JP2003191315A - Extrusion equipment for hollow resin molded plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide extrusion equipment for molding a hollow resin molded plate having a constant quality, while enhancing molding efficiency. <P>SOLUTION: The extrusion equipment is constituted by connecting an extruder heating and kneading a material and extruding it by a screw with molding dies each of which is equipped with a molding chamber for molding an extruded ground from the extruder to be of a prescribed section and a core body for molding a hollow part in the extruded ground. The core body is composed of a plurality of rod-like members and base parts each molded integrally with each rod-like member. Each rod-like member has a sectional shape almost the same as one of each hollow part molded in the hollow resin molded plate, and the members are disposed parallel with each other in the length direction identical with the direction of extrusion of the extruded ground and also fixed to the molding die in the melting part of the die. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion molding apparatus for molding a hollow resin molding plate having a hollow portion and having a predetermined wall thickness, and more specifically, when molding the hollow resin molding plate, the quality is deteriorated. TECHNICAL FIELD The present invention relates to an extrusion molding device for a hollow resin molded plate, which can improve the molding speed without the need.

[0002]

2. Description of the Related Art A wood-based synthetic board obtained by heating and kneading wood powder and a thermoplastic resin and molding it into a predetermined shape has a specific gravity of 0.97, although it depends on the mixing ratio of these materials.
〜 1.48, which is much heavier than general wood plate materials (for example, plywood such as plywood has a specific gravity of 0.45 to 0.75). Attempts have been made to form a hollow portion in a wooden synthetic board.

As a method of molding a hollow resin molded plate which is a wood-made synthetic plate having a hollow portion, an extruded dough heated and kneaded by an extruder equipped with a screw is provided with a core body in a molding chamber. There is a method in which the resin is discharged into a molding die, molded into a molding plate having a predetermined wall thickness, a hollow portion is formed by the core, and the speed at which the hollow resin molding plate is extruded from the molding die is suppressed by the braking means ( JP-A-8
-118452 publication). In this way, by using the braking means during the extrusion molding, the density of the extruded material in the molding die can be increased, and a lightweight hollow resin molding plate can be molded without causing molding defects such as depressions.

However, in the above-mentioned method, since the extrusion of the forming plate is suppressed by the braking means, the forming speed is slow at 4 to 5 m per hour, and the productivity is poor.

Further, since the extruded dough is cooled only from the outside of the extruded dough by the cooling water introduced into the channel provided in the wall thickness of the forming die, the screw rotation speed of the extruder is increased in order to increase the forming speed. If it is raised, the extruded material will be extruded from the molding die before it is sufficiently cooled to the inside, and sinking or bending is likely to occur in the molded hollow resin molded plate, and in particular, it will take a long time to complete cooling. This phenomenon is remarkable in the ribs between the parts, which causes a problem that the quality of the molded plate is uneven.

In order to solve such a problem, a cooling medium is caused to flow in a core body forming a hollow portion in a molding plate to cool the extruded dough not only from the molding die wall surface but also from the core body surface. There is a method of accelerating the completion of cooling of the forming plate (Japanese Patent Laid-Open No. 2000-351105).

[0007]

According to the above method, since the extruded material can be cooled in a short time, it is possible to mold a high-density hollow resin molding plate without sink marks or warpage even if the molding speed is increased. As described above, not only is it unnecessary to suppress the speed at which the hollow resin molding plate is extruded from the molding die by the braking means, but instead of this braking means, a pulling means is used to pull the molding plate at the exit of the molding die. Therefore, the molding speed can be further improved.

Further, in the above-mentioned conventional method, in addition to the cooling in the above-mentioned method, a fluororesin sheet obtained by coating a glass fabric with a fluororesin is attached to the inner wall surface of the molding die, thereby extruding through the molding die. It is also proposed that the dough is prevented from receiving a large resistance due to the friction with the inner wall surface of the forming die, and that the flow of the extruded dough is made smooth, thereby further improving the forming speed in combination with the shortening of the cooling time. ing.

However, even if the friction between the extruded material and the inner wall surface of the forming die is reduced by the fluororesin sheet, there is a core body forming a hollow portion in the forming plate in the forming die. If the friction with the body is not reduced, the flow of the extruded dough deteriorates due to the friction with the surface of the core body, so that the amount of the extruded dough introduced into the forming die has a certain limit.

