WO2013172340A1

WO2013172340A1 - Method for producing semi-processed product for molding rotating resin-body, method for producing rotating resin-body, and heating and pressurization device

Info

Publication number: WO2013172340A1
Application number: PCT/JP2013/063413
Authority: WO
Inventors: 昌也小澤; 貴博森川; 直樹古畑; 直己小林
Original assignee: 新神戸電機株式会社
Priority date: 2012-05-14
Filing date: 2013-05-14
Publication date: 2013-11-21
Also published as: JP5794316B2; JPWO2013172340A1

Abstract

The present invention enables production of a highly reliable rotating resin-body by which a resin molded body can be formed with a simple process, an overlay interface of a base material is not created, and joining strength between the resin molded body and a turning-stopper section provided to an outer peripheral section of a bush made of metal is enhanced. The present invention comprises a first step for aggregating short fiber and a powdered resin on the perimeter of an outer peripheral section of a bush (2) by filtering and dewatering and thereby forming an aggregate (8) of the short fiber and the powdered resin surrounding the outer peripheral section of the bush (2), and a second step for compressing the aggregate (8) of the short fiber and the powdered resin in the axial direction of a rotating shaft to form a molding material (5). Then, the molding material is heated and pressurized to form a resin molded body.

Description

Method of manufacturing resin-made rotating body molding semi-finished product, method of manufacturing resin-made rotating body, and heating and pressing apparatus

The present invention relates to a method for producing a resin-made rotary body-molding semi-finished product, and the present invention relates to a method for producing a resin-made rotary body. Furthermore, the present invention relates to a heating and pressurizing device.

A resin-made rotating body using a reinforcing fiber base is excellent in durability performance, and is suitable as a resin-made rotating body such as a resin-made gear used for automotive parts, industrial parts and the like.

JP-A 2009-154338 (Patent Document 1) and JP-A 2009-250364 (Patent Document 2) use a slurry obtained by mixing water and a reinforcing fiber consisting of short fibers at the outer peripheral part of the bush. There is disclosed a method of manufacturing a resin rotating body for forming a reinforcing fiber base. In the methods described in these publications, the slurry is placed in a fixed mold containing a metal bush, dewatered from the slurry so that the reinforcing fibers do not leak, and the reinforcing fibers are gathered around the bush to form an aggregate. The assembly is then compressed to form a reinforcing fibrous substrate. Thereafter, the reinforcing fiber base is impregnated with the resin, and the resin is cured to manufacture a resin rotating body.

JP, 2009-154338, A JP, 2009-250364, A

The conventional methods described in

Patent Documents

1 and 2 prevent the deterioration of the durability performance by using a reinforcing fiber base in which a metal bush and reinforcing fibers are integrated. However, in this conventional method, the reinforcing fiber base material is disposed in the molding die, and while the reinforcing fiber base material is pressed from the axial direction, the pressure in the molding die is reduced to a vacuum and the resin is flowed. The reinforcing fiber base should be impregnated with resin. As a result, the structure of the molding die becomes complicated, and the number of processes increases.

Moreover, in the conventional method, it was not possible to produce a molding material in a short time without leaking the short fibers.

The object of the present invention is to provide a method for manufacturing a resin-made rotary member molding semi-finished product and a method for manufacturing a resin-made rotary member, which can form a resin rotary member molding semi-finished product and a resin rotary member. It is.

Still another object of the present invention is to provide a method for manufacturing a resin-made rotating body molding blank which can form a resin-made rotating body molding blank in a short time.

Another object of the present invention is to provide a heating and pressing device suitable for producing a resin rotating body.

In the method of manufacturing a semi-finished product for molding a resin rotary body to be improved according to the present invention, first, one or more detents are formed on the outer peripheral portion, and a bush capable of rotating about a rotation axis is prepared. Carry out the following steps. Next, the step of forming a forming material formed of an aggregate of short fibers and powdered resin and disposed in a state of being fitted to the bush so as to surround one or more rotation preventing portions is performed on the outer peripheral portion of the bush. .

In the present invention, the step of forming the forming material is constituted by the following two steps. In the first step, a slurry prepared by mixing short fibers, powdered resin and water is collected by filtration and dewatering, and short fibers and powdered resin are accumulated around the outer periphery of the bush to prevent one or more rotations. An assembly of short fibers and powdered resin surrounding the outer periphery of the bush including the part is formed. The filtration and dewatering method is a method in which a slurry containing short fibers is placed in a predetermined container and dewatered while filtering the slurry in the container to form an aggregate of short fibers and a powdered resin. is there. When an aggregate of short fibers and powdered resin is produced by such a method, a boundary portion which causes peeling is not formed at the central portion of the molding material. Furthermore, when dewatering while filtering, the short fibers and the powdered resin reliably wrap around the one or more detents, so the bonding strength between the resin molded body and the detents of the bush can be increased. Then, in the second step, the aggregate of short fibers and powdered resin is compressed in the axial direction of the rotating shaft to form a forming material on the outer peripheral portion of the bush. While this compression makes sure that the short fiber and powdery resin are embedded in the detent portion, the density of the short fibers around the detent portion increases and the bond between the bush and the resin molding further increases. .

Note that the first step and the second step may be performed continuously in the same device containing a bush and an aggregate of short fibers and powdered resin. If the assembly of short fibers and powdered resin is continuously compressed using the same apparatus, it is not necessary to handle an aggregate that is bulky and weak in strength (it is easy to lose shape). It will be less. In addition, since the density of the forming material is increased by the compression performed in the second step, the strength of the forming material can be enhanced, and the workability (handling ability) is significantly improved.

The first step is preferably performed in a state where the housing space of the bush and the aggregate of the short fibers and the powdered resin is vacuumed and sucked. As a result, the time for accumulating the short fibers and the powdered resin around the outer peripheral portion of the bush can be shortened.

In the first step, the slurry is prepared by adding one or more types of polymer flocculating agent of the electrostatic attraction aggregation type to a mixture of short fibers, powdered resin and water. You may do so. When an electrostatic attractive aggregation type polymer flocculant is added, the polymer flocculant functions not only as an aggregating function but also as a fixing agent, so that the short fibers are fixed together and the short fibers and the powder form The resin is fixed. As a result, the amount of short fibers and powdered resin remaining in the aggregate can be increased. That is, the fixing rate of the short fiber and the powdered resin can be increased.

Furthermore, after adding a cationic polymer flocculant (cationic polymer flocculating agent) to the mixed solution as one or more kinds of electrostatic attractive flocculation type polymer flocculants, an anionic polymer flocculating agent (anionic polymer flocculating agent) Is preferably added. When a cationic polymer flocculant is added to the mixed solution, a part of short fibers and a part of powdered resin gather to form a large number of aggregates called floc. Thereafter, when an anionic polymer flocculant is added, the flocs aggregate together to form larger flocs, and a large number of flocs with large dimensions are formed. When such floc is formed, the dewaterability is improved. As a result, the dewatering can be performed in a short time, and the fixing rate of the short fiber and the powdered resin is improved. In particular, when a cationic styrenic polymer aqueous solution is used as the cationic polymer flocculant and an anionic acrylic polymer aqueous solution is used as the anionic polymer flocculant, high dewaterability can be obtained.

