JPH11333870A - Mold rotatable molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight and inexpensive mold rotatable molding apparatus low in production cost and having a simple structure capable of rotating even a mold for molding a relatively large molded object without generating deflection. SOLUTION: In a mold rotatable molding apparatus 11 for performing molding while rotating a mold 2, ring parts 8 equipped with the mold 2 and drive rollers 12, 14 having the drive outer peripheral surfaces coming into contact with the outer peripheral surfaces to be driven of the ring parts 8 to rotate the ring parts 8 along with the ring parts 8 are provided and projected curved surfaces of a first radius of curvature projected in the vicinity of the central part in the rotary axis direction of the ring parts are provided to the outer peripheral surfaces to be driven of the ring parts 8 and recessed curved surfaces 11 of a second radius of curvature depressed in the vicinity of the central parts in the rotary axis direction of the drive rollers 12, 14 are provided to the drive outer peripheral surfaces of the drive rollers 12, 14 and the second radius of curvature is larger than the first radius of curvature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold-rotatable molding apparatus, and more particularly to a mold-rotating molding apparatus suitable for use in a method in which a reaction solution is reacted in a mold and polymerized while the mold is being rotated. And a mold rotatable molding apparatus.

[0002]

2. Description of the Related Art In U.S. Pat. No. 4,808,364, a reaction stock solution is mixed and put into a rotating mold.
A rotary molding method is disclosed in which a mold is rotated to react and polymerize a reaction stock solution inside a mold while applying centrifugal force to the reaction stock solution.

In this publication, means for rotating the mold is not always clear. However,
In particular, when trying to obtain a large rotary molded body, a means for rotating the mold becomes a problem, and means for rotating the mold without causing rotational blurring is required.

[0004] Japanese Patent Application Laid-Open No. 3-69357 discloses that
A technology is disclosed in which a polyethylene tube having adhesiveness to a molded body is used as a mold, a reactive polymerization reaction is performed while rotating the polyethylene tube around an axis, and the obtained molded body is integrated with the polyethylene tube. I have.

[0005]

However, according to the technique disclosed in the above publication, a hollow rotary drive shaft is attached to a mold,
Since the hollow rotary drive shaft is driven to rotate, it is suitable as a mold for centrifugally molding a molded product having a relatively small outer diameter, but a molded product having an outer diameter as large as about 400 mm or more is formed. It could not be said that it was suitable as a mold to perform. This is because if the rotary drive shaft is attached to the die along the axial direction of the die separately from the die, the rotary drive shaft is required to have sufficient rigidity to transmit the rotational torque, and the rotary drive shaft and the die This is because the strength of the connection with the mold also becomes a problem. In addition, a mold for molding a molded article having a relatively large outer diameter also becomes heavier, and the rotary drive shaft for rotating the mold must also be heavier. Is too large. Furthermore, it is difficult for the conventional apparatus to rotate the mold without shaking. For example, when the mold is shaken and rotated at the time of rotational molding, the quality of the molded body varies, for example, the thickness of the molded body varies.

The present invention has been made in view of such circumstances, and can be rotated without shaking even with a mold for forming a relatively large molded body, is lightweight, has a low manufacturing cost and is simple. It is an object of the present invention to provide a mold rotatable molding apparatus having a simple structure.

[0007]

To achieve the above object, a mold rotatable molding apparatus according to the present invention is a mold rotatable molding apparatus for performing molding while rotating a mold, A ring portion provided in the mold, a drive roller having a drive-side outer peripheral surface in contact with a driven-side outer peripheral surface of the ring portion, and a drive roller rotating the ring portion together with the mold; The outer peripheral surface on the driven side of the portion has a convex curved surface having a first radius of curvature that protrudes near the center in the rotation axis direction of the ring portion, and the outer peripheral surface on the driving side of the driving roller includes There is provided a concave curved surface having a second radius of curvature depressed near the center in the rotation axis direction, and the second radius of curvature is larger than the first radius of curvature.

The second radius of curvature r2 is equal to the first radius of curvature r
It is preferably 1.2 to 5 times, more preferably 1.3 to 2.0 times, of 1. The axial width b2 of the drive-side outer peripheral surface of the drive roller may theoretically be equal to or greater than the elastic contact width between the ring and the roller. However, in practice, the axial width b1 of the driven-side outer peripheral surface of the ring portion is larger than the axial width b1. Is also preferably long. Axial width b of the outer peripheral surface on the driving side of the driving roller
2 is preferably 1.1 to 3 times, more preferably 1.3 times the axial width b1 of the driven-side outer peripheral surface of the ring portion.
It is preferably up to 2.0 times.