If it is attempted to introduce the extruded dough into the forming die beyond the above limit, the extruded dough, which is resisted by the friction with the core, acts as if it were a plug, and the inlet side of the forming die. Since the pressure applied by does not reach the portion where the extruded dough solidifies inside the forming die, the pressure of the extruded dough cannot be maintained at the required pressure, and as shown in FIG. 6, the rib 29a surface of the forming plate is However, there was a problem that molding was not sufficiently flat and a molding defect such as a dent occurred, or that sufficient extrusion material was not introduced into the molding die and the rib 29a itself was not formed.

As a method of alleviating the friction with the surface of the core body, it is conceivable to attach the fluororesin sheet also to the core body.

However, even if the above-mentioned fluororesin sheet obtained by coating a fluororesin on a glass fabric suitably used for adhering the inner wall surface of the die is adhered to the core body, the glass fiber constituting the matrix of the fluororesin sheet Has a strong tensile force but is a brittle material and is weak against bending, so that there is a problem that the core body which is three-dimensional rather than flat like the inner wall surface of the molding die is easily broken. Therefore, there is a limit to the improvement of the molding speed even by cooling and sticking the fluororesin sheet by the above method.

Further, in the conventional extrusion molding apparatus, the core body has a coupling portion 45 for coupling a plurality of rod-shaped members at the upstream end portion in the extrusion direction of the extruded dough as shown in FIG. Was. This joint portion has a great resistance to the flow of the extruded material, and also hinders the introduction of the extruded material into the gap formed between the rod-shaped members, which is one of the causes of defective molding such as unmolded ribs. It was one.

In order to solve the above problems, the present invention makes it easy to introduce the extruded material into the gap formed between the rod-shaped members, and also reduces the frictional resistance between the surface of the core body and the extruded material. By providing a structure that reduces the pressure, the molding speed can be further increased, and even when the molding speed is improved, it is possible to maintain the pressure of the extruded material in the molding die, and the extrusion that is introduced into the molding die. An object of the present invention is to provide an extrusion molding device for a hollow resin molded plate, which is capable of producing a hollow resin molded plate having uniform quality without causing molding defects such as unformed ribs due to lack of material.

[0015]

In order to achieve the above-mentioned object, the extrusion molding apparatus 1 for the hollow resin molding plate 29 of the present invention comprises:
Extruder 7 that heats and kneads raw materials and extrudes them with a screw
0, extrusion material 79 extruded from the extruder 70
A forming chamber 22 comprising a melting part 21a for heating the extruded dough 79 and a slow cooling part 21b for cooling the extruded dough 79 extruded from the melting part 21a; and the extruded dough 79 from the melting part 21a.
Of at least the slow cooling part 21 protruding in parallel with the extrusion direction of
In the extrusion molding apparatus 1 in which a molding die 10 having a core body 40 extending to b is connected, the core body 40 includes a plurality of rod-shaped members 48a to 48d and the rod-shaped members 48a.
To 48d, each of the rod-shaped members 48a to 48d has a cross-sectional shape substantially similar to the cross-sectional shape of each hollow portion formed in the hollow resin molding plate 29. The extruded dough 79 is arranged in parallel with each other with the extruding direction being the length direction, and is fixed to the forming die 10 in the melting portion 21a of the forming die 10 (claim 1). ).

In the extrusion molding apparatus 1 described above, it is preferable that at least the ends of the rod-shaped members 48a to 48d on the upstream side in the extrusion direction of the extruded material are covered with the container 50 of the fluororesin sheet 50 '( Claim 2).

As the fluororesin sheet 50 'forming the container 50, it is preferable to use a woven fabric of aramid fibers obtained by impregnating a fluororesin dispersion liquid, drying and firing (claim 3).

A container 50 for the fluororesin sheet 50 '
The coating may be performed by individually inserting the rod-shaped members 48a to 48d into the bag-shaped body 53 made of the fluororesin sheet 50 'in a close contact state (claim 4).

The extrusion molding apparatus 1 includes the molding die 10
The rod-shaped members 48a to 48d forming the core body 40 may be provided with a take-out means 30 for taking out the hollow resin molding plate 29 pushed out further. It can be fixed via 44 (claim 5).

Further, it is preferable that the above-mentioned fluororesin sheet 50 'is also attached to the inner wall surface of the molding die of the extrusion molding apparatus (claim 6).

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In this embodiment, as an example,
A kneaded material obtained by heating and kneading a cellulosic crushed material and a thermoplastic resin is cooled and solidified and pulverized to a predetermined particle size (herein referred to as "wood synthetic powder") as a raw material. The production of the hollow resin molded plate will be described.

