JP4013410B2 - Manufacturing method of resin panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a resin panel, and more specifically, a film is fixed in a mold and a part thereof is placed in a state in which the end can freely expand and contract, and a molten resin is injected into the mold. The present invention relates to a method for manufacturing a resin panel in which a film is integrally formed on the surface of the resin panel.
[0002]
[Prior art]
Conventionally, glass is generally used as a material for window members in automobiles. However, since glass has a large specific gravity, a resin window made of a resin such as polycarbonate or acrylic is used instead of glass to reduce the weight. . Since the resin window has a softer surface than glass, a resin (polycarbonate) film that has been hard-coated on one side is placed in an injection mold with the hard-coated surface facing the mold wall. A hard coat layer is formed on at least one surface by insert molding in which a molten resin is injected into a mold and integrally molded (for example, Japanese Patent Laid-Open No. 6-170883).
[0003]
The resin film can be formed into a shape that conforms to the shape of the mold wall surface before being placed in the mold, but it requires extra man-hours and is difficult to handle in operations such as hard coat processing. Become. Therefore, except when the product curvature is very large, a flat resin film is placed in the mold without preforming, and the molten resin injected into the cavity presses the resin film against the mold wall surface. A method of forming into a predetermined shape is common. And the upper end of a resin film is fixed, the other part is arrange | positioned in a metal mold | die in a free state, and the method which inject | emits so that molten resin may flow toward the lower side from the upper side of a cavity is implemented.
[0004]
In the film insert method, the larger the product shape and the larger the curvature, the more difficult the film follows the product shape, that is, the shape of the inner surface of the mold. As shown in FIGS. 7 and 8, the film 31 that has not been able to follow the shape of the inner surface of the mold when placed in the cavity 30 of the mold is large in a position far from the gate in the mold. Waves (wrinkles) 32 are generated. In FIG. 7, a gate (not shown) is arranged on the upper side. When the resin is injected in a state where the undulations 32 are large, the undulations are not eliminated, and as shown in FIG. 9, streaks caused by the folding of the film 31 on the product 33 or the wrapping of the resin to the opposite side of the film 31 Defects such as 34 and peeling of the film occur, resulting in product defects. Further, when the film 31 is bent, the hard coat layer may be broken, and the broken portion may remain in the mold. When the next product is manufactured with the hard coat layer debris remaining in the mold, the debris adheres to the next molded product and becomes a defective product up to the next product.
[0005]
As a method for preventing the occurrence of defective products due to such undulations, Japanese Patent Application Laid-Open No. 8-267504 and Japanese Patent Application Laid-Open No. 10-109327 disclose an insert film until a predetermined amount of molten resin is injected into a cavity. Has been disclosed in which a molten resin is injected in a state where wrinkles are prevented from being generated by pressing the mold onto a predetermined position of the mold with a movable member. The movable member retracts out of the cavity until the molten resin is completely injected into the cavity.
[0006]
[Problems to be solved by the invention]
However, the structure in which the film is held at a predetermined position using the movable member as described above has a problem that the structure becomes complicated, the apparatus becomes large, or the control of resin injection becomes complicated. .
[0007]
The present invention has been made in view of the above-mentioned problems, and its purpose is to form a product with a large curvature or mold, such as streaking on the product surface, wrapping around the resin, peeling of the film, etc. with a simple configuration. It is providing the manufacturing method of the resin panel which can prevent generation | occurrence | production.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the film is fixed in a molding die with a part thereof being arranged in a state where the end portion away from the fixing portion is free, and the molten resin is provided. In a resin panel manufacturing method in which a film is integrally formed on the surface of a resin panel body by being injected into a mold, the mold cavity has a portion whose depth is shallower at a portion far from the fixed position of the film. A part of the film is fixed to one of the movable mold and the fixed mold, and the free end of the film fixed to the mold is melted from the gate in a state corresponding to the shallow portion. Inject.
[0009]
According to a second aspect of the present invention, in the first aspect of the present invention, the fixing portion of the film is disposed in the vicinity of the injection port of the gate.