In addition, an amphoteric polymer flocculating agent may be used as one or more types of electrostatic attractive flocculation type polymer flocculants. Amphoteric polymer flocculant refers to the neutralization effect (cation) of short fibers and powdery particles in the mixed liquid, formation of entanglement (high molecular weight) by the polymer chain, and entanglement (high molecular weight) It exerts a reinforcing effect by electrostatic attraction due to the charge of the anion and the cation.

The molding material is heated and pressurized to melt the powdery resin, and the molten resin produced is impregnated into the reinforcing fiber layer consisting of short fibers, and then the molten resin is cured to form a resin molded body. Can. In the present invention, as in

Patent Documents

1 and 2, while the molding material is pressed from the axial direction, the inside of the molding die is depressurized to a vacuum, and the resin is poured to impregnate the resin into the molding material. , The number of processes can be reduced. In addition, the structure of the molding die can be simplified.

In addition, as a short fiber, the thing of various materials and kinds can be used. In the claims of the present application, the term "short fibers" is intended to encompass not only fibers having literally short lengths but also fine fibers and / or pulp-like fibers obtained by fibrillating fibers. For example, the short fibers include aramid fibers having a length of 2 to 6 mm and fine fibers obtained by fibrillating the aramid fibers, the freeness of the fine fibers is 100 ml or more and 400 ml or less, and the content of the fine fibers is short fibers It is preferable to use what becomes 30 mass% or less among them. Use of such a short fiber makes it easy to compress and can obtain a necessary and sufficient bonding strength between the resin molded body and the detent.

As powdery resin, those of various materials such as thermosetting resin and thermoplastic resin can be used. Although the particle shape of the powdery resin is arbitrary, it is preferable to use a granular one. Further, the particle diameter is different depending on the fiber diameter of the short fiber, but a particle diameter which can be uniformly distributed in the gap of the aggregate of short fibers is preferable. When the particle diameter is large, the fiber orientation of the aggregate of short fibers is disturbed, or when forming a resin molded body by heating and pressure forming, the short fibers and the resin inside the molded body are not uniformly distributed. It is.

The short fibers consist of synthetic fibers having a thermal decomposition temperature or melting temperature of 250 ° C. or higher, and the powdered resin has a moldable temperature that is lower than the thermal decomposition temperature or melting temperature of synthetic fibers and a particle diameter of 50 μm or less It is preferable to be made of particles of a curable resin or a thermoplastic resin. When such a synthetic fiber and powdered resin are used, only the powdered resin is melted without thermally decomposing or melting the short fiber, and the molten resin is surely permeated around the short fiber, thereby the resin A rotating body can be formed. In the present specification, the particle diameter of 50 μm or less means the diameter dimension of the particles measured by the metal mesh sieving method defined in JIS-Z8801-1.

In addition, as for the ratio of the short fiber with respect to a resin molding, it is desirable that it is 30 volume% or more and 60 volume% or less. If the value is in this range, the mechanical strength required for the resin molding can be reliably obtained.

The heating and pressurizing apparatus that can be used in the present invention to heat and press the molding material is fixed with a recess that accommodates the molding material together with the bush so as to restrict the outward spread of the molding material. The first movable mold, which is disposed displaceably with respect to the fixing bracket so that the mold and the supporting portion for supporting the bush are displaced in the recessed portion of the fixed mold, and the supporting portion inserted into the recessed portion It is possible to use one having a supported bush and a second movable mold provided with a pressing portion for pressing the molding material toward the inner bottom surface of the recess. The heating and pressing device is configured such that the fixed mold, the first movable mold, and the second movable are movable in a state where the inner bottom surface of the fixed mold and the pressing portion of the second movable mold are in contact with the molding material. Preferably, the mold is heated to a moldable temperature of the powdery resin, and the second movable mold is moved toward the inner bottom surface in the molten state of the powdery resin. With such a heating and pressurizing device, heating and pressurization can be performed with a simple structure.

If a resin molded body is machined to form a plurality of teeth, it is possible to obtain a gear which is mechanically strong and which generates less noise at the time of use. Of course, in addition to the gears, rotating parts such as pulleys may be manufactured using the resin rotating body of the present invention.

The molding material formed by the method of the present invention has no overlapping interface of the substrate and does not peel off. From these facts, the durability performance of the resin rotary body such as the resin gear is greatly improved.

It is a longitudinal cross-sectional view of an example of embodiment of the resin-made rotary body of this invention shown typically. (A) and (B) are the top view and longitudinal cross-sectional view of metal bush. (A) thru | or (D) are figures which show the papermaking of a forming raw material, and a compression process in order. It is a schematic sectional drawing which shows an example of the metal mold | die for heat-pressure molding. (A) is a figure used in order to explain the problem which arises by mesh size, (B) is a figure used in order to explain the function of a polymer flocculant of an electrostatic attraction aggregation type. It is a figure used in order to demonstrate the function of a polymer flocculant of electrostatic attraction aggregation type. (A) And (B) is a figure which shows an example of a paper-making apparatus used in order to manufacture a prior art example, and the manufacture example of the conventional fiber base material for reinforcement. (A) is a schematic sectional drawing which shows an example of the metal mold | die for resin casting used in order to manufacture a prior art example, (B) is a longitudinal cross-sectional view of the resin-made rotary body manufactured by a prior art example. It is a figure which shows the structure of the apparatus which measures boss | hub removal strength.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First Embodiment
FIG. 1 is a longitudinal sectional view of an example of a first embodiment of a resin rotary body according to the present invention schematically shown. The resin rotating body 1 is provided with a metal bush 2 which rotates around a rotating shaft (not shown). A through hole 3 in which a shaft (not shown) is fitted is formed at the center of the metal bush 2. Further, on the outer peripheral portion 4 of the metal bush 2, protruding portions 4A constituting a plurality of detents are integrally formed at predetermined intervals in the circumferential direction. The shaft may be formed integrally with the metal bush 2. The thickness L2 measured in the axial direction of the plurality of protrusions 4A is smaller than the thickness L1 measured in the axial direction of the metal bush 2. And, as shown in FIG. 2, in order to enhance the action of the detent to bear the load in the rotational direction, preferably, the protrusion 4A to be the detent should have at least two protrusions 4A with height h1. It is preferable that the recesses 4B formed between the protrusions 4A and having the bottom of the height h2 be alternately arranged. With such an undercut shape and using a projecting portion 4A having an angle θ of 5 ° or more and 40 ° or less, a plurality of projections serving as a rotation stopping portion in the forming material 5 shown in FIG. 3 (D) and FIG. The portion 4A is completely filled, and the strength of the mechanical connection between the bush 2 and the molding material 5 can be made sufficient.