[Wood Synthetic Powder] Wood powder, which is a crushed product of cellulose and is a raw material of the wood synthetic powder used in the present embodiment, has good compatibility with a thermoplastic resin molding material and reduces friction resistance at the time of molding extrusion. In order to prevent wear and damage of the molding machine, a fine powder having a particle size of 50 to 300 mesh, preferably 60 (under sieve) to 150 (over sieve) mesh is used, and wood acid gas at the time of molding is used. Volatilize
With the intention of eliminating the risk of generation of water vapor or bubbles and preventing the surface from becoming rough, the water content is 15 wt% or less, preferably 11 wt% or less, ideally 0 to 5 wt.
%.

In order to further improve the characteristics of the wood powder, it is possible to immerse or add a material such as wood chips to the urea resin adhesive, heat-harden it, and then crush and pulverize it. .

Further, as the thermoplastic resin molding material, various discarded resin moldings are crushed as they are, or the resin molding having the surface resin coating film is crushed into a plurality of small pieces, which are subjected to compression grinding or the like. It is possible to use a resin such as PVC, PET, PP or the like, which is made into a raw material by adding the above to grind and peel the resin coating film.

The product may be colored by adding a pigment depending on the purpose of use.

25 to 80 wt% of a thermoplastic resin molding material is mixed with 20 to 75 wt% of a cellulosic crushed material having a water content of 15 wt% or less and an average particle size of 20 mesh or less, and the mixture is gelled and kneaded by a stirring impact blade, By using the woody synthetic powder obtained by cooling the gelled kneading material and further sizing it to a particle size of 8 mm or less, a well kneaded dough capable of reducing the frictional resistance of the wood powder is formed.

The synthetic wood powder used in this embodiment is
As an example, it is manufactured as follows.

(1) Drying Step As an example, a mixer is used to dry wood powder, which is a crushed product of cellulose. The temperature inside the mixer rises due to the shearing heat generated by rotating the stirring impeller of the mixer.
As a result, the wood flour put in the mixer is dried. In the present embodiment, the contained water content of the wood flour is 0.
Dry to%. In addition, when titanium oxide or the like is added as a pigment or the like, it is put in a mixer together with the wood flour in the drying step. In this embodiment, about 10 wt% of titanium oxide is added to 100 wt% of wood flour.

(2) Melting / kneading step With respect to 55 wt% of the wood powder dried as described above, 45 wt% of PP as a thermoplastic resin molding material is put into the mixer, and the mixture is stirred and pressurized. The thermoplastic resin molding material used in the present embodiment is a granular pellet having a diameter of about 3 mm.

The thermoplastic resin molding material is a recovered thermoplastic resin obtained from a waste material of a thermoplastic synthetic resin product, a virgin thermoplastic resin, or a virgin thermoplastic resin and the recovered thermoplastic resin, for example, 50% each. It can also be used individually.

In this step, PP does not form a large lump due to the wood powder in the raw material, and a clay-like "kneading material" having a diameter of about 10 to 100 mm is formed.

(3) Cooling / Granulation (Sizing) Step In this step, as an example, a so-called cooling mixer is used which can simultaneously cool and granulate the above-mentioned kneading material. The kneading material formed in the previous step is put into a cooling mixer and cooled on the inner peripheral wall surface of the mixer body cooled with cooling water to form a "granulation raw material" granulated to a diameter of about 25 mm or less.

The granulation raw material formed in the above step is further adjusted to a particle size of 8 mm or less by using a cutter mill, if necessary, to obtain a pellet-shaped "wood synthetic powder". The sizing step is not always necessary, and may be omitted depending on the size of the granulated product obtained by the cooling / granulating step described above.

From the above, the mixing and dispersion state of the wood powder and the thermoplastic resin molding material is constantly maintained, the fluidity is good, and the condensing and shrinking action by cooling causes
A synthetic wood powder is formed that does not rely on chemical reactions or adhesion.

[Extrusion Molding Apparatus] The extrusion molding apparatus 1 of the present invention for molding the above-mentioned synthetic wood powder into the hollow resin molding plate 29 has the extruder 70 and the extrusion dough 79 discharged by the extruder 70 in a predetermined shape. It comprises a molding die 10 for molding, and in the present embodiment, in addition to this, it is provided with a take-up means 30 for taking up the molding plate 29 extruded from the die outlet 23 of the molding die. The molding die 10 is connected to the extruder 70 via a connecting means composed of an extrusion die 19 and a flange 17.