According to a third aspect of the present invention, in the second aspect of the present invention, the film is fixed to the mold at one end, and a portion where the depth of the cavity is shallow is provided on the side opposite to the injection port. ing.
[0010]
According to a fourth aspect of the present invention, in the third aspect of the present invention, the mold is provided such that the movable mold is movable in the horizontal direction, and the film is fixed at the upper end and is cavityd so as to extend in the vertical direction. Placed inside.
[0011]
In invention of Claim 5, in the invention of Claim 3 or Claim 4, the said resin panel is a resin window for motor vehicles.
Therefore, in the invention described in claim 1, the free end of the film fixed in part to the mold is in a state corresponding to the portion where the depth of the cavity becomes shallow, and the free end is small when the film has undulations. Set to be in a wavy state. When molten resin is injected into the cavity from the gate in this state, the waviness at the free end of the film is small, so the film is pressed against the mold wall while being prevented from wrinkles and gaps being generated by the molten resin flow. Attached. As a result, defects such as wrinkles are not generated in the product.
[0012]
According to a second aspect of the present invention, in the first aspect of the present invention, the fixed portion of the film is disposed in the vicinity of the injection port of the gate, and in a portion of the free end of the film far from the injection port of the cavity. The part to be arranged is in a state corresponding to the part where the depth of the cavity is shallow.
[0013]
In the invention according to claim 3, in the invention according to claim 2, since the film is fixed to the mold at one end thereof, the undulation is generated at the end opposite to the fixing portion. However, since the cavity depth is shallow in this part, the waviness is dispersed and the wrinkles of the film on the surface of the injection-molded product even if the distance from the film end away from the injection port is large The defect part is not generated.
[0014]
In the invention of claim 4, in the invention of claim 3, since the film is fixed in the upper end and arranged in the cavity so as to extend in the vertical direction, it is compared with a case where the film is arranged so as to extend horizontally. And it is easy to arrange | position a film in the position along a cavity only by fixing the end of a film.
[0015]
In the invention according to claim 5, in the invention according to claim 3 or claim 4, the yield during production of the resin window for automobiles is improved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a method for manufacturing a resin window of an automobile will be described with reference to FIGS. As shown in FIG. 1 (a), the mold includes a fixed mold 1 and a movable mold 2, and the movable mold 2 is formed to be movable in the horizontal direction. The fixed mold 1 sucks the gate 3, two or more (four in FIG. 2) locking pins 5 as locking portions for locking one end of the insert film 4, and the upper end of the film 4. A suction hole 6 (shown only in FIG. 2A) is provided. As shown in FIGS. 2 (a) and 2 (b), the locking pin 5 protrudes on both the left and right sides of the injection port 3 a of the gate 3. A plurality of suction holes 6 are provided around the locking pin 5 so that negative pressure acts from a negative pressure source (not shown).
[0017]
Recesses 1 a and 2 a for forming a cavity 7 are formed on the opposing surfaces of the fixed mold 1 and the movable mold 2. When the fixed mold 1 is viewed from the movable mold 2 side, the shape of the cavity 7 corresponds to the attachment portion 4a of the film 4 on the upper side of the portion corresponding to the shape of the substantially rectangular molded product as shown in FIG. The shape to be bulged is formed. Moreover, when cut along a horizontal plane, as shown in FIG. 3, it is formed in an arc shape that is convex toward the fixed mold 1 side.
[0018]
The cavities 7 are not all formed at the same depth, but have a predetermined width so that the end far from the injection port 3a, in this embodiment, the lower end is along the side. This portion (the main portion 7a) is formed shallower and constitutes a wrinkle dispersion portion 7b. The wrinkle dispersion portion 7b is formed so as to smoothly continue to the main portion 7a.
[0019]
For example, when the size of the product is 500 mm × 800 mm and the depth of the main portion is 5 mm, the depth of the wrinkle dispersion portion 7b is formed to be 4 mm or less. Moreover, the width | variety of the wrinkle dispersion | distribution part 7b should just be several mm or more.
