Porous body manufacturing method and manufacturing device

Abstract

To provide a method for producing a porous body having a required quality, which is obtained by compressing and sintering synthetic resin powder so as to suppress a density variation.SOLUTION: There is provided a method for producing a porous body, comprising: a filling step of filling each through hole 15 formed in a mold 8 with a synthetic resin powder 2; and a suction compression step in which, after the filling step, the air remained in each through hole 15 is sucked out, thereby applying a compression load to the entire synthetic resin powder 2 in the through hole 15. Therefore, a porous body having a required quality can be produced by compressing and sintering so as to control a density distribution of the synthetic resin powder.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method and an apparatus for producing a porous body formed by sintering synthetic resin powder. [Background technology]

[0002] As a prior art method for producing porous bodies, Patent Document 1 describes that porous products can be formed by a sintering method in which polyethylene polymer powder is introduced into a mold and sufficient heat is applied to soften, expand, and bring the polyethylene particles into contact with each other, and that suitable methods include compression molding and casting, and that if adjustment of the porosity is required, proportionally lower pressures are applied to the powder. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2013-531083 Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1, conventional methods for manufacturing porous bodies involve filling the internal space between a pressing die and a receiving die with synthetic resin powder, then moving the pressing die to reduce the volume of the internal space, while heating and sintering the synthetic resin powder while applying a compressive load to the entire powder.

[0005] However, in this conventional manufacturing method, the synthetic resin powder filled in the internal space between the pressing die and the receiving die is sufficiently compressed in the areas close to the pressing die and the receiving die along the compression direction, resulting in bonding of the powder particles and a high density, while in the approximately central area in the compression direction, the bonding between the powder particles is insufficient, resulting in a low density. This is because the compressive force applied to the powder particles filled between the pressing die and the receiving die weakens as they move from both ends in the compression direction toward the approximately central area in the compression direction. Thus, there is a risk that the desired quality of the porous body cannot be obtained with the conventional manufacturing method.

[0006] That is, when a porous body used for, for example, a pen tip (a thin rod-shaped body) of a writing instrument is manufactured using this conventional manufacturing method, the above-mentioned phenomenon occurs significantly, and the tip portion of the pen tip (porous body) that comes into contact with the paper is hard, not only does it not provide a good writing feel, but it also impedes the flow of ink at the tip portion. Moreover, as mentioned above, the approximate center portion of the pen tip in the longitudinal direction has a low density and is porous, with insufficient bonding between the powder particles, so that bending strength is not ensured, and there is a risk of problems occurring during the assembly process. Furthermore, the approximate center portion of the pen tip in the longitudinal direction has low capillary force, so ink flow is not sufficient.

[0007] The present invention has been made in consideration of these points, and aims to provide a method and apparatus for producing a porous body having the required quality by compressing and sintering synthetic resin powder so as to suppress variations in density. [Means for solving the problem]

[0008] As a means for solving the above-mentioned problems, the present invention relates to a method for producing a porous body as claimed in claim 1, which is a method for producing a porous body obtained by sintering a synthetic resin powder, and includes: a filling step of filling a filling space provided in a mold with the synthetic resin powder; and a suction compression step of applying a compressive load to the entire synthetic resin powder in the filling space by sucking air from the filling space after the filling step. a closing step of closing the filling space filled with the synthetic resin powder after the suction and compression step; and a sintering step of heating the filling space to sinter the synthetic resin powder after the closing step. The present invention is characterized in that it comprises: In the invention of claim 1, in particular, the suction compression step makes it possible to compress the synthetic resin powder while suppressing variations in density within the filling space of the mold, and as a result, the density of the synthetic resin powder is approximately uniform, making it possible to produce a porous body with the required quality. Furthermore, in the invention of claim 1, the density of the synthetic resin powder becomes approximately uniform, and a porous body having the required quality can be produced.

[0010] Claim 2 The invention relating to the method for producing a porous body is characterized in that, in the invention of claim 1, the porous body is an elongated rod-shaped body. Claim 2 The invention is particularly effective when producing a long, thin rod-shaped porous body, which is prone to density variations in the synthetic resin powder when compressed and sintered by moving a mold or the like, as is the conventional method.

[0011] Claim 3 The invention relating to the method for producing a porous body is: In the invention of claim 1 or 2, The porous body is characterized in that it is used for a pen core of an applicator. Claim 3 The invention is particularly effective when manufacturing a porous body to be used as a pen tip of an applicator, which is a long, thin rod-shaped body. In other words, the porous body has the quality required for a pen tip. Note that applicators also include so-called writing implements.

