Sheet forming die

Abstract

To provide a sheet molded mouthpiece that can stably produce sheets by controlling leakage of sheet material from an end face of a side plate and a lip.SOLUTION: In a sheet molded mouthpiece of the present invention, a flow channel for discharging a sheet material is formed between a pair of opposing lips and side plates, a portion of one lip that serves as a discharge port of the flow channel is a flexible portion extending in a width direction of the sheet material, and a plurality of adjustment bolts that push and pull the flexible portion are attached side by side in the width direction of the sheet material. A groove is formed from an upstream end to a downstream end in the sheet material flow direction in an area sandwiched between the side plate and the adjustment bolt next to the side plate on a surface of the flexible portion that is pushed and pulled by the adjustment bolt.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a sheet forming die. [Background technology]

[0002] Please refer to FIG. 8. FIG. 8 is a diagram of a general sheet forming die, and the upper side is an arrow view observed from the sheet material width direction, and the lower side is an arrow view observed from the sheet material flow direction. A general sheet forming die is known in which a sheet material (typically molten resin, etc.) melted by an extruder or the like is molded into a sheet shape and discharged from a flow path 2 formed by a pair of opposing lips 1 and side plates 9 installed at both ends of each lip in the sheet material flow direction, and the thickness distribution in the sheet material width direction is adjusted by adjusting the gap of the flow path 2 with an adjustment bolt 4. The part of the lip 1 that becomes the discharge port of the flow path 2 is a flexible part 3 extending in the sheet material width direction, and multiple adjustment bolts 4 are attached in a line in the sheet material width direction. The adjustment bolt 4 pushes and pulls the flexible part 3 to adjust the gap of the flow path 2.

[0003] Patent Document 1 discloses an extrusion molding T-die in which a hollow through hole is introduced for the purpose of narrowing the range of interference while maintaining the installation space of the hexagonal nut that fixes the flexible lip adjustment bolt. FIG. 10 is an arrow view of the extrusion molding T-die of Patent Document 1 observed from the sheet material flow direction. As shown in FIG. 10, the flexible lip adjustment bolt 4 is fixed to the flexible part 3 by a hexagonal nut 6, so the flexible part 3 needs a sheet material width direction dimension that allows the seat of the hexagonal nut 6 to contact. On the other hand, by reducing the rigidity of the flexible part 3 between the adjustment bolts 4, the range of "interference" in which the adjustment bolt 4 adjacent to the pushed and pulled adjustment bolt 4 also moves can be narrowed. Therefore, in the extrusion molding T-die of Patent Document 1, in the flexible part 3 between the adjustment bolts 4, a slit 7 with a small sheet material width direction dimension is provided near the hexagonal nut 6 to maintain the installation space of the hexagonal nut 6, and a hollow through hole 8 with a large sheet material width direction dimension is provided near the lip land 2, thereby reducing the rigidity of the flexible part 3 and efficiently narrowing the range of interference. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-178386 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a strong demand for stability in film production in order to increase production volume and reduce prices. One of the defects that deteriorates this stability is leakage of sheet material that occurs from the contact surface between the side plate of the die and the end face of the lip. This leaked sheet material adheres to the sheet after molding and induces film rupture, which can cause a serious situation in which film production has to be stopped. Various studies have been conducted on this leakage, and many of its causes have been clarified, but there are still some causes that are not yet recognized by the public. One of them is the phenomenon in which the end face of the lip tilts when the adjustment bolt near the end is pushed and pulled, causing the sheet material to leak. This leakage cannot be suppressed by the general leakage prevention measure of increasing the force pressing the lip with the side plate.

[0006] The above-mentioned Patent Document 1 does not disclose that the end face of the lip is tilted, causing leakage of the sheet material, nor does it disclose a method for preventing this.