In the present invention, the mold is not particularly limited, but includes a split mold that can be divided into two or more, and at least a pair of ring portions arranged at predetermined intervals in the axial direction on the outer periphery of the split mold. It is preferable to have A rotation molding space for molding a tube in which the joint portion is integrally molded may be formed inside the mold.

[0010] At least one end of the mold in the direction of the rotation axis may be provided with a lid that is detachable in the axial direction. The inside of the lid may have a shape for forming a joint part of the obtained molded body. The lid may be a ring or a part thereof, and an outer peripheral surface of the lid may be in contact with a driving roller for rotating a mold.

The material that is put into the mold of the mold rotatable molding apparatus according to the present invention and is molded is not particularly limited.
The reaction solution is not limited to a reaction solution which is converted into a polymer, but may be another resin, concrete, metal or the like, but is preferably a reaction solution.

Reaction stock solution The reaction stock solution is not particularly limited.
Examples include urea-based, nylon-based, epoxy-based, unsaturated polyester-based, phenol-based, and norbornene-based ones, with the norbornene-based being particularly preferred. The temperature of the unreacted solution before entering the mold is preferably 20 to 80 ° C, and the viscosity of the unreacted solution is, for example, 30 ° C,
It is preferably about 20 cps to 1000 cps, and more preferably about 30 cps to 700 cps. If the viscosity of the reaction stock solution is too low, the reaction stock solution tends to stay at the bottom without centrifugal force acting.If the viscosity is too high, free-form molding using centrifugal force by rotational molding is performed. Tends to be difficult.

In such molding, a reinforced polymer (molded body) can be manufactured by placing a reinforcing material in a mold in advance and supplying a reaction liquid therein to polymerize.

Examples of the reinforcing material include glass fiber, aramid fiber, carbon fiber, ultrahigh molecular weight polyethylene fiber, metal fiber, polypropylene fiber, aluminum coated glass fiber, cotton, acrylic fiber, boron fiber, silicon carbide fiber, and alumina fiber. And the like. These reinforcing materials can be used in various shapes, such as those obtained by forming a long fiber or chopped strand into a mat, woven into a cloth, or remaining in a chopped shape. It is preferable that the surface of these reinforcing materials is treated with a coupling agent such as a silane coupling material in order to improve the adhesion to the resin. The amount to be used is not particularly limited, but is usually 10% by weight or more, preferably 20 to 60% by weight of the total weight of the molded article.

Further, various additives such as an antioxidant, a filler, a pigment, a colorant, a foaming agent, a flame retardant, a sliding agent, an elastomer, a dicyclopentadiene-based thermopolymerized resin and a hydrogenated product thereof are blended. Thereby, the properties of the obtained polymer can be modified.

As the antioxidant, there are various antioxidants for plastics / rubbers such as phenol type, phosphorus type and amine type. Fillers include inorganic fillers such as milled glass, carbon black, talc, calcium carbonate, aluminum hydroxide, mica, potassium titanate, calcium sulfate, and the like. Examples of the elastomer include natural rubber, polybutadiene, polyisoprene, styrene-butadiene copolymer (SBR), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and ethylene- Examples include propylene-diene terpolymer (EPDM), ethylene vinyl acetate copolymer (EVA) and hydrides thereof. The additive is usually mixed in advance with one or both of the reaction solutions.

In the present invention, when rotational molding is performed using the undiluted reaction solution (the concept includes centrifugal molding in the present invention), the temperature of the mold is preferably 10 to 150 ° C.
C, more preferably 20 to 120 ° C, still more preferably 30 to 100 ° C. Before injecting the unreacted solution into the mold, warm air is circulated inside the mold, and at least the inside of the cavity of the mold is heated to a predetermined temperature. The molding may be performed by pouring the unreacted solution into the cavity.

In the present invention, when rotational molding is performed using a reaction stock solution, the material of the mold is not particularly limited, and is not limited to metals such as cast iron, iron, stainless steel, aluminum, and nickel electroformed. Resin or other materials may be used. Molding using a reaction stock solution can be performed at a relatively low pressure, and it is not always necessary to use a highly rigid mold.

When the mold is made of a synthetic resin, the synthetic resin is not particularly limited, and may be polyethylene (LDP).
E, MDPE, HDPE, ultra-high molecular weight PE), polystyrene, polypropylene, polyvinyl chloride, urethane, epoxy, phenol, polyester and the like. When the mold is made of a non-polar resin such as polyethylene or polystyrene such as LDPE or MDPE, these resins are easily integrated with the molded body.
It can be disposable and used. That is, it is also possible to integrally mold a lining layer made of a polymer molded product of the undiluted reaction solution on the inner surface of a mold as a product.