(1) Extruder In FIG. 1, 70 is an extruder which constitutes the above-mentioned extrusion molding apparatus. Generally, the extruder 70 is of a screw type and includes a single-screw extruder and a multi-screw extruder, and there are those having a modification or a structure in which these are combined, but any extruder can be used in the present invention.

Reference numeral 71 denotes a screw, which is a single shaft type in the embodiment shown in FIG. 1. The screw 71 is driven by a motor (not shown) via a gear reducer 72 and rotates in a barrel 74. The synthetic wood powder fed from the hopper 73 is extruded forward while being kneaded by the rotation of the screw 71.

A band heater 75 is provided on the outer surface of the barrel 74. The band heater 75 heats the synthetic wood powder in the barrel 74 and gradually melts and kneads it while transporting it forward along the groove of the screw 71. To be done.

(2) Coupling means The synthetic wood powder melted and kneaded by the extruder 70 is extruded as extrusion material 79 into the molding die 10 through the coupling means composed of the extrusion die 19 and the flange 17.

In FIGS. 1 and 2, the extrusion die 19 is connected to the tip of the barrel 74. In the present embodiment, the extrusion die 19 has a diameter of 65 mm on the rear end face of the outlet side of the barrel 74. A circular inlet port 13 and an injection port 15 having a substantially elliptical shape with a width of 65 mm and a height of 25 mm are provided on the tip end surface on the molding die side.
A communication hole is formed so that its cross section gradually changes from 3 to the injection port 15 into a smaller diameter. However, the extrusion die 19 can be formed in various sizes depending on the size of the extruder 70.

The flange 1 is attached to the tip of the extrusion die 19.
7 is attached. In this embodiment, the flange 17 is provided with an inlet 16 having the same shape as the injection port 15 of the extrusion die 19 and an injection port 18 having a width of 97.5 mm and a height of 46.7 mm. Inflow port 16
A communication hole is formed which gradually cross-sections to a large diameter from the to the injection port 18.

A heater (not shown) as a heating means may be attached in the peripheral wall of the extrusion die 19 and the flange 17. The extruded dough 79 extruded from the extruder 70 by the heater is heated and kept warm even when passing through the communicating hole from the extruding die 19 and the flange 17, so that the extruding dough 79 flowing from the extruding die 19 into the forming die 10 is formed. Good fluidity.

Moreover, since the extrusion die 19 has a large injection port 15 unlike a general ordinary die, it is possible to discharge a large amount of molten raw material (wood synthetic powder in this embodiment). In addition, since it is formed in a shape that can promote compaction, the die clogging that occurs in a normal extrusion die does not occur.

(3) Molding Die In FIGS. 1 to 3, 10 is a molding die into which the extruded material 79 extruded from the extruder 70 is introduced through the connecting means.

The forming die 10 has the extruded dough 7 introduced therein.
A molding chamber 22 including a melting part 21a for heating 9 and a slow cooling part 21b for gradually cooling the extruded dough 79 extruded from the melted part 21a, and a core body 40 for forming a hollow portion in the extruded dough 79 are provided. There is.

The forming chamber 22 is formed in a rectangular cross section by metal spacers (not shown) in which upper and lower two metal plates respectively having heating and cooling means are arranged on both side edges.
The spacer is adjusted so that the desired thickness of the molded plate can be obtained by replacing the spacer.

The molding die 10 has a width of 230 m as an example.
It has a rectangular cross section of m and a height of 250.7 mm.
The distance from the entrance of 2 to the exit is 1000mm.

In the present embodiment, the fusion portion 21a is
Is a slow cooling part 21b which forms a flow path for an extruded dough 79 having a length of 61 mm, which has an inlet and an outlet having the same shape as the injection port 18 of the flange 17, and which has a cross-sectional shape similar to the inlet of the melting part 21a. Is formed, and the molding chamber 22 is formed to have a constant cross-sectional shape in the extrusion direction.

In FIG. 2, reference numeral 14 denotes a heater, which is composed of heating means such as an electric heater and heats and heats the extruded dough 79 and maintains the fluidity of the extruded dough 79.
Pipes are installed above and below 1a at equal intervals.

A cooling pipe 25 is an example of a cooling means for cooling the slow cooling part 21b of the molding chamber 22. A cooling liquid is supplied to the cooling pipe 25 to extrude the dough 79 in the molding chamber 22. Is cooled from the outside. The cooling pipes are installed at equal intervals in the gradually cooling part 21b that occupies three-fourths toward the die outlet 23 of the molding die 10. The cooling pipes 25 may be provided so as to be gradually narrowed, or the cooling pipes 25 may be arranged on the outer wall of the molding die 10. However, it is sufficient that the extruded dough 79 in the molding chamber 22 can be cooled. , But not limited to this structure.

