste paper such as cardboard or kraft paper, and has a basis weight of 30 g / m 2 More than 55g / m 2a thickness of 150 μm or less, and a sagging length of less than 80 mm in a stiffness test that measures the sagging length from a horizontal plane of a square sample with sides of 30 cm extended 10 cm, the method for producing glass interleaving paper is characterized in that the method includes a wire part that places a pulp slurry on a papermaking wire and removes moisture from the pulp slurry, and among the wires used in the wire part, a lower wire that receives the pulp slurry is composed of only one layer. Effect of the Invention

[0008] According to the first invention, since recycled cardboard or recycled kraft paper is included as a raw material for glass interleaving paper, the amount of recycled cardboard handled will not decrease due to the increase in logistics accompanying the advancement of IT, and the supply of recycled cardboard for recycling will not decrease and will be supplied steadily, thereby enabling a stable supply of glass interleaving paper with reduced manufacturing costs to be provided. According to the second invention, for glass interleaving paper having a specified basis weight and thickness, the sagging in a stiffness test is less than a specified value, making it easier to maintain its shape and easier to handle when removing or feeding the glass interleaving paper. According to the third invention, in a method for producing glass interleaving paper using raw materials containing recycled cardboard and the like, in which the sagging in a stiffness test is less than a predetermined value, the lower wire used in the wire part that receives the pulp slurry is composed of only one layer, making it possible to produce more uniform glass interleaving paper of 150 μm or less. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic diagram showing the configuration of a wire part that constitutes a manufacturing method for glass interleaving paper according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing a flow of a method for manufacturing glass interleaving paper according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Next, an embodiment of the present invention will be described with reference to the drawings. However, the embodiment shown below is an example of glass interleaving paper and a manufacturing method thereof for embodying the technical idea of ​​the present invention, and the present invention does not limit the glass interleaving paper and the manufacturing method thereof to the following. Note that the dimensions, materials, shapes, relative positions, etc. of the components described in the embodiment are merely illustrative examples and are not intended to limit the scope of the present invention unless otherwise specified.

[0011] <Embodiment> (Main ingredient of glass interleaving paper 15e) The glass interleaving paper 15e according to the present embodiment contains waste cardboard paper or waste craft paper as a raw material. The content ratio is not particularly limited. However, in consideration of the manufacturing cost of the glass interleaving paper 15e, the content ratio is preferably 20% or more, and more preferably 100%. Note that the main raw material other than the waste cardboard paper and the waste craft paper is preferably virgin pulp.

[0012] By including waste cardboard or waste craft paper as the raw material for glass interleaving paper 15e, glass interleaving paper 15e with reduced manufacturing costs can be stably provided. Paper recycling is usually horizontal recycling and cascade recycling. Glass interleaving paper 15e is a high-quality product that uses a relatively large amount of pulp, so waste paper from high-quality products such as newspapers has traditionally been used in its production. However, with the advancement of IT, the number of newspapers published has decreased significantly, and the number of paper books published due to the publishing recession has decreased significantly, so the amount of waste paper for these high-quality products has decreased, and there is a risk that waste paper for high-quality products will not be able to be stably supplied. In contrast, with the advancement of IT, the amount of cardboard used in logistics has tended to increase, and waste cardboard paper will be stably supplied. In paper recycling, low-quality products such as cardboard are not used as raw materials for high-quality products because the cost of removing foreign matter and ink tends to be high in the pulping process of waste paper, and this is to suppress the cost in this process. However, the degree of cost increase when adding to the above process is low. Therefore, it is possible to use cardboard and the like to manufacture high-quality products. The amount of waste paper handled for cardboard does not decrease due to the increase in logistics accompanying the advancement of IT. Therefore, the supply of waste paper for cardboard for recycling does not decrease and is supplied steadily, and glass interleaving paper 15e with reduced manufacturing costs is provided steadily.

[0013] The glass interleaving paper 15e according to the present embodiment can use the following main raw materials, including those contained in waste paper such as cardboard. For example, chemical pulp such as kraft pulp (KP), sulfite pulp (SP), soda pulp (AP), etc.; semi-chemical pulp such as semi-chemical pulp (SCP) and chemi-ground wood pulp (CGP); mechanical pulp such as groundwood pulp (GP), thermomechanical pulp (TMP, BCTMP), refiner ground wood pulp (RGP), etc.; non-wood fiber pulp made from camellia, mitsumata, hemp, kenaf, etc.; synthetic pulp; etc. can be used as the main raw material. Furthermore, the main raw material may be a mixture of these, or may be one containing cellulose, etc.