Further, when the mold is made of a polar resin such as phenol or polyester, the mold is not integrated with the reactive polymer molded product. Can be.

The polymerization time may be appropriately selected, but when a rotational force is applied after the completion of the injection of the undiluted reaction solution, it takes several seconds to several tens of seconds to raise the mold to a predetermined rotational speed. Is 5 to 30 seconds, more preferably 5 to 15 seconds.
Seconds. The undiluted solution may be injected while the mold is rotated.

The molding method in which the mold rotatable molding apparatus according to the present invention is used is not particularly limited, and may be rotational molding (1 G or less) or centrifugal molding (1 G or more). However, centrifugal molding is particularly effective because the rotational speed of the mold is higher.

[0023]

In the mold rotatable molding apparatus according to the present invention, the mold is rotated by rotating the drive roller and rotating the ring portion in contact with the drive roller. Therefore,
The weight of the rotating body including the mold can be reduced as compared with a conventional apparatus in which a mold is mounted on a rotary drive shaft and torque is transmitted to the rotary drive shaft to rotate the mold. When a rotary drive shaft is mounted on a mold and rotated, a rotational torque is applied to the rotary drive shaft and the mold. Therefore, it is necessary that the rotary drive shaft and the die be made of a rigid body that can withstand the rotational torque. Becomes larger. In the molding device according to the present invention, the rotating torque is applied directly to the ring portion provided in the mold to rotate the mold, and the ring portion also serves to reinforce the mold. , The weight of the rotating body can be reduced.

In the apparatus of the present invention, the outer peripheral surface on the driven side of the ring portion has a convex curved surface having a first radius of curvature, and the outer peripheral surface on the driving side of the driving roller has a concave surface having a second radius of curvature. Since the curved surface is provided and the second radius of curvature is larger than the first radius of curvature, the ring portion is stably rotated at a predetermined axial position by the rotation of the driving roller without being shaken in the axial direction. As a result, when performing rotary molding or the like using the apparatus of the present invention, it is possible to obtain a molded product of stable quality with little variation in the thickness of the molded product.

If no curved surfaces are formed on the outer peripheral surfaces of both the driving roller and the ring portion, the corners of the outer peripheral surface of the ring portion collide with the outer peripheral surface of the driving roller, and the rotational direction of the mold is changed. Vibration increases. In addition, during rotation of the mold, the mold moves in the direction of the rotation axis, and the vibration of the mold in the direction of the rotation axis also increases. Further, when a convex curved surface is provided only on the outer peripheral surface of the ring portion, vibration in the rotational direction of the mold can be suppressed, but the ring portion moves in the rotational axis direction with respect to the drive roller, and Vibration in the rotation axis direction cannot be suppressed. Furthermore, even if curved surfaces are formed on the outer peripheral surfaces of both the driving roller and the ring portion, the second radius of curvature is equal to the first radius of curvature.
If the radius of curvature is equal to or less than the radius of curvature, contact between the ring portion and the drive roller becomes difficult, and the mold cannot be rotated stably.

Further, since the molding apparatus according to the present invention can rotate the mold with a relatively simple structure, the manufacturing cost is low.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings.

FIGS. 1A and 1B are schematic perspective views of a mold according to an embodiment of the present invention, FIG. 1C is a schematic perspective view showing an example of a molded body, and FIG. 3 is a plan view of the driving device, FIG. 4 is a cross-sectional view of a main part taken along line IV-IV shown in FIG. 3, and FIG. 5 is a metal diagram according to another embodiment of the present invention. FIG. 6 is a schematic sectional view of a mold, and FIG. 6 is a schematic sectional view of a mold according to another embodiment of the present invention.

First Embodiment In this embodiment, a norbornene-based monomer is used by using a mold rotatable molding apparatus 11 shown in FIGS. 2 and 3 having a rotational molding die 2 shown in FIGS. 1A and 1B. A method for producing a tube by reacting and polymerizing a reaction stock solution containing

As shown in FIGS. 1A and 1B, the mold 2
Is a split mold 4 that can be vertically split into two along the split surface 3.
And a pair of rolling ring portions 8 attached axially to the outer periphery of both ends thereof in a state where the split mold 4 is combined.
And The split mold 4 is made of, for example, an aluminum casting, and the rolling ring portion 8 is made of cast iron.

