Fiber assembly and method for producing the same

Abstract

To provide a fiber assembly in which a cut fiber is hardly entangled in a dense part for practical use at the time of individual piece cut.SOLUTION: A fiber assembly includes a warp yarn group obtained by arraying a plurality of warp yarn pairs made of a high polymer material, and a weft yarn group obtained by arraying a plurality of weft yarn pairs made of a high polymer material, on a principal surface where a mold release treatment of a support sheet has been performed. The warp yarn group and the weft yarn group have a large number of first contact part regions and a non-contact part regions. The first contact part region is a region where the warp yarns and the weft yarns are integrated, and a line width of the warp yarn and the weft yarn is 1-10 μm. The fiber density of the first contact part region is larger than the fiber density of the non-contact part region. An interval between the warp yarns or between the weft yarns of the first contact part region is equal to or greater than 5 μm and equal to or less than 1000 μm, and the interval of the larger one out of between the warp yarns and between the weft yarns of the non-contact part is the interval of equal to or greater than 2000 μm.SELECTED DRAWING: Figure 1-2

Description

[Technical field]

[0001] The present invention relates to a fiber assembly including a plurality of intersecting fibers and a method for producing the fiber assembly. [Background technology]

[0002] In recent years, fiber substrates have been attracting attention as scaffolds for culturing biological tissues and microorganisms. In particular, when the growth of biological tissues and microorganisms is directional, it is desirable for the fibers constituting the fiber substrate to be aligned in a certain direction, and a method for improving the alignment by depositing the fibers in a circumferential manner on the circumferential surface of a winding rotor is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-79460 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the manufacturing method for a fiber assembly described in Patent Document 1 provides excellent fiber alignment, when the line width of the fibers aligned on the support sheet is as thin as 10 μm or less, fraying of the fibers occurs when the fibers aligned on the support sheet are cut into individual pieces, and the cut fibers become entangled in the divided parts, which hinders alignment.

[0005] For example, comparing a fiber with a line width of φ16μm with a fiber with a line width of φ4μm, the contact area of ​​the fiber with the support sheet is proportional to the line width to the first power, so the contact area is 1 / 4 times larger, while the tensile stiffness of the fiber is inversely proportional to the line width to the second power, so the tensile stiffness is 16 times larger. As a result, in order to peel a fiber with a thinner line width from the support sheet, it is necessary to use a support sheet with weak adhesive strength (peeling strength), which means that the cut fibers at the split section are more likely to fray and become entangled.

[0006] The present disclosure has been made in consideration of the above, and aims to provide a fiber assembly in which cut fibers are less likely to become entangled in dense parts in actual use when cut into individual pieces. [Means for solving the problem]

[0007] The fiber aggregate of the present invention comprises a warp thread group formed by arranging a plurality of warp threads made of a polymeric material on a main surface of a support sheet which has been subjected to a release treatment, and a weft thread group formed by arranging a plurality of weft threads made of a polymeric material, the warp thread group and the weft thread group having a number of first contact regions and non-contact regions, the first contact region being a region where the warp threads and the weft threads are integrated, the line width of the warp threads and the weft threads being 1 to 10 μm, the fiber density of the first contact region being greater than the fiber density of the non-contact region, the spacing between the warp threads or the weft threads in the first contact region being 5 μm or more and 1000 μm or less, and the larger spacing between the warp threads or the weft threads in the non-contact region being 2000 μm or more.

[0008] The method for producing a fiber assembly according to the present invention includes the steps of: moving a nozzle for supplying fibers made of a polymeric material relative to a rotating support sheet that is wound around a rotor in a cylindrical shape and fixed thereto, in a direction parallel to the axis of rotation, to spin fibers onto the support sheet so as to include a high fiber density portion on the support sheet where the spacing between adjacent fibers is 5 μm to 1000 μm, and a low fiber density portion where the spacing between adjacent fibers is 2000 μm or more, thereby forming a first layer; a step of spinning fibers on the support sheet so as to include a high fiber density portion on the support sheet where the spacing between adjacent fibers is 5 μm to 1000 μm and a low fiber density portion on the support sheet where the spacing between adjacent fibers is 2000 μm or more, while moving a nozzle for supplying fibers made of a polymeric material in a direction parallel to the rotation axis relative to the support sheet which is wound around the rotor and fixed to the rotor so that the direction in which the support sheet is wound around the rotor intersects with the spinning direction of the first layer, thereby forming a second layer; heating the support sheet into which the first layer and the second layer are spun at a temperature equal to or higher than the melting point of the polymer material; Includes. Effect of the Invention

