JP2015183296A - Welded paper and method for producing welded paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide welded paper that can be produced by mutually welding sheets of paper without requiring a special step, such as a step of forming an adhesion layer on a surface of paper and to provide a method for producing welded paper.SOLUTION: The welded paper is formed by mutually welding sheets of paper formed by binding a plurality of fibers through resin by ultrasonic waves. The welded paper includes resin dispersed in a paper thickness direction, and is weld by using part of the resin without an adhesion layer on a surface of the paper. In the welded paper, the amount of the resin is 15-50% with respect to a total amount of the fibers and the resin.

Description

  The present invention relates to a welding paper and a method for producing the welding paper.

  Conventionally, there is known a releasable sheet in which an adhesive layer is formed on the overlapping surface of the sheets and the overlapping surfaces of the sheets are adhered to each other so as to be removable by applying a predetermined pressure (Patent Literature). 1).

JP 2011-144212 A

  In the releasable sheet disclosed in Patent Document 1, it is necessary to apply an adhesive layer to the overlapping surface of the sheet and dry it, and an extra step is required.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

(1) One aspect of the welding paper according to the present invention is:
This is a welded paper in which a plurality of fibers formed by binding a plurality of fibers through a resin are welded by ultrasonic waves.

  According to the present invention, by ultrasonically welding papers that are formed by binding fibers through a resin, the resin that binds the fibers is melted by ultrasonic waves and the papers are welded together. It is possible to provide a welded paper in which papers are welded to each other without requiring a special process such as forming an adhesive layer on the surface of the paper.

(2) In the welding paper according to the present invention,
The resin may be dispersed in the thickness direction of the paper, and an adhesive layer may not be provided on the surface of the paper.

  ADVANTAGE OF THE INVENTION According to this invention, by using the paper which resin disperses in the thickness direction and does not have an adhesive layer, the welding paper which welded paper can be provided, without requiring the process of forming an adhesive layer.

(3) In the welding paper according to the present invention,
A part of the resin may be used for welding.

  According to the present invention, since a part of the resin that binds the fibers is melted by ultrasonic waves, the papers are welded together, so that a special process such as forming an adhesive layer on the surface of the paper is not required. It is possible to provide a welded paper in which papers are welded together.

(4) In the welding paper according to the present invention,
The amount of the resin relative to the paper may be 15 to 50%.

  According to the present invention, by setting the amount of the resin with respect to the paper to 15 to 50%, it is possible to provide a welded paper in which the papers are not peeled off and the papers are firmly welded.

(5) One aspect of the manufacturing method of the welding paper according to the present invention is
This is a method for manufacturing a welded paper, in which a plurality of fibers formed by binding a plurality of fibers through a resin are welded by ultrasonic waves.

  According to the present invention, by ultrasonically welding papers that are formed by binding fibers through a resin, the resin that binds the fibers is melted by ultrasonic waves and the papers are welded together. It is possible to produce a welded paper in which papers are welded together without requiring a special process such as forming an adhesive layer on the surface of the paper.

The figure which shows typically the paper manufacturing apparatus which manufactures the paper used for the welding paper which concerns on this embodiment. The figure which shows manufacture of a welding paper typically.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. Configuration of Paper Manufacturing Apparatus First, the configuration of a paper manufacturing apparatus that manufactures paper used for the welding paper according to the present embodiment will be described. FIG. 1 is a diagram schematically illustrating a paper manufacturing apparatus 100. The paper manufacturing apparatus 100 manufactures paper (paper containing resin) formed by binding a plurality of fibers via a resin using a material containing fibers as a raw material. The paper manufacturing apparatus 100 includes a crushing unit 10, a defibrating unit 20, a resin supply unit 50, a loosening unit 60, and a paper forming unit 70.

  The crushing unit 10 cuts (pulverizes) a raw material containing fibers such as a pulp sheet and a charged sheet (for example, A4-sized waste paper) into air to make a fine piece. Although the shape and size of the strip are not particularly limited, for example, it is a strip of several cm square. In the illustrated example, the crushing unit 10 has a crushing blade 11, and the charged raw material can be cut by the crushing blade 11. The crushing unit 10 may be provided with an automatic input unit (not shown) for continuously supplying raw materials.

