Die, extrusion molding device and molding method

Abstract

To contribute to a production of a molded product with a straight grain pattern on a surface.SOLUTION: A die 50 includes: a breaker plate 59; an upstream die 50a; and a downstream die 50b. The breaker plate 59 has first holes 59a, 59b, and a second hole 59c arranged to surround the first holes 59a, 59b. The upstream die 50a is attached between extruders 20, 40 and the breaker plate 59, has a first flow path leading to a first outlet port 21 of the first extruder 20 and the first holes 59a, 59b, and has a second flow path on an inside leading to a second outlet port 41 of the second extruder 40 and the second hole 59c. The downstream die 50b is attached to the breaker plate 59 on an opposite side of the upstream die 50a with respect to the breaker plate 59, and has a third flow path on an inside leading to the first holes 59a, 59b, and the second hole 59c.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a die, an extrusion molding apparatus, and a molding method. [Background technology]

[0002] Wood-like products with a texture similar to that of natural wood are manufactured, for example, by extrusion molding. Various techniques have been proposed to make the texture of wood-like products closer to that of natural wood. For example, Patent Document 1 discloses an extrusion molding device equipped with two extruders and two dies. The two dies are connected in series, and the cross-sectional area of ​​the flow path of the upstream die is smaller than the cross-sectional area of ​​the flow path of the downstream die. The core material is sent from upstream to downstream in the flow paths of the two dies, and one extruder supplies an adhesive resin to the flow path of the upstream die, so that the entire outer surface of the core material is coated with an adhesive layer. The other extruder supplies a coating resin to the flow path of the downstream die, so that the entire outer surface of the adhesive layer is coated with a coating layer. The coating layer is composed of a matrix phase and a dispersed phase dispersed in the matrix phase. The dispersed phase extends in the longitudinal direction of the molded product. The dispersed phase is exposed on the surface of the coating layer, forming a striped pattern. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-79099 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for the surface pattern of the molded product to be a straight grain pattern so that the texture of the molded product resembles that of natural wood. However, the pattern that appears on the surface of the molded product molded by the extrusion molding device described in Patent Document 1 cannot be called a straight grain pattern, and the molded product is far from the texture of natural wood.

[0005] Therefore, the present invention has been made in consideration of the above problems, and aims to contribute to the production of molded products having a straight grain pattern on the surface. [Means for solving the problem]

[0006] The following reference numerals in parentheses refer to FIGS. 1 to 5.

[0007] According to the invention of claim 1, there is provided a die (50) of an extrusion molding device (1), a breaker plate (59) having a plurality of first holes (59a and 59b) penetrating between both surfaces of the breaker plate (59) and a plurality of second holes (59c) penetrating between the both surfaces and arranged so as to surround the plurality of first holes (59a and 59b); an upstream die (50a) that is installed between a first extruder (20) that extrudes a first molten resin from a first outlet port (21) and the breaker plate (59), and that is installed between a second extruder (40) that extrudes a second molten resin including a molten base material and a line pattern agent (93) that is less molten than the base material from a second outlet port (41), and the breaker plate (59), and that has a first flow path leading to the first outlet port (21) and the plurality of first holes (59a and 59b) of the first extruder (20), and second flow paths (53e, 53c, 54f, and 54g) leading to the second outlet port (41) and the plurality of second holes (59c) of the second extruder (40); a downstream die (50b) attached to the breaker plate (59) on the opposite side of the upstream die (50a) with respect to the breaker plate (59), the downstream die (50b) having a third flow passage communicating with the plurality of first holes (59a and 59b) and the plurality of second holes (59c); A die (50) is provided, comprising:

[0008] According to the invention of claim 4, An extrusion molding apparatus (1) for extruding a molded product, a first extruder (20) that melts a first raw material (91) having a thermoplastic resin to produce a first molten resin and extrudes the first molten resin from a first outlet port (21); a second extruder (40) which melts a second raw material (92) having a thermoplastic resin to produce a base material, softens or melts a line pattern agent (93) which has a colored thermoplastic resin and is less likely to melt than the second raw material (92), and extrudes the base material and the line pattern agent (93) from a second outlet port (41) while kneading them; a breaker plate (59) having a plurality of first holes (59a and 59b) penetrating between both surfaces of the breaker plate (59) and a plurality of second holes (59c) penetrating between the both surfaces and arranged so as to surround the plurality of first holes (59a and 59b); an upstream die (50a) attached between the first extruder (20) and the breaker plate (59), the upstream die (50a) being attached between the second extruder (40) and the breaker plate (59), the upstream die (50a) having a first flow path leading to the first outlet port (21) and the plurality of first holes (59a and 59b) of the first extruder (20), and having second flow paths (53e, 53c, 54f and 54g) leading to the second outlet port (41) and the plurality of second holes (59c) of the second extruder (40); a downstream die (50b) attached to the breaker plate (59) on the opposite side of the upstream die (50a) with respect to the breaker plate (59), the downstream die (50b) having a third flow passage communicating with the plurality of first holes (59a and 59b) and the plurality of second holes (59c); The present invention provides an extrusion molding apparatus (1) comprising:

[0009] According to the invention of claim 7, A molding method comprising the steps of: melting a first raw material (91) having a thermoplastic resin by a first extruder (20) to produce a first molten resin; extruding the first molten resin from a first outlet port (21) of the first extruder (20); melting a second raw material (92) having a thermoplastic resin by a second extruder (40) to produce a base material; softening or melting a line pattern agent (93) having a colored thermoplastic resin and which is less likely to melt than the second raw material (92); and extruding the base material and the line pattern agent (93) from a second outlet port (41) of the second extruder (40) while kneading them, a breaker plate (59) having a plurality of first holes (59a and 59b) penetrating between both surfaces of the breaker plate (59) and a plurality of second holes (59c) penetrating between the both surfaces and arranged so as to surround the plurality of first holes (59a and 59b); an upstream die (50a) is attached between the first extruder (20) and the breaker plate (59), the upstream die (50a) is attached between the second extruder (40) and the breaker plate (59), the upstream die (50a) has first flow paths (51a, 52a, 53a, and 54a) leading to the first outlet port (21) and the plurality of first holes (59a and 59b) of the first extruder (20), and the upstream die (50a) has second flow paths (53e, 53c, 54f, and 54g) leading to the second outlet port (41) and the plurality of second holes (59c) of the second extruder (40); A downstream die (50b) is attached to the breaker plate (59) on the opposite side of the upstream die (50a) with respect to the breaker plate (59), and the downstream die (50b) has a third flow passage (55a, 60a, and 61a) therein that communicates with the plurality of first holes (59a and 59b) and the plurality of second holes (59c). A molding method is provided.

