JP2018052093A - Method for producing resin molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a resin molding that is capable of laminating a skin material only to a desired region of the surface of a thermoplastic resin sheet.SOLUTION: A method for producing a resin molding 16 includes the steps of: placing a skin material 18 on at least a part of the surface of a cavity 9 of a mold 8; hanging a thermoplastic resin sheet P in a molten state to the side of the cavity 9; clamping the molds 7,8, and face-bonding the skin material 18 to the thermoplastic resin sheet P such that the skin material 18 is laminated on the thermoplastic resin sheet P; and vacuum-suctioning the thermoplastic resin sheet P and the skin material 18 from the cavity 9 side.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing a resin molded product, in which a skin material is laminated and molded on a thermoplastic resin sheet.

  Conventionally, a method is known in which a thermoplastic resin sheet and a decorative sheet (skin material) are bonded and laminated, and a resin molded product is decoratively molded (for example, see Patent Document 1).

  In Patent Document 1, a molten thermoplastic resin sheet is disposed on the side of the cavity so as to protrude around the cavity in a state of being separated from the cavity of the mold, and the disposed thermoplastic resin sheet; In the first sealed space formed in cooperation with the cavity, the decorative sheet held so as to face the thermoplastic resin sheet and protrude from the cavity of the mold in a separated state is heated. The surface of the thermoplastic resin sheet is laminated to be laminated, and the first sealed space is vacuum-sucked from the cavity side so that the surface-bonded thermoplastic resin sheet and the decorative sheet are attached to the cavity. A decorative molding method having a step of pressing and shaping is disclosed.

  However, in Patent Document 1, since the skin material is combined with the plastic resin sheet extruded from the T-die and fed from a pair of rollers and bonded, it can be bonded to other than the desired region, or as a burr after molding There is a problem that the skin material is wasted because a part to be excised is generated.

Japanese Patent Laying-Open No. 2015-104886

  The present invention has been made in view of such circumstances, and its purpose is to form a resin material that can be used to bond a skin material only in a desired region when the skin material is bonded to the surface of a thermoplastic resin sheet. The manufacturing method of goods is provided.

The present invention is grasped by the following composition.
(1) A first aspect according to the present invention is a method for producing a resin molded article, comprising: arranging a skin material on at least a part of a surface of a cavity of a mold; and a molten thermoplastic resin sheet. A step of hanging down to the side of the cavity, a step of clamping the mold, and a surface bonding so as to laminate the skin material on the thermoplastic resin sheet; and the thermoplastic resin sheet and the skin material Vacuum suction from the cavity side.

(2) In the configuration of (1), the skin material has fine through holes, and in the vacuum suction step, the thermoplastic resin sheet is sucked through the through holes.

(3) In the configuration of (2) above, the through hole of the skin material is closed after the vacuum suction step.

(4) In any one configuration of the above (1) to (3), the skin material is composed of a decorative resin layer and a base material layer, and the decorative resin layer is formed on the thermoplastic resin sheet. It is bonded and the base material layer is peeled off.

(5) A second aspect of the present invention is a skin material that is bonded to a thermoplastic resin sheet to form a resin molded product, has a fine through-hole, and is bonded to the thermoplastic resin sheet. After that, the through hole is configured to be closed.

  ADVANTAGE OF THE INVENTION According to this invention, in bonding a skin material on the surface of a thermoplastic resin sheet, the manufacturing method of the resin molded product which can bond a skin material only to a desired area | region can be provided.