The inner wall surface of the molding die 10 is preferably covered with a fluororesin. This fluororesin coating method may be carried out by directly coating the surface of the fluororesin, but the base material sheet is coated with the fluororesin because it is easy to replace and has high durability. It is preferable to attach the fluororesin sheet 50 '.

The fluororesin sheet 50 'may be applied only to the upper and lower inner wall surfaces of the molding chamber 22, that is, the inner wall surfaces corresponding to the surfaces forming the front and back surfaces of the hollow resin molding plate 29, but the upper and lower molding chambers 22 may be formed. It is desirable to attach them in series on the entire left and right inner wall surfaces.

As the fluororesin sheet 50 'to be attached to the inner wall surface of the molding die 10, a glass fiber fabric is used as a base material,
A product coated with a fluororesin (hereinafter, referred to as "glass fiber fluororesin sheet" in the present specification) or the like can be used, but it is impregnated with a fluororesin dispersion liquid, which will be described later, and dried and baked. It is preferable to use a woven fabric of aramid fibers (hereinafter referred to as "aramid fiber fluororesin sheet").

2 and 3, reference numeral 40 denotes a core body,
In the present embodiment, four rod-shaped members 48a to 48d having a cross-sectional shape substantially similar to the cross-sectional shape of each hollow portion formed in the molding plate 29, and the rod-shaped members 48a to 48d.
And the rod-shaped members 48a to 48d on the upper and lower inner walls of the molding die 10 in the fusion zone 21a.
It is constituted by a base portion 44 for fixing.

Each of the rod-shaped members 48a to 48d projects from the melting portion 21a in parallel with the extrusion direction of the extruded dough 79 and extends at least to the slow cooling portion 21b, and in the present embodiment, In order to facilitate the extrusion of the molding plate 29, as shown in FIG. 3, the length is 946 mm, the height is 21.9 mm at the molding die 10 inlet side, the width is 29 mm, and the height is at the molding die 10 outlet 23 (left side in FIG. 3) side. 21.3
mm, width 27.6 mm, taper shape that gradually narrows the rectangular cross section, width 5.2 mm between each rod-shaped member
Are arranged in parallel at equal intervals so that the gaps are formed.

Further, in the present embodiment, the rod-shaped members 48a to 48d are provided at the inlet side of the molding die 10, that is, at both corners of the extruding material 79 on the upstream side in the extruding direction as shown in FIG. It is rounded in a plane and bulges in a semi-circular shape in a vertical cross section as shown in FIG. 2, and is formed in a rounded shape as a whole to reduce frictional resistance generated between the extrusion material 79 and the material. Is formed.

The rod-shaped members 48a to 48d can be three or less or five or more depending on the number of hollow portions formed in the hollow resin molding plate 29, and the cross-sectional shape is also hollow resin molding. Various shapes can be adopted according to the shape of the hollow portion formed in the plate 29.

As in the core body shown in FIG. 7 as a prior art, when a connecting portion 45 for connecting the rod-shaped members 48a to 48d in the melting portion 21a of the molding die 10 is provided, the rod is provided. Since the upstream side of the gap 46 formed between the strip-shaped members 48a to 48d is closed at the joint portion 45, the presence of the joint portion 45 causes the extruded material 79 to be extruded from the gap 46 forming the rib 29a of the forming plate 29. And the flow path of the extruded cloth 79 are narrowed and the flow of the extruded cloth 79 is resisted.

On the other hand, in the core body 40 of the present embodiment, since the rod-shaped members 48a to 48d are individually formed, the rod-shaped members 48a to 48d are formed.
Upstream of the gap 46 formed between 8d, there is no obstacle to the introduction of the extrusion dough 79, and the extrusion dough 79 can be smoothly flowed into the gap 46.
Therefore, it is possible to increase the density of the extruded material 79 in the gap 46 and effectively prevent the non-formation of the ribs 29a due to lack of the extruded material 79, and even when the molding speed is increased. A high quality hollow resin molding plate can be molded.

The rod-shaped members 48a to 48d are integrally formed with the base portion 44 on the inlet side of the molding die 10. In the present embodiment, the base portion 44 has the shape shown in FIG.
As shown in FIG. 3, it has two convex portions, and by fitting the two convex portions into concave portions provided on the inner wall surface of the molding die 10, respectively, as shown in FIG.
The rod-shaped members 48a to 48d integrally formed with the molding die 10 are fixed to the upper and lower inner walls of the melting portion 21a of the molding die 10 while maintaining the parallel state.