[0007] The present invention provides a sheet forming die that can suppress leakage of sheet material from the end faces of the side plates and lip and can stably produce sheets. [Means for solving the problem]

[0008] The first sheet forming die of the present invention, which solves the above problems, has a flow path for discharging a sheet material formed by a pair of opposing lips and side plates installed at both ends of each of the pair of lips, At least one of the pair of lips has a flexible portion that is a discharge port of the flow path and extends in the sheet material width direction, A plurality of adjustment bolts for pushing and pulling the flexible portion are arranged in a line in the width direction of the sheet material, A groove is formed on the surface of the flexible portion that is pushed and pulled by the adjustment bolt in the area between the adjustment bolt next to the side plate and the side plate, extending from the upstream end to the downstream end in the sheet material flow direction.

[0009] In the first sheet forming die of the present invention, when the dimension of the flexible portion in the thickness direction of the sheet material is T1 [mm] and the depth of the groove in the thickness direction of the sheet material is T2 [mm], it is preferable that (T1-T2) / T1 is 0.2 or less.

[0010] In the first sheet forming die of the present invention, when the dimension of the flexible portion in the thickness direction of the sheet material is T1 [mm], the depth of the groove in the thickness direction of the sheet material is T2 [mm], and the dimension of the groove in the width direction of the sheet material is W1 [mm], it is preferable that W1 / (T1-T2) is 1.0 or more.

[0011] In the first sheet forming die of the present invention, it is preferable that the bottom surface of the groove has an arc shape in a cross section perpendicular to the flow direction of the sheet material.

[0012] The second sheet forming die of the present invention, which solves the above problems, has a pair of opposing lips and side plates disposed at both ends of each of the pair of lips to form a flow path for discharging a sheet material, At least one of the pair of lips has a flexible portion that is a discharge port of the flow path and extends in the sheet material width direction, A plurality of adjustment bolts for pushing and pulling the flexible portion are arranged in a line in the width direction of the sheet material, A hole penetrating from the upstream side to the downstream side in the sheet material flow direction is formed in the flexible portion in a range between the side plate and the adjustment bolt adjacent to the side plate.

[0013] In the second sheet forming die of the present invention, when the dimension of the flexible portion in the thickness direction of the sheet material is T3 [mm] and the dimension of the hole in the thickness direction of the sheet material is T4 [mm], it is preferable that (T3-T4) / T3 is 0.2 or less.

[0014] In the second sheet forming die of the present invention, when the dimension of the flexible portion in the thickness direction of the sheet material is T3 [mm], the dimension of the hole in the thickness direction of the sheet material is T4 [mm], and the dimension of the hole in the width direction of the sheet material is W2 [mm], it is preferable that W2 / (T3-T4) is 1.0 or more.

[0015] In the second sheet forming die of the present invention, the hole is preferably circular or elongated in cross section perpendicular to the flow direction of the sheet material.

[0016] [Terminology] Next, the meaning of each term in the present invention will be explained. "Sheet material" refers to the material that constitutes the sheet. Examples of sheet materials include polyolefin resins such as polyethylene, polypropylene, polystyrene, and polymethylpentene, alicyclic polyolefin resins, polyamide resins such as nylon 6 and nylon 66, aramid resins, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polybutyl succinate, and polyethylene-2,6-naphthalate, polycarbonate resins, polyarylate resins, polyacetal resins, polyphenylene sulfide resins, fluororesins such as tetrafluoroethylene resin, trifluoroethylene resin, trifluorochloroethylene resin, tetrafluoroethylene-6fluoropropylene copolymer, and vinylidene fluoride resin, acrylic resins, methacrylic resins, polyacetal resins, polyglycolic acid resins, and polylactic acid resins, which are dissolved or melted in a solvent and made fluid. These thermoplastic resins may be homogeneous resins, copolymers, or blends of two or more types. In addition, various additives such as antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, organic particles, viscosity reducers, heat stabilizers, lubricants, infrared absorbers, ultraviolet absorbers, and doping agents for adjusting the refractive index may be added to each thermoplastic resin.