[0014] (Glass interleaving paper 15e) The glass interleaving paper 15e according to this embodiment has a basis weight of 30 g / m 2 More than 55g / m 2 It is preferable that the thickness is 40 g / m or less. 2 More than 50g / m 2 It is more preferable that the amount of waste cardboard or kraft paper required is less than 100% by weight, because this allows the necessary amount of waste cardboard or kraft paper to be secured while maintaining cost competitiveness.

[0015] The glass interleaving paper 15e according to the present embodiment is preferably 150 μm or less in thickness. This is preferable from the viewpoint of logistics, since a larger length of glass interleaving paper 15e can be obtained from one glass interleaving paper roll. This is also preferable when forming a glass plate package in which more glass plates and glass interleaving paper 15e are alternately laminated, since more glass plates can be laminated on a pallet. The thickness of the glass interleaving paper 15e is more preferably 90 μm or less, even more preferably 80 μm or less, and even more preferably 70 μm or less. The lower limit of the thickness of the glass interleaving paper 15e is not particularly limited, but is, for example, 10 μm or more.

[0016] The glass interleaving paper 15e according to the present embodiment preferably has a sagging of less than 80 mm in a so-called stiffness test. The stiffness test is a test in which a square sample with a side length of 30 cm is placed on a desk having a horizontal surface, and when a part of the sample is extended by 10 cm, the sagging length from the horizontal surface is measured. When the stiffness test is performed, the sagging is preferably less than 80 mm, and more preferably less than 50 mm.

[0017] For glass interleaving paper 15e having a predetermined basis weight and thickness, if the sagging in the stiffness test is smaller than a predetermined value, the shape can be easily maintained, and the glass interleaving paper 15e can be easily handled when removed or fed. The glass interleaving paper 15e is laid on glass placed on a horizontal surface, and glass is further laminated on the glass interleaving paper 15e. When laying the glass interleaving paper 15e on the glass, it is necessary to move the glass interleaving paper 15e at a predetermined speed and to prevent the glass interleaving paper 15e from bending. If the sagging in the stiffness test is smaller than a predetermined value, the paper subject to the stiffness test can easily maintain its shape and be easily handled. Therefore, for glass interleaving paper 15e having a predetermined basis weight and thickness, if the sagging in the stiffness test is smaller than a predetermined value, the shape can be easily maintained, and the glass interleaving paper 15e can be easily handled.

[0018] When the glass interleaving paper 15e is rectangular, it is preferable that the short side is 730 mm or more. This allows it to be inserted between glass plates of larger sizes, which are currently in demand. It is more preferably 100 mm or more, even more preferably 1500 mm or more, and even more preferably 2000 mm or more. The upper limit of the short side of the glass interleaving paper 15e is not particularly limited, but is, for example, 4000 mm or less.

[0019] In addition, in the lamination process between the glass plate and the glass interleaving paper 15e, where the thickness of the glass interleaving paper 15e becomes thinner and the short side becomes longer, the glass interleaving paper 15e needs to have higher strength, density, smoothness, water resistance, or moisture resistance, etc. For this reason, a larger amount of additives or new additives that have not been used before may be added.

[0020] (Additives added to the main ingredient) The glass interleaving paper 15e according to this embodiment can also contain the following substances. By optimizing these additives, the sagging length in the stiffness test can be made smaller than a predetermined value.

[0021] Internal paper strength enhancers can be added as additives. Internal paper strength enhancers are primarily used to improve the strength of paper. A typical example of the main component is polyacrylamide (PAM).

[0022] Pitch control agents can be added as additives. The main purpose of pitch control agents is to disperse or expel pitch (a sticky substance derived from resin or chemicals) from the system. Representative examples of the main components are cationic polymers such as cationic (C-)PAM, polyethyleneimine (PEI), C-acrylic, surfactants, polyacrylic acid, polyvinyl alcohol (PVA), and PAM.

[0023] Coagulants can also be added as additives. The main purpose of coagulants is to turn fiber particles into small, dense aggregates. The pulp slurry and fiber particles are anionic, so they are neutralized and coagulated by cationic coagulants. They also fix anionic sticky foreign matter to the pulp, preventing roll staining. Representative examples of the main components are polydiallyldimethylammonium chloride (PDADMAC), PEI, and cationic starch (CS).

[0024] Dry strength agents can also be added as additives. Dry strength agents are primarily used to improve the strength of paper, especially in a dry state. Typical examples of the main components are polyacrylate (AE), CS, PAM, and PVA.

[0025] Wet strength agents can also be added as additives. Wet strength agents are primarily used to improve the strength of paper, especially when it is wet. Representative examples of the main components are AE, polyamide polyamine epichlorohydrin (PAE), PVA, polyvinylamine (PVAm), melamine (formaldehyde) resin (MF), urea (formaldehyde) resin (UF), polyvinyl chloride (PVC), and polyvinylidene chloride (PVDC).