In the present embodiment, one forming material 5 shown in FIG. 3D and FIG. 4 is disposed at a position outside the outer peripheral portion 4 of the metal bush 2 in a state of being fitted to the outer peripheral portion 4. Then, the molding material 5 is heated and pressed to form the resin molded body 6.

When forming the forming material 5, as schematically shown in FIG. 3, the filtration dewatering and compressing device 7 capable of continuously performing filtration and dewatering and compression is used to form the outer peripheral portion 4 of the metal bush 2. An aggregate 8 of short fibers and powdered resin is formed at the outer position. Then, the aggregate 8 of the short fibers and the powdered resin is compressed in the axial direction of the rotation shaft to form the molding material 5.

First, short fibers and powdered resin are accumulated around the outer peripheral part 4 of the bush 2 by the filtration dehydration method, and the short fibers and powdered resin surrounding the outer peripheral part 4 of the bush 2 including one or more detents (4A) The first step of forming the aggregate 8 of FIG.

As shown in FIG. 3 (A), the mold used in the filtration dewatering and compressing device 7 restricts the aggregate 8 of the short fiber and the powdered resin from spreading outward in the radial direction of the metal bush 2 during the compression operation. A cylindrical mold 10 and a portion disposed inside the cylindrical mold 10 and positioned inside the outer peripheral portion of the metal bush 2 from both sides in the axial direction, and when compressed, a short fiber and a powdered resin A pair of

bush supporting molds

11 and 12 that restrict the aggregate 8 from spreading radially inward of the metal bush 2, and a position between the cylindrical mold 10 and the pair of bush supporting molds 11 and 12 A pair of

compression molds

13 and 14 are provided to sandwich and compress the short fiber / powder resin aggregate 8 from both sides in the axial direction during the compression operation. Then, in this mold, in order to impart water permeability or filterability to the lower compression mold 14, a plurality of through holes 15 for draining water are formed in the lower compression mold 14. ing. It is preferable to provide a pump for vacuum suction for the plurality of through holes 15 since drainage can be completed in a short time. In this example, a bottom member 16 having a filtering function is disposed on the lower compression mold 14 in order to prevent the outflow of the short fibers and the powdered resin during drainage.

A wire mesh can be used for the bottom member 16. When the mesh size of the wire mesh is larger than 100 mesh, the mesh (through holes) of the wire mesh becomes smaller, so that the filtration resistance of water, short fibers and powdered resin becomes large. As a result, even if the slurry containing the short fibers and the powdered resin contained in the inside of the mold is sucked by a pump and the water is drained from the mold, the short fibers and the powdered resin can be separated from water. The time required is longer and the manufacturing cycle is longer. If the mesh size is smaller than 10 mesh, even if short fibers with a long fiber length are used, the meshwork (through holes) of the wire mesh is large, so the filtration function is low, and many of the short fibers and powdered resin flow out with water. Resulting in. As a result, there arises a problem that the fiber density and the resin amount of the aggregate 8 of the short fibers and the powdered resin are significantly reduced. Therefore, the mesh size to be used is preferably 10 mesh or more and 100 mesh or less.

The pair of

bush supporting molds

11 and 12 are positioned inward of the outer peripheral portion 4 of the metal bush 2 so that the short fibers and the powdered resin do not enter inside the outer peripheral portion of the metal bush 2 The cylindrical mold 10 is supported by being sandwiched from both sides in the direction in which the center line of the cylindrical mold 10 extends. In this example, the lower bush support mold 12, the upper bush support mold 11, the lower compression mold 14, the upper compression mold 13 and the cylindrical mold 10 are independent of each other. It is configured to be movable up and down.

When the metal bush 2 is sandwiched between the pair of

bush supporting molds

11 and 12, as shown in FIG. 3A, the upper bush supporting mold 11 is moved upward. Then, after the metal bush 2 is positioned on the lower bush support mold 12, as shown in FIG. 3 (B), the upper bush support mold 11 is moved downward to form a pair of bushes. The metal bush 2 is held between the

bush supporting molds

11 and 12.

The slurry formed by mixing the short fiber, the powdered resin, and the water is supplied from the upper opening of the cylindrical mold 10, as shown in FIG. 3 (B). At this time, by performing vacuum suction from the plurality of through holes 15 of the lower compression mold 14, the time for accumulating the short fibers and the powdered resin around the outer peripheral portion 4 of the bush 2 is shortened. Can. Then, vacuum suction is continued, and water is discharged from the plurality of through holes 15 provided in the lower compression mold 14, whereby short fibers and powdered resin surrounding the periphery of the metal bush 2 are made. An aggregate 8 is formed. When the pair of

bush supporting molds

11 and 12 is used as described above, positioning and support of the metal bush 2 can be easily performed. The shape of the outer peripheral surface of the aggregate 8 of the short fibers and the powdery resin is determined by the shape of the inner peripheral surface of the cylindrical mold 10. As a result, by forming the inner peripheral surface of the cylindrical mold 10 into a gear shape, it becomes possible to form a gear-shaped unevenness on the outer peripheral surface of the aggregate 8 of short fibers and powdered resin. The slurry may be supplied from a plurality of places on the upper opening of the cylindrical mold 10.

Next, a second step of compressing the aggregate of the short fibers and the powdered resin in the axial direction of the rotating shaft to form a molding material will be described.

In the case of a mold used in the above-described filtration dewatering and compression device 7, when the aggregate 8 of short fibers and powdered resin is compressed with the pair of

compression molds

13 and 14, the inner side in the radial direction of the metal bush 2 In addition, it is possible to reliably prevent the short fibers and the powdered resin from bulging in both the outer and outer directions.

After the water is discharged from the plurality of through holes 15 provided in the lower compression mold 14, as shown in FIG. 3C, the metal bush 2 is between the pair of

compression molds

13 and 14. The upper compression mold 13 is lowered to a position where it is positioned at the center. Thereafter, as shown in FIG. 3D, the pair of

compression molds

13 and 14 are respectively moved in a state where the metal bush 2 is positioned at the center of the pair of

compression molds

13 and 14, and the short fibers are And the aggregate 8 of powdery resin is compressed to a predetermined thickness. The compression time and temperature are arbitrary depending on the type of short fiber and powdered resin used, but during the compression, a heater may be attached to the upper compression mold 13 and compressed in a heated state . Thus, the time for removing the water contained in the molding material 5 can be shortened. Further, during the compression, by compressing in a vacuum suction state from the through holes 15 of the lower compression mold 14, the time for removing the water contained in the forming material 5 after the sheet making can be shortened.