[0017] The term "sheet forming die" refers to a device that forms sheet material into a sheet shape and extrudes it. The terms "thickness direction of sheet material" and "width direction of sheet material" refer to directions that coincide with the thickness direction and width direction, respectively, of the sheet when the sheet material is formed into a sheet by a die. "Sheet material flow direction" refers to the direction in which the sheet material flows through the flow channel. The term "lip" refers to a pair of members that form a surface perpendicular to the thickness direction of the flow path through which the sheet material flows. The term "side plate" refers to a member that is provided at both ends of the lip in the width direction of the sheet material and forms a surface perpendicular to the width direction of the flow path through which the sheet material flows. The "adjustment bolt" refers to a member that is arranged in a line in the width direction of the sheet material and pushes and pulls the flexible part. The power for pushing and pulling can be a screw, thermal expansion, hydraulic pressure, pneumatic pressure, motor, etc. The "flexible portion" refers to the portion of the lip that becomes the outlet of the flow passage and moves when the adjustment bolt is pushed or pulled. Generally, it is in the range of 50 to 100 mm upstream from the outlet. The "surface pushed and pulled by the adjustment bolt of the flexible portion" refers to the surface of the flexible portion to which the adjustment bolt is attached, which is perpendicular to the thickness direction of the sheet material. The "adjustment bolt next to the side plate" refers to the adjustment bolt attached to both ends of the sheet material width direction of the lip in a line, among the multiple adjustment bolts attached in a line in the sheet material width direction of the lip, that is located closest to the side plate. Effect of the Invention

[0018] Use of the sheet forming die of the present invention makes it possible to stably produce sheets without the need for complicated equipment, prevent tilting of the lip end face, suppress leakage of sheet material, and produce sheets stably. [Brief description of the drawings]

[0019] [Figure 1] 1 is a diagram of a first sheet forming die of the present invention, the upper side being a view seen from the width direction of the sheet material, and the lower side being a view seen from the flow direction of the sheet material. [Diagram 2] 1 is a view of the first sheet forming die of the present invention in a state where an adjustment bolt next to a side plate is pulled, as viewed from the direction of flow of the sheet material. FIG. [Diagram 3]1 is a view of a first sheet forming die of the present invention, in which the bottom surface of the groove is arc-shaped, viewed from the direction of flow of the sheet material. [Figure 4] 1 is a view of a first sheet forming die of the present invention having a keyhole-shaped groove, viewed from the direction of flow of the sheet material. FIG. [Diagram 5] 1 is a view of a second sheet forming die of the present invention as seen from the direction of flow of the sheet material. FIG. [Figure 6] 1 is an arrow view of a second sheet forming die of the present invention having circular holes, viewed from the direction of flow of the sheet material. [Figure 7] 1 is a view of a second sheet forming die of the present invention having a long hole as viewed from the direction of flow of the sheet material. FIG. [Figure 8] FIG. 1 is a diagram of a typical sheet forming die, the upper side being a view seen from the width direction of the sheet material, and the lower side being a view seen from the flow direction of the sheet material. [Figure 9] FIG. 1 is a view of a typical sheet forming die with an adjustment bolt next to a side plate pulled, viewed from the direction of flow of the sheet material. [Figure 10] FIG. 1 is a view of the T-die for extrusion molding of Patent Document 1, as seen from the direction of flow of a sheet material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The sheet forming die of the present invention will be described in detail below with reference to the drawings. These drawings are conceptual diagrams for accurately conveying the gist of the present invention, and are simplified in illustration, and the number, size, shape, and forming positions of the grooves and holes can be changed according to the embodiment.

[0021] First, the mechanism of leakage of the sheet material, which is a problem in the conventional technology, will be described with reference to FIGS.

[0022] FIG. 8 is an arrow view of a typical sheet forming die observed from the sheet material width direction and the sheet material flow direction. FIG. 9 is an arrow view of a typical sheet forming die observed from the sheet material flow direction with the adjustment bolt 5 next to the side plate 9 pulled. First, the inventors of the present invention noticed that in a typical sheet forming die as shown in FIG. 8, when the adjustment bolt near the end is pushed and pulled, the sheet material leaks from the end face 14 of the side plate 9 and the lip 1, and identified the mechanism. As shown in FIG. 9, when the adjustment bolt 5 next to the side plate 9 is pushed and pulled, the surface 15 forming the flow path 2 of the flexible part 3 is tilted. Then, due to the rigidity of the flexible part 3 in the range sandwiched between the adjustment bolt 5 and the side plate 9, the end face 14 of the lip 1 is also tilted, and a gap is generated between the side plate 9 and the end face 14 of the lip 1, causing the sheet material to leak.