It is a whole front view which shows the shaping | molding apparatus which enforces the manufacturing method of the resin molded product which concerns on 1st Embodiment of this invention. FIG. 2 is a cross-sectional view showing a process of arranging a skin material and a thermoplastic resin sheet in a mold in the molding apparatus of FIG. 1. In the molding apparatus of FIG. 1, it is sectional drawing which shows the process of closing between the cavity of a thermoplastic resin sheet and a metal mold | die from the aspect shown in FIG. FIG. 4 is a cross-sectional view showing a process of closing and molding a mold from the embodiment shown in FIG. 3 in the molding apparatus of FIG. It is a perspective view of the front side of the resin molded product shape | molded in the shaping | molding apparatus of FIG. It is a side view of the resin molded product shape | molded in the shaping | molding apparatus of FIG. It is sectional drawing which shows the process which has arrange | positioned a pair of thermoplastic resin sheet and skin material in a metal mold | die in the shaping | molding apparatus which enforces the manufacturing method of the resin molded product which concerns on 2nd Embodiment of this invention. FIG. 8 is a cross-sectional view showing a step of closing a pair of thermoplastic resin sheets and a mold cavity with a mold frame from the embodiment shown in FIG. FIG. 9 is a cross-sectional view showing a process of vacuum-sucking a pair of thermoplastic resin sheets and a skin material from the embodiment shown in FIG. FIG. 10 is a cross-sectional view showing a process of clamping and molding a mold from the embodiment of FIG. 9 in the molding apparatus of FIG. FIG. 11 is a cross-sectional view showing a process of opening a mold and taking out a resin molded product from the embodiment of FIG. 10 in the molding apparatus of FIG. 7.

(Embodiment)
DESCRIPTION OF EMBODIMENTS Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described in detail with reference to the accompanying drawings. The same number is attached | subjected to the same element through the whole description of embodiment.

(First embodiment)
First, with reference to FIG. 1 to FIG. 5, a method for manufacturing a resin molded product 16 according to the first embodiment using a molding apparatus X for a single thermoplastic resin sheet P will be described. As shown in FIG. 1, the molding apparatus X includes an accumulator 1, a plunger 2, a T die 3, an extruder 4, a thermoplastic resin supply hopper 5, a pair of rollers 6 and 6, and a pair of molds 7 and 8. ing. The thermoplastic resin is melted and kneaded by the extruder 4 and then temporarily stored in the accumulator chamber in the accumulator 1 and supplied to the T die 3 by the plunger 2 at regular intervals. Form frames 14 and 15 are located on the outer periphery of the molds 7 and 8, and a slit at the tip of the T die 3 is provided on the T die 3 in order to adjust the thickness of the thermoplastic resin sheet P. A slit clearance adjusting device 19 that adjusts the clearance interval is provided.

Specifically, the extrusion speed is first set by the accumulator 1 and the T die 3. Although the extrusion capability of the extruder 4 connected to the accumulator 1 can be appropriately selected depending on the size of the resin molded product 16, it is preferably 100 Kg / hour or more from the viewpoint of shortening the molding cycle. For this reason, the thermoplastic resin stored in the accumulator 1 of the accumulator 1 is extruded at 50 Kg / hour or more, preferably 60 Kg / hour or more per 1 cm ² from the opening of the slit of the T die 3.

  The thermoplastic resin supplied to the T die 3 is extruded as a thermoplastic resin sheet P from the slit through a resin flow path from a manifold (not shown) of the T die 3 main body. The T die 3 main body is formed by superposing a pair of dies, and one die lip and the other die lip are opposed to each other with a slit gap at the tip portion of the T die 3 main body. Is set. The thickness of the thermoplastic resin sheet P extruded by the slit gap is determined. Specifically, it is extruded from the T die 3 as a thermoplastic resin sheet P having a thickness of 0.6 to 6.0 mm.

  As the slit gap adjusting device 19 of the T-die 3 main body, there is a thermal expansion type or a mechanical type, and it is preferable to use a device having both functions. A plurality of slit gap adjusting devices 19 are arranged at equal intervals along the width direction of the slit, and the slit gap adjusting device 19 narrows or widens the slit gap to thereby increase the thickness of the thermoplastic resin sheet P in the width direction. It should be uniform.

  Specifically, the mechanical adjustment means has a die bolt provided so as to be able to advance and retreat toward one die lip (not shown), and an adjustment shaft is disposed at the tip thereof via a pressure transmission portion. An engagement piece is coupled to the adjustment shaft by a fastening bolt, and the engagement piece is connected to one die lip. When the die bolt is moved forward, the adjustment shaft is pushed out in the distal direction through the pressure transmission portion, and one die lip is pressed. As a result, the die lip is deformed at the portion of the concave groove, and the slit gap is narrowed. To widen the slit gap, the die bolt is moved backward. Furthermore, the slit gap can be adjusted with high accuracy by using a thermal expansion type adjusting means in accordance with the mechanical adjusting means. Specifically, one die lip is pressed by heating the adjustment shaft by an electric heater (not shown) to cause thermal expansion, thereby narrowing the slit gap. In order to widen the slit gap, the electric heater is stopped, and the adjusting shaft is cooled and contracted by a cooling means (not shown).