  The strips cut by the crushing unit 10 are received by the hopper 15 and then conveyed to the defibrating unit 20 via the first conveying unit 81. The first transport unit 81 communicates with the introduction port 21 of the defibrating unit 20. The shape of the 1st conveyance part 81 and the 2nd conveyance part 82 mentioned later is a tubular shape, for example.

  The defibrating unit 20 performs a defibrating process on the fine pieces (defibrated material). The defibrating unit 20 generates fibers that have been unraveled into a fibrous shape by defibrating the strip.

  Here, the “defibration treatment” refers to unraveling a strip formed by binding a plurality of fibers into one fiber. What passed through the defibrating unit 20 is referred to as “fiber”. “Fiber” may contain ink particles such as ink, toner, and a bleeding prevention material in addition to unraveled fibers. In the following description, the “fiber” is at least a part of what has passed through the defibrating unit 20, and what is added after passing through the defibrating unit 20 may be mixed.

  The defibrating unit 20 performs a defibrating process on the strip introduced from the introduction port 21 with a rotary blade. The defibrating unit 20 performs defibration in a dry manner in the air. The defibrating unit 20 preferably has a mechanism for generating an airflow. In this case, the defibrating unit 20 can suck the fine pieces together with the airflow from the introduction port 21 by the airflow generated by itself, perform the defibrating process, and convey the strip to the discharge port 22. The fiber discharged from the discharge port 22 is transferred to the introduction port 66 of the loosening unit 60 via the second transfer unit 82. The second transport unit 82 is provided with a supply port 51 for supplying a resin that binds the fibers together.

  The resin supply unit 50 supplies resin in the air from the supply port 51 to the second transport unit 82. That is, the resin supply part 50 supplies resin to the path | route from which the fiber thing goes to the loosening part 60 from the defibrating part 20. Although it will not specifically limit as the resin supply part 50 if resin can be supplied to the 2nd conveyance part 82, A screw feeder, a circle feeder, etc. are used. The resin supplied from the resin supply unit 50 is a resin for binding a plurality of fibers. When the resin is supplied to the second transport unit 82, the plurality of fibers are not bound. The resin is cured when passing through a paper forming unit 70 described later, and binds a plurality of fibers. The resin is a thermoplastic resin such as polyester resin or polyethylene resin, and may be fibrous or powdery. The amount of resin supplied from the resin supply unit 50 is such that the ratio of resin to fiber (weight ratio) is 15:85 to 50:50 (the total weight of fiber and resin (weight of paper) in the manufactured paper. The resin weight ratio is set to 15 to 50%. In addition to the resin that binds the fibers, a colorant or the like for coloring the fibers may be supplied depending on the type of paper to be produced.

  The resin supplied from the resin supply unit 50 is mixed by the mixing unit (not shown) provided in the second transport unit 82 so that the fiber discharged from the discharge port 22 is evenly distributed. The mixing unit generates an air flow for transporting the fiber and the resin to the loosening unit 60 while mixing the fibers and the resin.

  The loosening unit 60 loosens tangled passing objects. Furthermore, the loosening part 60 loosens the entangled resin when the resin supplied from the resin supply part 50 is fibrous. Further, the loosening unit 60 uniformly deposits the passing material and the resin on the deposition unit 72 described later. In other words, the term “unwind” includes the action of breaking up intertwined things and the action of depositing them uniformly. If there is no entanglement, the film is uniformly deposited. As the loosening part 60, a sieve is used. The loosening part is a rotary sieve whose net part is rotated by a motor (not shown). Here, the “sieving” used as the loosening unit 60 may not have a function of selecting a specific object. That is, the “sieving” used as the unraveling part 60 means a thing provided with a net part having a plurality of openings, and the unraveling part 60 removes all of the fiber and resin introduced into the unraveling part 60. , It may be discharged outside through the opening. Note that the loosening unit 60 may be omitted as a configuration of the paper manufacturing apparatus 100.

  In the state where the loosening part 60 is rotating, the mixture of fibers and resin is introduced into the loosening part 60 from the introduction port 66. The mixture introduced into the loosening part 60 moves to the mesh part side by centrifugal force. As described above, the mixture introduced into the loosening part 60 may contain entangled fibers and resin, and the entangled fibers and resin are loosened in the air by the rotating mesh part. The loosened fibers and resin pass through the openings.