[0012] Claim 4 The invention relating to the porous body manufacturing apparatus is: To realize the method for producing a porous body according to claim 1 A porous body manufacturing apparatus comprising: a mold having a filling space to be filled with synthetic resin powder; The synthetic resin powder filled a suction pump that sucks air from the filling space; a closing member that closes the filling space of the mold after the air in the filling space filled with the synthetic resin powder has been sucked out by the suction pump, and a heating member that heats the filling space to sinter the synthetic resin powder after closing the filling space with the closing member; The present invention is characterized by the following features. Claim 4In the invention of claim 2, in particular, by using a suction compression pump to suck out air from the filling space of the mold where the synthetic resin powder is filled, it is possible to compress the synthetic resin powder while suppressing variations in density within the filling space of the mold. As a result, similar to the invention of claim 1, it is possible to produce a porous body with a synthetic resin powder having a substantially uniform density and the required quality.

[0013] Claim 5 The invention relating to the porous body manufacturing apparatus is as follows: 4 In the invention, the apparatus comprises a suction member having a suction space communicating with the filling space of the mold, and a mesh member arranged between the filling space and the suction space to prevent synthetic resin powder from entering the suction space from the filling space, and the suction space of the suction member is characterized in that it communicates with the suction pump. Claim 5 In the invention, the mesh member can prevent the synthetic resin powder from entering the suction space of the suction member from the filling space of the mold, and a porous body having the required quality can be reliably produced in the filling space of the mold. Furthermore, the configuration of the manufacturing device, including the suction pump that sucks air from the filling space of the mold, can be simplified, thereby reducing equipment costs, etc.

[0014] Claim 6 The invention relating to the porous body manufacturing apparatus is as follows: 5 The invention is characterized in that a sealing member is provided between the suction member and the mold, which increases the adhesion between them. Claim 6 In the invention, the sealing member can increase the adhesion between the suction member and the mold, and as a result, the efficiency of the suction pump in suctioning air from the filling space of the mold can be improved.

[0015] Claim 7 The invention relating to the porous body manufacturing apparatus is as follows: 4 In the invention, the mold has a plurality of through holes formed therein as the filling space, and the porous body is an elongated rod-like body. Claim 7 In the invention of claim 2 and 3 As with the invention of (1), this is particularly effective when producing a porous body to be used in a pen core of an applicator, which is an elongated rod-like body. [Effects of the Invention]

[0016] According to the manufacturing method and manufacturing apparatus of the present invention, a porous body having the required quality can be manufactured by compressing and sintering synthetic resin powder so that variations in density can be suppressed. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of components constituting a porous body manufacturing apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of components used in the filling step and the suction and compression step of the porous body manufacturing apparatus according to the embodiment of the present invention. [Figure 3] FIG. 3 is a perspective view of components used in the plugging step and the sintering step of the porous body manufacturing apparatus according to the embodiment of the present invention. [Figure 4] FIG. 4 is a flow chart illustrating a method for producing a porous body according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to Figures 1 to 4. For convenience of the following description, the lower side of the drawings (in the direction in which the symbols can be read correctly) will be referred to as the lower end side, and the upper side will be referred to as the upper end side. Note that in this embodiment, Figures 1 to 4 show the porous body manufacturing apparatus 1 used in a vertical position, but it may also be used in a horizontal position.

[0019] 1 and 4, the porous body manufacturing apparatus 1 according to the embodiment of the present invention is an apparatus for manufacturing a porous body that sinters a synthetic resin powder 2 in each through-hole 15 of a mold 8. More specifically, the porous body manufacturing apparatus 1 according to the present embodiment includes a mold 8 having through-holes 15 (filling spaces) into which the synthetic resin powder 2 is filled, a suction member 9 having a suction space 31 communicating with each through-hole 15 of the mold 8, a mesh member 10 provided between each through-hole 15 of the mold 8 and the suction space 31 of the suction member 9 to prevent the synthetic resin powder 2 from entering the suction space 31 through each through-hole 15, a suction pump 11 communicating with the suction space 31 of the suction member 9 to suck air from within each through-hole 15 of the mold 8, a pair of closing members 13 that close both axial ends of each through-hole 15 of the mold 8, and a heating member 12 that heats and sinters the synthetic resin powder 2 in each through-hole 15 of the mold 8.

