JPH05131523A - Ring resin laminated die - Google Patents

Abstract

PURPOSE:To manufacture a ring resin laminated body of improved product strength and outer appearance at low cost. CONSTITUTION:The subject die is composed of a ring flow path 5 for extruding main resin formed between a hollow outer cylinder 3 and a rotating columnar mandrel 4 provided rotatably inside the outer cylinder and a nozzle 6 protruding in said ring flow path 5, opened facing the downstream in the flowing direction and extruding sub-material resin 7 into the main material resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annular resin laminated die which can be applied to a die for extruding a resin for processing a resin pipe or a plastic blow molded product, a die for extruding a kneaded product of food, a rubber extruding die and the like. is there.

[0002]

2. Description of the Related Art Among conventional dies for molding an annular resin laminate, an example of a three-layer resin pipe extrusion die will be described with reference to FIG. The annular resin laminate may be formed by combining the inner and outer resins into two layers, like the multilayer film sheet,
In addition, a multi-layer pipe is formed according to the application by putting a low-cost plastic resin in the middle to form three layers. FIG. 6 shows a conventional annular resin laminating die, in which molten resins a, b and c extruded from the extruders A, B and C flow down through the resin paths 20, 21 and 22 formed in the same annular shape. Then, a three-layer resin pipe is molded as an annular resin laminated body of three layers in the order of the resins b, a, and c from the inside. FIG. 7 shows a conventional two-layer multi-manifold die, in which concentric annular resin passages 23 and 24 are formed, and the resin from the extruder A is provided in the passage 24 and the resin from the extruder B is provided in the passage 23. Flow down to form a two-layer annular laminate. FIG. 8 shows a die having three layers made of three kinds of plastics. By making the spindle movable in the axial direction, the cross-sectional area of the outlet of the annular resin passage is variable, and one resin layer Of 1
One resin layer is sequentially laminated in an annular shape, which is essentially the same as that shown in FIG. In the figure, 25 is a hydraulic cylinder, 26 is a ring piston, 27 is an extruder, 28 is a parison wall, 29 is a manifold, 30 is an accumulator, 31 is a parison, and 32 is a mandrel.

FIGS. 9 and 10 show Japanese Patent Laid-Open No. 62-99115.
33 shows a multilayer parison extrusion molding apparatus in Japanese Patent Publication No.
Is an accumulator head, and a cylinder 34 and a cylinder 3 are provided in the lower half of the accumulator head 33.
4. The ring piston 35 that slides up and down along the inner peripheral surface of
And the accumulator head 3
A core 36, which penetrates the ring piston 35 and is fixed to the cylinder 34, is provided in the central portion of 3. Inside the cylinder 34, a resin storage chamber 37 defined by a ring piston 35 and surrounded by the cylinder 34 and a core 36 is formed. The resin storage chamber 37 is connected to the resin storage chamber 37 continuously from an extruder 38. The main resin in a molten state extruded by the above is supplied through an annular communication passage 39 connected to the extruder 38. The main material resin stored in the resin storage chamber 37 is the cylinder 34
The temperature is adjusted by a temperature adjusting device including a heater or the like provided in the. Further, in the resin passage 40, a ring member 41 having a substantially hexagonal cross section is arranged concentrically with the resin passage 40. Ring member 40
Is supported at a predetermined distance from the inner peripheral surface of the cylinder 34 by the four columns 42, and the outer peripheral surface of the core 36 by the four columns 43 provided at different positions in the circumferential direction from the column 42. Is supported at a predetermined distance from
The resin passage 40 is divided by the ring member 41 into an inner annular passage 40a and an outer annular passage 40b. Further, inside the ring member 41, an annular barrier resin passage 44 located substantially in the center thereof and two annular adhesive resin passages 45, 45 located on both sides of the barrier resin passage 44 are formed. And these resin passages 4
4, 45 communicate with three concentric annular nozzles 46, 47, 48 formed on the lower surface of the ring member 41 through the annular slits. A blow molding method disclosed in Japanese Patent Publication No. 43-20784 has been proposed as a mandrel that rotates, but this is not intended for lamination, and the mandrel is an annular passage wall for forming an annular member. Neither is a rotating wall.

