KR940003715B1 - Extrusion method and apparatus for plastic pipe - Google Patents

Abstract

A distributor for extrusion consists of one disc in which the annular inlets for inner and outer walls of the pipe are formed together, and another disc in which an annular inlet for intermediate wall of the pipe is formed, and the discs are assembled in a multiple layered shape. The multi-blades are positioned on each annular inlet in radial directions. Then, an extrusion head to which first extruder is assembled, is mounted to one-side of the distributor, and a mandrel and an extruding die are mounted to the other-side of that. And a second extruder is assembled on the outer periphery of the distributing head around which the distributor surrounds. The appts. enhances a pipe quality and a productivity.

Description

Triple Wall Plastic Pipe Extrusion Method and Apparatus

1 is a longitudinal sectional view showing a configuration of the present invention.

2 is a sectional view taken along the line A-A of FIG.

* Explanation of symbols for main parts of the drawings

1: Dispensing Head 2: Extrusion Head

3: first extruder 4: second extruder

3a, 4a: Inlet 1a, 5a, 28a, 33a, 35a: Guided slope

5: extrusion die 6: mandrel

7: annular outflow path 8: outlet

10: divider 11: front distribution plate

13,14,18: Fantasy Inlet 15: Fantasy Inlet

16,17: inlet hole 17: guide protrusion

19: blade portion 21: rear distribution plate

28: induction plate 29: derivative

30,36: Inner wall road 31,34: Outer wall road

32: raw material inlet furnace 33: information board

35: guide

The present invention relates to an extrusion method for a triple wall plastic pipe and an apparatus thereof. Plastic pipes, which are widely used, are light in weight and have excellent corrosion resistance, and thus are easily connected to each other.

The structure of the plastic pipe is generally composed of a triple wall composed of an inner wall and outer wall of the same material and an intermediate wall made of a material that is relatively lighter than the inner wall and the outer wall, and such a triple wall plastic pipe is usually formed of an inner wall, an outer wall and an intermediate wall. It is produced by the co-extrusion method of.

Looking at the co-extrusion method in more detail, the first and second extruders are respectively installed on one side of the distributor having three annular inlet paths for forming a triple wall in a multi-layered state and at the same time the extrusion die for pipe forming is installed on the other side , The annular inlet of the distributor is provided by the circular center and the intermediate and the outer body arranged in a multi-layer state, each annular inlet is provided with a plurality of support blades to support the assembly of the core, intermediate and the external body Inside the extrusion die, a conical mandrel is assembled and installed through a plurality of blades so that an annular flow path is formed between the inner diameter of the extrusion die and the outer diameter of the mandrel, so that the molten state is press-fitted through the first extruder. The raw material passes through each annular inflow path located in the inner and outer parts and is pressed through the second extruder. The raw materials in the state are combined while passing through the annular inflow path located in the middle portion, and then flow out through the outlet of the end of the extrusion die while passing through the annular flow path formed between the extrusion die and the mandrel so that a pipe having a predetermined diameter is manufactured and molded. .

In the pipe forming process, the molten raw material, which is fed at an appropriate pressure, is divided into several parts by a plurality of support blades installed in the annular inlet path, and then merged in three layers at a predetermined position, and then annular between the mandrel and the extrusion die. In the course of passing through the distribution channel, the plurality of blades are supported by the plurality of blades, and the parts are again pushed to the outlet side of the end of the extrusion die in a state where they are separated. The formation of straight joint marks (scratches) in the inner and outer diameters of pipes has caused a problem of lowering the impact strength of the product. In order to reduce or remove these joint marks to a minimum, the blades of the annular flow path and Ensure sufficient distance between outlets at the end of extrusion die As the eoyaman was a difficult point that its own length of the apparatus to be much longer.