[0023] [First sheet forming die] Next, a first sheet forming die of the present invention that solves the above problem will be described with reference to Fig. 1. Fig. 1 is a diagram of the first sheet forming die, with the upper side being a view seen from the width direction of the sheet material, and the lower side being a view seen from the flow direction of the sheet material. Note that the same reference numerals may be used to refer to members that have the same uses and functions as those in the prior art.

[0024] As a result of extensive research, the inventors have discovered that by forming a groove 10 extending from the upstream end 12 to the downstream end 13 in the sheet material flow direction in the area sandwiched between the side plate 9 and the adjustment bolt 5 next to the side plate 9 of the surface 16 that is pushed and pulled by the adjustment bolts 4 and 5 of the flexible section 3, as shown in Figure 1, it is possible to suppress leakage of sheet material from the end face 14 of the side plate 9 and the lip 1, and to stably produce sheets.

[0025] The technical meaning of the present invention will be described below with reference to FIG. 2. FIG. 2 is an arrow view of the first sheet forming die in a state where the adjustment bolt next to the side plate 9 is pulled, as viewed from the sheet material flow direction. By forming the groove 10, the volume of the flexible part 3 in the range sandwiched between the adjustment bolt 5 and the side plate 9 is reduced, and the rigidity is lowered. Then, as shown in FIG. 2, even if the surface 15 forming the flow path 2 of the flexible part 3 is tilted when the adjustment bolt 5 is pushed and pulled, the end surface 14 of the lip 1 is not tilted, and leakage of the sheet material caused from the contact surface between the side plate 9 and the end surface 14 of the lip 1 can be suppressed. Note that two or more grooves 10 may be formed in the range sandwiched between the adjustment bolt 5 and the side plate 9.

[0026] In the first sheet forming die, it is preferable that (T1-T2) / T1 is 0.2 or less, where T1 [mm] is the dimension of the flexible portion 3 in the thickness direction of the sheet material, and T2 [mm] is the depth of the groove 10 in the thickness direction of the sheet material. The effect of the present invention can be obtained even when (T1-T2) / T1 is greater than 0.2, but by making (T1-T2) / T1 0.2 or less, the difference in rigidity of the flexible portion 3 depending on whether the groove 10 is present or not becomes large, so that the effect of the present invention becomes prominent. It is more preferable that (T1-T2) / T1 is 0.15 or less. There is no particular limit to the lower limit of (T1-T2) / T1, but if T2 is too large, the rigidity of the flexible portion 3 becomes too low, so that in reality, (T1-T2) / T1 is preferably 0.1 or more.

[0027] In the first sheet forming die, it is preferable that W1 / (T1-T2) is 1.0 or more, where T1 [mm] is the dimension of the flexible portion 3 in the thickness direction of the sheet material, T2 [mm] is the depth of the groove 10 in the thickness direction of the sheet material, and W1 [mm] is the dimension of the groove 10 in the width direction of the sheet material. Even if W1 / (T1-T2) is smaller than 1.0, the effect of the present invention can be obtained, but by making W1 / (T1-T2) 1.0 or more, the difference in rigidity of the flexible portion 3 depending on whether or not the groove 10 is present becomes large, so that the effect of the present invention becomes remarkable. It is more preferable that W1 / (T1-T2) is 1.2 or more. There is no particular upper limit to W1 / (T1-T2), but if W1 is too large, the rigidity of the flexible portion 3 becomes too low, so that W1 / (T1-T2) is preferably 2.0 or less in reality.