[0010] According to the invention of claim 1, 4 or 7 as described above, the fact that the linear pattern agent (93) of the second molten resin is less likely to melt than the base material of the second molten resin contributes to the dispersion of the linear pattern agent (93) accompanied by deformation and fragmentation of the linear pattern agent (93) during kneading of the second molten resin by the second extruder (40). Since the upstream die (50a) has therein the first flow paths (51a, 52a, 53a, and 54a) which communicate with the first outlet port (21) of the first extruder (20) and the multiple first holes (59a and 59b) of the breaker plate (59), when the first extruder (20) extrudes the first molten resin from the first outlet port (21) into the first flow paths (51a, 52a, 53a, and 54a) of the upstream die (50a), the first molten resin is forced into the first holes (59a and 59b). Since the upstream die (50a) has second flow paths (53e, 53c, 54f, and 54g) on ​​the inside thereof, which are connected to the second outlet port (41) of the second extruder (40) and the second holes (59c) of the breaker plate (59), when the second extruder (40) extrudes the second molten resin from the second outlet port (41) into the second flow paths (53e, 53c, 54f, and 54g) of the upstream die (50a), the second molten resin is forced into the second holes (59c). When the second molten resin passes through the second holes (59c), the linear pattern agent (93) is deformed and cut, and dispersed into the base material. Since the multiple second holes (59c) of the breaker plate (59) are arranged to surround the multiple first holes (59a and 59b) of the breaker plate (59), the second molten resin that comes out from the multiple second holes (59c) of the breaker plate (59) to the third flow path (55a, 60a and 61a) of the downstream die (50b) is laminated on the outer periphery of the first molten resin that comes out from the multiple first holes (59a and 59b) of the breaker plate (59) to the third flow path (55a, 60a and 61a) of the downstream die (50b). When the first and second molten resins flow through the third flow paths (55a, 60a, and 61a) of the downstream die (50b), the second molten resin experiences wall friction resistance from the downstream die (50b), causing the linear pattern agent (93) in the second molten resin to extend linearly. The linear linear pattern agent (93) forms the lines of the grain pattern on the surface of the molded product. The deformation and breaking of the linear pattern agent (93) as described above contributes to the formation of the grain pattern on the surface of the molded product.

[0011] According to the invention of claim 2, there is provided a die (50) according to claim 1, The perimeter of the third flow passage (55a, 60a, and 61a) gradually increases with increasing distance from the breaker plate (59). A die (50) is provided, characterized in that

[0012] According to the invention of claim 5, there is provided the extrusion molding apparatus (1) according to claim 4, The perimeter of the third flow passage (55a, 60a, and 61a) gradually increases with increasing distance from the breaker plate (59). The present invention provides an extrusion molding apparatus (1).

[0013] According to the invention of claim 2 or 5 as described above, the gradual increase in the peripheral length of the third flow path (55a, 60a, and 61a) as it moves away from the breaker plate (59) causes the linear pattern agent (93) in the second molten resin to be circumferentially separated. When the first molten resin and the second molten resin flow through the third flow paths (55a, 60a, and 61a) of the downstream die (50b), the linear pattern agent (93) in the second molten resin extends in thin lines. The thin linear pattern agent (93) forms the lines of the grain pattern on the surface of the molded product.

[0014] According to the invention of claim 3, there is provided a die (50) according to claim 1 or 2, The plurality of second holes (59c) are arranged along the circumference of the third flow passage (55a, 60a, and 61a). A die (50) is provided, characterized in that

[0015] According to the invention of claim 6, there is provided the extrusion molding apparatus (1) according to claim 4 or 5, The plurality of second holes (59c) are arranged along the circumference of the third flow passage (55a, 60a, and 61a). The present invention provides an extrusion molding apparatus (1).

[0016] According to the invention of claim 3 or 6 as described above, since the multiple second holes (59c) are arranged along the circumference of the third flow path (55a, 60a, and 61a), the second molten resin that comes out of the multiple second holes (59c) of the breaker plate (59) into the third flow path (55a, 60a, and 61a) of the downstream die (50b) is layered over the entire outer periphery of the first molten resin that comes out of the multiple first holes (59a and 59b) of the breaker plate (59) into the third flow path (55a, 60a, and 61a) of the downstream die (50b). Effect of the Invention

[0017] According to the present invention, the second molten resin is laminated around the first molten resin in the third flow path of the downstream die, and the first and second molten resins flow through the third flow path of the downstream die, which contributes to the linear pattern agent in the second molten resin extending linearly. The linearly extending linear pattern agent forms lines of the grain pattern on the surface of the molded product. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a side view of an extrusion molding apparatus. [Diagram 2] FIG. 2 is a cross-sectional view of the molded product. [Diagram 3] FIG. 3 is a cross-sectional view of the die. [Figure 4] FIG. 4 is an enlarged view of a portion of FIG. [Diagram 5] FIG. 5 is a plan view showing the breaker plate of the die as viewed in the extrusion direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, the embodiments will be described with reference to the drawings. The features and technical effects of the embodiments will be understood from the following detailed description and drawings. However, the scope of the present invention is not limited to the embodiments disclosed below. The drawings are provided for illustrative purposes only, and therefore the scope of the present invention is not limited to the illustrations in the drawings.