As the types of short fibers used to form the molding material 5 or the short fibers and the aggregate 8 of powdery resin, various types can be used as described later. The length of the short fiber is determined as follows, for example, when using a metal bush 2 as shown in FIG. That is, the protrusion dimension of the protrusion 4A (height of the protrusion 4A measured in the radial direction from the center portion 2A of the metal bush 2) is h1, and the height of the bottom of the recess 4B (diameter from the center portion 2A of the metal bush 2) Assuming that the height of the bottom of the concave portion 4B measured in the direction is h2, the length of the short fiber is equal to or larger than the smaller value of 0.5 × h1 mm and 1 × h2 mm, and 5 × h1 mm and 10 × h2 mm It is preferable to be less than or equal to the larger value of. Here, when the height dimensions h1 and h2 are the same, the effect of the detent becomes weak. For the height dimension h1 or h2 of the bottom of the protrusion 4A or the recess 4B, a fiber length sufficient for the short fiber to cover is required, and the length of the short fiber is 0.5 × h1 mm and 1 It is appropriate that the value is smaller than or equal to the smaller value of h2 mm. In addition, even if the short fibers are too long, they may cause the uniform dispersion of the slurry, resulting in a non-uniform fiber distribution that does not contribute to the increase in strength. Therefore, the length of the short fiber is suitably equal to or less than the larger value of 5 × h1 mm and 10 × h2 mm. Of course, as the protrusion 4A, a protrusion (a protrusion having two or more different protrusion sizes) having a height h3 larger than h1 may be used in combination. .

The fiber length of the short fiber thus determined is preferably 2 mm to 6 mm, more preferably 3 mm. If the fiber length is less than 2 mm, the mechanical properties of the fiber-reinforced resin molded product are degraded. When the fiber length exceeds 6 mm, when the fiber bundle is dissociated and dispersed in water, the dissociation of the fiber bundle becomes difficult. In addition to the short fibers (fiber chops) described above, fine fibers and / or pulp fibers obtained by fibrillating aramid fibers and the like may be used in combination.

The projecting portion 4A constituting the anti-rotation portion having the undercut shape can be formed as designed with high accuracy if it is molded by a sintering method. The optimum structure of the protrusion 4A is, for example, in the case of a resin gear having an outer diameter of 60 mm, the number of protrusions (crests) is 30 and the number of recesses or valleys formed between the protrusions is 29. Of course, these numbers may be suitably changed according to the diameter and thickness of the resin gear and the structure of the teeth.

The short fibers used are preferably fibers having a thermal decomposition temperature or melting temperature of 250 ° C. or higher. By forming the molding material 5 using such short fibers, the short fibers in the resin rotating body do not undergo thermal deterioration at the molding temperature and processing temperature at the time of molding, and the ambient temperature during actual use. It is possible to form a resin rotary body excellent in the properties. As fibers that can be used in the present embodiment, para-aramid fibers, meta-aramid fibers, carbon fibers, glass fibers, boron fibers, ceramic fibers, ultra-high strength polyethylene fibers, polyketone fibers, polyparaphenylene benzobisoxazole At least one or more synthetic fibers selected from fibers, wholly aromatic polyester fibers, polyimide fibers, and polyvinyl alcohol-based fibers can be used.

Further, it is preferable that the short fibers contain at least 20% by volume or more of high strength and high elasticity modulus fibers having a tensile strength of 15 cN / dtex or more and a tensile elastic modulus of 350 cN / dtex or more. The resin rotating body using the molding material 5 obtained in this manner can withstand high load applied during use.

Also, in order to impart strength for maintaining the shape when moving or transporting the one formed by integrating the forming material 5 with the metal bush 2 using the filtration dewatering and compressing device 7 to the next step, It is preferred that the short fibers contain fine fibers and / or pulp fibers obtained by fibrillating aramid fibers. The freeness (degree of freeness) of fine fibers and / or pulp fibers usable here is 100 ml or more and 400 ml or less, and the content of the fine fibers is 30% by mass or less in the short fibers Is desirable. As a desirable mode, it is preferable to mix aramid microfibers and short fibers which are fibrillated at an axial direction of the fiber by mechanical shearing of para-aramid fiber. If the freeness exceeds 400 ml, the fibrillation is insufficient, which is not preferable for imparting strength to maintain the shape of the molding material. In addition, when freeness is less than 100 ml, not only tearing in the axial direction of the fiber but also shearing in the radial direction to become a powder state, the entanglement of the fibers becomes worse and the shape of the molding material is maintained It is not preferable to impart strength. It is preferable to blend 5 to 10% by weight of fibrillated fibrils which can impart adequate strength to the molding material.

As powdery resin, those of various materials such as thermosetting resin and thermoplastic resin can be used. For example, epoxy resin, polyaminoamide resin, phenol resin, unsaturated polyester resin, polyimide resin, polyether sulfone resin, polyether ether ketone resin, polyamide imide resin, polyamide resin, polyester resin, polyphenylene sulfide resin, polyethylene resin, polypropylene A combination of one or more resins selected from resins can be used. Among these, phenol resins are preferable in view of the strength and heat resistance of the cured resin.

Although the particle shape of the powdery resin is arbitrary, it is preferable to use a granular one. Moreover, although a particle diameter changes with fiber diameters of a short fiber, 50 micrometers or less are preferable. The particle size was measured by the metal mesh sieving method defined in JIS-Z8801-1. Thereby, powdery resin can be uniformly distributed to the clearance gap of the collection of a staple fiber. When the particle diameter of the powdery resin is large, the fiber orientation of the aggregate of short fibers is disturbed, or when heat and pressure molding is performed to form a resin rotating body, the short fibers are formed inside the resin rotating body. This causes the powdery resin to be not uniformly distributed with the melted and cured resin.

The concentration at which the short fibers are dispersed in water is preferably 0.3 g / liter to 20 g / liter. In the case of using a fiber having a short fiber length, it is possible to disperse with a high concentration slurry having a concentration of 20 g / liter because the fibers are less entangled and the dispersion is good. On the other hand, when using a fiber with a long fiber length, the fiber length is too long and sufficient dispersion can not be achieved unless the concentration is as low as 0.3 g / liter.

Incidentally, in the case where the above-mentioned short fibers contain fine fibers and / or pulp-like fibers obtained by fibrillating aramid fibers, an aggregate of short fibers and powdered resin used when the diameter of the metal bush 2 is 5 cm. Thickness dimension (axial dimension) is about 10 cm. Then, the aggregate 8 of the short fiber and the powdered resin is compressed to about 2 cm and molded into a molding material 5 by a compression operation described later. The molded material 5 is molded on the bush 2 to form a resin-made rotary body-forming semi-finished product 21.

Next, a step of forming a resin molded body by heat and pressure molding a forming material will be described.