  The fiber and resin that have passed through the opening of the loosening part 60 are deposited on the accumulation part 72 of the paper forming part 70 in a state where the resin is dispersed throughout the fiber. For this reason, the resin is dispersed in the thickness direction of the deposit. Further, the resin is dispersed in the fiber in the direction along the surface of the deposit. The paper forming unit 70 includes a stacking unit 72, a stretching roller 74, a heater roller 76, a tension roller 77, and a cutting unit 78. The paper forming unit 70 forms paper using the fiber and the resin that have passed through the loosening unit 60.

  The depositing unit 72 of the paper forming unit 70 receives the fibers and the resin that have passed through the opening of the loosening unit 60 and deposits them to generate a deposit. The deposition part 72 is located below the loosening part 60. The accumulation unit 72 is, for example, a mesh belt. A mesh stretched by a stretch roller 74 is formed on the mesh belt. The deposition unit 72 moves as the stretching roller 74 rotates. A web having a uniform thickness is formed on the accumulation portion 72 by the fiber material and the resin continuously falling from the loosening portion 60 while the accumulation portion 72 continuously moves.

  A suction device 79 that sucks the deposit from below is provided below the deposition section 72. The suction device 79 is positioned below the unwinding unit 60 via the deposition unit 72 and generates a downward airflow (an airflow from the unwinding unit 60 toward the deposition unit 72). Thereby, the fiber and the resin dispersed in the air can be sucked, and the discharge speed from the loosening part 60 can be increased. As a result, the productivity of the paper manufacturing apparatus 100 can be increased. Further, the suction device 79 can form a downflow in the dropping path of the fiber and the resin, and can prevent the fiber and the resin from being entangled during the dropping.

  The fiber and resin deposited on the depositing section 72 of the paper forming section 70 are heated and pressurized by passing through the heater roller 76 as the depositing section 72 moves. By heating, the resin functions as a binder to bind the fibers together, is thinned by pressurization, and further passes through a calendar roller (not shown) to smooth the surface, and the paper P is formed. In addition, you may heat and pressurize by passing the heater roller 76 after passing a calendar roller.

  On the downstream side of the heater roller 76, as a cutting unit 78 for cutting the paper P, a first cutting unit 78 a for cutting the paper P in a direction intersecting with the conveyance direction of the paper P, and along the conveyance direction of the paper P A second cutting part 78b for cutting the paper P is disposed. The first cutting unit 78a includes a cutter, and cuts the continuous paper P into a sheet according to a cutting position set to a predetermined length. The second cutting unit 78b includes a cutter and cuts according to a predetermined cutting position in the transport direction of the paper P. Thereby, paper of a desired size is formed. The cut paper P is loaded on the stacker 99 or the like. In addition, you may comprise so that the paper P may be wound up with a winding roller, without cut | disconnecting the paper P.

  As described above, the method for manufacturing the paper P for welding paper according to the present embodiment includes a step of defibrating the raw material containing fibers in air, a step of mixing the defibrated fibers and a resin, and fibers. And a step of forming the paper P by heating a mixture of the resin and the resin.

2. Production of welded paper The welded paper according to the present embodiment can be produced by welding the paper P produced by the paper production apparatus 100 with ultrasonic waves (ultrasonic welding). As a means for ultrasonically welding the papers P, an ultrasonic welder can be used. The ultrasonic welder generates frictional heat on the joint surface between two thermoplastic resins by fine ultrasonic vibration and pressure applied by a vibrator to melt and bond the resins.

  In the paper P, the resin is dispersed in the thickness direction and the direction along the surface. When ultrasonic welding is performed on a portion where the papers P are overlapped, the resin existing on the welding surface side of each paper P is instantaneously melted, and the molten resin spreads between the fibers by pressurization. Thus, the resin existing on the welding surface side of one paper P is entangled with the fibers existing on the welding surface side of the other paper P, and the resin existing on the welding surface side of the other paper P is welded to the one paper P. It gets entangled in the fiber existing on the surface side. That is, the fibers of one paper P and the fibers of the other paper P are bonded through the resin of one paper P, and the fibers of one paper P and the fibers of the other paper P are resin of the other paper P. As a result, the one paper P and the other paper P are welded together.