[0020] <1. Overview of the extrusion molding equipment> FIG. 1 is a side view of an extrusion molding apparatus 1. FIG. 2 is a cross-sectional view of a molded product 99. The extrusion molding apparatus 1 manufactures a molded product 99 by extruding molten resin. In a cross section perpendicular to the extrusion direction, a surface layer 99a of the molded product 99 is laminated on the entire outer peripheral surface of an interior 99b of the molded product 99. The surface layer 99a of the molded product 99 has a straight grain pattern like wood. A straight grain pattern refers to a pattern in which a large number of lines of various lengths and widths extending in the extrusion direction are randomly distributed on the surface of the molded product 99. The cross-sectional shape of the molded product 99 can take various variations, and the cross-sectional shape shown in FIG. 2 is one example. For example, the cross-sectional shape of the molded product 99 may be hollow.

[0021] <2. Components of extrusion molding equipment> The extrusion molding apparatus 1 includes a first hopper 11, a first feeder 12, a first extruder 20, a second hopper 32, a third hopper 33, a fourth hopper 34, a second feeder 37, a third feeder 38, a fourth feeder 39, a first measuring device 81, a second measuring device 82, a first switch 83, a second switch 84, a blender 85, a second extruder 40, and a die 50.

[0022] (1) First hopper and first raw material The first hopper 11 is connected to the upper part of the first feeder 12. The top face of the first hopper 11 is open, and the first raw material 91 in the form of pellets or granules is automatically or manually fed into the first hopper 11 through the opening of the first hopper 11. The first hopper 11 stores the first raw material 91 fed therein.

[0023] The first raw material 91 is the raw material inside the molded product 99. The first raw material 91 contains a thermoplastic resin. The thermoplastic resin may be colored with a pigment or dye, or may be uncolored. The first raw material 91 may contain wood powder in addition to the thermoplastic resin. In this case, the thermoplastic resin is the base material, and the wood powder is dispersed in the base material.

[0024] (2) First Feeder The first feeder 12 is connected between the lower end of the first hopper 11 and the rear of the first extruder 20. The first feeder 12 takes out the first raw material 91 from the lower end of the first hopper 11 and supplies the first raw material 91 to the first extruder 20. The first feeder 12 adjusts the supply speed of the first raw material 91. The first feeder 12 is, for example, a screw feeder.

[0025] (3) First Extruder The first extruder 20 is connected to the first feeder 12. The first extruder 20 receives a supply of a first raw material 91 from the first feeder 12. The first extruder 20 melts the first raw material 91 by heating the first raw material 91 supplied thereto. The first extruder 20 extrudes the first molten resin into the die 50 while kneading the first molten resin formed by melting the first raw material 91.

[0026] The first extruder 20 has a cylinder, a screw, a motor, a heater, a thermostatic case, and the like. The cylinder is installed in the thermostatic case so that its central axis extends in the front-rear direction. The heater is attached to the outer periphery of the cylinder in the thermostatic case. The heater heats the cylinder and the first raw material 91 inside it to melt the first raw material 91. The screw is housed in the cylinder along its central axis. The screw is connected to a motor. The motor is attached to the rear of the cylinder. When the motor drives the screw to rotate, the first molten resin is kneaded by the screw and sent toward the front end of the cylinder. As a result, the first molten resin is extruded from the front end of the cylinder into the die 50.

[0027] (4) Second hopper and second raw material The second hopper 32 is connected to the upper part of the second feeder 37. The upper surface of the second hopper 32 is open, and the second raw material 92 in the form of pellets or granules is automatically or manually fed into the second hopper 32 through the opening of the second hopper 32. The second hopper 32 stores the second raw material 92 fed therein.

[0028] The second raw material 92 is the raw material for the surface layer of the molded product 99, particularly the base material for the surface layer. The second raw material 92 contains a thermoplastic resin. The thermoplastic resin may be colored with a pigment or dye, or may be uncolored. The second raw material 92 may contain wood powder in addition to the thermoplastic resin. In this case, the thermoplastic resin is the base material, and the wood powder is dispersed in the base material. The second raw material 92 does not have to contain wood.

[0029] (5) Second feeder, first meter and first switch The second feeder 37 is, for example, a screw feeder. The second feeder 37 is provided between the lower end of the second hopper 32 and the inlet of the first measuring device 81. The first switch 83 is provided at the outlet of the first measuring device 81. The first measuring device 81 and the first switch 83 are provided above the blender 85. The first switch 83 opens and closes the outlet of the first measuring device 81 regularly or periodically.

[0030] First, the first switch 83 closes the discharge port of the first weighing device 81. After that, the second feeder 37 takes out the second raw material 92 in the second hopper 32 from the lower end of the second hopper 32 and supplies the second raw material 92 to the first weighing device 81. During the supply operation of the second feeder 37, the first weighing device 81 weighs the second raw material 92 supplied from the second feeder 37. When the weighing value of the first weighing device 81 reaches the set value, the second feeder 37 receives a signal from the first weighing device 81 and stops the supply operation. After that, the first switch 83 opens the discharge port of the first weighing device 81, so that the second raw material 92 is fed from the first weighing device 81 to the blender 85 by gravity. After that, the first weighing device 81 resets the weighing value. Thereafter, the second feeder 37, the first switch 83, and the first weighing device 81 repeat the same operation.

[0031] (6) Third hopper and line patterning agent The third hopper 33 is connected to the upper part of the third feeder 38. The top surface of the third hopper 33 is open, and the line pattern agent 93 in pellet or granular form is automatically or manually fed into the third hopper 33 through the opening of the third hopper 33. The third hopper 33 stores the line pattern agent 93 fed therein.