In FIG. 4, an example of the heating-pressing apparatus 20 which pressurizes the shaping | molding material 5 while heating is shown. The mold 22 used in this apparatus is a fixed mold 25 provided with a recess 23 for accommodating the semi-finished product 21 composed of the bush 2 and the forming material 5 so as to restrict the outward spread of the forming material 5 in the radial direction. The first movable mold 27 disposed displaceably with respect to the fixed mold 25 so as to be displaced within the recessed section 23 of the fixed mold 25, and the support portion 26 supporting the bush 2 is inserted into the recessed section 23. The second movable mold 29 is provided with a pressing portion 29A for pressing the bush 2 supported by the support portion 26 and the molding material 5 toward the inner bottom surface 24 of the recess 23. The stationary mold 25 is held in the heating device 30. The first movable mold 27 is also heated by the heating device 30. The second movable mold 29 is also heated by another heating device (not shown). Therefore, the heating and pressurizing device 20 is configured such that the fixed mold 25 and the first mold 25 are in a state where the inner bottom surface 24 of the fixed mold 25 and the pressing portion 29A of the second movable mold 29 are in contact with the forming material. The movable mold 27 and the second movable mold 29 are heated to the moldable temperature of the powdery resin, and the second movable mold 29 moves toward the inner bottom surface 24 in the molten state of the powdered resin. It is configured.

In the heating and pressing device 20, when the pressing portion 29A of the second movable mold 29 is inserted into the recess 23 of the fixed mold 25 and the metal bush 2 is pressed, the first movable mold 27 , And is displaced downward according to the insertion amount of the second movable mold 29. When the powdery resin is a thermosetting resin, after the resin is melted, when the resin is cured, a resin-made rotating body provided with a resin molded body mainly formed of short fibers as a core material (reinforcing fiber layer) It takes out from the mold 22, and the manufacture of the resin rotary body is completed.

A resin gear can be obtained by machining the outer peripheral portion of the resin molded body of the resin rotary body molded in this manner to form a tooth. If a groove is formed along the outer peripheral surface, a pulley can be obtained.

The proportion of the short fibers contained in the resin molding having the short fiber as a core material varies depending on the strength of the desired resin molding, etc., but is preferably 30% by volume or more and 60% by volume or less with respect to the resin molding . When the proportion of short fibers in the resin molded product is less than 30% by volume, the effect of reinforcing the resin with fibers is hardly observed, and the filling of the fibers into the detent portion of the metal bush 2 also becomes insufficient. . When the proportion of short fibers exceeds 60% by volume, the proportion of fibers is too high, and the molten resin during heating and pressure molding does not flow in the entire resin molded body, and a resin-deficient portion is easily generated. Problems occur. Therefore, the ratio of the fibers contained in the resin molded body is the strength of the resin rotary body, and the fibers are surely filled in the detent for depression 4B formed between the two projecting portions 4A, and further, the resin More preferred is 35 to 45% by volume which does not inhibit the impregnation.

Second Embodiment
In the first embodiment, short fibers and water are mixed to form a slurry. When such a slurry is used, for example, the mesh size of the wire mesh used for the bottom member 16 of the compression mold 14 shown in FIG. 3 becomes small (the mesh size of the wire mesh becomes large) because the viscosity of the slurry is low. In addition, the fixing yield of the short fibers and the powdered resin in the molding material 5 is deteriorated. As schematically shown in FIG. 5A, for example, when using a metal mesh having a mesh size of 100 μm on one side, if the particle diameter of the powdery resin is 10 μm, the filtration performance will be poor, The amount of powdered resin that is discharged together with the In order to prevent such a situation, if the mesh size is increased (the mesh size of the wire mesh is reduced), the filtration performance is improved but the dewatering time is increased. Therefore, in the second embodiment, in order to cope with such a problem, in the first step described above, at least one type of electrostatic attraction is applied to the mixed solution in which the short fiber, the powdered resin and the water are mixed. A slurry is prepared by adding a flocculating type polymer flocculant. When an electrostatic attraction aggregation type polymer flocculant is added, as shown schematically in FIG. 5B, the electrostatic attraction aggregation type polymer flocculant functions not only as an aggregation function but also as a fixing agent, When the short fibers are fixed to each other, the short fibers and the powdered resin are fixed. As a result, the amount of short fibers and powdered resin remaining in the assembly 8 shown in FIG. 3 (B) can be increased. That is, the fixing rate of the short fiber and the powdered resin can be increased.

Any usable electrostatic attraction aggregation type polymer flocculant may be used as long as it can increase the fixing rate of the short fiber and the powdery resin and does not significantly inhibit the dewatering property. As the cationic polymer flocculant, for example, styrenic polymers, polyamine condensates, dicyandiamide condensates, cationically modified acrylic copolymers, polymethacrylic acid esters, polyamidine hydrochloride can be used. Moreover, as an anionic polymer flocculant, for example, an acrylic copolymer, a sulfonated polyphenol, a polyhydric phenol resin, a polyacrylic ester type, a polyacrylic acid soda / amide derivative can be used.

In the aggregation method using a typical polymer coagulant, after adding a cationic polymer coagulant to a mixed solution, an anionic polymer coagulant is added. As schematically shown in FIG. 6, when a cationic polymer flocculant is added to the mixed solution, a plurality of short fibers and a part of powdery resin are gathered to form an aggregate called flock. Ru. Thereafter, when an anionic polymer flocculant is added, the flocs gather together to form a larger floc, and a large number of floc having a large size are formed. When such floc is formed, the dewaterability is improved. As a result, the dewatering can be performed in a short time, and the fixing rate of the short fiber and the powdered resin is improved. In particular, when a cationic styrenic polymer aqueous solution is used as the cationic polymer flocculant and an anionic acrylic polymer aqueous solution is used as the anionic polymer flocculant, high dewaterability can be obtained.

In addition, as the polymer coagulant, an amphoteric polymer coagulant can be used. Amphoteric polymer flocculant refers to the neutralization effect (cation) of short fibers and powdery particles in the mixed liquid, formation of entanglement (high molecular weight) by the polymer chain, and entanglement (high molecular weight) It exerts a reinforcing effect by electrostatic attraction due to the charge of the anion and the cation. As such an amphoteric polymer flocculant, for example, acrylamide, acrylic acid, alkylamino acrylate quaternary salt copolymer, polyacrylic acid ester type, polymethacrylic acid ester type can be used.

Hereinafter, examples of the present invention will be described.

Example 1
In order to produce a slurry, a tank filled with short fibers and water having a concentration of 4 g / l when the powdered resin is charged is prepared. In this tank, short fibers in an amount such that the total amount of short fibers in the resin molding is 40% by volume, and powdered resin in an amount such that the total amount of resin in the resin molding is 60% by volume. Specifically, as a fiber chop used as a short fiber, 50 mass% of a para-aramid fiber having an aspect ratio of 200 “Teconra (trademark)” manufactured by Teijin Limited, a meta-aramid fiber having an aspect ratio of 200, “Teijin ( 45% by mass of "CornexTM" manufactured by Co., Ltd. and 5% by mass of fine fibers "KevlarTM" manufactured by DuPont Co., Ltd., which are fibrillated to a freeness value of 300 ml In addition, as a powdered resin, a phenolic resin powder "Air-Bell-Balpearl Co., Ltd.""Velpearl(trademark)" having a particle diameter of 20 μm is introduced. Next, the water in the tank is stirred with a stirrer to disperse the fiber chops and the phenolic resin powder to produce a slurry.