[0020]
The film 4 set in the mold is formed in a shape corresponding to the cavity 7 as shown by a chain line in FIG. 2A, and the hole 4b into which the locking pin 5 is inserted into the mounting portion 4a. And a hole 4c formed at a position corresponding to the injection port 3a and larger than the injection port 3a. The film 4 is hard-coated on one side. In this embodiment, polycarbonate is used as the film material.
[0021]
Next, the procedure and operation when a resin window is molded using the mold formed as described above will be described.
First, with the movable mold 2 moved to the open position, the film 4 is positioned on the locking pin 5 with the hard coat processing surface facing the fixed mold 1. Then, a suction action is exerted on the suction hole 6 from the negative pressure source, and the film 4 is fixed to the fixed mold 1 at the mounting portion 4a. Since the cavity 7 is formed so as to extend in the vertical direction, the film 4 is arranged along the cavity 7 by its own weight. In this state, the movable mold 2 is closed, and a part of the film 4 is sandwiched between the fixed mold 1 and the movable mold 2. When the curvature of the molded product is large, a portion far from the attachment portion 4a of the film 4 is wavy.
[0022]
Next, molten resin (polycarbonate) is injected from the gate 3 into the cavity 7. When the molten resin is injected into the cavity 7, the film 4 expands due to the heat. The molten resin then flows in the cavity 7 while pressing the film 4 against the wall surface of the fixed mold 1 sequentially toward the side away from the injection port 3a and downward.
[0023]
When the molded product is large, the absolute amount of elongation due to the thermal expansion of the film 4 becomes large, and the film 4 becomes loose in the cavity 7. Then, the slack is sequentially pushed toward the free end side of the film 4 by the flow of the molten resin, and the free end side is wavy. 4A shows a schematic cross-sectional view cut at a position corresponding to the wrinkle dispersion portion 7b, and FIG. 4B shows the case where the cavity 7 has a constant depth without the wrinkle dispersion portion 7b. And a corresponding schematic cross-sectional view. As shown in FIG. 4 (b), when there is no wrinkle dispersion 7b, the cavity 7 is deep, so that the waviness 8 of the film 4 becomes large. When the molten resin reaches the undulation portion in a state where the undulation 8 is large in this way, it becomes difficult for the molten resin to uniformly press the undulation portion against the wall surface of the fixed mold 1. As a result, as shown in FIG. 4C, the molded product 9 has a wrinkle 10 at a position corresponding to the top of the corrugation 8, the film 4 is bent, or a gap remains, resulting in a defective product. It becomes.
[0024]
However, in this embodiment, there is a wrinkle dispersion portion 7b shallower than the main portion 7a at the end of the cavity 7, so that there is no large undulation and there are many small undulations 8 as shown in FIG. A state, that is, a state where large undulations are dispersed. When the undulation 8 is small, that is, when the wave height is low, the film 4 is uniformly spread and pressed against the mold surface when the molten resin moves while pressing the undulation portion, and the film 9 is applied to the molded product 9. It is possible to prevent the occurrence of wrinkles, bends or gaps.
[0025]
After the injection of the predetermined amount of molten resin is completed and the mold is cooled, the molded product is taken out from the mold, the mounting portion 4a is removed, and the molded product (resin window) 9 is completed. As shown in FIG. 5, the molded product 9 is formed in a state in which the film 4 is integrally formed on the surface of the panel body 9a.
[0026]
This embodiment has the following effects.
(1) A wrinkle dispersion portion 7b having a shallower depth than the main portion 7a of the cavity 7 is provided at a portion of the cavity 7 far from the injection port 3a of the mold gate 3, and a part of the film 4 is placed on the mold at the injection port 3a. The molten resin is injected from the gate 3 in a state where the free end of the film 4 fixed to the mold and the free end of the film 4 fixed to the mold corresponds to the wrinkle dispersion portion 7b. Accordingly, when undulation occurs due to the curvature of the cavity 7 or the expansion of the molten resin due to the heat, the undulation is dispersed into the small undulations 8 without generating a large undulation, and a wrinkle, a bend or a gap of the film 4 occurs in the molded product 9. Is prevented.