[0032] The line pattern agent 93 is a raw material for the surface layer of the molded product 99, particularly for the lines of the grain pattern on the surface layer. The line pattern agent 93 contains a thermoplastic resin. The thermoplastic resin is colored by a pigment or dye. The line pattern agent 93 is less likely to melt than the first raw material 91, the second raw material 92, and the colorant 94. In other words, the melting point of the line pattern agent 93 is higher than the melting points of the first raw material 91, the second raw material 92, and the colorant 94, and the glass transition temperature of the line pattern agent 93 is higher than the glass transition temperatures of the first raw material 91, the second raw material 92, and the colorant 94. The line pattern agent 93 is also called a master patch.

[0033] (7) Fourth hopper and coloring agent The fourth hopper 34 is connected to the upper part of the fourth feeder 39. The top surface of the fourth hopper 34 is open, and the colorant 94 in pellet or granular form is automatically or manually fed into the fourth hopper 34 through the opening of the fourth hopper 34. The fourth hopper 34 stores the colorant 94 fed therein.

[0034] The colorant 94 is a raw material that colors the surface layer of the molded product 99, particularly the base material of the surface layer. The colorant 94 contains the thermoplastic resin as the base material and a pigment or dye dispersed in the thermoplastic resin. The colorant 94 has the same melting property as the second raw material 92. The colorant 94 melts more easily than the line pattern agent 93. In other words, the melting point of the colorant 94 is lower than the melting point of the line pattern agent 93, and the glass transition temperature of the colorant 94 is lower than the glass transition temperature of the line pattern agent 93. The colorant 94 is also called a master patch.

[0035] It is not necessary to use colorant 94. In particular, if second feedstock 92 is colored, it is not necessary to use colorant 94.

[0036] (8) Third feeder, fourth feeder, second meter and second switch The third feeder 38 and the fourth feeder 39 are, for example, screw feeders. The third feeder 38 is provided between the lower end of the third hopper 33 and the inlet of the second weighing device 82. The fourth feeder 39 is provided between the lower end of the fourth hopper 34 and the inlet of the second weighing device 82. The second switch 84 is provided at the outlet of the second weighing device 82. The second weighing device 82 and the second switch 84 are provided above the blender 85. The second switch 84 opens and closes the outlet of the second weighing device 82 periodically or cyclically in synchronization with the opening and closing operation of the second switch 84.

[0037] First, the second switch 84 closes the discharge port of the second weighing device 82. After that, the third feeder 38 takes out the line pattern agent 93 in the third hopper 33 from the lower end of the third hopper 33 and supplies the line pattern agent 93 to the second weighing device 82. The fourth feeder 39 also takes out the coloring agent 94 in the fourth hopper 34 from the lower end of the fourth hopper 34 and supplies the coloring agent 94 to the second weighing device 82. During the supply operation of the third feeder 38 and the fourth feeder 39, the second weighing device 82 measures the line pattern agent 93 and coloring agent 94 supplied from the feeders 38 and 39. When the measured value of the second weighing device 82 reaches the set value, the feeders 38 and 39 receive a signal from the second weighing device 82 and stop the supply operation. Thereafter, the second switch 84 opens the outlet of the second metering device 82, and the line pattern agent 93 and the colorant 94 are fed by gravity from the second metering device 82 into the blender 85. The second metering device 82 then resets the measured value. Thereafter, the third feeder 38, the fourth feeder 39, the second switch 84, and the second metering device 82 repeat the same operations.

[0038] Note that multiple types of colorants 94 with different colors may be used. In this case, multiple fourth hoppers 34 and multiple fourth feeders 39 are provided, and the colorants 94 are sorted by type and fed into the fourth hoppers 34.

[0039] (9) Blender The blender 85 is provided between the first metering device 81 and the second metering device 82 and the second extruder 40 .

[0040] The first switch 83 and the second switch 84 are opened and closed periodically or periodically in synchronization with each other, so that the measured second raw material 92, the line pattern agent 93, and the colorant 94 are supplied periodically or periodically to the blender 85. The blender 85 mixes the supplied second raw material 92, the line pattern agent 93, and the colorant 94, and supplies the mixture to the second extruder 40.

[0041] (10) Second extruder The second extruder 40 is connected to the blender 85. The second extruder 40 receives a mixture of the second raw material 92, the line pattern agent 93, and the colorant 94 from the blender 85. The second extruder 40 receives the line pattern agent 93 from the third feeder 38. The second extruder 40 heats the second raw material 92, the line pattern agent 93, and the colorant 94 supplied thereto. The heating temperature is higher than the melting points of the second raw material 92 and the colorant 94. The heating temperature is lower than the melting point of the line pattern agent 93 and lower than the glass transition temperature of the line pattern agent 93. Therefore, the second extruder 40 melts the second raw material 92 and the colorant 94 by heating, and softens the line pattern agent 93 to a rubber-like state. The second extruder 40 extrudes the second molten resin into the die 50 while kneading it. The second molten resin refers to a mixture of the molten resin obtained by melting the second raw material 92, the molten resin obtained by melting the colorant 94, and the softened linear pattern agent 93. By kneading the second molten resin by the second extruder 40, the color of the base material of the second molten resin is made uniform, and the linear pattern agent 93 is dispersed in the base material while being deformed and divided. The base material refers to a mixture of the molten resin obtained by melting the second raw material 92 and the molten resin obtained by melting the colorant 94. The second extruder 40 may melt the linear pattern agent 93. In this case, the viscosity of the molten linear pattern agent 93 is higher than the viscosity of the molten second raw material 92 and the colorant 94. The molten linear pattern agent 93 is difficult to mix with the base material of the second molten resin, that is, the molten second raw material 92 and the colorant 94, and the molten linear pattern agent 93 is dispersed in the base material while being deformed and divided.