[0004]

In each of the conventional annular laminated dies described above, in order to make the thickness distribution of each layer in the circumferential direction uniform, the slit inflow pressure in the circumferential direction is made uniform on the upstream side of the annular slit. A manifold with a large cross-sectional area of the flow channel was installed with the policy of increasing the number of channels, and it was necessary to process the mandrel and the outer wall ring with increased concentricity. Further, in order to make the temperature uniform in the circumferential direction, it was necessary to pay attention to the heater arrangement and temperature control method. For this reason, there are disadvantages that the number of parts is large and the processing accuracy is required, so that the manufacturing cost is high and that disassembly and cleaning are troublesome. Further, in these conventional examples, the molten resin supplied from the extruder flows in from one end of the ring-shaped manifold and is distributed in the circumferential direction in the ring-shaped manifold, but in the axially symmetric portion from the resin inlet to the manifold, Since the resin that has flowed through the manifold splits into left and right parts, there are drawbacks such as the so-called weld at the confluent part, which impairs the appearance of the product and reduces the strength of this part. The present invention has been proposed in order to solve the above-mentioned conventional problems, and an object thereof is to provide a ring-shaped resin laminated die which is small in size, low in cost, easy to maintain, and free from welds.

[0005]

Therefore, according to the present invention, there is provided an annular flow path for resin extrusion of a main material formed between a hollow member and a cylindrical member rotatably provided inside the hollow member, and the annular flow path. The nozzle is a nozzle that projects into the passage, opens downstream in the resin flow direction, and pushes out the auxiliary material resin into the flow of the main material resin, which serves as means for solving the problem.

[0006]

The secondary material resin extruded from the nozzle inserted in the flow path of the primary resin material in the annular shape is circumferentially sheared by the rotating mandrel, and the circumferential resin material flows in the circumferential direction together with the velocity due to the axial pressure flow. The speed is to be obtained, and the auxiliary material resin extruded at a fixed position in the circumferential direction of the annular main material resin flow path spreads like a bandage around the entire circumference in the circumferential direction, and the annular resin layer is embedded in the annular main material resin. Form. By changing the ratio of the pushing speed of the main material resin in the axial direction to the circumferential speed proportional to the rotation speed of the rotating mandrel, the auxiliary material resin formed in a spiral shape is generated for each one rotation of the axial spiral. The degree of overlap can be changed. In addition, since the auxiliary material resin is more strongly subjected to shearing in the circumferential direction than in the axial direction, the auxiliary material resin is oriented in the circumferential direction, and when the fiber-containing auxiliary material resin is extruded, the strength in the circumferential direction is increased. Increase.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side sectional view showing a first embodiment of the present invention.
The resin that is melted and pressurized by the screw 1 that plasticizes the main resin passes through the flow path 2 and is guided to the die. When the main material resin guided to the die passes through the annular flow path 5 constituted by the outer cylinder 3 and the mandrel 4 which is inserted therein and rotates, the main material resin penetrates the outer cylinder 3 into the annular flow path 5. The auxiliary material resin 7 extruded from the inserted nozzle 6 is joined and laminated to form an annular multi-layer resin laminated body and extruded from the die outlet 8. FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, showing a situation in which the auxiliary material resin 7 extruded from the nozzle 6 spreads in the circumferential direction as the rotating mandrel 4 rotates. The nozzle 6 projects into the annular flow path 5 and opens downstream in the resin flow direction.