[0028] Please refer to Figures 3 and 4. Figure 3 is an arrow view of the first sheet forming die with a groove having an arc-shaped bottom surface, as viewed from the sheet material flow direction, and Figure 4 is an arrow view of the first sheet forming die with a keyhole-shaped groove, as viewed from the sheet material flow direction. As shown in Figure 3, the first sheet forming die preferably has a groove 10 with a bottom surface that is arc-shaped in a cross section perpendicular to the sheet material flow direction. The effect of the present invention can be obtained even if the bottom surface of the groove 10 is not arc-shaped in a cross section perpendicular to the sheet material flow direction. However, by making the bottom surface of the groove 10 arc-shaped, the stress generated at the bottom surface of the groove 10 when the adjustment bolt 5 next to the side plate 9 is pushed and pulled is reduced, and plastic deformation of the flexible portion 3 is suppressed, so that the effect of the present invention can be continuously obtained. In addition, as long as the bottom surface of the groove 10 is arc-shaped, it may be a keyhole-shaped groove as shown in Figure 4.

[0029] When the bottom surface of the groove 10 is arc-shaped, T2 is the length from the surface 16 of the flexible portion 3 to the deepest point in the thickness direction of the sheet material of the arc-shaped portion. W1 is the width of the widest part of the groove 10 in the width direction of the sheet material, including the arc-shaped portion.

[0030] [Second sheet forming die] Please refer to Fig. 5. Fig. 5 is an arrow view of the second sheet forming die of the present invention, observed from the sheet material flow direction. In the second sheet forming die, a rectangular hole 11 is formed in the flexible portion 3 in the area between the side plate 9 and the adjustment bolt 5 next to the side plate 9, penetrating from the upstream side to the downstream side in the sheet material flow direction. Although the groove 10 is formed in the first sheet forming die, even if the hole 11 is formed instead of the groove 10, leakage of the sheet material from the side plate 9 and the end surface 14 of the lip 1 is suppressed, as in the first sheet forming die, and the sheet can be stably produced.

[0031] In the second sheet forming die, it is preferable that (T3-T4) / T3 is 0.2 or less, where T3 [mm] is the dimension of the flexible portion 3 in the thickness direction of the sheet material, and T4 [mm] is the dimension of the hole 11 in the thickness direction of the sheet material. The effect of the present invention can be obtained even when (T3-T4) / T3 is greater than 0.2, but by making (T3-T4) / T3 0.2 or less, the difference in rigidity of the flexible portion 3 depending on whether the hole 11 is present or not becomes large, so that the effect of the present invention becomes remarkable. It is more preferable that (T3-T4) / T3 is 0.15 or less. There is no particular limit to the lower limit of (T3-T4) / T3, but if T4 is too large, the rigidity of the flexible portion 3 becomes too low, so in reality, it is preferable that (T3-T4) / T3 is 0.1 or more.

[0032] In the second sheet forming die, it is preferable that W2 / (T3-T4) is 1.0 or more, where T3 [mm] is the thickness dimension of the flexible portion 3, T4 [mm] is the thickness dimension of the flexible portion 11, and W2 [mm] is the width dimension of the flexible portion 11. The effect of the present invention can be obtained even when W2 / (T3-T4) is smaller than 1.0, but by making W2 / (T3-T4) 1.0 or more, the difference in rigidity of the flexible portion 3 depending on whether or not the hole 11 is present becomes large, so that the effect of the present invention becomes more pronounced. It is more preferable that W2 / (T3-T4) is 1.2 or more. There is no particular upper limit for W2 / (T3-T4), but if W2 is too large, the rigidity of the flexible portion 3 becomes too low, so that W2 / (T3-T4) is preferably 2.0 or less in reality.

[0033] Please refer to Fig. 6 and Fig. 7. Fig. 6 is an arrow view of the second sheet forming die having a circular hole, as viewed from the sheet material flow direction. Fig. 7 is an arrow view of the second sheet forming die having an elongated hole, as viewed from the sheet material flow direction. In the second form of the sheet forming die of the present invention, as shown in Fig. 6 and Fig. 7, it is preferable that the hole 11 is circular or elongated in a cross section perpendicular to the sheet material flow direction. The effect of the present invention can be obtained even if the hole 11 is not circular or elongated in a cross section perpendicular to the sheet material flow direction. However, by making the hole 11 circular or elongated, the stress generated at the bottom of the hole 11 is lowered and the plastic deformation of the flexible portion 3 is suppressed, so that the effect of the present invention can be continuously obtained.