  The thermoplastic resin sheet P extruded from the opening of the slit of the T-die 3 is sent out while being pinched between a pair of rollers 6 and 6 in order to prevent thickness variation due to drawdown, neck-in, etc. It is.

  The thermoplastic resin sheet P extruded from the opening of the slit of the T-die 3 is preferably an amorphous thermoplastic resin material having high fluidity in order to improve transferability to the mold and followability. Specifically, a melt tension at 230 ° C. (using a melt tension tester manufactured by Toyo Seiki Seisakusho Co., Ltd., a preheating temperature of 230 ° C., an extrusion rate of 5.7 mm / min, and a strand from an orifice of 2.095 mm in diameter and 8 mm in length) Extruded and the strand is wound on a roller having a diameter of 50 mm at a winding speed of 100 rpm. The tension is 50 mN or more, MFR at 200 ° C. (test temperature 200 ° C. according to JIS K-7210, test load 2) The resin material is 3.0 to 60 g / 10 min, more preferably 30 to 50 g / 10 min. For example, acrylonitrile / butadiene / styrene copolymer, polystyrene, high impact polystyrene (HIPS resin), acrylonitrile / styrene copolymer (AS resin) or a mixture thereof can be used.

  As shown in FIG. 2, the molten thermoplastic resin sheet P extruded from the T-die 3 hangs down between a pair of rollers 6 and 6 arranged at intervals. The pair of rollers 6 and 6 can be opened and closed by an opening / closing mechanism (not shown), and the interval between the pair of rollers 6 and 6 can be adjusted by the opening / closing mechanism. The thermoplastic resin sheet P sent out by the pair of rollers 6 and 6 is disposed between the molds 7 and 8. The mold 8 is provided with a cavity 9, and the cavity 9 may have a textured transfer surface to be transferred to the resin molded product 16.

  Here, in the present embodiment, the skin material 18 (decorative sheet or the like for decorating the surface of the thermoplastic resin sheet P or the like) is disposed on at least a part of the surface of the cavity 9. This is for bonding the skin material 18 to a desired region of the thermoplastic resin sheet P. Details of the skin material 18 will be described later.

  Subsequently, as shown in FIG. 3, the molds 14 and 15 positioned on the outer periphery of the molds 7 and 8 are moved forward relative to the molds 7 and 8 so as to be in close contact with the molten thermoplastic resin sheet P. Let The mold 8 is provided with a vacuum suction chamber 10 and a suction hole 11 on the back side of the cavity 9. By vacuum suction from the suction hole 11, the thermoplastic resin sheet P and the skin material 18 are combined into the cavity 9. It is made to adsorb | suck and it is set as the shape which followed the shape of the cavity 9 in general.

  Next, as shown in FIG. 4, the mold is clamped after the thermoplastic resin sheet P is placed along the cavity 9, and the pressurized fluid is introduced into the molds 7 and 8 from the pressure fluid introduction holes 12 provided in the mold 7. The thermoplastic resin sheet P and the skin material 18 are pressed and formed into a shape along the cavity 9. As a result, the skin material 18 is bonded to the surface of the thermoplastic resin sheet P, and the embossed pattern is transferred. Thereafter, the resin molded product 16 cooled in the molds 7 and 8 is completed by opening the molds 7 and 8 and releasing the burrs on the outer periphery.

  The skin material 18 will be described in detail. In FIG. 5, the example of the resin molded product 16 by which the skin material 18 was bonded by the surface 17 is shown. In the present embodiment, as illustrated, the skin material 18 is bonded to a desired region of the resin molded product 16.

  By bonding the skin material 18 to the resin molded product 16, the resin molded product 16 having a multilayer structure made of a plurality of different resins can be obtained. The skin material 18 has an appearance improvement, a decorative property, and a protection function for an object that comes into contact with the molded product. The form of the skin material 18 is a sheet, a film, or the like, and a resin sheet having a printed layer attached to the outer surface, a transparent or colored resin sheet, a synthetic leather, or the like having a thickness of 0.1 to 3.0 mm can be used. In addition, when the thickness of the skin material 18 is too large, it does not follow the mold shape and molding becomes difficult.