[0026] Internal sizing agents can also be added as additives. The main purpose of internal sizing agents is to reduce water permeability, suppress bleeding, and strengthen water resistance. Representative examples of the main components are AE, rosin, PVA, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA), and carboxymethyl cellulose (CMC).

[0027] Surface sizing agents can also be added as additives. The main purpose of surface sizing agents is to reduce water permeability, suppress bleeding, and enhance water resistance. Representative examples of the main components are oxidized starch (OS) and styrene-acrylic copolymer (AS).

[0028] Thickeners can also be added as additives. The main purpose of thickeners is to increase viscosity, disperse pulp fibers evenly in water, and prevent settling. Representative examples of the main components are AE, PAM, polyethylene oxide (PEO), CMC, and alginic acid (AA).

[0029] A water-resistant crosslinking agent can also be added as an additive. The main purpose of the water-resistant crosslinking agent is to improve water resistance and strength through crosslinking. A typical example of the main component is epoxy resin (ER).

[0030] Adhesives can also be added as an additive. The main purpose of adhesives is to bond paper together in a Yankee dryer, etc. The main components are AE, styrene-butadiene copolymer rubber (SBR), and starch.

[0031] In principle, the above-mentioned additives are preferably used in appropriate amounts for their respective main purposes.

[0032] In particular, the additive preferably contains a substance that is highly effective for each purpose of each papermaking chemical, i.e., at least one substance selected from the group consisting of alginic acid, polyacrylic acid ester, alkyl ketene dimer, styrene-acrylic copolymer, alkenyl succinic anhydride, epoxy resin, melamine resin, polyamide polyamine epichlorohydrin, polyvinyl chloride, polyvinylidene chloride, styrene-butadiene copolymer rubber, rosin, and polyethylene terephthalate, or a derivative thereof.

[0033] (Manufacturing method of glass interleaving paper 15e) FIG. 2 shows a schematic diagram showing the flow of the manufacturing method of the glass interleaving paper 15e. The flow of this manufacturing method runs from left to right on the page. The manufacturing method of this glass interleaving paper 15e is carried out by one papermaking machine 10. That is, one papermaking machine 10 is formed from multiple parts, and the glass interleaving paper 15e is manufactured by carrying out a predetermined process in each part. Although it has been explained that the manufacturing method of the glass interleaving paper 15e is carried out by one papermaking machine 10, the manufacturing method of the glass interleaving paper 15e is not limited to this. For example, it is also possible to carry out the method by connecting together devices that carry out only some of the multiple parts.

[0034] The object to be manufactured flows from left to right on the paper surface of Fig. 2. In this specification, the left side of the paper surface of Fig. 2 may be referred to as the upstream side, and the right side as the downstream side. The object to be manufactured is expressed as passing paper 15 throughout all the manufacturing processes, and the expression changes with each process for ease of understanding.

[0035] Before the papermaking machine 10, the user of the papermaking machine 10 preferably carries out a preparation step of preparing pulp, which is used as a raw material for preparing the paper stock liquid, and a pulp slurry step of producing pulp slurry 15a from the pulp. The raw material for the pulp prepared in the preparation step, i.e., the raw material for the glass interleaving paper 15e, contains waste cardboard or waste kraft paper. It is also preferable to refer to the results of a stiffness test carried out in advance and add necessary additives so that the sagging is less than 80 mm.

[0036] FIG. 1 is a schematic diagram showing the configuration of the wire part 11 constituting the manufacturing method of the glass interleaving paper 15e. In FIG. 1, each wire moves in the direction indicated by the arrow, and a head box that supplies the pulp slurry 15a is located in the upper left of FIG. 1, although not shown. The user of the papermaking machine 10 performs a wire process in which the pulp slurry 15a is made into a wet paper 15b in the wire part 11 constituting the papermaking machine 10. First, the user of the papermaking machine 10 supplies the pulp slurry 15a to the head box provided in the wire part 11. In the wire part 11, the pulp slurry 15a is supplied in a sheet form from the head box onto the wire installed in the wire part 11. To explain in more detail, the wire is composed of a lower wire 30a and an upper wire 30b, and the pulp slurry 15a supplied to the lower wire 30a is then sandwiched between the lower wire 30a and the upper wire 30b, spread to a uniform thickness, and dewatered to become a wet paper 15b.

[0037] The lower wire 30a and the upper wire 30b of the wire part 11 are permeable membranes formed in an endless belt shape. Specifically, they are endless bodies made of nets made of plastic or metal materials, or felt made of natural or synthetic fibers.