[0034] When the hole 11 is circular or elongated, T4 is the length of the longest part in the thickness direction of the sheet material, and W2 is the length of the longest part in the width direction of the sheet material. EXAMPLES

[0035] Examples of sheet manufacturing using the sheet forming die of the present invention are shown below. In Examples 1 to 4, the dimension of the flexible portion in the thickness direction of the sheet material is T1 [mm], the dimension of the groove in the thickness direction of the sheet material is T2 [mm], and the dimension of the groove in the width direction of the sheet material is W1 [mm]. In Examples 5 to 8, the dimension of the flexible portion in the thickness direction of the sheet material is T3 [mm], the dimension of the hole in the thickness direction of the sheet material is T4 [mm], and the dimension of the hole in the width direction of the sheet material is W2 [mm].

[0036] [Example 1] The following describes the results of actually producing a sheet using the first sheet forming die shown in Fig. 1 and evaluating the leakage of the sheet material from the lip end face. The specific specifications of the sheet forming die, the sheet production method, and the leakage evaluation method in this embodiment are as follows. (1)Sheet material: Polypropylene. (2) Extrusion: The sheet material was fed to an extruder set at 190°C, passed through a gear pump and a filter, and then fed to a sheet forming die while increasing the flow rate from 100 to 500 kg / h. (3) Sheet molding die: The discharge width was 900 mm, and the installation interval of the adjustment bolts was 25 mm. A groove 10 was formed in the surface 16 of the flexible section 3, which was pushed and pulled by the adjustment bolt, between the adjustment bolt 5 next to the side plate 9 and the side plate 9, spanning from the upstream end to the downstream end in the sheet material flow direction. T1 was 25 mm, T2 was 16 mm, W1 was 2 mm, (T1-T2) / T1 was 0.36, and W1 / (T1-T2) was 0.22. The bottom surface of the groove 10 was a straight line in a cross section perpendicular to the sheet material flow direction. The force with which the side plate 9 pressed the end surfaces of the pair of lips was 20 MPa. (4) Adjustment bolt operation: From a state in which the dimension of the discharge port in the thickness direction of the sheet material was uniform at 2.0 mm in the width direction of the sheet material, the adjustment bolt 5 next to the side plate 9 was reduced by 0.2 mm. (5) Molding: After being extruded into a sheet from a sheet molding die, it was cooled and solidified in a casting drum and molded. (6) Leakage evaluation: The maximum discharge amount at which no visible leakage of sheet material occurred (hereinafter referred to as the limit discharge amount) was confirmed to be 200 kg / h. This is called condition 1. As condition 2, the limit discharge amount was confirmed again after pushing and pulling the adjustment bolt 5 next to the side plate 9 0.2 mm 200 times, and the result was 150 kg.

[0037] [Example 2] Except for changing T2 to 22 mm, a sheet was produced using a sheet forming die having the same configuration as in Example 1 under the same conditions as in Example 1. (T1-T2) / T1 was 0.12, and W1 / (T1-T2) was 0.67. The maximum discharge rate was 300 kg / h under condition 1 and 200 kg / h under condition 2.

[0038] [Example 3] Except for changing W1 to 4 mm, a sheet was produced under the same conditions as in Example 2 using a sheet forming die having the same configuration as in Example 2. W1 / (T1-T2) was 1.33. The limit discharge rate was 400 kg / h under condition 1 and 250 kg / h under condition 2.

[0039] [Example 4] Except for changing the bottom surface of the groove to have an arc shape in a cross section perpendicular to the flow direction of the sheet material, the same sheet forming die as in Example 3 was used to produce a sheet under the same conditions as in Example 3. That is, a film was produced using the sheet forming die shown in Figure 3. The maximum throughput rate for both conditions 1 and 2 was 400 kg / h.

[0040] [Example 5] A sheet was produced using the second sheet forming die shown in FIG. 5. Specifically, a sheet was produced under the same conditions as in Example 1 using a sheet forming die having the same configuration as in Example 1, except that one hole 11 was formed instead of a groove 10 in the area between the adjustment bolt 5 next to the side plate 9 of the flexible part 3 and the side plate 9. T3 was 25 mm, T4 was 16 mm, W2 was 2 mm, (T3-T4) / T3 was 0.36, and W2 / (T3-T4) was 0.22. The shape of the hole 11 was rectangular in a cross section perpendicular to the sheet material flow direction. The limit discharge rate was 200 kg / h under condition 1 and 150 kg / h under condition 2.