It is preferable that a sealing material is mounted on the split surface 3 of the split mold 4. By installing the sealant, it is possible to prevent inconvenience such as leakage of the undiluted reaction solution from the split surface 3. The sealing material is not particularly limited, but a silicone rubber sealing material or the like can be used.

The sealing material is formed, for example, in the form of a string having a circular or elliptical cross section. In use, the sealing material is cut into a predetermined length and mounted in a gap to be sealed. Further, this sealing material can be used in combination with a conventional sponge packing or the like.

An inner peripheral surface is formed inside the split mold 4 combined with the split surface 3, and a reaction stock solution having a predetermined viscosity is pressed against the inner peripheral surface by centrifugal force. I have. End plates 6 and 6 are formed at both ends in the axial direction of the split mold 4 so that the through holes 5 are formed. A nozzle for supplying the undiluted reaction solution is inserted from the through hole 5, so that the undiluted reaction solution can be supplied into the mold 2.

As shown in FIGS. 2 and 3, in the mold rotatable molding apparatus 11 according to this embodiment, a pair of flanged drive rollers 12 are engaged with one rolling ring 8 of the mold 2. A similar drive roller 14 is also engaged with the other rolling ring portion 8. These drive rollers 12 and 14 are connected to a transmission 16 and a constant torque inverter motor 18 and all rotate at substantially the same rotational speed. These drive rollers 12
And 14 all rotate at substantially the same rotational speed,
The rolling ring portions 8 engaged with them also rotate around their axes, and simultaneously rotate the mold 2 composed of the split dies 4 and 4 around their axes. The drive rollers 12 and 14 and the transmission 16
The motor 18 is mounted on a base 20.

The mold rotatable molding apparatus 1 according to the present embodiment.
In FIG. 1, as shown in FIG. 4, a convex curved surface 9 having a first radius of curvature r1 is formed on the driven-side outer peripheral surface of the rolling ring portion 8 near the center of the ring portion 8 in the rotation axis direction. It is. The outer peripheral surface of the drive roller 12 on the drive side is provided with a concave curved surface 11 having a second radius of curvature r2 that is depressed near the center of the drive roller 12 in the rotation axis direction.

The second radius of curvature r2 is preferably 1.2 to 5 times, more preferably 1.3 to 2.0 times the first radius of curvature r1. The axial width b2 of the concave curved surface 11 of the driving roller 12 is
With respect to the axial width b1 of the convex curved surface 9 of 1.
It is preferably 1 to 3 times, more preferably 1.3 to 2.0 times. Such a convex curved surface 9 and a concave curved surface 1
1 can be formed by cutting the outer peripheral surfaces of the rolling ring portion 8 and the driving roller 12, but may be formed simultaneously when the rolling ring portion 8 and the driving roller 12 are formed by casting or the like. good.

In the present embodiment, not only the pair of drive rollers 12 but also the other pair of drive rollers 14 are formed with similar concave curved surfaces 11 and are engaged with the concave curved surfaces 11 of the drive rollers 14. A convex curved surface 9 similar to the above is also formed on the outer peripheral surface of the rolling ring portion 8. However, in the present invention,
It is not always necessary to form the concave curved surface 11 on the outer peripheral surface of either pair of drive rollers 12 or 14.

Next, a method of forming a tube by a polymerization molding method using a reaction stock solution using the mold rotatable molding apparatus 11 will be described.

First, as shown in FIG.
Then, as shown in FIG. 1A, the rolling rings 8, 8 are attached to both ends of the combined split dies 4, 4, and the mold 2 is assembled. Next, the mold 2 is rotatably mounted on the drive rollers 12 and 14 shown in FIGS.

Thereafter, molding using the reaction stock solution is performed. In the present embodiment, molding is performed using a norbornene-based monomer. Specific examples of the norbornene-based monomer to be used include bicyclics such as norbornene and norbornadiene; dicyclopentadiene (cyclopentadiene dimer), and dihydrodicyclopentadiene. Tricyclics such as tetracyclododecene; pentacyclics such as cyclopentadiene trimers; heptacyclics such as cyclopentadiene tetramers; alkyls such as methyl, ethyl, propyl and butyl Substituents such as alkenyl such as vinyl, alkylidene such as ethylidene, and aryl such as phenyl, tolyl, and naphthyl; and substituents having polar groups such as ester group, ether group, cyano group, and halogen atom. You. These monomers may be used in combination of one or more kinds. Tricyclic, tetracyclic, or pentacyclic monomers are preferred from the viewpoint of easy availability, excellent reactivity, and excellent heat resistance of the obtained resin molded product.