On the other hand, in the combination of the center body, the intermediate body, the outer body, the plurality of blades, the mandrel and the extrusion die, etc., the annular inlet and the annular flow path must be formed in the correct concentric state. In addition, the addition of such attachment means increased the manufacturing difficulty by making the structure of the device more complicated, and also resulted in an increase in the production cost. In addition, in order to ensure that the inner and outer diameters of the finished product have a correct concentric circle, difficulties arise in the assembly technology in which the annular inlet path formed in a double-layer state and the annular flow path form an accurate concentric circle. In fact, it was very difficult to eliminate the phenomenon that the finished product is distorted to any one side. Accordingly, the thickness of each wall was formed unevenly, so that the defective rate of the finished product was remarkably high. As the raw material is sandwiched between the minute gaps of the blades installed in the annular inlet and the annular channel, carbonization is often performed to lower the surface roughness of the inner and outer diameters of the finished pipe, thereby requiring frequent mold maintenance. There were various problems.

The present invention has been researched and developed in view of the above problems, bar, the annular inlet of the raw material to form the inner, outer wall is formed on a single disk body having a predetermined diameter and thickness in a multi-layered state, the intermediate wall The raw material inflow to form the inner and outer walls by forming the annular inlet of the raw material forming the inner wall and the annular inlet coinciding with the annular inlet of the raw material forming the inner and outer walls in a double layer state on another disk. The annular inflow path for the raw material inflow, which forms the intermediate wall and the intermediate wall, constitutes a unitary distributor formed in a double-layered state, and on each of the annular inflow paths, a plurality of blades are processed and formed in a radiation form to refer to the annular inflow path. Separate assembly means are required while forming the central body, intermediate body and external body separated by On the other hand, the extrusion head in the state where the first extruder is assembled on one side and the second extruder is installed on the central portion of the outer diameter of the distribution head in which the mandrel and the extrusion die are sequentially assembled on the other side, thereby introducing the intermediate wall material of the distributor. By providing a simple principle extrusion method and apparatus for directly extruding the raw material into the annular inlet furnace, it improves the impact strength against external force while effectively excluding the closed end in which the joint marks are formed at the outer diameter in the finished pipe. The first purpose is to form and process a double-layered annular inlet as an exact concentric circle on one disc to solve the assembly difficulties, as well as to uniformize the thickness of the inner and outer and intermediate walls of the finished product and the distribution of raw materials. The second purpose is to minimize the defect rate and at the same time achieve the effect of improving productivity. The purpose is to simplify disassembly and maintenance work by simplifying the self-structure of the mold making the device, making it easy to manufacture, and reducing the production cost. If it be described in detail on the basis of the accompanying drawings and its effect and effect as follows.

As shown in FIG. 1 and FIG. 2, a first extruder is installed in the extrusion head 2 on one side of the distribution head 1 having an appropriate shape to extrude the molten raw material forming the inner and outer walls of the pipe to be formed. The mandrel 6 is installed inside the extrusion die 5 on the other side of the dispensing head 1 so that the annular outflow path is gradually narrowed toward the outlet 8 between the inner diameter of the extrusion die 5 and the outer diameter of the mandrel. 7) is formed, the dispensing head (1) inside the distributor 10 is installed through the first raw material in the molten state that is extruded through the extruder (3) after passing through the distributor 10 annular outflow path (7) In the extrusion apparatus configured to form an inner wall and an outer wall of a plastic pipe that is extruded into the outflow path 8 and molded while passing through, the distributor 10 installed inside the distribution head 1 includes two fronts having the same diameter. The rear distribution plates 11 and 21 are combined with each other as the bolt 12, and the front and rear distribution plates are respectively In (11, 21), annular inlets 13a, 14a, 13b, 14b are formed in concentric circles, respectively, as inflow paths of raw materials forming the inner and outer walls of the pipe, and are located in the same line with each other, and are in the form of a multi-layer annular inlet. To form the furnace 13, 14, and the portion located between each annular inlet (13b, 14b) of the rear distribution plate 21 is formed in the shape of a protrusion to form a guide protrusion 17, the guide protrusion 17 In the central portion of the) is formed an annular inlet path 18 of the raw material to form an intermediate wall, and each of the annular inlets 13a, 14a (13b, 14b) and the annular inlet path in the form of a radiation portion of the predetermined width 19 ) And forming a plurality of annular inflow paths (13, 14, 18) on a single plate body, and the outer side of the annular inflow path (14) formed in each of the front and rear distribution plates (11, 21) At the same time, the annular guide groove 15 is formed in the contact portion, and at the same time, the distributor head 1 is installed. In the central portion of the outer diameter, the second extruder 4 is assembled and installed for the extrusion of the molten raw material to form an intermediate wall, and the inlet passage 4a and the distributor of the second extruder 4 are disposed on the distribution head 1 and the distributor 10. (10) forming a through hole 16 connecting the annular induction grooves 15 of the front and rear distribution plates 11 and 21 to form a through hole, and at the same time, the annular induction groove 15 and the rear distribution plate 21. The inlet hole 17 connecting the annular inlet passages 18) is penetrated toward each blade portion 19 so that the raw material extruded from the second extruder 4 is partitioned by the blade portion 19. It is made to be conveyed to the annular inflow path 18 in a state.