[0020] The porous body 5 (see FIG. 4(d)) produced by the production apparatus 1 according to this embodiment is a thin rod-like body, more specifically, a thin rod-like body having a circular cross section. In this embodiment, the outer diameter of the thin rod-like body (porous body 5) is set within a range of 1.5 mm to 5.0 mm, and the length is set within a range of 5.0 mm to 50 mm. In the production apparatus 1 according to this embodiment, the longer the length of the porous body 5, the more effective its action and effect (described later) can be achieved. The porous body 5 is also employed as a pen core for applicators including writing implements. The axial end of the porous body 5, which is a thin rod-like body, can be formed into a desired shape, such as a spherical shape.

[0021] The synthetic resin powder 2 is a thermoplastic resin, such as polyacetal resin, polyethylene resin, acrylic resin, polyester resin, polyamide resin, polyurethane resin, polyolefin resin, polyvinyl resin, polycarbonate resin, polyether resin, polyphenylene resin, fluorine resin, styrene resin, etc. The outer diameter of the particles of the synthetic resin powder 2 is about 20 μm.

[0022] 1 to 3, the mold 8 is formed in a rectangular parallelepiped shape. The mold 8 has pin holes 20 formed at its four corners, through which positioning pins 17 are inserted. A plurality of through holes 15 are formed in the mold 8 along the vertical direction inside each pin hole 20. For example, if the area of ​​the mold 8 is 200 mm × 100 mm, approximately 150 through holes 15 are formed. The number of through holes 15 is not particularly limited. The through holes 15 are formed in an elongated shape and have a circular shape in a plan view. Each through hole 15 in the mold 8 functions as a filling space into which the synthetic resin powder 2 is filled. The inner diameter of each through hole 15 and the vertical dimension of the mold 8 are set corresponding to the desired dimensions of the porous body 5 described above. Referring to FIGS. 1, 3, and 4(c), the through holes 15 are blocked by a pair of blocking pins 28, 28 provided at both axial ends in a blocking step and a sintering step described below. A pair of closing members 13 are arranged in the mold 8 so as to abut on the upper and lower surfaces thereof, respectively.

[0023] 1, 3, and 4(c), a plurality of closing pins 28 are integrally formed on the closing member 13 so as to align with each of the through holes 15 of the mold 8. The closing member 13 is formed in a plate shape. The outer shape of the closing member 13 matches the outer shape of the mold 8. Pin holes 21, through which positioning pins 17 are inserted, are formed at the four corners of the closing member 13. The closing pins 28 protrude slightly from the surface of the closing member 13 facing the mold 8 toward the through holes 15 of the mold 8. Although not particularly limited, the closing pins 28 protrude by approximately 0.5 mm from the opposing surface of the closing member 13.

[0024] 1, 2, and 4(a) and (b), a suction member 9 is disposed on the lower end surface of a mold 8 in the filling step and suction compression step, which will be described later. The suction member 9 is formed in a plate shape. The outer shape of the suction member 9 matches the outer shape of the mold 8. Pin holes 22, through which positioning pins 17 are inserted, are formed at the four corners of the suction member 9. A suction space 31 is formed inside the suction member 9. A plurality of suction holes 32 communicating with the suction space 31 are formed in the suction member 9. Each suction hole 32 is drilled from the upper end surface of the suction member 9. Each suction hole 32 is aligned with and communicates with each through-hole 15 of the mold 8. A coupler 34 communicating with the suction space 31 is connected to the side of the suction member 9. A suction hose 36 of the suction pump 11 is connected to the coupler 34. An air tank 37 is disposed midway along the suction hose 36. An opening / closing cock 38 of the air tank 37 is disposed on the suction hose 36 between the air tank 37 and the tip thereof.

[0025] 1, 2, and 4(a) and (b), a sealing member 14 is disposed between the mold 8 and the suction member 9 to enhance their mutual adhesion during the filling step and suction compression step described below. The sealing member 14 is formed in a plate shape. The outer shape of the sealing member 14 matches the outer shape of the mold 8. Pin holes 23 for inserting positioning pins 17 are formed through the four corners of the sealing member 14. The sealing member 14 is made of soft rubber or silicone resin, which is capable of slight deformation so as to conform to the unevenness of the opposing surfaces of the mold 8 and the suction member 9. A mesh member 10 is integrally formed on the sealing member 14 and is positioned between each of the through holes 15 of the mold 8 and each of the suction holes 32 of the suction member 9 when the suction member 9 is disposed on the lower end side of the mold 8. The mesh members 10 are disposed corresponding to each of the through holes 15 of the mold 8 and each of the suction holes 32 of the suction member 9. A plurality of mesh members 10 are disposed in a stacked manner along the vertical direction. In this embodiment, about three to five mesh members 10 are stacked.