The resulting ring-opening polymer is preferably of a thermosetting type. For this purpose, among the above norbornene-based monomers, it has two or more reactive double bonds such as cyclopentadiene trimer. Those containing at least a crosslinkable monomer are used. The proportion of the crosslinkable monomer in all the norbornene monomers is preferably from 2 to 30% by weight.

It should be noted that, within a range not to impair the object of the present invention,
Monocyclic cycloolefins such as cyclobutene, cyclopentene, cyclopentadiene, cyclooctene and cyclododecene, which can be ring-opening copolymerized with norbornene monomers,
It may be used as a comonomer.

The metathesis catalyst which can be used in molding using a norbornene-based monomer is a norbornene-based catalyst such as tungsten hexachloride, or an organic ammonium molybdate such as tridodecyl ammonium molybdate or tri (tridecyl) ammonium molybdate. There is no particular limitation as long as it is a known metathesis catalyst as a catalyst for bulk polymerization of monomers, but an organic ammonium molybdate is preferred.

As the activator (cocatalyst), JP-A-58-1983
127728, JP-A-4-226124,
JP-A-58-129003, JP-A-4-1452
There is no particular limitation as long as it is a known activator as disclosed in Japanese Patent No. 47, for example, alkyl aluminum halides such as ethyl aluminum dichloride and diethyl aluminum chloride, organic aluminum compounds such as alkoxyalkyl aluminum halides, and organic tin. And the like.

As preparation before molding, a molding material mainly composed of a norbornene-based monomer, a metathesis catalyst and an activator was mixed with a solution B comprising a norbornene-based monomer and a metathesis catalyst, and the above-mentioned norbornene-based monomer and activator. The liquid is divided into two stable liquids and the liquid A, each of which is placed in a separate tank.

To start molding, control the mixer,
The solution A and the solution B from the tank are mixed, and the mixed solution is used as a reaction stock solution by using a nozzle or the like to form the through-hole 5 of the mold 2.
From the mold 2. The viscosity of the reaction solution supplied into the mold 2 is 50 cps to 10 at 30 ° C.
By rotating the mold 2, the undiluted reaction solution adheres to the inner peripheral surface of the mold 2 in a tubular shape by rotating the mold 2.

In the present embodiment, the mold 2 does not necessarily need to be heated, but may be heated using a heating medium or warm air from the viewpoint of facilitating the polymerization reaction.

The number of revolutions of the mold 2 is not less than 1 G
It is designed such that an acceleration of 1 G or more and 5 G or less, preferably 1 G or more and 4 G or less, particularly preferably 1.2 or more and 4 G or less is applied. The acceleration differs depending on the diameter of the inner peripheral surface of the mold 2. Is 400 to 600 mm,
The rotation speed of the mold 2 around the axis is preferably about 80 to 150 rpm. The initial startup time required to rotate the mold 2 around the axis at a constant rotation speed is several seconds to 30 seconds.
On the order of seconds. After that, rotation is possible at a constant rotation speed. After the mold 2 is rotated around the axis thereof at a constant rotation speed, a nozzle may be inserted through the through-hole 5 to supply the reaction solution.

By rotating the mold 2 around the axis thereof at a constant rotational speed, the undiluted reaction solution supplied to the inside of the mold 2 is formed into a tube shape on the inner peripheral surface of the mold 2 by centrifugal force. It will stick. By maintaining this state for, for example, 1 to 10 minutes, the reaction in the undiluted reaction solution proceeds, bulk polymerization is performed, and a tubular shaped body is obtained.

Thereafter, the rotation of the mold 2 is stopped, and after the mold 2 is cooled, the rolling ring portion 8 is moved from the state shown in FIG. 1A to the state shown in FIG. Remove, split mold 4,
By opening 4, a tubular shaped body 10 as shown in FIG. This tubular shaped body 1
0 is constituted by a reactive polymer molded product of a norbornene-based monomer.

Mold rotatable molding apparatus 1 according to this embodiment
In the molding method using No. 1, by applying a centrifugal force to the reaction stock solution, bubbles are separated from the reaction stock solution by the centrifugal force during molding, and voids are eliminated in the obtained molded body.

Further, the inner peripheral surface of the tubular molded body 10 shown in FIG. 1C obtained by the molding method using the mold rotatable molding apparatus 11 of the present embodiment touches anything during the molding process. In addition, since the surface is obtained by centrifugal force, there is no inconvenience such as poor curing of the reaction solution during molding, and the inner peripheral surface is smooth. The obtained tubular molded body 10 is used, for example, as a fluid pipe or the like, and since a fluid flows through the pipe, it is convenient to use the pipe as a pipe having a smooth inner peripheral surface.