As with the rod-shaped members 48a to 48d, the base portion 44 is formed such that both corners of the extruding material upstream side end portion of the extruding material 79 are rounded and the extruding material downstream side end portion thereof is rounded. It is formed in a substantially streamlined shape that narrows its width toward, and is configured so that the extruded dough 79 flowing in the fusion zone 21a flows without resistance.

The upper inner wall surface of the molding die 10 to which the base 44 is fixed penetrates the wall surface of the molding die 10 and supplies a cooling medium such as water, liquid such as oil, air, or other gas. An introduction path 41 communicating with a supply source of the cooling medium is formed. The introduction path 41 of the cooling medium penetrates the wall surface of the molding die 10 and the base portion 44, and each rod of the core body 40 in the melting portion 21a. The circular members 48a to 48d are communicated with a cooling medium passage 42, which will be described later, formed in each of the rod-shaped members 48a to 48d in the slow cooling section 21b.

The cooling medium introducing passage 41 formed in each of the rod-shaped members 48a to 48d is surrounded by the heat insulating material 43, and the cooling medium passing through the introducing passage 41 cools the extruded dough at the portion. In addition to preventing this, the temperature of the cooling medium is maintained to improve the cooling effect when the cooling medium is introduced into the flow path 42 of the cooling medium described later.

In the present embodiment, the wall surface of the molding die 10, the base portion 44 and the core body 40 are made of a metal pipe having a diameter of 4 mm with Myolex PMX-575 (Ryoden Kasei Co., Ltd.) arranged on the outer periphery as a heat insulating material. Through which the cooling medium is introduced.

In this embodiment, the flow path 42 communicates with the cooling medium introduction path 41 at one end as described above.
The other end is opened at the end of the core body 40 (in the exit direction of the molding die 10). When the cooling medium introduced into the flow passage 42 passes through the flow passage 42 formed in each of the rod-shaped members 48 a to 48 d and the hollow portion formed in the forming plate 29, the extruded material 79 and the forming plate 29. Is gradually cooled from the inside.

Instead of the above-described structure, the flow path 42 has a double pipe structure in which, for example, the rod-shaped members 48a to 48d of the slow cooling part 21b communicate with each other at the outlet side end of the molding die 10. , One of which is connected to an introduction source of a cooling medium and the other of which is connected to an outlet of the cooling medium so that cooling water or cooling oil, which is a cooling medium, circulates in the core 40. Also, as long as the extruded material 79 can be gradually cooled from the inside, various design changes can be made according to the type of cooling medium to be introduced and other various conditions.

Similar to the inner wall surface of the molding die 10, the rod-shaped members 48a to 48d of the core body 40 are individually covered with the container 50 of the fluororesin sheet 50 'in order to reduce the friction with the extrusion material 79. Preferably.

The fluororesin sheet 50 'forming the container 50 may be any as long as it can be formed as the container 50, but a woven fabric of aramid fibers is impregnated with the fluororesin dispersion liquid. The dried and fired aramid fiber fluororesin sheet described above is preferably used.

This aramid fiber fluororesin sheet 50 '
The aramid (wholly aromatic polyamide) that constitutes the base material is excellent in heat resistance, has high strength and high Young's modulus and is therefore also used as a reinforcing material. The resin sheet 50 ′ has flexibility and bending resistance suitable for being used by being attached to the core 40 having a three-dimensional shape, and has high tensile strength so that it can withstand long-term use. Has become.

The fluororesin used for the aramid fiber fluororesin sheet 50 'includes polytetrafluoroethylene (Teflon TFE; DuPont), fluorinated ethylene-propylene copolymer (Teflon FEP), polytrifluorochloroethylene ( Teflon CTFE), polyvinylidene fluoride (Teflon VdF) and the like.

In this embodiment, as the aramid fiber fluororesin sheet 50 ', a fluororesin coating sheet for liner belt "MAX LINER BELT" (HAS-P506) manufactured by Honda Sangyo Co., Ltd. is used. ing.

The aramid fiber fluororesin sheet 50 '
In order to alleviate the friction with the extruded cloth 79, at least at the end of the extruded cloth 79 on the upstream side in the extruding direction of the extruded cloth 79, the rod-shaped members 48a are covered. ~ 48d may be performed on the whole, and in the present embodiment, the entire rod-shaped members 48a to 48d in the fusion zone 21a are covered.