[0027]
(2) The film 4 is fixed by the locking pin 5 and the suction hole 6 at the attachment portion 4a. By removing the attachment portion 4a, the trace and the injection port 3a do not remain in the product.
[0028]
(3) The mold is provided so that the movable mold 2 can be moved in the horizontal direction, and the film 4 is fixed in the mold at the upper end and disposed in the cavity 7 so as to extend in the vertical direction. Therefore, as compared with the case where the film 4 is disposed so as to extend horizontally, the film 4 can be easily disposed at a position along the cavity 7 only by fixing one end of the film 4, and the setting of the film 4 is simplified.
[0029]
(4) Since the panel main body 9a and the film 4 are both formed of the same material, the adhesion at the interface is improved as compared with the case where the panel main body 9a and the film 4 are formed of different materials.
[0030]
(5) Since polycarbonate is used for the material of the panel main body 9a and the film 4, a material conventionally used as a resin window of an automobile can be used as it is, and a necessary function as a resin window can be secured.
[0031]
(6) Since the wrinkle dispersion portion 7b can be configured only by partially changing the shapes of the concave portions 1a and 2a of the fixed mold 1 and the movable mold 2 constituting the cavity 7, the configuration is simple.
[0032]
The embodiment is not limited to the above, and may be embodied as follows, for example.
○ The shape of the wrinkle dispersion portion 7b is not limited to the configuration in which the end portion of the cavity 7 is formed shallower than the main portion 7a, but has a function of suppressing the height of the undulation generated on the free end side of the film 4 and dispersing it to a small undulation. As shown in FIG. 6A, the end of the cavity 7 may be substantially the same depth as the main portion 7a, and the depth of the cavity 7 in a portion slightly inside from the end may be made shallower. Further, as shown in FIG. 6B, the width W of the shallow portion may be narrowed. In the case of FIG. 6B, the width W of the protrusion 11 protruding into the cavity 7 may be 5 mm or more, and the distance L between the protrusion 11 and the end of the cavity 7 may be 1 mm or more.
[0033]
O Instead of fixing the film 4 to the fixed mold 1, the film 4 may be fixed to the movable mold 2. In that case, the shape of the cavity 7 is convex toward the movable mold 2, and the film 4 is disposed so that the hard coat treatment surface faces the wall surface of the movable mold 2.
[0034]
○ When the film 4 is fixed to the mold, the suction action from the suction hole 6 is eliminated, the positioning by the locking pin 5, and the portion closer to the end of the film 4 than the locking pin 5 is movable with the fixed mold 1. It is good also as a structure only clamped with the metal mold | die 2. FIG. In this case, a negative pressure source becomes unnecessary, and the configuration becomes simpler. Further, only positioning by the locking pin 5 and suction by the suction hole 6 may be used.
[0035]
The mold may have a configuration in which the movable mold 2 moves in the vertical direction, that is, a configuration in which the cavity 7 extends horizontally.
O It may apply not only to the resin window for motor vehicles but to other resin panels, such as a resin window for building windows, a partition, or a panel for decoration. In this case, the hard coat process on one side of the film 4 may be omitted. That is, the film 4 is not limited to the one that is subjected to a hard coat treatment and is intended to cure the surface, but may be, for example, intended for decoration (patterning), and its purpose is particularly limited. is not.
[0036]
The film 4 does not necessarily have to be fixed in the vicinity of the injection port 3a of the gate 3. For example, when the molded product is relatively small or the like, and the absolute amount that is extended by the thermal expansion of the film is small, the fixing position can be one end of the film and the injection port can be near the center of the film.
[0037]
○ Even when the film 4 must be fixed in the vicinity of the injection port 3a of the gate 3, if it is not a transparent resin panel, the position of the injection port 3a is not the position facing the end of the molded product, but the center. You may arrange | position in the position which opposes. In this case, it is preferable to use a suction hole for fixing the film 4.
[0038]
Inventions (technical ideas) other than the claims that can be grasped from the embodiment will be described together with the effects thereof.