[0009] In the fiber assembly according to the present invention, the fibers arranged on the support sheet are formed in a visible dense pattern with the actual use portion being dense and the cut pieces being sparse. Therefore, by passing the blade width when cutting into individual pieces through the sparse fiber density portion, it is possible to prevent the cut fibers of the divided portion from being caught in the actual use portion with dense fiber density. [Brief description of the drawings]

[0010] [Figure 1-1] 1 is a schematic diagram showing an enlarged example of a case in which, on the main surface of a fiber aggregate according to the first embodiment, the warp yarns have a pattern of dense and sparse fiber densities, and the weft yarns have a pattern of only sparse fiber densities. [Figure 1-2] FIG. 2 is a schematic diagram showing a division between a first contact region and a non-contact region in the case of FIG. 1-1. [Figure 2-1] 1 is a schematic diagram showing an enlarged example of a case in which the warp yarns and the weft yarns both have a pattern of dense and sparse fiber densities on the main surface of a fiber aggregate according to Variation 1 of the first embodiment. FIG. [Figure 2-2] FIG. 2-2 is a schematic diagram showing a division between a first contact area and a non-contact area in the case of FIG. 2-1. [Figure 3-1] This is an enlarged schematic diagram showing an example in which, on the main surface of a fiber aggregate relating to variant example 2 of embodiment 1, the warp thread group has a pattern of dense and sparse fiber density and has diagonal warp threads, and the weft thread group has a pattern of only sparse fiber density. [Figure 3-2] 3-2 is a schematic diagram showing division into a first contact region, a non-contact region, and a second contact region in the case of FIG. 3-1. FIG. [Figure 4-1] This is an enlarged schematic diagram showing an example in which the main surface of a fiber aggregate relating to variant example 3 of embodiment 1 of the present invention has warp threads and weft threads that both have patterns of dense and sparse fiber density and have diagonal warp threads and diagonal weft threads. [Figure 4-2] 4-2 is a schematic diagram showing division into a first contact region, a non-contact region, and a second contact region in the case of FIG. 4-1. FIG. [Diagram 5] 4 is a schematic cross-sectional view showing an enlarged example of a cross-sectional structure of a part of a first contact region in a fiber aggregate according to the first embodiment, as viewed from a plane perpendicular to the thickness direction. FIG. [Figure 6A] 3 is a schematic diagram showing a cutting line when cutting individual pieces of actual use portions from the fiber assembly according to the first embodiment. FIG. [Figure 6B] 6B is a perspective view showing a part of an operation of pressing and bonding a frame body to the part cut into individual pieces in FIG. 6A. FIG. [Figure 6C] FIG. 6C is a perspective view of the frame in FIG. 6B after it has been peeled off from the support sheet. [Figure 6D] FIG. 6D is a perspective view of the fiber group that is free-standing via a frame in FIG. 6C and adhered to the opening surface of the container. [Figure 7-1] FIG. 1 is a schematic diagram showing a configuration of an example of a spinning device for producing a fiber aggregate according to the first embodiment. [Figure 7-2] 7-2 is a side view of the spinning device of FIG. 7-1 as viewed from the direction of the rotation axis of the winding drum (X direction). [Figure 8] 1 is a flowchart of each step in a method for producing a fiber assembly according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The fiber assembly according to the first aspect is provided with a support sheet on a release-treated main surface thereof. A warp yarn group formed by arranging a plurality of warp yarns made of a polymer material; A weft yarn group including a plurality of weft yarn sets each made of a polymer material; Equipped with The warp yarn group and the weft yarn group have a number of first contact areas and non-contact areas, The first contact region is a region where the warp yarns and the weft yarns are integrated, The line width of the warp yarn and the weft yarn is 1 to 10 μm, The fiber density of the first contact region is greater than the fiber density of the non-contact region, The interval between the warp yarns or the weft yarns in the first contact area is 5 μm or more and 1000 μm or less, The larger of the distance between the warp threads or the distance between the weft threads in the non-contact region is 2000 μm or more.