The aramid fiber fluororesin sheet 50 '
Has flexibility and bending resistance, and is joined by sewing, bonding, etc. as an example, as shown in FIG.
It is possible to form the container 50 of the bag-shaped body 53 as shown in FIG.

The bag-shaped body 53 of the aramid fiber fluororesin sheet 50 'is, for example, as shown in FIGS. 5 (A) to 5 (C), one substantially rectangular aramid fiber fluororesin sheet 5
The long sides b and d of 0'are folded back along the central xx line so that the opposing short sides a and c overlap each other, and by this folding back, the side b and the side d are bisected around the xx line, respectively. Edge b'and edge b ", edge d'and edge d"
And (b) are sewn along the sewing lines shown by broken lines in FIG. 5 (B), respectively, and then turned over so that the seams are on the inside.

Instead of the above-mentioned forming method, two substantially rectangular sheets divided along the line xx in FIG. 5 (A) may be used. In this case, the side a and 3 excluding side c
Sew the edges in the same way.

An accommodating body 50 of a bag-like body 53 having one side opening corresponding to the shape of each of the rod-shaped members 48a to 48d is formed, and the bag-like body 53 is extruded from the inlet side of the molding die 10 with the dough 79. By covering the rod-shaped members 48a to 48d of the core body 40 in the pushing direction, the rod-shaped members 4 are formed.
8a to 48d can be covered with the container 50 of the aramid fiber fluororesin sheet 50 '.

The core body 40 of the present invention includes the rod-shaped members 48a to 48a.
Since 48d is formed independently, the conventional connecting portion 4
As compared with the core body 40 having 5, the fluororesin sheet 50 ′ can be individually covered with the containing body 50, and the detachment thereof can be facilitated.

Further, by changing the length of the bag-shaped body 53 of the fluororesin sheet 50 ', each rod-shaped member 48a.
The length covering ~ 48d can be easily adjusted.

In this embodiment, the container 50 of the bag-like body 53 of the aramid fiber fluororesin sheet 50 'is covered with the rod-shaped members 48a-4a in the melting portion 21a.
8d, the extruded material 79 is maintained in a molten state without being cooled in the melting portion 21a, and therefore the surface of the bag-like body 53 that comes into contact with the extruded material 79 is slightly uneven due to the seams. However, this unevenness does not affect the shape of the finally obtained molding plate 29.

The side surface of the base portion 44 integrally formed with each of the rod-shaped members 48a to 48d may be covered with the container 50 of the aramid fiber fluororesin sheet 50 '. This allows the extruded cloth 79 to flow without resistance in combination with the substantially streamlined shape of the plane of the base 44.

(4) Taking-up Means In FIG. 4, numeral 30 is a taking-out means which is arranged on the outlet 23 side of the forming die 10 and takes out the extruded forming plate 29 via the outlet of the forming die 10.

In the embodiment shown in FIG. 4, this transaction means 30 has a plurality of rollers 31 simultaneously wound by an endless belt 33 arranged vertically opposite to each other, and the endless belt 33 arranged vertically. , 33 so that the molding plate 29 can be sandwiched between them.
One of them is a driving roller 31a connected to a driving source, and the molding plate 29 sandwiched between the upper and lower rollers 31 and 31 via an endless belt 33 is configured to be pulled in the pushing direction by the rotation of the driving roller 31a. There is.

[0083]

According to the above-described extrusion molding apparatus for hollow resin molded plate of the present invention, the rod-shaped members of the core are individually formed without connecting portions. Like the core body shown as the prior art, the flow of the extruded dough is not hindered by the joint part of the core body, and the extruded dough is placed in the forming chamber of the forming die including the gap formed between the rod-shaped members. It can be made to flow without resistance.

Further, by covering each of the independent rod-shaped members with the container of the fluororesin sheet, the frictional resistance between the extruded cloth and the surface of the rod-shaped member can be further reduced, so that the extrusion in the molding die is performed. The flow of the dough can be made smoother.

Therefore, the density of the extruded material in the molding die can be kept high, and molding defects such as unformed ribs due to insufficient extruded material introduced into the gap formed between the rod-shaped members can be effectively prevented. We were able to.

Further, by using an aramid fiber fluororesin sheet as the fluororesin sheet to be used, it becomes possible to cover the three-dimensional core body for a long period of time,
By forming the aramid fiber fluororesin sheet covering each rod-shaped member into a bag-shaped body, the attachment / detachment / replacement of the sheet could be facilitated.