The outer surface of the front distribution plate 11 protrudes to form a ring-shaped coupling protrusions 22 and 23 at appropriate intervals, and the coupling recess 24 corresponding to the coupling protrusion 23 is formed at one side and hollow at the center. Assembling and mounting of the annular guide plate 28 through which the 26 is formed in the engaging protrusion 23 of the front distribution plate 11 and at the same time the coupling recess 25 corresponding to the engaging protrusion 22 is provided on one side. The conical derivative 29 formed is assembled to the coupling protrusion 22 of the front distribution plate 11, and the front and rear distribution plates 11 and 21 are disposed between the guide plate 28 and the derivative 29. Dispensing head (1) by forming the inner wall body flow path 30 corresponding to the inner annular inflow path 13 to be provided at the same time, and at the outer surface of the guide plate 28 to form an inclined surface 28a of an appropriate angle The outer wall flow path 31 is formed between the inclined slope 1a of the inner diameter, and the end of the conical derivative 29 is the inflow path 3a of the first extruder 3. It is gradually positioned between the annular inlet passage 14 formed by the front and rear distribution plates 11 and 21 and the inlet passage 3a of the first extruder 3 assembled to the extrusion head 2 while being positioned at the end. The raw material inlet passage 32 to be widened is formed.

An annular guide plate 33 is interposed between the extrusion die 5 and the rear distribution plate 21 which are fixedly assembled to the distribution head 1 by the fixing plate 40 and the bolts 41 and 42. An inclined surface 33a of an appropriate angle connecting the inclined surface 5a of the extrusion die 5 to the annular inlet path 14 formed by the front and rear distribution plates 11 and 21 has an inner diameter thereof. The outer wall body guide path is formed between the outer diameter of the guide protrusion 17 formed on the rear distribution plate 21 and the inclined surface 33a, and the inclined surface 35a at an appropriate angle on the center of the rear distribution plate 21. The inner wall body guideway 36 is formed between the inner diameter of the guide protrusion 17 and the inclined plane while assembling and installing a trapezoidal guide body 35 having a splitter 10. Each molten raw material supplied from the two extruders 3 and 4 is annular oil of the inner and outer wall flow paths 36 and 34 and the guide protrusion 17. After passing through each of the furnaces 18, the three overlapping state is passed through the annular outlet (7) to the outlet 8 is configured to be manufactured by molding the triple wall plastic pipe of a predetermined diameter, the reference numeral 37 is extruded A bushing interposed between the head 2 and the dispensing head 1 and 38 denote assembly bolts.

On the other hand, the mandrel 6 installed inside the extrusion die 5 is assembled and assembled to the high information bolt 39 screwed to the guide body 34 assembled to the rear distribution plate 21, wherein the extrusion die ( The inner diameter of the outlet 8 of 5) and the outer diameter of the mandrel 6 are appropriately suited to the outer diameter of the pipe to be molded so as to form a pipe having a predetermined diameter.

Looking at the process of forming the triple wall plastic pipe by the present invention having such a configuration in detail as follows.