[0041] [Example 6] Except for changing T4 to 22 mm, a sheet was produced under the same conditions as in Example 5 using a sheet forming die having the same configuration as in Example 5. (T3-T4) / T3 was 0.12, and W2 / (T3-T4) was 0.67. The maximum throughput was 300 kg / h under condition 1 and 200 kg / h under condition 2.

[0042] [Example 7] Except for changing W2 to 4 mm, the same sheet forming die as in Example 6 was used to produce a sheet under the same conditions as in Example 6. W2 / (T3-T4) was 1.33. The limit discharge rate was 400 kg / h under condition 1 and 250 kg / h under condition 2.

[0043] [Example 8] Except for changing the hole 11 to have an elongated hole shape in a cross section perpendicular to the flow direction of the sheet material, the same sheet forming die as in Example 7 was used to produce a sheet under the same conditions as in Example 7. That is, a sheet was produced using the sheet forming die shown in Fig. 7. The maximum throughput rate for both conditions 1 and 2 was 400 kg / h.

[0044] [Comparative Example 1] A sheet was produced under the same conditions as in Example 1 using a sheet forming die having the same configuration as in Example 1, except that neither the groove 10 nor the hole 11 was formed in the area between the side plate 9 and the adjustment bolt 5 next to the side plate 9 of the flexible portion 3. The maximum discharge rate in both conditions 1 and 2 was 100 kg / h.

[0045] [Comparative Example 2] Using a sheet forming die having the same configuration as in Comparative Example 1, a sheet was produced under the same conditions as in Comparative Example 1, except that the force with which the side plate 9 pressed the end faces of the pair of lips was changed to 60 MPa. The maximum discharge rate in both Conditions 1 and 2 was 150 kg / h.

[0046] Table 1 shows the configurations of the sheet molding die in Examples 1 to 8 and Comparative Examples 1 and 2, and the sheet formation results.

[0047] [Table 1]

[0048] [Evaluation of Results of Examples and Comparative Examples] In the sheet forming die of Examples 1 to 8, a groove 10 or a hole 11 was formed in the flexible portion 3, so that the rigidity of the flexible portion 3 in the area sandwiched between the adjustment bolt 5 next to the side plate 9 and the side plate 9 was reduced, and the end face 14 of the lip did not tilt even when the adjustment bolt 5 was operated, so that the maximum discharge rate under condition 1 was 200 kg / h or more in all cases.

[0049] For the sheet forming die of Example 2, (T1-T2) / T1 was 0.2 or less, and for the sheet forming die of Example 6, (T3-T4) / T3 was 0.2 or less, so that the limit discharge rate under condition 1 was improved to 300 kg / h.

[0050] For the sheet forming die of Example 3, (T1-T2) / T1 was 0.2 or less, and W1 / (T1-T2) was 1.0 or more, and for the sheet forming die of Example 7, (T3-T4) / T3 was 0.2 or less, and W2 / (T3-T4) was 1.0 or more, so that the limit discharge rate under condition 1 was further improved to 400 kg / h.

[0051] In the sheet forming die of Examples 1 to 3 and 5 to 7, under condition 2 in which the adjustment bolt 5 next to the side plate 9 was pushed and pulled multiple times, excessive stress was generated in the groove 10 or hole 11, causing plastic deformation of the flexible portion 3 and reducing the critical discharge rate. However, since the frequency with which the adjustment bolt 5 next to the side plate 9 is pushed and pulled by 0.2 mm is not high in reality, there is no practical problem even if the critical discharge rate reduces after the adjustment bolt 5 is pushed and pulled by 0.2 mm 200 times.

[0052] On the other hand, in the sheet forming die of Examples 4 and 8, the bottom of the groove 10 is made arc-shaped in the cross section perpendicular to the flow direction of the sheet material, or the hole 11 is made elongated, thereby suppressing excessive stress, and the maximum discharge volume under condition 2 was equivalent to that under condition 1.