Further, since the tubular molded body 10 obtained by the method according to the present embodiment is a polymer obtained by utilizing a bulk polymerization reaction of a norbornene-based monomer, impact resistance and durability are improved. Has excellent mechanical properties. Further, according to the molding method using the rotatable molding apparatus 11, even a relatively large-diameter tubular molded body can be molded relatively easily.

In particular, in the mold rotatable molding apparatus 11 according to the present embodiment, a convex curved surface 9 having a first radius of curvature r1 is formed on the driven-side outer peripheral surface of the rolling ring portion 8, and the driving roller 12, a concave curved surface 11 having a second radius of curvature r2 is formed on the outer peripheral surface on the drive side, and the second radius of curvature r2 is larger than the first radius of curvature r1. The rotation stably rotates at a predetermined axial position without being shaken in the axial direction. As a result, the rotation of the mold 2 is also stabilized, and when molding is performed using the apparatus 11 of the present embodiment, it is possible to obtain a molded product of stable quality with little variation in the thickness of the molded product.

Further, in the present embodiment, the split dies 4, 4 are used, and the rolling ring portions 8, 8 are mounted on the outer periphery thereof, and the die 2 is mounted by using the rolling ring portions 8, 8. Since it is rotated around the axis, it is possible to realize both free-form molding of the molded body by using the split mold and rotation with less rotational runout using the ring portion. In addition, when rotational blur occurs, the rotational blur can be suppressed by shaving the outer periphery of the ring portions 8 during rotation. Also,
The replacement of the ring portions 8, 8 is also easy. Moreover, in the mold 2 according to the present embodiment, it is not necessary to separately attach a rotary drive shaft to the mold, so that the weight of the rotating body can be significantly reduced, and particularly, a large molded body (outer diameter of 400 mm Above, preferably 400 to 4000 mm, especially 100 to 2500
mm large diameter pipe-shaped molded article).

Second Embodiment In this embodiment, except for using the mold 2a shown in FIG. 5,
In the same manner as in the first embodiment, the mold rotatable molding apparatus is assembled, the mold 2a is rotated, and the norbornene-based monomer is added to the reaction solution in the mold 2a under an acceleration of 1 G or more. The reaction stock solution is reacted to polymerize.

In the present embodiment, the mold 2a is composed of a pair of split dies 4a, 4a, and a ring portion 8 mounted on the outer periphery of the split dies 4a, 4a from the axial direction in a state where the split dies are combined.
a, 8a. As in the first embodiment, a convex curved surface having a first radius of curvature is formed on the outer peripheral surfaces of the ring portions 8a, 8a in the vicinity of the central portion in the rotation axis direction of the ring portions 8a, 8a. The configuration of the drive roller is shown in Figs.
4 is the same as that of the first embodiment shown in FIG. Therefore, also in the present embodiment, the ring portions 8a, 8a
The rotation of the driving roller stably rotates at a predetermined axial position without being shaken in the axial direction. As a result, when performing molding using the apparatus of the present embodiment, it is possible to obtain a molded body of stable quality with little variation in the thickness of the molded body.

In the present embodiment, the outer diameter of the split dies 4a, 4a is not uniform in the axial direction, and the outer diameter is increased at one end 22 in the axial direction. An enlarged diameter portion 26 for a joint can be integrally formed at the end of the joint 24. This joint enlarged diameter portion 26
The small-diameter-side end of another pipe-shaped molded body 24 is inserted into the inside of, and can be connected.

Even such a pipe-shaped molded article with a joint can be easily molded by the mold rotatable molding apparatus of the present embodiment. In addition, it is not necessary to increase the thickness of the split dies 4a, 4a more than necessary, and the lightweight mold 2a can be obtained. The mold 2a according to the present embodiment is driven to rotate in the same manner as in the above-described embodiment.
Its handling is easy. In addition, since only the ring portion is mounted on the outer periphery of the split mold, its attachment and removal are easy.

Third Embodiment In this embodiment, as shown in FIG.
b is a pair of metal split dies 35 and 35 that are combined into a tube shape, and a pair of ring portions 3 that are removably attached to the outer periphery of both ends of the combined split dies 35 and 35.
6, and a cap (lid) 37 attached to the outer periphery of each ring portion 36, 36 to form a joint forming space 38. A through hole 39 is formed in the center of the cap 37. Through this through-hole 39, a nozzle for supplying the undiluted reaction solution enters the split molds 35, 35, so that the undiluted reaction solution can be supplied.