  In order to securely weld the papers P to each other by ultrasonic welding, it is necessary to set the ratio of the weight of the resin to the total weight of the fibers and the resin in the range of 15 to 50% in the welded paper (paper P). . When the ratio of the weight of the resin to the total weight of the fibers and the resin is less than 15%, the welding force between the papers P becomes weak and the papers P are easily peeled off. On the other hand, when the ratio of the weight of the resin to the total weight of the fibers and the resin is larger than 50%, the texture (paperiness) as paper is impaired.

  The resin contained in the welding paper (paper P) needs to be a thermoplastic resin, and a polyester resin, a nylon resin, an acrylic resin, polyethylene, polypropylene, or the like can be selected as the thermoplastic resin. In order to firmly weld the papers P by ultrasonic welding, it is preferable to select an amorphous resin (for example, an amorphous polyester resin) as the thermoplastic resin contained in the paper P. In addition, the resin mixed with the fiber when manufacturing the paper P may be in the form of a fiber or powder, but the resin melts and extends thinly by heating when manufacturing the paper P. It is preferable to use this resin.

  In ultrasonic welding, since the welding ends instantaneously, even if the melting temperature of the resin contained in the paper P is high, the paper P is welded while minimizing damage (burning etc.) to the paper P. be able to. In consideration of damage to the paper P, the softening temperature of the resin contained in the paper P may be 210 ° C. or lower.

  Further, ultrasonic welding is suitable when the papers P are welded in a small area, and is also suitable when the paper P is welded in a linear shape or a curved shape. For example, in a state where a plurality of papers P are overlapped, a plurality of papers P are partially welded by performing ultrasonic welding on a part (corner, end) of the surface of the paper P. It is possible to manufacture a welded paper in which the paper P is bound. In this way, a plurality of sheets P can be bound without using a stapler or a clip.

  In the welded paper of the present embodiment, the paper P is formed by using a paper P formed by binding a plurality of fibers via a resin, and a part of the resin binding the fibers is melted by ultrasonic waves. Because it is welded, it can be manufactured by welding papers without the need for special processes such as forming an adhesive layer on the surface of the paper (applying glue, pressing film, applying varnish). A welded paper can be realized. Moreover, since the drying process after apply | coating an adhesive agent or glue is not required and it can weld in a short time around 1 second, productivity can be improved.

3. Experimental Examples The experimental examples are shown below to further explain the present invention, but the present invention is not limited to the following examples.

  A paper containing a thermoplastic resin was produced, and the produced papers were welded together by ultrasonic welding to produce a welded paper. Moreover, the tensile test was done about manufactured manufactured paper.

As raw materials for paper, pulp (dry defibrated softwood bleached kraft pulp) and polyethylene powder (manufactured by Asahi Kasei Chemicals Corporation, trade name “LH600”, average particle size: 86 μm, melting point: 130 °) were used. 100 g of a mixture of these pulp and polyethylene powder was put into a blender (trade name “Warling Blender”, manufactured by Waring Co., Ltd.), and stirred and mixed for 60 seconds at a rotational speed of 3000 rpm. The mixture subjected to the treatment was deposited on a flat plate with a sieve of 10 mesh (number of meshes per inch was 10). The deposited mixture was pressed and heated by a flat press at a pressure of 30 MPa and a temperature of 150 ° C. for 15 seconds to obtain a sheet (paper) having a basis weight of 100 g / m ² and a paper thickness of 180 μm.

  The obtained sheet was cut into a width of 25 mm and a length of 100 mm. As schematically shown in FIG. 2, an ultrasonic welder UW (trade name “SONAC-37”, manufactured by Honda Electronics Co., Ltd.) is applied to a portion where two cut sheets ST are stacked with a length of 10 mm. ) To perform ultrasonic welding to weld two sheets ST to obtain a welded paper.

  A tensile test was performed on two sheets ST (welded paper) subjected to ultrasonic welding, and the strength (welding force) of the welded portion was measured. In this experiment, the case where the sheet was manufactured with a weight ratio of the resin (polyethylene powder) and pulp of 5:95 was set as Example 1, the case where the sheet was manufactured with the weight ratio of 10:90 was set as Example 2, and the case When the sheet is manufactured with a weight ratio of 15:85 as Example 3, when the sheet is manufactured with the weight ratio of 20:80 as Example 4, and when the sheet is manufactured with the weight ratio of 30:70 Was designated as Example 5, and the case where the sheet was produced at a weight ratio of 50:50 was designated as Example 6. Each example was subjected to a tensile test to measure the breaking strength (tensile strength necessary for breaking the sheet).