[0042] The second extruder 40 has a cylinder, a screw, a motor, a heater, a thermostatic case, and the like. The cylinder is installed in the thermostatic case so that its central axis extends in the front-rear direction. The heater is attached to the outer periphery of the cylinder in the thermostatic case. The heater heats the cylinder and the second raw material 92, the line patterning agent 93, and the coloring agent 94 inside the cylinder to generate a second molten resin from the second raw material 92, the line patterning agent 93, and the coloring agent 94. The screw is housed in the cylinder along the central axis of the cylinder. The screw is connected to a motor. The motor is attached to the rear of the cylinder. When the motor rotates and drives the screw, the second molten resin is kneaded by the screw and sent toward the front end of the cylinder. As a result, the second molten resin is extruded from the front end of the cylinder to the die 50.

[0043] (11) Dice Fig. 3 is a cross-sectional view of the die 50. Fig. 4 is an enlarged view of a portion of Fig. 3. Fig. 5 is a plan view showing a breaker plate 59 of the die 50 as viewed in the extrusion direction.

[0044] The die 50 guides the first molten resin and the second molten resin in the extrusion direction, and shapes the first molten resin and the second molten resin into a predetermined shape in a cross section perpendicular to the extrusion direction.

[0045] The die 50 includes cores 57 and 58, a breaker plate 59, an upstream die 50a, and a downstream die 50b. The upstream die 50a includes a joint ring 51, a cylinder 52, and insert plates 53 and 54, and the downstream die 50b includes a cylinder 55, a joint ring 60, and an outlet die 61. The upstream die 50a includes a first flow path on the inside, which includes flow paths 51a, 52a, 53a, and 54a for the first molten resin to flow. The upstream die 50a includes a second flow path on the inside, which includes flow paths 53e and 53c for the second molten resin to flow, holes 54f, and grooves 54g. The downstream die 50b includes a third flow path on the inside, which includes flow paths 55a, 60a, and 61a for the first molten resin and the second molten resin to flow after passing through the breaker plate 59.

[0046] The joint ring 51 is sandwiched between the cylinder 52 and the first extruder 20, and the cylinder 52 is fixed to the first extruder 20 by a fastener or the like. The joint ring 51 is fitted into the first outlet port 21 of the first extruder 20, and thus the joint ring 51 is connected to the first extruder 20. The joint ring 51 has a truncated cone-shaped flow path 51a on its inside. The flow path 51a communicates with the first outlet port 21. The flow path 51a is coaxial with the first outlet port 21.

[0047] The cylinder 52 has a cylindrical flow path 52a inside. A portion of the flow path 52a close to the first extruder 20 holds the joint ring 51, thereby connecting the cylinder 52 to the joint ring 51. The flow path 52a communicates with the flow path 51a of the joint ring 51. The flow path 52a is coaxial with the flow path 51a.

[0048] The insert plate 53 is placed on the insert plate 54, and these insert plates 53, 54 are sandwiched between the cylinder 52 and the cylinder 55. The insert plates 53, 54 have flow paths 53a, 54a, respectively, in the center. The flow paths 53a, 54a communicate with each other, and the flow path 53a communicates with the flow path 52a of the cylinder 52. The flow paths 53a, 54a are coaxial with the flow path 52a.

[0049] The insert plate 53 has a groove 53b on one of both sides of the insert plate 53 that contacts the insert plate 54. The groove 53b is formed in a ring shape so as to surround the flow path 53a. On the other hand, the insert plate 54 has a groove 54b on one of both sides of the insert plate 54 that contacts the insert plate 53. The groove 54b is formed in a ring shape so as to surround the flow path 54a. The grooves 53b and 54b face each other and overlap each other, thereby forming a ring-shaped flow path 53c on the butting surfaces of the insert plates 53 and 54. The flow path 53c is a ring-shaped hollow that surrounds the flow paths 53a and 54a of the insert plates 53 and 54.

[0050] The insert plate 53 has a groove 53d on the surface of the insert plate 53 that contacts the insert plate 54. The groove 53d is a flow path connecting the groove 53b and the second extruder 40. The insert plate 54 has a groove 54d on the surface of the insert plate 54 that contacts the insert plate 53. The groove 54d is a flow path connecting the groove 54b and the second extruder 40, similar to the groove 53d. The grooves 53d and 54d face each other and overlap, and a flow path 53e connecting to the second extruder 40 is formed on the butting surfaces of the insert plates 53 and 54. The flow path 53e opens at the outer periphery of the insert plates 53 and 54. The outer periphery of the insert plates 53 and 54 is connected to the second extruder 40, and the flow path 53e is connected to the second outlet port 41 of the second extruder 40. The flow path 53e is provided from its opening to the flow path 53c and is connected to the flow path 53c.

[0051] The insert plate 54 has a plurality of holes 54f at the bottom of the groove 54b. The holes 54f are arranged at regular intervals in the circumferential direction. The holes 54f penetrate from the bottom of the groove 54b to the back side.

[0052] The insert plate 54 has a groove 54g on one of the two surfaces of the insert plate 54 that contacts the breaker plate 59 and the cylinder 55. The groove 54g is formed in a ring shape so as to surround the flow path 54a. The hole 54f opens at the bottom of the groove 54g.

[0053] The cylinder 55 has a cylindrical flow passage 55a on its inside. The flow passage 55a is coaxial with the flow passages 52a, 53a, and 54a of the cylinder 52 and the insert plates 53 and 54.

[0054] The cylinder 55 has a circular recess on the end surface in contact with the insert plate 54, and the recess is integrated with the flow passage 55a and has a diameter larger than that of the flow passage 55a. A breaker plate 59 is fitted into the recess and overlaps the insert plate 54, covering the groove 54g.