FIG. 3 shows another embodiment of the present invention. At the tip of the screw 1 for plasticizing the main resin,
A torpedo 9 that rotates integrally with the screw 1 is installed, and a sub-material resin 7 is introduced from a cylinder 10 corresponding to this portion into a flow path of a main-material resin formed between the cylinder 10 and the torpedo 9. By providing the extrusion nozzle 6,
As in FIG. 1, the annular resin laminate is formed. In the present embodiment, the once formed annular resin laminated body is formed into a cylindrical resin laminated body having a layer of the auxiliary material resin 7 concentrically when passing through 9 parts of the torpedo, and then the annular flow passage installed on the downstream side. It is a device for forming a circular resin laminate again by the die 11 and extruding it. In FIG. 3, in the annular flow path 5 formed by the cylinder 10 and the torpedo 9 provided at the tip of the screw 1, once the annular resin laminate is formed,
Since this resin has a high viscosity and is extruded in a laminar flow state, an appropriate laminated state can be maintained even in the process of being extruded again as an annular resin laminate by the annular flow path die 11 through the cylindrical resin laminate.

FIG. 4 shows still another embodiment, in which the auxiliary material resin discharge nozzles are provided along the flow path of the annular passage 5 at two different positions and depths to form a layer of the auxiliary material resin 7. An example in which the number of layers is 2 and the total number of layers is 5 is shown. In this way, an arbitrary multilayer annular laminate can be obtained. 5 shows a perspective view of the nozzle 6 according to the embodiment of the present invention. This is a nozzle having a rectangular cross section that is long (length L) along the flow path.
Can be taken arbitrarily. The cross section of the nozzle may be circular. The direction in which the annular main material resin is extruded is preferably the circumferential direction, but a direction slightly inclined in the axial direction,
Alternatively, it is possible to form the annular resin laminate even in the axial direction. Further, the shape of the tip of the nozzle 6 for extruding the auxiliary material resin 7 is preferably a slit shape, but the annular resin laminated body can be formed even if the cross section has an arbitrary shape.

[0010]

As described above in detail, the annular resin laminated die of the present invention has a small number of parts, is compact and can be manufactured at low cost. Further, since it is possible to form an annular resin laminate without weld lines, it is possible to improve the product strength and appearance, and to increase the degree of orientation of the auxiliary material resin in the circumferential direction, thereby improving the strength in the circumferential direction. Blow molded products can be manufactured. This improves the strength of the parison and enables blow molding of large products.

[Brief description of drawings]

FIG. 1 is a side sectional view of an annular resin laminated die according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIGS. 1 and 3.

FIG. 3 is a side sectional view of an annular resin laminated die showing another embodiment of the present invention.

FIG. 4 is a cross-sectional view of an annular resin five-layer laminate formed according to still another embodiment of the present invention.

5 is a perspective view of the nozzle in FIGS. 1 and 3. FIG.

FIG. 6 is a side sectional view showing a conventional annular resin laminated die for pipe.

FIG. 7 is a side sectional view showing a conventional annular resin laminated die for forming an inflation film.

FIG. 8 is a side sectional view showing a conventional blow molding annular resin laminated die.

FIG. 9 is a side sectional view of a conventional blow molding annular resin laminated die in which a ring nozzle for extruding a secondary material resin is formed in a main material resin flow path.

FIG. 10 is an enlarged sectional view of a B part in FIG.

[Explanation of symbols]

 1 Main Material Resin Plasticizing Screw 2 Main Material Resin Flow Path 3 Outer Cylinder 4 Rotating Mandrel 5 Annular Flow Path 6 Secondary Material Resin Extrusion Nozzle 7 Secondary Material Resin 8 Die Exit 9 Torpedo 10 Cylinder 11 Annular Channel Die

Claims (1)

[Claims] 1. An annular flow path for resin extrusion of a main material formed between a hollow member and a columnar member rotatably provided inside the hollow member, and a downstream in the resin flow direction protruding into the annular flow path. An annular resin laminated die, which is characterized in that it is formed with a nozzle that opens toward the main material resin and that extrudes the auxiliary material resin into the flow of the main material resin.