At this time, after adding and stirring the cationic styrenic polymer aqueous solution sold by Meisei Chemical Industry Co., Ltd. under the name "Cerafix ST" (trade name) as a cationic polymer flocculant, an anionic polymer flocculant As an aqueous solution of an anionic acrylic polymer sold by Meisei Chemical Industry Co., Ltd. under the name of "FYLEX M" (trademark) as a slurry, the slurry used in this example was added and stirred. The addition amount of the cationic styrenic polymer aqueous solution is 0.2% by mass with respect to the total amount of the short fibers and the powdery resin, and the addition amount of the anionic acrylic polymer aqueous solution is the short fibers and the powdery resin It was 0.1 mass% with respect to the total amount of.

Next, the metal bush 2 is positioned on the lower bush supporting mold 12 using the filtration dewatering and compressing device 7 shown in FIG. 3 (A). The shapes of the protrusion 4A and the recess 4B of the metal bush 2 used are h1 = 2 mm, h2 = 0.5 mm, and are undercut shapes, and between the virtual center cross section of the metal bush 2 and the side face SF Is 20 °. Then, as shown in FIG. 3B, the upper bush support mold 11 is moved downward to sandwich the metal bush between the pair of

bush support molds

11 and 12. Here, the position of the lower compression mold 14 is a position at which the distance from the axial center of the metal bush 2 to the top surface of the bottom member 16 is 50 mm. A slurry containing dispersed fiber chops and phenolic resin powder is filled in the filtration dewatering and compressing device 7 while vacuum suction is being performed. Then, by continuing the vacuum suction and draining the water from the plurality of through holes 15 provided in the lower compression mold 14, the fiber chops and the phenol resin powder are separated from the water, and the cylindrical short fibers are separated. And an aggregate 8 of powdered resin is obtained. In addition, in order to prevent the fiber chops and the phenolic resin powder from flowing out from the through holes 15 at the time of drainage, the bottom member 16 is disposed on the lower compression mold 14. As the bottom member 16, a metal mesh of 20 mesh was used.

Next, the metal bush 2 is compressed in order to more firmly wick the fiber into the detent portion of the metal bush 2. First, as shown in FIG. 3C, the upper compression die 13 is lowered to a position where the distance from the axial center of the metal bush 2 to the lower surface of the upper compression die 13 is 50 mm. This position is a position where the metal bush 2 is located at the center between the pair of compression dies 13 and 14. Then, as shown in FIG. 3 (D), with the metal bush 2 positioned at the center between the pair of compression dies 13 and 14, the pair of compression dies 13 and 14 are set to speed 1 to 5 respectively. It is moved in a direction approaching each other at 5 mm / s and compressed until the aggregate 8 of short fibers and powdered resin becomes 20 mm thick. By compressing for 1 minute in this state, a forming material 5 integrated with the metal bush 2 was obtained. In the case of the said compression, it compresses in the state vacuum-sucked from the through-hole 15 of the lower mold 14 for compression.

The molding material 5 is dried until the water content becomes 0.5 mass% or less. Incidentally, in the present embodiment, the thickness of the molding material 5 becomes 20 to 50 mm by the drying.

Next, as shown in FIG. 4, a first movable mold which is heated at 200 ° C. to a forming material 5 (a semi-finished product for forming a rotating body made of resin) integrated with the metal bush 2 obtained in the above process. Place at 27 and clamp. Then, the molding material 5 is heat and pressure molded to harden the powdery resin to obtain a gear material. Incidentally, in the present embodiment, the molding material 5 having a thickness of 20 to 50 mm becomes 13 mm having substantially the same thickness as the metal bush 2 by the heat and pressure molding.

A resin gear is obtained by forming teeth by cutting this gear material.

Example 2
The same slurry as that produced in Example 1 was stirred without adding a cationic polymer flocculant and an anionic polymer flocculant to prepare a slurry used in this example. The resin gear was manufactured similarly to Example 1 using the slurry produced in this way. The mesh size of the metal wire mesh used in the filtration dehydration compression device 7 shown in FIG. 3A was 20 mesh as in the first embodiment.

[Example 3]
A cationic styrenic polymer aqueous solution was added as a cationic polymer flocculant to the same slurry as that produced in the above Example 1 and stirred to obtain a slurry used in this example. The addition amount of the cationic styrenic polymer aqueous solution was 0.2% by mass with respect to the total amount of the short fibers and the powdered resin. The resin gear was manufactured similarly to Example 1 using the slurry produced in this way.

Example 4
An anionic acrylic polymer aqueous solution was added as the anionic polymer flocculant to the same slurry as that produced in Example 1 above, and the mixture was stirred to obtain a slurry used in this example. The addition amount of the anionic acrylic polymer aqueous solution was 0.1% by mass with respect to the total amount of the short fibers and the powdered resin. The resin gear was manufactured similarly to Example 1 using the slurry produced in this way.

[Example 5]
By simultaneously adding a cationic styrenic polymer aqueous solution as a cationic polymer flocculant and an anionic acrylic polymer aqueous solution as an anionic polymer flocculant to the same slurry produced in Example 1 above. The mixture was stirred to obtain a slurry used in this example. The addition amount of the cationic styrenic polymer aqueous solution is 0.2% by mass with respect to the total amount of the short fibers and the powdery resin, and the addition amount of the anionic acrylic polymer aqueous solution is the short fibers and the powdery resin It was 0.1 mass% with respect to the total amount of. The resin gear was manufactured similarly to Example 1 using the slurry produced in this way.

[Example 6]
An anionic acrylic polymer aqueous solution is added as an anionic polymer flocculant to the same slurry as prepared in Example 1 above and stirred, and then a cationic styrenic polymer as a cationic polymer flocculant The aqueous solution was added and stirred to obtain a slurry used in this example. The addition amount of the anionic acrylic polymer aqueous solution is 0.1% with respect to the total amount of the short fiber and the powdered resin, and the addition amount of the cationic styrenic polymer aqueous solution is that of the short fiber and the powdered resin It was 0.2 wt% with respect to the total amount. The resin gear was manufactured similarly to Example 1 using the slurry produced in this way.

[Example 7]
In place of the electrostatic attraction aggregation type polymer flocculant added to the slurry in Example 1, a polyethylene oxide type flocculant was used as the thickening aggregation type polymer flocculant. As a polyethylene oxide type coagulant | flocculant, the polyethylene oxide type coagulant | flocculant which Sumitomo Seika Co., Ltd. sells under the name of "Peo" (trademark) was added and stirred, and it was set as the slurry used by the present Example. The addition amount of the polyethylene oxide type flocculant was 0.05% by mass with respect to the total amount of the short fibers and the powdered resin. The resin gear was manufactured similarly to Example 1 using the slurry produced in this way. The mesh size of the metal wire mesh used in the filtration dehydration compression device 7 shown in FIG. 3A was 20 mesh as in the first embodiment.