  Examples of the material of the skin material 18 include polyester, polypropylene, polyamide, polyurethane, acrylic resin, and thermoplastic elastomer. In the present embodiment, the skin material 18 is placed on the surface of the cavity 9 of the mold 8 in advance as described above in order to adhere the skin material 18 to the surface of the resin molded product 16. As an arrangement method, for example, the skin material 18 can be adhered to the cavity 9 in advance. And the thermoplastic resin sheet P and the skin material 18 can be bonded and integrated by heat welding by vacuum-sucking the thermoplastic resin sheet P from the skin material 18 side. At the same time, the embossed pattern can be transferred to the side of the resin molded product 16 where the skin material 18 is adhered.

  The configuration of the skin material 18 will be described. As shown in FIG. 6, the skin material 18 includes a decorative resin layer 181 and a base material layer 182. The base material layer 182 is attached to the cavity 9, and the decorative resin layer 181 is attached to the thermoplastic resin sheet P. Here, vacuum suction is performed from the side of the skin material 18, but the skin material 18 is a material as described above, and therefore has no air permeability unlike a nonwoven fabric or the like. Therefore, the skin material 18 is provided with a fine through hole 18a in order to suck the skin material 18 and the thermoplastic resin sheet P constantly. Thus, when vacuum suction is performed from the vacuum suction chamber 10 and the suction hole 11 provided on the back side of the cavity 9 of the mold 8, the thermoplastic resin sheet P can be reliably sucked through the through hole 18 a. Here, as will be described later, a crystallization retarder is mixed in the decorative resin layer 181, and even if the through hole 18 a is provided, the through hole 18 a is finally closed and the surface is clean. A resin molded product 16 can be obtained. In addition, the decorative resin layer 181 containing the crystallization retarder can prevent the appearance of the suction holes 11 of the mold 8 from being transferred to the resin molded product 16. In addition, as the base material layer 182, it can select from the material which can be stuck to the thermoplastic resin sheet P, Furthermore, it is preferable that it is the same material. Further, the crystallization retarder only needs to be mixed in at least the decorative resin layer 181, but may be mixed in the base material layer 182.

  As shown in FIG. 6, the base material layer 182 is peeled off after molding. However, if the through hole 18 a remains in the decorative resin layer 181, the aesthetic appearance of the resin molded product 16 is impaired. Therefore, in the present embodiment, the through hole 18a remaining in the decorative resin layer 181 is closed by the following means. For example, when the decorative resin layer 181 is made of polypropylene, by mixing a crystallization retarder, the crystallization temperature is lowered by 10 ° C. or more, and the through hole 18a is closed. When the crystallization retarder is mixed in this way and the melting temperature is lowered, the thermoplastic resin sheet P is sucked through the through holes 18a, and the thermoplastic resin sheet P and the skin material 18 are bonded by thermal welding. After the integration, it is possible to lengthen the melting time of the skin material 18, and the through hole 18a is closed during mold clamping.

  Explaining this ring-closing mechanism, the crystallization temperature of the decorative resin layer 181 decreases due to the mixing of the crystallization retarder. For this reason, even if the molding step proceeds as usual, it is possible to maintain a long time until the skin material 18 is cooled and solidified. While the crystallization is delayed, the decorative resin layer 181 contracts (see the arrow shown in FIG. 6), and acts to close the through hole 18a. As a result, the decorative resin layer 181 is transferred to the thermoplastic resin sheet P without any problem in aesthetic appearance. In addition, since the through hole 18a is fine (for example, about 300 μm), the thermoplastic resin sheet P does not enter the through hole 18a.

  As the crystallization retarder, for example, atactic polypropylene or silicone oil which is a polyolefin resin can be used. Specific examples of silicone oil include dimethylpolysiloxane, monomethylpolysiloxane, methylphenylpolysiloxane, alkyl modified silicone, amino modified silicone, epoxy modified silicone, carboxyl modified silicone, mercapto modified silicone, alkyl higher alcohol modified silicone, alcohol modified silicone. Chloroalkyl-modified silicone, polyether-modified silicone, fluorine-modified silicone, and the like.