[0026] When each through-hole 15 of the mold 8 is filled with synthetic resin powder 2 having a predetermined outer diameter (20 μm), the mesh member 10 allows air to pass through during suction by the suction pump 11, while preventing the synthetic resin powder 2 from entering the suction holes 32 of the suction member 9 through the through-holes 15 of the mold 8. The mesh member 10 is made of, for example, a steel material woven with stainless steel wire. When synthetic resin powder 2 with different outer diameters is mixed in each through-hole 15 of the mold 8, particles with smaller outer diameters than the predetermined outer diameter can pass through the mesh member 10, while only particles with the predetermined outer diameter remain in each through-hole 15. Therefore, the mesh member 10 can also be used to sort the synthetic resin powder 2 in each through-hole 15 based on its outer diameter. This allows the porosity between particles of the synthetic resin powder 2 in the through-holes 15 to be approximately uniform throughout the entire area.

[0027] 1, 3, and 4(d), in the sintering step described below, a pair of heating members 12, 12 are placed on the surfaces of the pair of closing members 13, 13 opposite the mold 8 side. The heating members 12 are formed in a plate shape. The outer shape of the heating members 12 matches the outer shape of the mold 8. Pin holes 24, through which positioning pins 17 are inserted, are formed at the four corners of the heating member 12. An electric heating coil 42, which generates heat when an electric current is passed through it, is placed inside the heating member 12. Then, by passing an electric current through the electric heating coils 42, 42 inside the pair of heating members 12, 12, the pair of heating members 12, 12 generate heat, and the inside of each through-hole 15 of the mold 8 can be heated to a predetermined temperature.

[0028] Next, a method for producing the porous body 5 according to this embodiment using the porous body production apparatus 1 according to this embodiment described above will be described in detail based on FIG. 4, with reference also to FIG. 2 and FIG. 3 as appropriate. The method for producing the porous body 5 according to this embodiment is carried out in the following order: filling step → suction compression step → closing step → sintering step. First, the filling step is carried out. That is, in the filling step, referring to FIGS. 2 and 4(a) and (b), a sealing member 14 including mesh members 10 is placed on the lower end surface of the mold 8, and a suction member 9 is placed on the lower end surface of the sealing member 14.

[0029] Then, positioning pins 17 are inserted into the pin holes 20, 23, and 22 of the mold 8, seal member 14, and suction member 9, respectively, to position and integrate the mold 8, seal member 14, and suction member 9. This aligns the positions of the through holes 15 of the mold 8 with the suction holes 32 of the suction member 9. Mesh members 10 are also placed between the through holes 15 and the suction holes 32. The lower end surface of the mold 8 and the upper end surface of the suction member 9 are tightly attached to each other via the seal member 14. A suction hose 36 of the suction pump 11 is connected to the coupler 34 of the suction member 9. Next, synthetic resin powder 2 is filled into the upper openings of each through hole 15 of the mold 8. The synthetic resin powder 2 is filled into each through hole 15 of the mold 8 until it overflows around the upper openings.

[0030] Next, a suction compression step is performed. That is, in the suction compression step, referring to FIGS. 2 and 4(b), the suction pump 11 is operated, and then the on-off cock 38 of the air tank 37 is opened. Then, air is sucked out of each through-hole 15 (filling space) of the mold 8 via the suction space 31 and each suction hole 32 of the suction member 9. A compressive load is then applied uniformly throughout the synthetic resin powder 2 in each through-hole 15, and the synthetic resin powder 2 that overflowed around the upper ends of each through-hole 15 in the mold 8 also moves into each through-hole 15 and is compressed. The compression referred to here means that the overall volume of the synthetic resin powder 2 is reduced so that the inter-particle porosity of the synthetic resin powder 2 throughout the through-hole 15 becomes a predetermined value. As a result, the synthetic resin powder 2 in each through-hole 15 does not vary in density depending on the location, and the density of the synthetic resin powder 2 throughout each through-hole 15 becomes approximately uniform. In other words, the void ratio between particles of the synthetic resin powder 2 is approximately uniform throughout the entire area of ​​each through-hole 15. The suction pressure by the suction pump 11 is set appropriately according to the desired void ratio between particles of the synthetic resin powder 2.