[0055] The breaker plate 59 has a plurality of holes 59a, 59b, and 59c penetrating between both sides of the breaker plate 59. The holes 59a and 59b are first holes, and the holes 59c are second holes. The holes 59a are arranged at regular intervals in the circumferential direction. The holes 59b are arranged at regular intervals in the circumferential direction outside the row of the holes 59a. The holes 59c are arranged at regular intervals in the circumferential direction outside the row of the holes 59b. The rows of the holes 59a, the holes 59b, and the holes 59c are arranged coaxially. The rows of the holes 59a and the holes 59b are arranged inside the periphery of the flow passage 54a of the insert plate 54. Therefore, these holes 59a and 59b communicate with the flow passage 54a. The row of the holes 59c is arranged outside the periphery of the flow passage 54a of the insert plate 54. Therefore, these holes 59a and 59b do not communicate with the flow passage 54a. The row of holes 59c is disposed between the inner peripheral edge and the outer peripheral edge of groove 54g of insert plate 54. Therefore, these holes 59c communicate with groove 54g. The row of holes 59a, the row of holes 59b, and the row of holes 59c are disposed inside the peripheral edge of flow passage 55a of cylinder 55. Therefore, these holes 59a, 59b, and 59c communicate with flow passage 55a.

[0056] The core 57 is shaped like a truncated cone. The core 57 is fixed to the center of the breaker plate 59. The core 57 protrudes from the breaker plate 59 toward the first extruder 20 inside the flow paths 52a, 53a, and 54a of the cylinder 52 and the insert plates 53 and 54. The core 57 has a tip that is rounded into a hemisphere. The core 57 is arranged coaxially with the flow paths 52a, 53a, and 54a of the cylinder 52 and the insert plates 53 and 54, and is spaced inward from the inner circumference of the cylinder 52 and the insert plates 53 and 54. The diameter of the core 57 gradually increases from the tip of the core 57 toward the breaker plate 59.

[0057] The core 58 is fixed to the center of the breaker plate 59. The core 58 protrudes from the breaker plate 59 in the extrusion direction inside the flow passage 55a of the cylinder 55. The core 58 has a tip that is rounded into a hemisphere. The core 58 is disposed coaxially with the flow passage 55a of the cylinder 55 and is spaced inward from the inner circumference of the cylinder 55. The diameter of the core 58 gradually increases from the tip of the core 58 toward the breaker plate 59.

[0058] The joint ring 60 is sandwiched between the cylinder 55 and the outlet die 61, and the outlet die 61 is fixed to the cylinder 55 by a fastener or the like. The joint ring 60 has a cylindrical flow passage 60a on its inside. The flow passage 60a of the joint ring 60 communicates with the flow passage 55a of the cylinder 55. The flow passage 60a of the joint ring 60 is coaxial with the flow passage 55a of the cylinder 55. The flow passage 60a of the joint ring 60 has a diameter equal to the diameter of the flow passage 55a of the cylinder 55.

[0059] The outlet die 61 has a flow passage 61a on its inside. The flow passage 61a is coaxial with the flow passages 52a, 53a, 54a, 55a, and 60a of the cylinder 52, the insert plates 53 and 54, the cylinder 55, and the joint ring 60. The cross-sectional area of ​​the flow passage 61a of the outlet die 61 gradually increases from the joint ring 60 toward the outlet port 61b of the outlet die 61. The circumferential length of the flow passage 61a of the outlet die 61 gradually increases from the joint ring 60 toward the outlet port 61b of the outlet die 61. The cross-sectional shape of the outlet port 61b is flat, and the size of the outlet port 61b along a first direction perpendicular to the extrusion direction is smaller than the size of the outlet port 61b along a second direction perpendicular to the extrusion direction and the second direction. The cross-sectional shape of the outlet port 61b can take various variations according to the cross-sectional shape of the molded product 99. A mandrel may be provided in the flow path 61a so that the cross-sectional shape of the molded product 99 is hollow.

[0060] <3. Operation of the extrusion molding device and molding method of molded products> By controlling the first extruder 20 and the first feeder 12, a first molten resin consisting of a first raw material 91 is extruded into the die 50 by the first extruder 20. In parallel with this, by controlling the second extruder 40, the second feeder 37, the third feeder 38, the fourth feeder 39, the measuring devices 81 and 82, the switches 83 and 84, and the blender 85, a second molten resin consisting of a second raw material 92, a line pattern agent 93, and a colorant 94 is extruded into the die 50 by the second extruder 40. Specifically, the first molten resin and the second molten resin are extruded as follows.

[0061] The heater of the first extruder 20 is controlled to a constant temperature by the control device, and the temperature of the heater of the first extruder 20 increases until it exceeds the melting point of the first raw material 91 . The rotation speed of the motor of the first extruder 20 is controlled by a control device, and the screw of the first extruder 20 is rotationally driven by the motor. The first raw material 91 is automatically or manually charged into the first hopper 11 . The feeding speed of the first feeder 12 is controlled by the control device, and the first raw material 91 in the first hopper 11 is fed to the first extruder 20 by the first feeder 12 .

[0062] The heat and temperature of the heater of the first extruder 20 melts the first raw material 91 supplied to the first extruder 20 . The rotation of the screw of the first extruder 20 kneads the first molten resin made of the first raw material 91 while feeding the first molten resin in the extrusion direction within the cylinder of the first extruder 20 .

[0063] The heater of the second extruder 40 is controlled to a constant temperature by the control device, and the temperature of the heater of the second extruder 40 is increased until it exceeds the melting points of the second raw material 92 and the colorant 94. The temperature of the heater of the second extruder 40 is higher than the glass transition temperature of the line pattern agent 93 and lower than the melting point of the line pattern agent 93. Alternatively, the temperature of the heater of the second extruder 40 is higher than the melting point of the line pattern agent 93. Note that the melting point of the line pattern agent 93 is higher than the melting points of the first raw material 91, the second raw material 92, and the colorant 94, and the glass transition temperature of the line pattern agent 93 is higher than the glass transition temperatures of the first raw material 91, the second raw material 92, and the colorant 94. The glass transition temperature of the line pattern agent 93 may be higher or lower than the melting points of the first raw material 91, the second raw material 92, and the colorant 94. The rotation speed of the motor of the second extruder 40 is controlled by the control device, and the screw of the second extruder 40 is rotated by the motor. A second raw material 92, a line pattern agent 93 and a coloring agent 94 are automatically or manually charged into the second hopper 32 and the third hopper 33, respectively. By the operation of the feeders 37 , 38 , 39 , the meters 81 , 82 , the switches 83 , 84 and the blender 85 , a mixture of the second raw material 92 , the line pattern agent 93 and the colorant 94 is supplied to the second extruder 40 .