[0053] In the sheet molding die of Comparative Example 1, when the adjustment bolt 5 next to the side plate 9 was pushed or pulled, the surface forming the flow path of the flexible part 3 tilted, and due to the rigidity of the flexible part 3 in the area sandwiched between the adjustment bolt 5 and the side plate 9, the end face 14 of the lip also tilted, and the maximum discharge rate was 100 kg / h under both conditions 1 and 2.

[0054] In the sheet forming die of Comparative Example 2, the force with which the side plates 9 pressed the end faces 14 of a pair of lips was increased to 60 MPa in the sheet forming die of Comparative Example 1, but the inclination of the end faces 14 of the lips was not eliminated, and the maximum discharge rate was 150 kg / h under both conditions 1 and 2.

[0055] From the above results, it can be seen that the effect of the sheet forming die configuration of the present invention is significant, even when compared to the leakage countermeasure in general sheet forming die, which is to increase the force pressing against the end faces of a pair of lips by using side plates. [Industrial Applicability]

[0056] According to the present invention, the inclination of the lip end surface is prevented, which suppresses leakage of the sheet material, and the sheet can be stably manufactured. [Explanation of symbols]

[0057] 1 pair of lips 2 Flow Path 3 Flexible part 4 Adjustment bolt 5 Adjustment bolt next to side plate 6 Hexagon Nut 7 Slit 8 Cavity hole 9 Side Panel 10 grooves 11 holes 12 End on the upstream side in the sheet material flow direction 13 Downstream end of sheet material flow direction 14 Lip 1 End Face 15 Surface forming flow path of flexible section 16 Surface that is pushed and pulled by the adjustment bolt of the flexible section

Claims

1. A flow path for discharging the sheet material is formed by a pair of opposing lips and side plates installed at both ends of each of the pair of lips, a portion of at least one of the pair of lips that becomes a discharge port of the flow path is a flexible portion extending in the sheet material width direction, A sheet forming die, in which a plurality of adjustment bolts for pushing and pulling the flexible portion are attached in a line in a width direction of the sheet material, A groove is formed on the surface of the flexible portion that is pushed and pulled by the adjustment bolt in a range between the adjustment bolt adjacent to the side plate and the side plate, the groove extending from the upstream end to the downstream end in the sheet material flow direction; When the dimension of the flexible portion in the thickness direction of the sheet material is T1 [mm] and the depth of the groove in the thickness direction of the sheet material is T2 [mm], (T1-T2) / T1 is 0.2 or less. Sheet forming nozzle.

2. A sheet forming die as claimed in claim 1, wherein when the width direction dimension of the groove in the sheet material is W1 [mm], W1 / (T1-T2) is 1.0 or more.

3. 3. The sheet forming die according to claim 1, wherein the bottom surface of said groove is arcuate in a cross section perpendicular to the flow direction of the sheet material.

4. A flow path for discharging the sheet material is formed by a pair of opposing lips and side plates installed at both ends of each of the pair of lips, a portion of at least one of the pair of lips that becomes a discharge port of the flow path is a flexible portion extending in the sheet material width direction, A sheet forming die, in which a plurality of adjustment bolts for pushing and pulling the flexible portion are arranged in a line in a width direction of the sheet material, A hole is formed in the flexible portion in a range between the side plate and the adjustment bolt adjacent to the side plate, the hole penetrating from the upstream side to the downstream side in the sheet material flow direction, When the dimension of the flexible portion in the sheet material thickness direction is T3 [mm] and the dimension of the hole in the sheet material thickness direction is T4 [mm], (T3-T4) / T3 is 0.2 or less. Sheet forming nozzle.

5. A sheet forming die as claimed in claim 4, wherein when the width direction dimension of the hole in the sheet material is W2 [mm], W2 / (T3-T4) is 1.0 or more.

6. 6. A sheet forming die according to claim 4 or 5, wherein said holes are circular or oblong in cross section perpendicular to the flow direction of the sheet material.

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