The drive rollers 12, 14 shown in FIGS. 2 and 3 are engaged with the outer periphery of the cap 37, which is a part of the ring portion 36, and are driven to rotate by the drive rollers 12, 14, which are different from those of the first embodiment. Similarly, a reaction solution containing a norbornene-based monomer is reacted and polymerized under a state where centrifugal force is applied to the reaction solution. To take out the obtained molded body, first, the cap 37 is removed from the ring portion 36, and then the ring portion 36 is removed from the split mold 35, and the split mold 35 is removed.
By opening the hollow pipe, it is possible to obtain a hollow pipe made of a rotary molded body in which flange-like joints are integrally formed at both ends.

Also in this embodiment, the ring portions 36, 3
A convex curved surface having a first radius of curvature is formed on the outer peripheral surface of the cap 37 which is a part of the convex portion 6 in the vicinity of the central portion in the rotation axis direction of the ring portions 36, 36 as in the first embodiment. is there. The configuration of the driving roller is the same as that of the first embodiment shown in FIGS. Therefore, also in the present embodiment, the ring portion 36 including the cap 37 is stably rotated without being shaken in the axial direction at a predetermined axial position by the rotation of the driving roller. As a result, when performing molding using the apparatus of the present embodiment, it is possible to obtain a molded body of stable quality with little variation in the thickness of the molded body.

Other Embodiments The present invention is not limited to the above-described embodiments, but can be variously modified within the scope of the present invention. For example, in the above embodiment, only two rolling ring portions are mounted, but three or more rolling ring portions may be mounted in the axial direction. Further, the drive rollers 12 and 14 do not need to be engaged with all the rolling ring portions, and even if a ring portion with which the drive rollers 12 and 14 are not engaged is mounted on the outer periphery of the split dies 4 and 4. good.

In the above-described embodiment, the split dies 4, 4
Although a to 4c are divided into two, they may be divided into three or more.

Further, the mold rotatable molding apparatus according to the present invention can be used not only for centrifugal molding but also for rotational molding. In the rotational molding, the gravitational acceleration applied to the reaction stock solution is as small as about 1 G or less, and the rotational speed of the mold is small as compared with the centrifugal molding. Also, not only rotation around one axis,
The apparatus of the present invention can also be applied to rotational molding that rotates around two axes. In the rotational molding, the molded body can be formed into a relatively free shape as compared with the centrifugal molding. For example, a tank body of a septic tank can be manufactured.

[0066]

EXAMPLES Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples.

Example 1 A mold 2 shown in FIG. 1A was prepared and set on drive rollers 12 and 14 of a mold rotatable molding apparatus 11 shown in FIGS. The pair of split dies 4 and 4 are made of aluminum casting, and have an outer diameter of 500 mm and an inner diameter of 400 m.
m, and its axial length was 1200 mm. The inner diameter of the through hole 5 of the end plate 6 formed at both ends of the split dies 4 and 150 was 150 mm.

The split dies 4 and 4 were combined with the split face 3. The split surface 3 was sealed with a silicone rubber sealing material. The rolling ring portions 8, 8 were attached with the split surfaces 3 of the split dies 4, 4 sealed. The rolling ring portions 8, 8 were made of cast iron, had an outer diameter of 700 mm, and an axial width b1 of 50 mm. The curvature r1 of the convex curved surface 9 on the outer peripheral surface of the rolling rings 8, 8 was R200 mm. The outer diameter of the drive rollers 12 and 14 is φ200 mm, the width b2 is 120 mm, and the curvature r2 of the concave curved surface 11 on the outer peripheral surface is R.
It was 300 mm.

The rolling rings 8 are connected to the driving rollers 12
The reaction solution was supplied to the inside of the mold 2 by using a nozzle through the axial through hole 5 of the split mold. The preparation of the reaction stock solution was performed as follows. Dicyclopentadiene (DC
P) 85% by weight and 15% by weight of tricyclopentadiene
And a total monomer amount of 10
5 parts by weight of styrene-isoprene-styrene block copolymer (Clayton 1170, manufactured by Shell) and 2 parts by weight of Irganox 1010 (Ciba-Geigy), which is a phenolic antioxidant, based on 0 parts by weight. Was dissolved in two containers, one of which was charged with 4 parts of diethyl aluminum chloride (DEAC) based on the mixed monomers.
0 mmol, n-propanol was added at 44 mmol, and silicon tetrachloride was added at 20 mmol (Solution A). On the other hand, tri (tridecyl) ammonium molybdate was added to the mixed monomer at a concentration of 10 mmol (solution B).