[0064] The heat and temperature of the heater of the second extruder 40 melt the second raw material 92 and the colorant 94 supplied to the second extruder 40. The heat and temperature of the heater of the second extruder 40 soften the line pattern agent 93 supplied to the second extruder 40 or melt the line pattern agent 93. Note that the line pattern agent 93 is more difficult to melt than the first raw material 91, the second raw material 92, and the colorant 94. The rotation of the screw of the second extruder 40 kneads the second molten resin consisting of the second raw material 92, the line pattern agent 93, and the colorant 94 while feeding the second molten resin in the cylinder of the second extruder 40. When the second molten resin is kneaded, the second raw material 92 and the colorant 94 are mixed uniformly, and the second raw material 92 and the colorant 94 become the base material of the second molten resin. Therefore, the base material of the second molten resin has a uniform color without unevenness. When the second molten resin is kneaded, the line pattern agent 93 is deformed and broken down and dispersed in the base material of the second molten resin.

[0065] The first molten resin is sent from the first outlet port 21 of the first extruder 20 into the die 50. The first molten resin is sent to the breaker plate 59 through the flow paths 51a, 52a, 53a, and 54a in this order. Because the flow of the first molten resin is impeded by the breaker plate 59, the back pressure of the first molten resin in the flow paths 51a, 52a, 53a, and 54a increases. The back pressure of the first molten resin pushes the first molten resin into the holes 59a and 59b of the breaker plate 59, causing the first molten resin to pass through the flow path 55a.

[0066] On the other hand, the second molten resin is sent from the second outlet port 41 of the second extruder 40 into the die 50. The second molten resin is sent to the breaker plate 59 through the flow path 53e, the flow path 53c, the hole 54f, and the groove 54g in order. Since the flow of the second molten resin is hindered by the breaker plate 59, the back pressure of the second molten resin in the flow path 53e, the flow path 53c, the hole 54f, and the groove 54g increases. The back pressure of the second molten resin pushes the second molten resin into the hole 59c of the breaker plate 59, causing the second molten resin to pass through the flow path 55a. When the second molten resin passes through the hole 59c of the breaker plate 59, the line pattern agent 93 is deformed and divided and dispersed into the base material of the second molten resin. Therefore, the line pattern agent 93 is a particle in the second molten resin and is a cause of color unevenness of the second molten resin.

[0067] The second molten resin exiting from hole 59c into flow path 55a is laminated over the entire outer periphery of the first molten resin exiting from holes 59a and 59b into flow path 55a. The first molten resin and the second molten resin are sent inside flow path 55a toward outlet die 61. At this time, the second molten resin is subjected to wall friction resistance from cylinder 55, so that linear pattern agent 93 in the second molten resin is deformed so as to extend in the extrusion direction.

[0068] The first molten resin and the second molten resin are sent to the outlet port 61b of the outlet die 61 in the flow path 61a of the outlet die 61. At this time, since the circumferential length of the flow path 61a gradually increases from the joint ring 60 toward the outlet port 61b, the linear pattern agent 93 in the second molten resin is divided in the circumferential direction. Since the second molten resin receives wall friction resistance from the outlet die 61, the linear pattern agent 93 in the second molten resin is deformed so as to extend in the extrusion direction.

[0069] The first molten resin and the second molten resin are discharged from the outlet port 61b. This is a molded product 99, with the first molten resin forming the interior 99b of the molded product 99 and the second molten resin forming a surface layer 99a of the molded product 99. The line pattern agent 93 forms lines in the grain pattern of the surface layer 99a.

[0070] <4. Summary> Since the linear pattern agent 93 is less likely to melt than the second raw material 92 and the colorant 94, the linear pattern agent 93 is deformed and broken when the second molten resin is kneaded by the second extruder 40, and the linear pattern agent 93 is dispersed in the base material of the second molten resin.

[0071] The upstream die 50a is assembled from a joint ring 51, a cylinder 52, and insert plates 53 and 54. When the upstream die 50a is assembled, a first flow path consisting of the flow paths 51a, 52a, 53a, and 54a is formed in the upstream die 50a, and a second flow path consisting of the flow paths 53e, 53c, holes 54f, and grooves 54g is formed in the upstream die 50a. Since the first flow path leads from the first outlet port 21 of the first extruder 20 to the multiple holes 59a and 59b of the breaker plate 59, when the first extruder 20 extrudes the first molten resin from the first outlet port 21 into the first flow path of the upstream die 50a, the first molten resin is forced into the holes 59a and 59b of the breaker plate 59. Since the second flow path is connected from the second outlet port 41 of the second extruder 40 to the multiple holes 59c of the breaker plate 59, when the second extruder 40 extrudes the second molten resin from the second outlet port 41 into the second flow path of the upstream die 50a, the second molten resin is forced into the holes 59c of the breaker plate 59. Since the second flow path of the upstream die 50a surrounds the first flow path of the upstream die 50a, the multiple holes 59c of the breaker plate 59 surround the multiple holes 59a and 59b of the breaker plate 59, and the multiple holes 59c are arranged along the circumference of the flow path 55a of the cylinder 55, the second molten resin that has passed through the holes 59c of the breaker plate 59 is laminated on the outer periphery of the first molten resin that has passed through the holes 59a and 59b of the breaker plate 59 in the flow path 55a of the cylinder 55. The second molten resin becomes a surface layer 99 a of the molded article 99 , and the first molten resin becomes an interior layer 99 b of the molded article 99 .

[0072] When the second molten resin passes through the holes 59c of the breaker plate 59, the linear pattern agent 93 is deformed and broken, so that the linear pattern agent 93 is dispersed in the base material of the second molten resin.