[0031] During this suction compression step, a seal member 14 is interposed between the lower end surface of the mold 8 and the upper end surface of the suction member 9, thereby improving the efficiency with which the suction pump 11 suctions air from within each through-hole 15 of the mold 8. Furthermore, a mesh member 10 is disposed between each through-hole 15 of the mold 8 and each suction hole 32 of the suction member 9, thereby preventing the synthetic resin powder 2 (with a predetermined outer diameter) within each through-hole 15 of the mold 8 from being sucked into each suction hole 32 of the suction member 9 during suction by the suction pump 11.

[0032] Next, a closing step is performed. That is, in the closing step, the positioning pins 17 are removed from the pin holes 20, 23, and 22 of the mold 8, the sealing member 14, and the suction member 9, and the suction member 9 including the sealing member 14 and the suction pump 11 including the air tank 37 are removed. Note that even if the sealing member 14 and the suction member 9 are removed from the mold 8, the synthetic resin powder 2 in each through hole 15 of the mold 8 will not fall from each through hole 15. Next, referring to FIGS. 3 and 4(c), a pair of closing members 13 are placed above and below the mold 8 so as to abut against the upper and lower surfaces of the mold 8, respectively. Also, referring to FIGS. 3 and 4(d), a pair of heating members 12 are placed so as to abut against the surfaces of the pair of closing members 13 on the side opposite the mold 8. Next, positioning pins 17 are inserted into the pin holes 24, 21, 20 of the pair of heating members 12, 12, the pair of closing members 13, 13, and the mold 8, respectively, to position and integrate the pair of heating members 12, 12, the pair of closing members 13, 13, and the mold 8.

[0033] 4(c), the closing pins 28, 28 of the pair of closing members 13, 13 are slightly inserted into both axial ends of each through hole 15 of the mold 8, and each through hole 15 of the mold 8 is closed with the synthetic resin powder 2 filled therein. Note that, by slightly inserting the closing pins 28, 28 of the pair of closing members 13, 13 into both axial ends of each through hole 15 of the mold 8, it is possible to prevent burrs from forming on the axial ends of the porous body 5 sintered in each through hole 15, and also to apply a slight compressive load to the synthetic resin powder 2 in each through hole 15.

[0034] Next, a sintering step is carried out. That is, in the sintering step, referring to Figures 3 and 4(d), an electric current is passed through the electric heating coils 42, 42 in the pair of heating members 12, 12, thereby heating the inside of each through-hole 15 of the mold 8 to a predetermined temperature and sintering the synthetic resin powder 2 in each through-hole 15. As a result, a porous body 5 composed of an elongated rod-like body with a circular cross section is produced in the through-hole 15 of the mold 8.

[0035] The porous body manufacturing apparatus 1 according to the embodiment of the present invention described above comprises a mold 8 having through holes 15 into which synthetic resin powder 2 is filled, a suction pump 11 that communicates with each through hole 15 of the mold 8 and sucks out air from within each through hole 15 of the mold 8, a pair of closing members 13 that close both axial ends of each through hole 15 of the mold 8, and a pair of heating members 12 that heat and sinter the synthetic resin powder 2 in each through hole 15 of the mold 8, and by rearranging these suction pump 11, closing members 13 and heating members 12 in relation to the mold 8 between the suction compression step and the closing step, the porous body 5 can be easily manufactured.

[0036] Using this manufacturing apparatus 1, the following steps can be carried out: a filling step in which synthetic resin powder 2 is filled into each through hole 15 formed in the mold 8; a suction compression step in which, after the filling step, air is sucked out of each through hole 15, thereby applying a compressive load to the entire synthetic resin powder 2 in each through hole 15; a closing step in which, after the suction compression step, each through hole 15 of the mold 8 filled with synthetic resin powder 2 is closed; and a sintering step in which, after the closing step, each through hole 15 of the mold 8 is heated to sinter the synthetic resin powder 2. This allows compression while suppressing variations in density of the synthetic resin powder 2 in each through-hole 15 of the mold 8, and as a result, a porous body 5 having a desired quality and a substantially uniform density throughout the synthetic resin powder 2 (a substantially uniform void ratio between particles throughout the synthetic resin powder 2) can be produced within each through-hole 15 of the mold 8. In short, this embodiment is particularly effective when the outer diameter of the porous body 5 to be produced is set within the range of 1.5 mm to 5.0 mm and the length is set within the range of 5.0 mm to 50 mm.