  The diameter, the number of arrangement, and the pitch of the through holes 18a of the skin material 18 will be described. Since the through hole 18a of the skin material 18 is set so as to be finally closed as described above, it is generally configured with a smaller diameter than the suction hole 11 of the mold 8 (the skin shown in FIG. 6). (See the positional relationship between the through hole 18a of the material 18 and the suction hole 11 of the mold 8). Since it is difficult to change the suction hole 11 of the mold 8 every time of molding, the diameter, the number of arrangement, and the pitch of the through-holes 18a of the skin material 18 are suitably set for each molding in order to obtain the effect of vacuum suction. Is done. For example, the number of through-holes 18a is increased in order to strengthen the vacuum suction, or the diameter of the through-hole 18a is made to be twice or less the thickness of the decorative resin layer 181 in order to ensure ring closure, In order to prevent the suction holes 11 of the mold 8 from being completely closed, the pitch of the through holes 18a is set to 30 mm or less.

(Second Embodiment)
With reference to FIG. 7 to FIG. 11, a method for manufacturing the resin molded product 16 according to the second embodiment using the molding apparatus Y for the two thermoplastic resin sheets P will be described. As shown in the figure, the molding apparatus Y is for manufacturing a resin molded product 16 using a pair of thermoplastic resin sheets P, P. The accumulator 1, the plunger 2, the T die 3, the extruder 4, Each of the thermoplastic resin supply hopper 5 and the pair of rollers 6 and 6 is disposed separately corresponding to the pair of thermoplastic resin sheets P and P. In addition, the same code | symbol is attached | subjected to the location similar to the structure of 1st Embodiment shown in FIGS. 1-6, and description is abbreviate | omitted.

  In 2nd Embodiment, the resin molded product 16 of a hollow double wall structure is shape | molded similarly to 1st Embodiment with a pair of thermoplastic resin sheet P, P. Here, an example in which the skin material 18, 18 is laminated on the surface of both walls of the resin molded product 16 having a hollow double wall structure is shown. Of course, the skin material 18 is formed only on the surface of one wall. May be laminated. Further, the embossed pattern by the cavity 9 can also be transferred to both or one of the skin materials 18 and 18.

  As mentioned above, although this invention was demonstrated using embodiment and an Example, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. Further, it is apparent from the scope of the claims that embodiments with such changes or improvements can also be included in the technical scope of the present invention. In addition, this embodiment can be applied even if the to-be-polished body S is a molded product by blow molding or a molded product by injection molding.

DESCRIPTION OF SYMBOLS 1 ... Accumulator 2 ... Plunger 3 ... T die 4 ... Extruder 5 ... Thermoplastic resin supply hoppers 6, 6 ... A pair of rollers 7, 8 ... Mold 9 ... Cavity 10 ... Vacuum suction chamber 11 ... Suction hole 12 ... Pressure Fluid introduction holes 14, 15 ... Mold 16 ... Resin molded product 18 ... Skin material 19 ... Slit gap adjusting device P ... Thermoplastic resin sheet

Claims (5)

A method for producing a resin molded product, comprising:
Placing the skin material on at least a portion of the surface of the mold cavity;
Dripping a molten thermoplastic resin sheet to the side of the cavity;
Clamping the mold and bonding the surfaces so that the skin material is laminated on the thermoplastic resin sheet;
A vacuum suction of the thermoplastic resin sheet and the skin material from the cavity side.   The manufacturing method according to claim 1, wherein the skin material has fine through holes, and the thermoplastic resin sheet is sucked through the through holes in the vacuum suction step.   The manufacturing method according to claim 2, wherein the through hole of the skin material is closed after the vacuum suction step.   The said skin material is comprised from the resin layer for decorating and a base material layer, the said resin layer for decorating is bonded by the said thermoplastic resin sheet, The said base material layer is peeled, It is characterized by the above-mentioned. The manufacturing method of any one of 1-3. A skin material that is bonded to a thermoplastic resin sheet to form a resin molded product,
With fine through holes,
A skin material, wherein the through hole is closed after being bonded to the thermoplastic resin sheet.

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