[0012] The fiber assembly according to the second aspect of the present invention is the fiber assembly according to the first aspect of the present invention, further comprising: The fabric may have a second contact region where one or more and three or less diagonal warp threads or diagonal weft threads that are not in parallel with the warp threads or weft threads are integrated with the weft threads or warp threads.

[0013] A method for producing a fiber assembly according to a third aspect includes the steps of: moving a nozzle for supplying fibers made of a polymeric material relative to a rotating support sheet that is wound around a rotor in a cylindrical shape and fixed thereto, in a direction parallel to the axis of rotation, to spin fibers onto the support sheet so as to include a high fiber density portion in which the spacing between adjacent fibers is 5 μm to 1000 μm and a low fiber density portion in which the spacing between adjacent fibers is 2000 μm or more, thereby forming a first layer; a step of spinning fibers on the support sheet so as to include a high fiber density portion on the support sheet where the spacing between adjacent fibers is 5 μm to 1000 μm and a low fiber density portion on the support sheet where the spacing between adjacent fibers is 2000 μm or more, while moving a nozzle for supplying fibers made of a polymeric material in a direction parallel to the rotation axis relative to the support sheet which is wound around the rotor and fixed to the rotor so that the direction in which the support sheet is wound around the rotor intersects with the spinning direction of the first layer, thereby forming a second layer; heating the support sheet into which the first layer and the second layer are spun at a temperature equal to or higher than the melting point of the polymer material; Includes.

[0014] In the method for producing a fiber aggregate according to the fourth aspect, in at least one of the steps of forming the first layer and the step of forming the second layer, a plurality of nozzles aligned in a direction parallel to the rotation axis direction may be used.

[0015] A fiber assembly according to an embodiment will be described below with reference to the accompanying drawings, in which substantially identical members are denoted by the same reference numerals.

[0016] (Embodiment 1) <Fiber assembly> The fiber aggregate of embodiment 1 comprises a warp thread group formed by arranging a set of multiple warp threads made of a polymeric material on a main surface of a support sheet which has been subjected to a release treatment, and a weft thread group formed by arranging a set of multiple weft threads made of a polymeric material, the warp thread group and the weft thread group having a number of first contact regions and non-contact regions, the first contact region being a region where the warp threads and the weft threads are integrated, the line width of the warp threads and the weft threads being 1 to 10 μm, the fiber density of the first contact region being greater than the fiber density of the non-contact region, the spacing between the warp threads or the weft threads in the first contact region being 5 μm or more and 1000 μm or less, and the larger spacing between the warp threads or the weft threads in the non-contact region being 2000 μm or more.

[0017] The fiber assembly according to the first embodiment will be described in detail below with reference to the accompanying drawings. 1-1 to 4-2 are schematic diagrams illustrating enlarged examples of the main surface of the fiber assembly according to the first embodiment. The fiber assembly 100 according to the first embodiment is composed of a support sheet 101 and a group of warp threads 102 and a group of weft threads 103 arranged on the main surface of the support sheet 101.

[0018] <Support sheet> Support sheet 101 is made of a PET film having a thickness of 75 μm, and its main surface is subjected to a release treatment (not shown) using a fluorine material. The reason why a release-treated film is used for the support sheet 101 will be explained in detail in the manufacturing method of the fiber assembly described later.

[0019] <Warp and weft thread groups> The polymer material of the warp thread group 102 and the weft thread group 103 is polystyrene, and the line width is 2 μm. The materials of the warp thread group 102 (and the oblique warp thread 202 described later) and the weft thread group 103 (and the oblique weft thread 203 described later) can be used to prepare a support by a spinning method as described later. For example, materials that can be spun into a solution include not only polystyrene but also silicone, polyurethane, silicone-polyurethane copolymer collagen, etc. In addition, materials that can be spun into a melt include polylactide (PLA), poly-L-lactic acid (PLLA), polyglycolide (PGA), lactic acid-glycolic acid copolymer (PLGA), etc. However, the present invention is not limited to these, and inorganic fillers may be dispersed in a material mainly composed of a polymer, for example, to provide a certain level of conductivity. In addition, the warp thread group 102 (and the oblique warp thread 202 described later) and the weft thread group 103 (and the oblique weft thread 203 described later) may be made of the same material or a combination of different materials.