[0038] The lower wire 30a and the upper wire 30b are stretched over a number of rollers, and are rotated at a predetermined speed in the direction indicated by the arrow in Fig. 1 by transmitting the driving force of a motor to a driving roller among the rollers. In this embodiment, the lower wire 30a that receives the pulp slurry is preferably made of only one layer.

[0039] A user of the papermaking machine 10 performs a pressing process in the press part 12 of the papermaking machine 10 to turn the wet paper 15b into a pressed wet paper 15c.

[0040] The wet paper 15b formed in the wire part 11 is transported to the press part 12 having a press roller, an endless felt, and a pair of press rollers, where the wet paper 15b is further dehydrated and pressed simultaneously to become a pressed wet paper.

[0041] A user of the papermaking machine 10 performs a drying process in the dryer part 13 of the papermaking machine 10, in which the pressed wet paper 15c is made into a dried paper 15d.

[0042] The pressed wet paper 15c that has passed through the press part 12 is transported to the dryer part 13 consisting of a plurality of rollers, and while passing through the dryer part 13, it is dried in an atmosphere at about 120° C., for example, to become a dried paper 15d.

[0043] The user of the papermaking machine 10 performs a calendering process in which the dried paper 15d is made into glass laminated paper 15e in the calendering part 14 of the papermaking machine 10. The dried paper 15d dried in the dryer part 13 is transported to the calendering part 14, where it is subjected to calendering processing such as sandwiching and transporting with calender rolls, and the front and back surfaces are smoothed. The expression "calender rolls" refers to a configuration including a pair of rolls arranged to be able to sandwich the dried paper 15d.

[0044] The calender part 14 of this embodiment will be described with reference to Fig. 1. In this embodiment, two pairs of calender rolls are used. The upstream calender rolls are composed of a first upper roll and a first lower roll. The downstream calender rolls are composed of a second upper roll and a second lower roll.

[0045] The paper that has been subjected to the calendering process in the calender part 14 is wound on a reel as the glass interleaving paper 15e, and is formed into a jumbo roll.

[0046] In the papermaking machine 10 used in the manufacturing method of the glass interleaving paper 15e of this embodiment, the glass interleaving paper 15e is sent out from a jumbo roll, cut to a predetermined width by a cutter (cut in the longitudinal direction), and wound up by a winder. When the glass interleaving paper 15e sent out from the jumbo roll reaches a predetermined length, it is cut to the predetermined length by a cutter (cut in the width direction) to form an interleaving paper roll in which the long glass interleaving paper 15e is wound up to the predetermined width. The long glass interleaving paper 15e wound around the interleaving paper roll is cut into cut sheets (rectangular shapes) of a size corresponding to the glass plates to be laminated, and is interposed between the glass plates to be laminated.

[0047] In a manufacturing method for glass interleaving paper using raw materials containing recycled cardboard, etc., and having a sagging value smaller than a specified value in a stiffness test, the lower wire 30a, which receives the pulp slurry, among the wires used in the wire part 11, is composed of only one layer, making it possible to manufacture more uniform glass interleaving paper of 150 μm or less.

[0048] The manufacturing method of the glass interleaving paper 15e has been described above, but this is only one example of the manufacturing method of the glass interleaving paper 15e, and is not limited to this configuration. For example, if necessary, a coater part for applying paint or the like to the smoothed surface of the paper can be provided between the dryer part 13 and the calendar part 14. [Explanation of symbols]

[0049] 10 Paper machine 11 Wire Part 30a Lower Wire

Claims

1. The raw materials include recycled cardboard or recycled kraft paper, A glass interleaving paper characterized by:

2. Basis weight: 30 g / m ２ 55g / m or more ２ is as follows: The thickness is 150 μm or less, In a stiffness test that measures the length of sagging from a horizontal surface when a square sample with sides of 30 cm is extended by 10 cm, the sagging is less than 80 mm. The glass interleaving paper according to claim 1 .

3. The raw materials used include recycled cardboard and recycled craft paper. Basis weight: 30 g / m ２ 55g / m or more ２ is as follows: The thickness is 150 μm or less, A method for manufacturing glass interleaving paper in which a sagging length from a horizontal plane when a square sample with one side of 30 cm is extended by 10 cm is measured in a stiffness test, the sagging length being less than 80 mm, The method for producing the glass interleaving paper includes a wire part for placing a pulp slurry on a wire for papermaking and removing moisture from the pulp slurry, Among the wires used in the wire part, the lower wire that receives the pulp slurry is composed of only one layer. A method for producing glass interleaving paper.

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