Conventional Example 1
In order to produce a slurry, prepare a tank filled with water in such an amount that the concentration when short fiber is charged is 4 g / liter. Then, in the tank, short fibers of an amount such that the total amount of short fibers in the resin molded body is 40% by volume are placed. The type and mixing ratio of the fiber chops used as the short fibers are as shown in Example 1. Next, the water in the tank is stirred with a stirrer to disperse the fiber chops.

Next, the metal bush 2 is positioned on the lower bush supporting mold 12 using the filtration dewatering and compressing device 7 shown in FIG. 3 (A). The shape of the metal bush 2 used is as shown in the first embodiment. Then, as shown in FIG. 3B, the upper bush support mold 11 is moved downward to sandwich the metal bush between the pair of

bush support molds

11 and 12. Here, the position of the lower compression mold 14 is a position at which the distance from the axial center of the metal bush 2 to the top surface of the bottom member 16 is 40 mm. In the filtration dewatering and compressing device 7, a slurry containing dispersed fiber chops is filled. Then, by vacuum suction and draining water from the plurality of through holes 15 provided in the lower compression mold 14, the fiber chops and the water are separated to obtain a cylindrical short fiber accumulation body. In addition, in order to prevent the fiber chops from flowing out from the through holes 15 at the time of drainage, the bottom member 16 is disposed on the lower compression mold 14. A metal mesh of 100 mesh was used as the bottom member 16.

Next, the metal bush 2 is compressed in order to more firmly wick the fiber into the detent portion of the metal bush 2. First, as shown in FIG. 3C, a position at which the distance from the axial center of the metal bush 2 to the lower surface of the upper compression mold 13 becomes 40 mm, as the upper compression mold 13 heated to 150 ° C. Lower to This position is a position where the metal bush 2 is located at the center between the pair of compression dies 13 and 14. Then, as shown in FIG. 3 (D), with the metal bush 2 positioned at the center between the pair of compression dies 13 and 14, the pair of compression dies 13 and 14 are set to speed 1 to 5 respectively. It is moved in a direction approaching each other at 5 mm / s, and the short fiber aggregate is compressed to a thickness of 10 mm. And it compressed for 2 minutes in the heated state, and obtained the fiber base material for reinforcement integrated with metal bush 2. In the case of the said compression, it compresses in the state vacuum-sucked from the through-hole 15 of the lower mold 14 for compression.

Next, as shown in FIG. 4, the reinforcing fiber base integrated with the metal bush 2 obtained in the above process is placed in a first movable mold 27 heated to 200 ° C. and clamped. Then, after the inside of the first movable mold 27 is depressurized to a pressure of 90 kPa or less, 69 parts by mass of 2,2 '-(1,3 phenylene) bis 2-oxazoline and 31 parts by mass of 4,4'-diaminodiphenylmethane are mixed. The melted resin is melted at a temperature of 140 ° C., 1 part by mass of octyl bromide is added, and the stirred resin is injected into the inside of the mold to impregnate the reinforcing fiber base and heat-cured in the first movable mold 27 Get the gear material. A resin gear is obtained by forming teeth by cutting this gear material.

[Conventional example 2]
A tank filled with water is prepared, and fiber chops are dispersed at the same fiber composition and concentration as in Conventional Example 1. As shown in FIG. 7A, the papermaking apparatus 307 includes a bottom surface portion 313 and a rectangular cylindrical papermaking cylinder 309. In addition, only the bottom surface part 313 was comprised with the wire mesh. The wire mesh used was a sheet mesh of 100 mesh. Then, the slurry containing the dispersed fiber chops described above was introduced into the paper-making apparatus 307 to obtain an aggregate 310. The stack 310 was removed and dewatered and dried. Then, as shown to FIG. 7 (B), it pierce | punched in the doughnut shape of outer diameter (phi) 80 mm x internal diameter (phi) 55 mm, and obtained the accumulation | aggregation body 308 of short fibers.

Next, as shown in FIG. 8 (A), using the two staple fiber accumulations 308 obtained in the above step, the projecting portion 4A provided on the metal bush 2 is sandwiched and heated. Placed in H.323 and clamped. The subsequent steps were the same as in Conventional Example 1 to manufacture a resin gear. FIG. 8 (B) is a schematic longitudinal sectional view of the resin rotating body manufactured in this manner. There is almost no entanglement of short fibers at the superposed interface BS of the two reinforcing fiber bases 305 in the resin molded body 306 of the resin rotary body.

[Evaluation 1]
A semi-finished product for molding a resin-made rotational body manufactured by the method shown in Example 1 above, a reinforcing fiber base integrated with a metal bush manufactured by the method shown in Conventional Example 1 and a method shown in Conventional Example 2 Table 1 shows the results of measurement of the actual working time required for producing a gear material using the short fiber aggregate. Further, with respect to the resin gears obtained in Example 1 and Conventional Examples 1 and 2, the results of measuring the boss removal strength are shown in Table 1. The measurement method is as follows.

Boss removal strength: As shown in FIG. 9, the resin gear 51 is disposed on a cylindrical base 55 having an inner diameter larger than the outer diameter of the metal bush 2 in contact with only the resin molded body. A metal fitting 56 for holding the metal bush 2 was attached from the upper side, a load was applied to the metal fitting 56, and the maximum load until the resin gear 51 was broken was measured.

As is clear from Table 1, the semi-finished product for resin rotary body molding according to the present invention has a pressure reduction inside the mold for molding while pressing the reinforcing fiber base from the axial direction as in the conventional example. Then, the work of pouring the resin and impregnating the reinforcing fiber base with the resin can be omitted, and the actual working time can be shortened.

In addition, the resin rotary body according to the present invention does not form the boundary surface of the fiber layer inside the molding material, and can improve the bonding strength between the resin molded body and the detent portion of the bush. Therefore, the boss removal strength is improved.

[Evaluation 2]
Table 2 shows the results of the evaluation of the fixing yield and the drainage time in the case where the resin rotary body molding semi-processed article was prepared by the method shown in the above-mentioned Examples 1 to 7. The measurement method is as follows.

Fixing yield: 100% of fiber chops and phenol resin powder contained in the slurry, which is an index showing how many% of fiber chops and phenol resin powder remain after dehydration. The fixing yield is determined by adding a coagulant and preparing a slurry with the material combination specified in Examples 1 to 7, and measuring the mass after drying of the formed material 5 produced using the filtration dehydration compression device 7. Calculated.

Drainage time: It was measured as the time for the slurry liquid level to reach the bottom member 16 after the slurry was filled in the filter dewatering and compressing device 7.

It can be seen that Example 1 has a high fixing yield as compared to Example 2, and the drainage time is almost the same as Example 2. In addition, although the fixing yield is high in Example 7, the drainage time is nearly eight times longer than those in Examples 1 to 6, and it is understood that it is not practical.