[0020] In addition, as described below, it is necessary to integrate the contact portions of the warp threads and weft threads, but the candidate materials listed here exhibit thermoplasticity and can be integrated by thermal fusion.

[0021] The line width of the warp yarn group 102 and the weft yarn group 103 means the average thickness of the cross section perpendicular to the length direction of the original yarn. For example, when the lattice formed by the warp yarn group 102 and the weft yarn group 103 is used as a scaffold for culturing cells as biological tissue, the line width of the warp yarn group 102 and the weft yarn group 103 is preferably 1 μm to 10 μm from the viewpoint of cell adhesion. Furthermore, it may be 1 μm to 5 μm, 2 μm to 4 μm, etc.

[0022] The warp threads constituting the warp thread group 102 and the weft threads constituting the weft thread group 103 may have different diameters in the range of 1 μm to 10 μm. In consideration of the planar uniformity of the lattice formed by the warp thread group 102 and the weft thread group 103 and the securing of strength of the contact portion by the approximately flattening accompanied by heat fusion described later, it is preferable that the warp threads constituting the warp thread group 102 and the weft threads constituting the weft thread group 103 have the same diameter.

[0023] <Gaps between warp and weft threads> Next, the spacing between the gaps of the warp yarn group 102 and the spacing between the gaps of the weft yarn group 103 will be described with reference to Figs. 1-1, 1-2, 2-1, and 2-2.

[0024] Fig. 1-1 illustrates a case where the warp yarn group 102 has a pattern with dense and sparse fiber densities, and the weft yarn group 103 has a pattern with only sparse fiber densities. Fig. 1-2 is a schematic diagram showing the division of the first contact area A and the non-contact area B in the case of Fig. 1-1.

[0025] In the warp yarn group 102 in FIG. 1-1, the gaps between each warp yarn are 5 μm in the dense fiber density portion, and the gaps between each warp yarn and each weft yarn are 2000 μm in the sparse fiber density portion.

[0026] (Variation 1) Fig. 2-1 is a schematic diagram illustrating a case where both the warp yarn group 102 and the weft yarn group 103 have a pattern with dense and sparse fiber densities on the main surface of the fiber aggregate 100a according to the first modification of the present embodiment 1. Fig. 2-2 is a schematic diagram showing the division of the first contact area A and the non-contact area B in the case of Fig. 2-1. In the warp yarn group 102 in FIG. 2-1, the gaps between each warp yarn and each weft yarn in the dense fiber density portion are 5 μm, and the gaps between each warp yarn and each weft yarn in the sparse fiber density portion are 2000 μm.

[0027] By "gap spacing" is meant the average distance between adjacent yarn edges in a direction perpendicular to the length of the original yarn. For example, when the lattice formed by the warp thread group 102 and the weft thread group 103 is used as a scaffold for culturing cells as biological tissue, the gaps in the dense fiber density portion are preferably 5 μm to 1000 μm in consideration of culturing cells on the threads or in the openings of the lattice. Alternatively, the gaps may be 5 μm to 500 μm, 5 μm to 200 μm, etc. The gaps in the low fiber density areas should be visible when cutting the fiber assembly 100 into individual pieces for actual use, and should be large enough for the blade width to pass through when cutting into individual pieces, and are desirably spaced at intervals of 2000 μm or more.

[0028] [effect] In other words, with this fiber aggregate, as shown in Figures 1-2 and 2-2, by cutting the fiber aggregate in the area with sparse fiber density, i.e., the non-contact area B, the cut fibers of the divided area are less likely to become entangled in the area with dense fiber density, i.e., the first contact area A. 1-1 and 1-2, and 2-1 and 2-2 show an example in which there is no contact area in the portion where the fiber density of the warp yarn group or the weft yarn group is sparse, that is, in the non-contact area B.