When a predetermined molten raw material is supplied at an appropriate pressure through the inflow paths 3a and 4a of the first extruder 3 assembled to the extrusion head 2 and the second extruder 4 assembled to the distribution head 1, The raw material supplied through the first extruder 3 flows into the raw material inflow path 32 between the inclined guide surface 32 inside the distribution head 1 and the outer diameter of the derivative, and then the conical derivative 29 and the annular In the annular inflow paths 13 and 14 and the guide plate 33 provided on the inner and outer wall flow paths 30 and 31 and the front and rear distribution plates 11 and 21 formed by the guide plate 28. The molten raw material supplied through the second extruder 4 is sequentially passed through the inner and outer wall flow paths 36 and 34 provided by the annular inflow path of the inflow path 4a and the distributor 10 ( 14) the annular inflow path (13), after being directly sent to the annular inlet path (18) on the rear distribution plate 21 through the annular guide groove (15), inlet hole (16) and inlet hole (17) formed on the outside Each outflow through 14 The triple wall is formed by a series of continuous processes that flow into the outflow path 8 through the annular outflow path 7 formed between the mandrel 6 and the extrusion die 5 in the state of being overlapped in threefold while being located between the molten raw materials of The plastic pipe of the manufacturing is to be molded, wherein the raw material that passes through each annular inlet path (13, 14, 18) is to be conveyed while being instantaneously divided by a plurality of blades 19 arranged in the form of radiation, Completely integrated in the process of being conveyed in a compressed state for a considerable time until entering the annular outflow passage 11 and entering the annular outflow passage 11 and then flowing out to the outlet opening 8 in the combined state just before entering the annular outflow passage 7 After the outflow is to effectively exclude the closed end in which the joint marks are formed in the outer diameter, the pipe being formed.

In the present invention as described above, as shown in FIG. 2, the monolithic annular inflow paths 13, 14, and 18, which are main components, are supported by a plurality of blade portions 19. As it is formed on both the front and rear distribution plates (11, 21) assembled with a separate assembly means for forming each annular inflow path (13, 14, 18) is not necessary at all, the distributor (10) By preforming a double-layer annular inlet on each front and rear distribution boards to make accurate concentric circles at all times, simplifying the mold's own structure and making the assembly, disassembly and maintenance work quickly and easily. The exact concentricity of the annular inlet paths (13, 14, 18) minimizes the defect rate while ensuring uniform distribution of the raw material distribution and thickness of the inner, outer and middle walls that make up the pipe. It is an excellent invention that completely eliminates the concern of raw material carbonization phenomenon by removing the assembly part in the annular inlet furnace.

Claims (2)