[0073] The downstream die 50b is assembled from a cylinder 55, a joint ring 60, and an outlet die 61. When the downstream die 50b is assembled, a third flow path consisting of flow paths 55a, 60a, and 61a is formed in the downstream die 50b. When the first molten resin and the second molten resin flow through the third flow path of the downstream die 50b, the second molten resin receives wall friction resistance from the downstream die 50b, so that the linear pattern agent 93 in the second molten resin extends linearly. The linear linear pattern agent 93 forms the lines of the grain pattern on the surface of the molded product 99. The deformation and separation of the linear pattern agent 93 as described above contributes to the formation of the grain pattern on the surface of the molded product 99.

[0074] Since the circumferential length of the flow passage 61a of the outlet die 61 gradually increases with increasing distance from the breaker plate 59, when the first molten resin and the second molten resin flow in the flow passage 61a to the outlet port 61b of the outlet die 61, the linear pattern agent 93 in the second molten resin is divided in the circumferential direction. Therefore, the linear pattern agent 93 in the second molten resin extends in thin lines. The thin linear pattern agent 93 forms the lines of the straight grain pattern on the surface of the molded product 99.

[0075] Core 57 contributes to an appropriate back pressure of the first molten resin. Core 58 contributes to an appropriate back pressure of the first molten resin and the second molten resin. Since the back pressure of the first molten resin and the second molten resin is appropriate, the wall friction resistance that the second molten resin receives from the downstream die 50b becomes appropriate.

[0076] If wood flour is used as a raw material for molded products99, it will be possible to reduce the amount of resin used and effectively utilize the wood flour generated at lumber factories. The use of wood flour will contribute to the realization of an energy-saving society, the reduction of carbon dioxide emissions, the realization of a decarbonized society, and the realization of the Sustainable Development Goals (SDGs). [Explanation of symbols]

[0077] 1. Extrusion molding equipment 20 First Extruder 40 Second Extruder 50 Dice 51 Joint Ring 51a Flow path 52 cylinders 52a Flow path 53 Insert Plate 53a Flow path 53c Flow path 53e Flow path 54 Insert Plate 54a Flow path 54f hole 54g groove 59 Breaker Plate 59a hole 59b hole 59c hole 99 Molded products 99a Surface layer 99b internal

Claims

1. A die of an extrusion molding device, a breaker plate having a plurality of first holes penetrating between both surfaces of the breaker plate and a plurality of second holes penetrating between the both surfaces and arranged to surround the plurality of first holes; an upstream die which is installed between a first extruder which extrudes a first molten resin from a first outlet port and the breaker plate, and which is installed between a second extruder which extrudes a second molten resin including a molten base material and a line patterning agent which is less molten than the base material from a second outlet port and the breaker plate, the upstream die having a first flow path leading to the first outlet port and the plurality of first holes of the first extruder and a second flow path leading to the second outlet port and the plurality of second holes of the second extruder; a downstream die attached to the breaker plate on an opposite side of the breaker plate from the upstream die, the downstream die having a third passageway communicating with the first plurality of holes and the second plurality of holes; A die comprising:

2. 2. A die according to claim 1, The perimeter of the third flow passage gradually increases with distance from the breaker plate. A dice characterized by:

3. A die according to claim 1 or 2, The plurality of second holes are arranged along a circumference of the third flow path. A dice characterized by:

4. An extrusion molding apparatus for extruding a molded product, a first extruder for melting a first raw material having a thermoplastic resin to produce a first molten resin and extruding the first molten resin from a first outlet port; a second extruder for producing a base material by melting a second raw material having a thermoplastic resin, softening or melting a line-patterning agent having a colored thermoplastic resin and being less meltable than the second raw material, and extruding the base material and the line-patterning agent from a second outlet port while kneading them; a breaker plate having a plurality of first holes penetrating between both surfaces of the breaker plate and a plurality of second holes penetrating between the both surfaces and arranged to surround the plurality of first holes; an upstream die mounted between the first extruder and the breaker plate, the upstream die being mounted between the second extruder and the breaker plate, the upstream die having a first flow passage leading to the first outlet port and the plurality of first holes of the first extruder, and a second flow passage leading to the second outlet port and the plurality of second holes of the second extruder; a downstream die attached to the breaker plate on an opposite side of the breaker plate from the upstream die, the downstream die having a third passageway communicating with the first plurality of holes and the second plurality of holes; An extrusion molding apparatus comprising:

5. 5. The extrusion molding apparatus according to claim 4, The perimeter of the third flow passage gradually increases with distance from the breaker plate.

1. An extrusion molding apparatus comprising:

6. The extrusion molding apparatus according to claim 4 or 5, The plurality of second holes are arranged along a circumference of the third flow path.

1. An extrusion molding apparatus comprising:

7. A molding method comprising: melting a first raw material having a thermoplastic resin by a first extruder to produce a first molten resin; extruding the first molten resin from a first outlet port of the first extruder; melting a second raw material having a thermoplastic resin by a second extruder to produce a base material; softening or melting a line pattern agent having a colored thermoplastic resin and being less meltable than the second raw material; and extruding the base material and the line pattern agent from a second outlet port of the second extruder while kneading them, The breaker plate has a plurality of first holes penetrating between both surfaces of the breaker plate, and a plurality of second holes penetrating between the both surfaces and arranged to surround the plurality of first holes, an upstream die is mounted between the first extruder and the breaker plate, the upstream die is mounted between the second extruder and the breaker plate, the upstream die has a first flow passage leading to the first outlet port and the plurality of first holes of the first extruder, and the upstream die has a second flow passage leading to the second outlet port and the plurality of second holes of the second extruder; A downstream die is attached to the breaker plate on an opposite side of the upstream die with respect to the breaker plate, the downstream die having a third passage therein communicating with the first plurality of holes and the second plurality of holes. A molding method comprising the steps of:

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