[0029] Next, Figures 3-1 and 2, and Figures 4-1 and 2 will be used to explain an example where the fiber density of the warp yarn group or weft yarn group is sparse, i.e., the non-contact area B, has a second contact area which is an area where the diagonal warp yarn and the weft yarn group are integrated and / or an area where the diagonal weft yarn and the warp yarn group are integrated.

[0030] (Variation 2) Fig. 3-1 is a schematic diagram illustrating a case where the warp yarn group 102 has a pattern of dense and sparse fiber densities and has a diagonal warp yarn 202, and the weft yarn group 103 has a pattern of only sparse fiber densities on the main surface of the fiber aggregate 100b according to the second modification of the first embodiment. Fig. 3-2 is a schematic diagram showing the division of the first contact area A, the non-contact area B, and the second contact area C in the case of Fig. 3-1. In the dense fiber density portion of the warp yarn group 102 in FIG. 3-1, the gap between each warp yarn is 5 μm, and the gap between each weft yarn in the weft yarn group 103 is 2000 μm. In addition, as shown in Figure 3-1, there are two oblique warp threads 202 that are not parallel to the warp thread group, sandwiched between the dense parts of the warp thread group. Although the oblique warp threads 202 and the warp thread group 102 are not parallel, the angle between them is small, for example, 30 degrees or less. As a result, as shown in Figure 3-2, the non-contact area B includes a second contact area C, which is an area where the oblique warp threads 202 and the weft thread group 103 are integrated.

[0031] (Variation 3) Fig. 4-1 is a schematic diagram illustrating a case where, on the main surface of a fiber assembly 100c according to a third modification of the first embodiment, a warp yarn group 102 and a weft yarn group 103 both have a pattern with dense and sparse fiber density, and have oblique warp yarns 202 and oblique weft yarns 203. Fig. 4-2 is a schematic diagram illustrating the division of a first contact region A, a non-contact region B, and a second contact region C in the case of Fig. 4-1. In the warp yarn group 102 in FIG. 4-1, the gaps between each warp yarn and each weft yarn in the dense fiber density portion are 5 μm, and the gaps between each warp yarn and each weft yarn in the sparse fiber density portion are 2000 μm. In addition, as shown in FIG. 4-1, there are two oblique warp threads 202 that are not parallel to the warp thread group, sandwiched between the dense parts of the warp thread group 102. There are also two oblique weft threads 203 that are not parallel to the weft thread group 103, sandwiched between the dense parts of the weft thread group 103. Although the oblique weft threads 203 and the weft thread group 103 are not parallel, the angle between them is small, for example, 30 degrees or less. As a result, as shown in FIG. 4-2, the non-contact region B includes a region where the oblique warp threads 202 and the weft thread group 103 are integrated, and a second contact region C where the oblique weft threads 203 are integrated with the warp thread group 102.

[0032] As described above, the gaps in the areas with high fiber density are preferably 5 μm to 1000 μm, and may be 5 μm to 500 μm, 5 μm to 200 μm, or the like. As described above, it is also desirable that the gaps in the portions where the fiber density is sparse have intervals of 2000 μm or more.

[0033] [effect] Here, as shown in Figures 3-2 and 4-2, by cutting the fiber aggregate into individual pieces in the area with sparse fiber density, i.e., the non-contact area B, the non-contact area includes a second contact area C, but by keeping the number of diagonal warp threads or diagonal weft threads that are not in a parallel relationship with the warp threads or weft threads and are surrounded by the dense areas of the warp threads or weft threads to around 1 to 3, the cut fibers of the divided area are less likely to become entangled in the area with dense fiber density, i.e., the first contact area A.

[0034] <First contact area> Next, FIG. 5 is a schematic cross-sectional view showing an enlarged example of a cross-sectional structure of a part of the first contact region A in the fiber aggregate according to the first embodiment, as viewed from a direction perpendicular to the thickness direction.

[0035] The average thickness t of the contact portion 30 between the warp yarns 12 and the weft yarns 13 of the fiber assembly 100 according to the present embodiment 1 is equivalent to 3 μm. Here, the average thickness t of the contact portion means the average sum of the thicknesses of the warp threads and the weft threads at the contact portion 30 where the warp threads and the weft threads are integrated. In order to make the lattice formed by the warp thread group 102 and the weft thread group 103 thin and smooth, it is better to reduce the thickness of the contact portion that is integrated by a heat treatment as described later.