The liquid A and the liquid B are respectively sent to the mixer by a gear pump so as to have a volume ratio of 1: 1 and then supplied from the through hole 5 of the mold 2 to the inside of the mold 2 using a nozzle. did. The temperature of the reaction stock solution was 30 ° C., and its viscosity was 300 cps at 30 ° C.

Immediately after the completion of the supply of the reaction stock solution, the drive rollers 12, 14 were rotated, and the mold 2 was rotated about its axis. In 15 seconds, the rotation speed of the mold 2 becomes 120 rpm
And maintained that speed. The acceleration acting on the reaction stock solution was calculated to be 3G. There was no vibration or vibration of the mold, and the mold quietly and stably rotated.

After maintaining this state for 5 minutes, the rotation was stopped, the mold 2 was taken out, the rolling ring portions 8, 8 were removed, and the split dies 4, 4 were opened. A tubular molded body 10 as shown was obtained.

For confirmation, the tubular molded body 10 was cut at a plurality of locations, and the cross-sectional state was examined, but no void was found. Further, when the inner peripheral surface of the tube molded body 10 was observed, it was confirmed that there was no trouble such as poor curing and the tube was smooth. Further, when the roundness of the cross section of the hollow portion of the tubular molded body was measured, it was confirmed that good roundness with almost no eccentricity was obtained.

COMPARATIVE EXAMPLE 1 The convex curved surface 9 was not formed on the outer peripheral surfaces of the rolling rings 8, 8, and the concave curved surface 1 was formed on the outer peripheral surfaces of the drive rollers 12 and 14.
Molding was performed in the same manner as in Example 1 except that No. 1 was not formed. During the rotation of the mold, rotational shake occurred, and the mold vibrated in the radial direction and the axial direction of the rotating shaft.

The mold could not be rotated to the same number of revolutions as in Example 1, and a tubular molded article could not be formed.

[0076]

As described above, according to the mold rotatable molding apparatus of the present invention, the outer peripheral surface on the driven side of the ring portion is provided with a convex curved surface having the first radius of curvature. The outer peripheral surface of the driving roller on the driving side is provided with a concave curved surface having a second radius of curvature. Since the second radius of curvature is larger than the first radius of curvature, the ring portion is moved to a predetermined axial position by rotation of the driving roller. , And rotates stably without shaking in the axial direction and without vibrating in the radial direction of rotation. Therefore, the thickness and the like of the molded article obtained by using the molding apparatus according to the present invention become constant, and the quality is improved.

Also, in comparison with a conventional apparatus in which a rotary drive shaft is mounted on a mold and a rotary torque is transmitted to the rotary drive shaft to rotate the mold, the molding apparatus according to the present invention has a rotary mechanism including the mold. Body weight can be reduced.

Further, since the molding apparatus according to the present invention can rotate the mold with a relatively simple structure, the manufacturing cost is low.

[Brief description of the drawings]

FIGS. 1A and 1B are schematic perspective views of a mold according to an embodiment of the present invention, and FIG. 1C is a schematic perspective view showing an example of a molded body.

FIG. 2 is a side view of a driving device for rotating a mold.

FIG. 3 is a plan view of a driving device.

FIG. 4 is a cross-sectional view of a main part along line IV-IV shown in FIG.

FIG. 5 is a schematic sectional view of a mold according to another embodiment of the present invention.

FIG. 6 is a schematic sectional view of a mold according to another embodiment of the present invention.

[Explanation of symbols]

 2, 2a, 2b Mold 3 Split face 4, 4a, 4b, 35 Split mold 8, 8a, 8b Rolling ring part 11 Mold rotatable molding apparatus 10 Molded body 12, 14 Drive roll 24 ... molded body 37 ... cap (lid)

Claims (1)

[Claims] 1. A mold rotatable molding apparatus for performing molding while rotating a mold, wherein a ring portion provided on the mold and an outer peripheral surface on a driven side of the ring portion are contacted. A driving roller having a driving-side outer peripheral surface and rotating the ring portion together with a mold; a first protruding portion of the driven-side outer peripheral surface of the ring portion protruding near the center of the ring portion in the rotation axis direction; A convex curved surface having a radius of curvature is provided, and a drive-side outer peripheral surface of the drive roller is provided with a concave curved surface having a second radius of curvature depressed in the vicinity of a central portion in the rotation axis direction of the drive roller; A mold rotatable molding apparatus, wherein the two radii of curvature are larger than the first radius of curvature.