[0037] In addition, the porous body manufacturing apparatus 1 of this embodiment is equipped with a suction member 9 having a suction space 31 communicating with each through hole 15 of the mold 8, and a mesh member 10 arranged between each through hole 15 of the mold 8 and the suction hole 32 (suction space 31) of the suction member 9, which prevents the synthetic resin powder 2 from entering the suction space 31 of the suction member 9 from each through hole 15. When the opening / closing cock 38 of the air tank 37 connected to the suction space 31 of the suction member 9 is opened, the mesh member 10 prevents the synthetic resin powder 2 from entering the suction space 31 of the suction member 9 through each through hole 15 of the mold 8, and a porous body 5 having the required quality can be reliably produced within each through hole 15 of the mold 8.

[0038] Furthermore, in the porous body manufacturing apparatus 1 according to this embodiment, a seal member 14 is provided between the suction member 9 and the mold 8 to enhance the adhesion between them. Furthermore, the sealing member 14 can improve the efficiency with which the suction pump 11 (air tank 37) suctions air from within each through hole 15 of the mold 8, which also makes it possible to reliably produce a porous body 5 of the required quality within each through hole 15 of the mold 8.

[0039] Furthermore, the above-described embodiment is particularly effective when manufacturing a porous body 5 used as a pen tip for an applicator, including a writing implement, which is a thin, rod-shaped body. In other words, the porous body 5 manufactured in this embodiment has the quality required for a pen tip. That is, the tip of the porous body 5 used as a pen tip, which comes into contact with the paper, is not extremely hard but has an appropriate hardness, resulting in a good writing feel. Furthermore, since an appropriate amount of void space is provided at the tip of the pen tip (porous body 5), ink flow is not impeded. Furthermore, the pen tip (porous body 5) can be made strong enough in its entire longitudinal direction, eliminating problems such as breakage during the assembly process. Furthermore, the pen tip (porous body 5) has the desired capillary force in its entire longitudinal direction, ensuring the desired ink flow.

[0040] Furthermore, in this embodiment, the suction pressure of the suction pump 11 can be appropriately set, so that the porosity of the entire porous body 5 can also be appropriately set. [Explanation of symbols]

[0041] 1 Manufacturing equipment, 2 Synthetic resin powder, 5 Porous body, 8 Mold, 9 Suction member, 10 Mesh member, 11 Suction pump, 15 Through hole (filling space), 31 Suction space, 40 Sealing member

Claims

1. A method for producing a porous body obtained by sintering synthetic resin powder, comprising: a filling step of filling a filling space provided in the mold with synthetic resin powder; a suction compression step of applying a compression load to the entire synthetic resin powder in the filling space by sucking air from the filling space after the filling step; a closing step of closing the filling space filled with the synthetic resin powder after the suction and compression step; a sintering step of heating the filling space after the closing step to sinter the synthetic resin powder; A method for producing a porous body, comprising:

2. 2. The method for producing a porous body according to claim 1, wherein the porous body is in the form of an elongated rod.

3. 3. The method for producing a porous body according to claim 1, wherein the porous body is used for a pen tip of a liquid applicator.

4. A porous body manufacturing apparatus for realizing the porous body manufacturing method according to claim 1, comprising: a mold having a filling space to be filled with synthetic resin powder; a suction pump communicating with the filling space of the mold and configured to suck air from the filling space filled with synthetic resin powder; a closing member that closes the filling space of the mold after the air in the filling space filled with the synthetic resin powder is sucked by the suction pump; a heating member that heats the filling space to sinter the synthetic resin powder after the filling space is closed with the closing member; A porous body manufacturing apparatus comprising:

5. a suction member having a suction space communicating with the filling space of the mold; a mesh member disposed between the filling space and the suction space to prevent the synthetic resin powder from entering the suction space from the filling space, 5. The porous body manufacturing apparatus according to claim 4, wherein the suction space of the suction member communicates with the suction pump.

6. 6. The porous body manufacturing apparatus according to claim 5, further comprising a sealing member disposed between the suction member and the mold to enhance adhesion therebetween.

7. A plurality of through holes are formed in the mold as the filling space, 5. The porous body manufacturing apparatus according to claim 4, wherein the porous body is an elongated rod-shaped body.

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