[0036] With regard to the average thickness t of the contact portion, assuming that the average diameters of the warp and weft raw yarns are a and b, it is desirable to set the average thickness t of the contact portion to 80% or less of their sum (a+b), that is, 0.8 x (a+b), from the viewpoint of ensuring the strength of the contact portion by the approximate flattening accompanied by heat fusion described later. The lower limit can be appropriately determined by the parties concerned so long as the openings do not disappear, with respect to the size and position of the openings designed in the lattice formed by the materials constituting the warp and weft thread groups and the spacing of the gaps.

[0037] Furthermore, in terms of smoothness, the weft yarns 13 are always located above the warp yarns 12 in the cross section of the contact portion 30, so that the fabric can be maintained in a thin and smooth state. In other words, if the weft yarns 13 and the warp yarns 12 are not only in the upward direction but also in the downward direction in the contact area 30, the smoothness is impaired, which is undesirable. Also, it is desirable for the smoothness to be such that the thicknesses of the weft yarns 13 and the warp yarns 12 are consistent in the contact area 30 by making the average diameters of the raw yarns of the warp yarns 12 and the weft yarns 13 the same.

[0038] <Attaching individual pieces of fiber to a container> Next, FIG. 6 is a schematic diagram showing a mode in which a group of fibers is attached to a container from the fiber assembly via a frame in the first embodiment. FIG. 6A is a schematic diagram showing a cutting line 601 when cutting the fiber assembly 100 according to the first embodiment into individual pieces for actual use. As described above, by cutting the partial fiber aggregate having a low fiber density, the cut fibers of the divided portion are less likely to be caught in the portion having a high fiber density. FIG. 6B is a perspective view showing a part of the operation of pressing and adhering a frame body 602 to the parts cut into individual pieces in FIG. 6A.

[0039] FIG. 6C is a perspective view of frame 602 in FIG. 6B after it has been peeled off from support sheet 101. FIG. An adhesive layer (not shown) is coated on the surface of the frame body 602 opposite the main surface of the support sheet having the warp thread group 102 and weft thread group 103, and when it is pressed against the support sheet 101 and then peeled off, it becomes possible to transfer the fiber group 604 consisting of the warp thread group 102 and the weft thread group 103 to the adhesive layer of the frame body 602.

[0040] FIG. 6D is a perspective view of the fibers 604 that are freestanding via the frame 602 in FIG. 6C and bonded to the opening surface of the container 603.

[0041] In the first embodiment, polystyrene is used for container 603, and fiber group 604 is bonded to the open surface of the container by thermocompression bonding to adhere to container 603. However, thermocompression bonding is not necessary, and for example, bonding may be performed via an adhesive.

[0042] <Spinning equipment> Fig. 7-1 is a schematic diagram showing the configuration of an example of a spinning apparatus for producing a fiber aggregate according to the present embodiment 1. By the spinning apparatus shown in Fig. 7-1, a group of warp threads and a group of weft threads are formed on a support sheet 101. Fig. 7-2 is a side view seen from the direction of the rotation axis (X direction) of the winding drum 303 of the spinning apparatus 300 in Fig. 7-1. For convenience, in the drawings, the direction of the rotation shaft of the winding drum 103 is designated as the X direction, the vertical upward direction is designated as the Y direction, and the direction from the front to the back of FIG. 4-1 is designated as the Z direction.

[0043] The spinning device 300 includes a plurality of nozzles 301, a winding drum 303, a guide 305, and a nozzle moving means. A polymeric material is extruded from a nozzle 301 in a molten or liquid state. The take-up drum 303 takes up in one stroke the fibers 302 which are made of the polymer material extruded from the nozzle 301 and naturally cooled or dried. A guide 305 regulates the winding position of the fiber 302 onto the winding drum 303 .

[0044] Further, the nozzle 301 is moved relatively in a direction parallel to the rotation shaft 304 of the winding drum 303 by a nozzle moving means (not shown). In this spinning apparatus 300, the nozzle 301 and the guide 305 move together. In this spinning apparatus 300, a polymeric material such as polystyrene is extruded from a nozzle 301 in a solution or molten state by swelling with an organic solvent or heating, and then naturally cooled or dried to form solid fibers 302.