Examples 2 to 5 have a concern that the fixing yield of the phenol resin powder is particularly low and mechanical strength of the resin gear gear is reduced as compared with Example 1, and therefore phenol is taken into consideration in fixing production when slurry is produced. Resin powder is compounded in excess.

According to the present invention, in the process of forming the aggregate of the short fiber and the powdery resin on the outer peripheral portion of the bush, the necessary amount of the short fiber and the powdery resin is accumulated around the detent of the bush and the bush is detented The part can be completely surrounded by a collection of short fibers and powdered resin. Further, by compressing this, it is possible to ensure penetration of the short fiber and the powdered resin into the detent portion of the bush and to increase the density of the short fiber in the vicinity of the outer periphery of the bush. For this reason, as in the conventional case, the bonding strength between the resin molded product and the detent portion of the bush can be improved without forming the boundary surface of the fiber layer inside the reinforcing fiber base material, and it is made of resin The advantage is obtained that the durability performance of the resin rotary body such as a gear can be greatly improved.

In addition, since a resin molded body can be formed by heating and pressure forming a forming material, as in the prior art, the pressure in the forming mold is reduced to a vacuum while the reinforcing fiber base material is pressed from the axial direction. Then, the work of pouring the resin and impregnating the reinforcing fiber base with the resin can be omitted, and the number of processes can be reduced. In addition, the structure of the molding die can be simplified.

Reference Signs List 1 resin rotating body 2 metal bush 3 through hole 4 outer peripheral portion 4A protruding portion (rotation preventing portion)
DESCRIPTION OF SYMBOLS 4B Recess 5 Molding material 7 Paper-making compression device 8 A collection of short fiber and powdered resin 10

Tubular mold

11, 12

Bush support mold

13, 14 Compression mold 15 Through hole 16 Bottom member

Claims

Providing a bush having one or more detents formed on the outer periphery and capable of rotating about a rotation axis;
Forming a forming material formed of an aggregate of short fibers and powdered resin on the outer peripheral portion of the bush and disposed in a state of being fitted to the bush so as to surround the one or more detents; Become
The step of forming the molding material is
Using a slurry prepared by mixing the short fiber, the powdery resin and water, the short fiber and the powdery resin are collected around the outer peripheral portion of the bush by a filter-dehydration method to obtain an aggregate A first step of forming
A second step of compressing the aggregate in the axial direction of the rotary shaft to form the molding material on the outer peripheral portion of the bush; Production method.
In the first step, the slurry is prepared by adding one or more types of electrostatic attraction aggregation type polymer coagulant to a mixed solution of the short fiber, the powdered resin and water. The manufacturing method of the half-processed goods for resin-made rotary body formation as described in 1.
The resin according to claim 2, wherein a cationic polymer flocculant is added to the mixed solution as the one or more electrostatic attractive flocculation type polymer flocculants, and then an anionic polymer flocculant is added. A method of manufacturing a semi-finished product for forming a rotating body.
The semi-finished product for molding resin rotary body according to claim 2, wherein an amphoteric polymer coagulant is added to the mixed solution as the one or more kinds of electrostatic attractive force aggregation type polymer coagulants. Production method.
In the first step, the short fibers and the powdered resin are gathered around the outer peripheral portion of the bush in a state where the space for housing the bush and the collection housing is suction-filtered. The manufacturing method of the resin-made rotational-body-formed semi-processed goods according to claim 1.
The semi-finished product for resin rotary body molding according to claim 3, wherein the cationic polymer flocculant is a cationic styrenic polymer aqueous solution, and the anionic polymer flocculant is an anionic acrylic polymer aqueous solution. Manufacturing method.
Providing a bush having one or more detents formed on the outer periphery and capable of rotating about a rotation axis;
Forming a forming material formed of an aggregate of short fibers and powdered resin on the outer peripheral portion of the bush and disposed in a state of being fitted to the bush so as to surround the one or more detents;
The molded material is heated and pressurized to melt the powdered resin, and the molten resin produced is impregnated into the reinforcing fiber layer consisting of the short fibers, and then the molten resin is cured to form a resin molded body It consists of steps and
The step of forming the molding material is
Using a slurry prepared by mixing the short fiber, the powdery resin and water, the short fiber and the powdery resin are collected around the outer peripheral portion of the bush by a filter-dehydration method to obtain an aggregate A first step of forming
A second step of compressing the aggregate in an axial direction of the rotation shaft to form the molding material on the outer peripheral portion of the bush.
The short fibers include aramid fibers having a length of 2 to 6 mm, and fine fibers and / or pulp fibers obtained by fibrillating the aramid fibers, and the freeness of the fine fibers is 100 ml or more and 400 ml or less. The method for producing a resin rotating body according to claim 7, wherein the content is 30% by mass or less in the short fibers.
The short fibers are made of synthetic fibers having a thermal decomposition temperature or melting temperature of 250 ° C. or higher,
9. The resin according to claim 8, wherein the powdery resin comprises particles of thermosetting resin or thermoplastic resin having a moldable temperature lower than the thermal decomposition temperature or melting temperature of the synthetic fiber and having a particle diameter of 50 μm or less. Method of manufacturing rotating body.
The resin product according to claim 7, wherein, in the first step, the slurry is prepared by adding one or more polymer coagulants to a mixed solution of the short fibers, the powdered resin, and water. Method of manufacturing rotating body.
The method according to claim 10, wherein a cationic polymer flocculant is added to the liquid mixture as the one or more polymer flocculants, and then an anionic polymer flocculant is added.
The method for producing a resin rotating body according to claim 10, wherein an amphoteric polymer flocculant is added to the mixed liquid as the one or more polymer flocculants.
The method for manufacturing a resin rotating body according to claim 7, wherein a ratio of the short fibers to the resin molded body is 30% by volume or more and 60% by volume or less.
A heating and pressurizing apparatus for heating and pressing the molding material in the method for manufacturing a resin rotary body according to claim 7, wherein
A fixed mold provided with a recess for receiving the molding material together with the bush so as to restrict the radially outward expansion of the molding material;
A support portion for supporting the bush is disposed in the recess of a first movable mold displaceably disposed relative to a fixing bracket so as to be displaced in the recess of the fixed mold, and is inserted into the recess to the support portion And a second movable mold provided with the supported bush and a pressing portion for pressing the molding material toward the inner bottom surface of the recess.
The fixed mold, the first movable mold, and the second movable with the inner bottom surface of the fixed mold and the pressing portion of the second movable mold being in contact with the molding material. The mold is heated to a moldable temperature of the powdery resin, and the second movable mold is configured to move toward the inner bottom surface in a state where the powdery resin is melted. Heat and pressure device.
A resin gear formed by subjecting a resin molded body of a resin rotary body manufactured by the method according to claim 7 to a gear cutting process.