A first extruder is installed in the extrusion head on one side of the distribution head having a proper shape to extrude the molten raw material forming the inner and outer walls of the pipe to be molded, and a mandrel is installed inside the extrusion die on the other side of the distribution head, An annular outflow path that becomes narrower toward the outlet side is formed between the mandrel, and a distributor is installed inside the distribution head so that the molten raw material extruded through the first extruder 3 passes through the distributor and then passes through the annular outflow path. In the extrusion method of forming the inner and outer walls of the plastic pipe which is extruded into the outflow path and formed, the distributor disposed inside the distribution head is formed by combining two front and rear distribution plates having the same diameter, respectively. In the front and rear distribution boards, concentric annular inlets are formed as inflow paths of the raw materials that form the inner and outer walls of the pipe. By forming the annular inflow path of the double layer while being located on the same line and forming the annular inflow path in the center, the guide projection is formed in the part located between each annular inlet of the rear distribution plate. On the annular inlet and the annular inlet path to form a plurality of blades in the form of radiation to form a plurality of annular inlet paths on a single plate, and to form annular inlet paths formed on the front and rear distribution plates. At the outer contact portion, the annular induction groove is formed at the same time, and the second extruder is installed at the outer diameter of the distribution head in which the distributor is installed, but the distribution head and the distributor have the inflow path of the second extruder and the annular induction of the front and rear distribution plates. An inlet hole connecting the groove and simultaneously connecting the annular induction groove and the annular inlet path on the rear distribution plate The ball is penetrated to the side of the blade, respectively, so that the raw material extruded from the second extruder flows into the annular inflow path of the rear distribution plate, and the outer surface of the front distribution plate has an annular guide plate and a conical derivative formed through the hollow. While installing and assembling, the inner wall induction path is formed between the guide plate and the derivative to match the inner annular inlet path formed on the front and rear distribution plates, and at the same time, an inclined surface is formed on the outer surface of the guide plate to distribute the inner diameter of the distribution head. The outer wall induction path is formed between the inclined surface of the conical derivative and the end of the conical derivative is positioned at the end of the inflow path of the first extruder while the annular inflow path outside the front and rear distribution plates and the inflow path of the first extruder. In order to form a wider conical raw material inflow path therebetween, between the extrusion die on one side of the distribution head and the rear distribution plate forming the distributor. An annular guide plate is interposed therebetween, and the inner diameter thereof is formed between the guide slope of the inner side of the extrusion die and the guide protrusion of the rear plate to form an inclined slope connecting the annular inlet paths outside the front and rear distribution plates. By forming the outer wall induction path, the inner wall induction path is formed between the inner diameter of the guide protrusion and the inclined surface of the guide while assembling and installing a guide having an inclined surface in the center of the rear distribution plate, thereby forming the distributor. The predetermined molten raw material supplied from the first and second extruders passes through the annular inflow path of the inner and outer wall flow paths and the guide protrusions, respectively, and then flows into the outflow path while passing through the annular outflow path in the state of being overlapped in threefold at a predetermined point. Triple-wall plastic pipe extrusion method characterized in that the pipe of the diameter is manufactured and molded. A first extruder is installed in the extrusion head on one side of the dispensing head to extrude a predetermined raw material which forms the inner and outer walls of the pipe to be formed, and a mandrel is installed in the extrusion die on the other side of the dispensing head and the extrusion die and An annular outflow path is formed between the mandrel, and a distributor is installed inside the distribution head so that the molten raw material extruded through the first extruder passes through the distributor and passes through the annular outflow path and is extruded into the outflow path to be formed. In the extrusion device to form an outer wall, the distributor inside the distribution head is made by combining two front and rear distribution plates, and each of the front and rear distribution plates is a raw material inflow path forming the inner and outer walls of the pipe. Concentric annular inlets formed on the same line are formed to form an annular inlet path of a double layer, and each annular annulus of the rear distribution plate. The protrusions are formed in a trapezoidal shape between the entrances to form guide protrusions, and an annular inlet path is formed in the center of the guide protrusions, and a plurality of blades are formed in each annular inlet and the annular inlet path in the form of radiation. At the same time, the annular induction groove is formed in the outer contact portion of the annular inlet path formed on the front and rear distribution plates, and the second extruder is installed at the outer diameter of the distribution head, and the inlet and front of the second extruder are disposed at the distribution head and the distributor. In addition, through the inlet hole connecting the annular guide groove of the rear distribution plate and at the same time through the inlet hole connecting the annular guide groove and the annular guide groove of the rear distribution plate through the side of each blade portion, the middle of the pipe The molten raw material forming the wall is introduced into the annular inflow path of the rear distribution plate through the second extruder, and the outside of the front distribution plate. In the assembly of the annular guide plate and the cone-shaped derivatives are installed, but between the inner diameter of the guide plate and the outer diameter of the guide plate to form an inner wall induction path matching the annular inlet path inside the front and rear distribution plate and at the same time the outer surface of the guide plate An inclined surface is formed to form an outer wall induction path between the inclined head surface of the distribution head inner diameter, and the end of the conical derivative is positioned at the end of the inflow path of the first extruder while being annular outside the front and rear distribution plates. A conical raw material inflow path is formed between the inflow path and the inflow path of the first extruder, and an annular guide plate is interposed between the extrusion die on one side of the distribution head and the rear distribution plate forming the distributor. Rearward distribution by forming an inclined slope that connects the inclined surface of the die and the annular inflow path outside the front and rear distribution plates The outer wall guide path is formed between the outer diameter of the guide protrusion and the inclined slope of the inner wall of the distribution plate, and by guiding a trapezoid-shaped guide body having an inclined slope in the center of the rear distribution plate, between the inner diameter of the guide protrusion and the inclined slope of the guide body. Triple wall plastic pipe extrusion apparatus characterized in that the distributor is configured to form a wall induction furnace.