  The measurement results are shown in Table 1. In Table 1, when the sheet is peeled off at the welded part (welded part), it is indicated as “welded part peeling”, and when the sheet itself is broken, it is indicated as “non-welded part rupture”. .

実施例１、２では、溶着部での剥がれが見られた。これは、シートに含まれる樹脂が少なくシート同士の接合面に十分な樹脂が存在しないため、溶着が阻害されるためと考えられる。一方、実施例３〜６では、溶着部での剥がれが見られず、溶着していない部分が破断した。つまり、溶着部の破断強度が紙の破断強度を上回ったことになる。また、１５ＭＰａ以上でも溶着部は剥がれることがなく、良好であった。これらの結果から、樹脂とパルプ（繊維）の重量比を１５：８５〜５０：５０として製造したシートに対して超音波溶着を行うことで、シート同士を強固に溶着できることが確認できた。

In Examples 1 and 2, peeling at the welded portion was observed. This is presumably because welding is hindered because the resin contained in the sheet is small and sufficient resin is not present on the bonding surface between the sheets. On the other hand, in Examples 3 to 6, peeling at the welded portion was not seen, and the unwelded portion was broken. That is, the breaking strength of the welded portion exceeds the breaking strength of the paper. Further, even at 15 MPa or more, the welded portion was not peeled off and was good. From these results, it was confirmed that the sheets could be firmly welded by performing ultrasonic welding on the sheet manufactured with a weight ratio of resin and pulp (fiber) of 15:85 to 50:50.

4). Modifications The present invention includes substantially the same configuration (configuration with the same function, method and result, or configuration with the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

  Note that the paper manufactured by the paper manufacturing apparatus 100 includes a mode in which pulp or waste paper is used as a raw material and is formed into a thin sheet, and the like, recording paper for writing and printing, wallpaper, wrapping paper, colored paper, drawing paper, Including Kent paper. The raw material may be plant fibers such as cellulose, or animal fibers such as wool or silk.

  In addition, a moisture sprayer for spraying and adding moisture to the deposit accumulated in the deposition unit 72 may be provided. Thereby, the intensity | strength of the hydrogen bond at the time of shape | molding paper P can be made high. The spray addition of moisture is performed on the deposit before passing through the heater roller 76. Starch, PVA (polyvinyl alcohol), or the like may be added to the moisture sprayed by the moisture sprayer. Thereby, the strength of the paper P can be further increased.

  The paper manufacturing apparatus 100 may not include the crushing unit 10. For example, if the material is roughly crushed with an existing shredder or the like, the crushing unit 10 is not necessary.

  A paper box can also be manufactured using paper manufactured by the paper manufacturing apparatus 100. In this case, a paper box can be manufactured in a short time without using an adhesive or the like by performing box assembly by bonding by ultrasonic welding.

DESCRIPTION OF SYMBOLS 10 Crushing part, 11 Roughing blade, 15 Hopper, 20 Defibration part, 21 Inlet port, 22 Outlet port, 50 Resin supply part, 51 Supply port, 60 Unraveling part, 66 Inlet part, 70 Paper forming part, 72 Deposition Section, 74 tension roller, 76 heater roller, 77 tension roller, 78 cutting section, 79 suction device, 81 first transport section, 82 second transport section, 99 stacker, 100 paper manufacturing apparatus

Claims (5)

  A welded paper in which a plurality of fibers formed by binding a plurality of fibers through a resin are welded by ultrasonic waves.   The welding paper according to claim 1, wherein the resin is dispersed in the thickness direction of the paper and does not have an adhesive layer on the surface of the paper.   The welding paper according to claim 1 or 2, which is welded using a part of the resin.   The welding paper according to any one of claims 1 to 3, wherein an amount of the resin with respect to the paper is 15 to 50%.   A method for producing a welded paper, in which a plurality of fibers formed by binding a plurality of fibers through a resin are welded by ultrasonic waves.

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