[0045] According to this spinning apparatus 300, the nozzle 301 and the guide 305 move together as one unit, so that the resistance frictional force that the guide receives from the fibers during the movement is extremely small. Therefore, even fine fibers 302 having a diameter of about 1 to 10 μm can be arranged accurately and at a uniform pitch on the winding drum 303 without being broken. Furthermore, by controlling the pitch when the nozzle 301 is moved in a direction parallel to the rotation shaft 304 of the winding drum 303, a gap can be formed between the yarns. The multiple nozzles 301 are arranged in a direction parallel to a rotation axis 304 of the winding drum 303 .

[0046] As shown in FIG. 3-1 and FIG. 4-1, there are 1 to 3 oblique warp threads that are not parallel to the warp thread group sandwiched between the dense parts of the warp thread group, or there are 1 to 3 oblique weft threads that are not parallel to the weft thread group sandwiched between the dense parts of the weft thread group. Here, when only one nozzle 301 is used, it is necessary to move from a dense fiber density part to a sparse fiber density part. The above oblique warp threads and oblique weft threads are generated, for example, when the nozzle moves between the pitches of the sparse part between the dense and dense parts. On the other hand, as shown in FIG. 7-1, when multiple nozzles 301 are used, there is no movement from a dense fiber density part to a sparse fiber density part, so there is no thread sandwiched between the dense part, and by cutting the fiber aggregate in the sparse fiber density part, the cut fibers of the division part are less likely to be caught in the dense fiber density part, which is desirable.

[0047] <Method of manufacturing fiber assembly> 8 is a flowchart showing a method for producing a fiber assembly according to the present embodiment 1. The method for producing this fiber assembly will be described below. (1) S01 is a step of preparing a support sheet. Specifically, for example, as described above, a PET film having a thickness of 75 μm is wound around the winding drum 303 of the spinning device 300. It is desirable that the surface of the PET film is one having an appropriate releasability by fluorine treatment or the like. This is because, when spinning the fibers 302 onto the support sheet in steps S02 and S04 described below, an adhesive function for the fibers 302 is required, and, in order to later handle the fiber group 604 as a free-standing film, a peeling function from the film is required in step S05.

[0048] (2) S02 is a process of spinning the first layer 402. Using the spinning device 300, a solution of a polymer material melted by heating or swollen with an organic solvent is applied in the same direction in the form of thin lines onto the support sheet prepared in S01. Here, the polymer material supplied in a molten or liquid state is naturally cooled or naturally dried to form fibers in a solid state only. In this embodiment 1, a solution of pellet-shaped polystyrene swollen in DMF (N,N-dimethylformamide), an organic solvent, is used to apply fibers with a diameter of 2 μm at intervals equivalent to a gap of 5 μm by controlling the movement speed of nozzle 301 relative to the rotation speed of winding drum 303.

[0049] (3) S03 is a step of rotating the support sheet on which the first layer 102 has been spun in step S02 at a predetermined angle in the same plane. In this embodiment, the yarn is rotated by 90° to form a lattice in which the first layer spun in step S01 and the second layer spun in step S04, which will be described later, are substantially perpendicular to each other. The rotation angle may be from 30° to 150°, but from the viewpoint of maintaining the shape of the lattice against external forces, it is preferable that the first layer and the second layer are in contact with each other by intersecting at an angle of 90°.

[0050] (4) S04 is a process of spinning a second layer onto the support sheet rotated 90° in S03. A solution of a polymer material, which is melted by heating or swollen with an organic solvent, is applied in the same direction in thin lines onto the support sheet prepared in S03.

[0051] In this embodiment 1, polystyrene with low cytotoxicity is adopted as the polymer material as in the S02 process, and a solution of pellet-shaped polystyrene swollen in DMF (N,N-dimethylformamide), an organic solvent, is used to apply fibers with a diameter of 2 μm at intervals equivalent to a gap of 5 μm by controlling the movement speed of the nozzle 301 relative to the rotation speed of the winding drum 303.