(1) A resin panel in which a film is integrally formed on the surface of a resin panel body, which is formed in a substantially rectangular shape, and a thickness corresponding to one side of the end portion or the vicinity of the end portion has a predetermined width. Resin panel that is thinner than other parts. In this case, the waviness of the film does not increase at the time of injection molding, and it is possible to prevent the film from being wrinkled, bent or formed with a gap.
[0039]
(2) In the invention according to claim 4, both the panel body and the film are made of polycarbonate. In this case, a material conventionally used as a resin window of an automobile can be used as it is, and a necessary function as a resin window can be secured.
[0040]
【The invention's effect】
As described above in detail, according to the first to fifth aspects of the invention, in film insert molding of a product with a large curvature or mold, a streak on the product surface, wraparound of the resin, and peeling of the film with a simple configuration Etc. can be prevented.
[0041]
According to the third aspect of the present invention, the attachment portion of the film is fixed near the injection port, and the film is positioned outside the product, so that the fixing mark and the injection port are not easily left in the product. .
[0042]
According to the fourth aspect of the present invention, compared to the case where the film is arranged to extend horizontally, the film can be easily arranged at a position along the cavity by simply fixing one end of the film, and the setting of the film is simple. become.
[0043]
According to the fifth aspect of the present invention, the yield during production is improved as a resin window for automobiles.
[Brief description of the drawings]
1A is a schematic cross-sectional view of a state in which a film is set on a mold according to an embodiment, and FIG. 1B is a partially enlarged view thereof.
2A is a schematic front view of a cavity portion of a fixed mold, and FIG. 2B is a schematic partial cross-sectional view showing a state where a film mounting portion is sandwiched between a fixed mold and a movable mold.
FIG. 3 is a schematic cross-sectional view of a state in which the mold is cut horizontally above the wrinkle dispersion portion.
4A is a schematic cross-sectional view showing a wavy state of a film at a wrinkle dispersion portion, FIG. 4B is a schematic cross-sectional view showing a wavy state without a wrinkle dispersion portion, and FIG. 4C is a wrinkle approach. FIG. 3 is a partial schematic cross-sectional view of a molded product in which a film is integrally molded in a state where
FIG. 5 is a partial schematic cross-sectional view of a molded product.
6A and 6B are schematic partial cross-sectional views showing the shapes of cavities in different embodiments, respectively.
FIG. 7 is a schematic front view showing a state of occurrence of undulations.
8 is a cross-sectional view taken along line VIII-VIII in FIG.
FIG. 9 is a perspective view of a molded product in which defects such as wrinkles are generated.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fixed metal mold, 2 ... Movable metal mold, 3 ... Gate, 3a ... Injection port, 4 ... Film, 7 ... Cavity, 7b ... Wrinkle dispersion | distribution part, 9 ... Molded article, 9a ... Panel main body.

Claims (5)

A part of the film is fixed in the molding die and the end away from the fixing point is placed in a free state, and the molten resin is injected into the die to put the film on the surface of the resin panel body. In the manufacturing method of the resin panel to be integrally molded
The cavity of the mold is provided with a portion whose depth is shallow at a portion far from the fixed position of the film, and a part of the film is fixed to one of the movable mold and the fixed mold and fixed to the mold. And a method of manufacturing a resin panel in which a molten resin is injected from a gate in a state where a free end of the film corresponds to a portion where the depth becomes shallow. The method for producing a resin panel according to claim 1, wherein the fixed portion of the film is disposed in the vicinity of the injection port of the gate. The method for producing a resin panel according to claim 2, wherein the film is fixed to the mold at one end, and a portion where the depth of the cavity is shallow is provided on the side opposite to the injection port. 4. The method of manufacturing a resin panel according to claim 3, wherein the mold is provided such that a movable mold is movable in the horizontal direction, and the film is fixed in an upper end and disposed in the cavity so as to extend in the vertical direction. The method for producing a resin panel according to claim 3 or 4, wherein the resin panel is a resin window for an automobile.

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