Further, by sticking the aramid fiber fluororesin sheet also to the inner wall surface of the molding die, the durability can be improved and the friction with the extruded material can be effectively reduced, and the molding speed can be further improved. Has become possible.

As described above, the extrusion of the hollow resin molded plate is capable of further increasing the molding speed and producing a hollow resin molded plate having uniform quality even when the molding speed is improved. A molding device could be provided.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an extruder of an extrusion molding apparatus according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of a connecting unit and a molding die of the extrusion molding apparatus according to the embodiment of the present invention.

FIG. 3 is a plan sectional view of a molding die of an extrusion molding apparatus according to an embodiment of the present invention.

FIG. 4 is a partial cross-sectional view of a molding die and a take-up means according to an embodiment of the present invention.

FIG. 5 is a diagram showing a method for forming a bag-shaped container for an aramid fiber fluororesin sheet according to an embodiment of the present invention, where (A) is a substantially rectangular aramid fiber fluororesin sheet, and (B) is The state where the sheet of (A) is sewn back at the center xx line, and (C) shows the bag-shaped body formed by turning over the sheet of (B).

FIG. 6 is a partial cross-sectional view of a hollow resin molded plate that is defectively molded.

FIG. 7 is a plan sectional view of a molding die of a conventional extrusion molding apparatus.

[Explanation of symbols]

1 Extrusion molding equipment 10 Molding die 12 Molding room entrance 13 Inlet (of extrusion die) 14 heater 15 Injection port (of extrusion die) 16 Inlet (of flange) 17 Flange 18 Injection port (flange) 19 Extrusion die 21a melting part 21b Annealing section 22 Molding room 23 Molding die exit 25 cooling pipe 29 Molded plate (hollow resin molded plate) 30 Collection means 31 Laura 31a Drive roller 33 endless belt 40 Core body 41 Introduction route 42 channels 43 Insulation 44 base 45 joint 46 Gap 48a-48d Rod-shaped member 50 container 50 '(aramid fiber) fluororesin sheet 53 bags 70 Extruder 71 screw 72 gear reducer 73 Hoppers 74 barrels 75 band heater 76 screen 79 Extruded fabric

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Maki Shirai             612-6 Bunsoji Temple, Itonuki Town, Motosu District, Gifu Prefecture F-term (reference) 4F207 AG02 AJ03 AJ09 KA01 KA17                       KK51 KK76 KL57 KL88 KL91                       KW26

Claims (6)

[Claims] 1. A melting part for heating an extruded dough extruded from the extruder, and a slow cooling for cooling the extruded dough extruded from the extruded dough, to an extruder for heating and kneading a raw material and extruding with a screw. An extrusion molding apparatus in which a molding die including a molding chamber including a molding portion and a core body protruding from the melting portion in the extrusion direction of the extruded dough and extending to at least the slow cooling portion is connected, Is composed of a plurality of rod-shaped members, and a base portion integrally formed with each of the rod-shaped members, each rod-shaped member is substantially the cross-sectional shape of each hollow portion formed in the hollow resin molding plate Hollow resin molding having the same cross-sectional shape, arranged in parallel to each other with the extruding direction of the extruded dough as the length direction, and being fixed to the forming die in the melting portion of the forming die. Extrusion of plates Location. 2. The extrusion molding apparatus for a hollow resin molding plate according to claim 1, wherein at least an end portion of each of the rod-shaped members on the upstream side in the extrusion direction of the extrusion material is covered with a container for the fluororesin sheet. 3. The fluororesin sheet forming the container,
The extrusion molding apparatus for a hollow resin molded plate according to claim 2, which is a woven fabric of aramid fibers impregnated with a fluororesin dispersion liquid, dried and fired. 4. The container for the fluororesin sheet comprises a bag-shaped body, and each of the rod-shaped members of the core body is individually and closely inserted into the bag-shaped body composed of the fluororesin sheet. The extrusion molding apparatus for a hollow resin molding plate according to claim 2 or 3, wherein a rod-shaped member is covered with a container for the fluororesin sheet. 5. The extrusion molding apparatus, wherein the extrusion molding apparatus comprises a take-out means for taking up the hollow resin molding plate extruded from the molding die, wherein each of the rod-shaped members forming the core body is the base portion. The extrusion molding apparatus for a hollow resin molded plate according to any one of claims 1 to 4, which is fixed to the upper and lower inner walls of the molding die via the base through the base. 6. The hollow resin molding plate extrusion molding apparatus according to claim 1, wherein a fluororesin sheet is attached to an inner wall surface of the molding die in the extrusion molding apparatus.