[0052] (5) S05 is a process in which the fibers prepared in S04 are heated on a support sheet. Specifically, the fibers are heated on the support sheet for a certain period of time at a temperature equal to or higher than the melting point of the polymer material (polystyrene in this embodiment). As a result, when the bottoms of the first and second layers in contact with the support sheet become molten, the shape is maintained constant even in the molten state due to the interfacial tension between the support sheet surface and the polymer. As a result, the bottom of the molten second layer sinks below the top of the molten first layer, ensuring integration by thermal fusion and at least a portion of the bottoms of the first and second layers becoming approximately flat.

[0053] Furthermore, by heating the fiber on the support sheet, the manner in which the second layer sinks into the first layer in the cross section of the contact area between the first and second layers is such that, when the spinning surface is viewed as the top surface of the contact area, the uppermost surface is the second layer, while when the spun surface is viewed as the top surface of the contact area, the uppermost surface is the first layer, making it possible to maintain a constant vertical relationship between the two layers and maintain smoothness.

[0054] Here, for convenience, the first layer corresponds to the warp threads and the second layer 403 corresponds to the weft threads, but it is also possible to consider the weft threads as the first layer and the warp threads as the second layer.

[0055] (6) S06 is a process for cutting the sparse fiber density parts of the fiber aggregate produced in the processes up to S05 into individual pieces. For example, in order to use the fiber group in a location where it is to be applied, such as the cell scaffold material described above, a portion of low fiber density on the outer periphery of a portion of high fiber density that has been pre-specified to a desired size is cut into individual pieces using scissors or the like. The fiber group obtained by cutting into individual pieces can be used for transferring and adhering the fiber group to a desired portion in the manner described with reference to Figs. 6B to 6D.

[0056] Here, if the contact surface with the application site is required to be flat, the bottom side of the first layer may be disposed on the contact surface side. If there is no particular restriction on the shape of the contact surface, the bottom side of the first layer may be disposed on the contact surface side, or the top side of the second layer may be disposed on the contact surface side.

[0057] In addition, the present disclosure includes appropriate combinations of any of the various embodiments and / or examples described above, and can achieve the effects of each embodiment and / or example. [Industrial Applicability]

[0058] According to the fiber assembly and the method for producing the fiber assembly of the present invention, the handleability of the fiber assembly containing thin, highly aligned fibers is improved, making it possible to apply the fiber assembly to various uses. [Explanation of symbols]

[0059] 100 Fiber assembly 101 Support Sheet 102 Warp thread group 103 Weft group A 1st contact area B Non-contact area C 2nd contact area 12 Warp threads 13 Weft 202 Diagonal warp thread 203 Diagonal weft 30 Contact part 601 Cutting line 602 Frame 603 Container 604 Fiber Group 301 Nozzle 302 Textiles 303 Winding drum 304 Rotating Axis 305 Guide S01 Support sheet preparation S02 First layer spinning S03 Support sheet rotation S04 Second layer spinning S05 Heat treatment S06 Individual cutting

Claims

1. a step of spinning fibers onto a support sheet, which is wound around a rotor in a cylindrical shape and fixed thereto, while moving a nozzle for supplying fibers made of a polymeric material in a direction parallel to the axis of rotation relative to the support sheet, so as to include a high fiber density portion on the support sheet, in which the spacing between adjacent fibers is 5 μm to 1000 μm, and a low fiber density portion, in which the spacing between adjacent fibers is 2000 μm or more, to form a first layer; a step of spinning fibers on the support sheet so as to include a high fiber density portion on the support sheet where the spacing between adjacent fibers is 5 μm to 1000 μm and a low fiber density portion on the support sheet where the spacing between adjacent fibers is 2000 μm or more, while moving a nozzle for supplying fibers made of a polymeric material in a direction parallel to the rotation axis relative to the support sheet which is wound around the rotor and fixed to the rotor so that the direction in which the support sheet is wound around the rotor intersects with the spinning direction of the first layer, thereby forming a second layer; heating the support sheet into which the first layer and the second layer are spun at a temperature equal to or higher than the melting point of the polymer material; A method for producing a fiber assembly comprising the steps of:

2. The method for producing a fiber aggregate according to claim 1 , wherein a plurality of nozzles arranged in a direction parallel to the rotation axis direction are used in at least one of the steps of forming the first layer and forming the second layer.

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