JP2969929B2 - Manufacturing method of sheet integrated molded product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is suitably used for a method of manufacturing a molded article provided with a design such as a character or a mark.
Even when the desired design providing portion is a slightly deep concave portion of the mold, it is possible to easily provide the product with high productivity.

[Conventional technology and its problems]

A thermoplastic resin sheet or film (hereinafter referred to as a "sheet") provided with a design in advance is mounted on a mold, and a thermoplastic resin molding material is injection-molded to be integrated with the film or sheet. There is known a method for producing a molded article by imparting the same.

As a method of mounting this sheet on a mold, there are an electrostatic method, a vacuum suction method, a pin fixing method, a magnet method, and the like.

However, in the electrostatic method or the vacuum suction method, if the mold cavity surface on which the sheet is mounted is not smooth and clean, a gap is formed between the sheet and the cavity surface, and the fixing force is weakened or lost, and the mold is closed. Problems such as dropping out during operation and misalignment are likely to occur, and there is a method of solving these problems by optimizing the timing of vacuum suction, but the mold becomes complicated, In addition, there is a problem that the auxiliary equipment is required and the molding operation itself is complicated. Further, in the case of the pin fixing method, there is substantially no problem such as dropping or displacement when the pin is once mounted. However, in order to fix the pins, it is necessary to previously form fixing holes and cutouts on the sheet, and these holes and cutouts remain in the molded product. Further, when the pin is large or deep, a hole remains in the molded product, and in particular, when the thickness of the molded product is small, a new problem arises that the hole becomes a through hole. Furthermore, in the case of the magnet fixing method, it is essential to mount a magnetic metal piece or the like for fixing on the sheet in advance, and since this mounting portion becomes unusable in appearance, a portion to be cut is provided. It is indispensable to devise such methods as mounting the product, and the shape of the molded product is limited.

As mentioned above, conventionally, in consideration of the shape of the molded product,
A method of appropriately selecting the best method according to each molded article and mounting a sheet has been used.

However, in the case where the mounting portion of the sheet is a concave portion of the mold cavity, particularly a portion that is relatively deep or a portion having a relatively small width and width, in any of the above-described methods, efficiently and easily and reliably. It was difficult to attach the seat.

[Means for solving the problem]

The present inventors have conducted intensive studies on a method for solving the above-described problem, and as a result, have reached the present invention.

That is, the present invention provides a mold cavity recess (a).
A method of manufacturing a molded article by mounting a thermoplastic resin sheet (b) having a predetermined shape with a pin (c) and injection molding a thermoplastic resin molding material, wherein the pin (c) is made movable, At the time of opening the mold, the pin (c) is advanced to at least substantially the mold parting surface, and the sheet (b) having a mounting portion for the pin is mounted on the pin (c). A method for manufacturing a sheet-integrated molded product, wherein (c) is retracted and set in a concave portion (a) of a mold to attach a sheet to a desired portion.

 Hereinafter, the configuration of the present invention will be described.

First, the molded product of the present invention is a molded product obtained by integrating a sheet formed with a desired design such as characters, marks, and patterns with an injection-molded resin at a peripheral portion or the entire surface of the sheet. It is suitably used for manufacturing a molded product in which the sheet mounting position in the mold cavity is located at the bottom of the relatively deep recess (a) or at the bottom of the narrow recess (a).

Specifically, the width of a car rear finisher (rear plaque) is 250 mm wide, 800 mm long, and parallel to the length direction.
A molded product obtained by integrating a sheet with a design printed on the back of a groove of a molded product having two grooves of 30 mm and a depth of 15 mm: an opening in a tachometer for an automobile with a depth of 50 mm at the center of a 120 mm square. Molded product that integrates a sheet with a dial pattern formed on a convex spherical surface with a radius of 300 mm and a convex spherical surface with a diameter of 100 mm φ and a bottom of 85 mm φ :; A molded product having a sheet with a blur pattern formed on the back surface of the molded product: a 65 mm-wide, 140 mm-long panel with a radius of 200 mm facing outward on the indicator panel, and a groove for scale display (10 mm wide) , 140mm in length, 5mm in depth) and a molded product that integrates a sheet with a mark-printed light-transmitting sheet in the groove for scale indication of a molded product that has an opening for incorporating a button, etc. You.

Injection molding materials for forming these molded product bodies include:
EVA resin; acrylic resin; polystyrene resin (PS), HI
-Styrene such as PS, AS and ABS or copolymers using styrene; PET, PBT, PNT and other saturated polyester resins; polycarbonate resin (PC), polycarbonate resin-based resin compositions (PC / PET, PC / PBT, PC / AS, PC / ABS, blends of these with elastomers, etc.); polyphenylene ether resin (PPE) based compositions (PPE / PS, PPE / HI-
PS, PPE / ABS, PPE / PA, PPE / PBT, PPE / PET, blends of these with elastomers, etc.); polysulfone resins, etc., which are fillers (materials), reinforcing materials, heat stabilizers ,
Known additives such as an ultraviolet absorber, a plasticizer, and a release agent are appropriately compounded. For example, as a filler or a reinforcing material, silica, alumina, titanium oxide, calcium sulfate powder, gypsum, gypsum whisker , Barium sulfate, talc, mica, asbestos, glass beads, glass flakes, calcium silicate, carbon black, graphite, iron powder, copper powder, molybdenum disulfide, carbon fiber, silicon carbide, silicon carbide fiber, silicon nitride, silicon nitride fiber Fibrous, plate-like, flake-like or powder-like fillers specifically exemplified by brass fibers, stainless steel fibers, potassium titanate fibers or whiskers, aromatic polyamide fibers and the like.

With the thermoplastic resin sheet (b) of the present invention, surface gloss, scratch resistance, ultraviolet resistance, infrared absorption, anti-glare properties,
It has anti-fogging property and other properties, and suitably forms desired designs such as characters, marks and patterns. In addition, a resin that is integrated with the injection-molded molten resin, has good adhesion to the resin used as the molded article main body, and does not deteriorate due to the injection-molded molten resin is selected.

Examples of the resin for such a sheet include a polycarbonate resin, a polysulfone resin, an acrylic resin, and other transparent thermoplastic resins, and are usually selected from a thickness of 0.2 to 1.0 mm. Particularly, in the present invention, those made of a polycarbonate resin are preferable.

Further, it is preferable to form an adhesive layer on one surface of the thermoplastic resin sheet (b), that is, the surface on the side of the injection molding resin, in order to improve the adhesiveness with the resin for injection molding.
For example, when using an acrylic resin, ABS resin, AS resin, polystyrene resin, etc. as an injection molding material using a polycarbonate resin sheet, a polycarbonate resin sheet having an acrylic resin layer formed thereon; PET, PBT, etc. as an injection molding material When using a polyester resin, a polycarbonate resin sheet having an amorphous polyester resin layer known for hot-melt bonding; when using other general-purpose resins, a polycarbonate resin sheet having an EVA resin layer formed Is mentioned.

The sheet (b) of the present invention has surface glossiness, scratch resistance,
UV resistance, infrared absorption, anti-glare, anti-fogging, photochromic, polarizing, metal plating, other functions at the same time or two or more at the same time.
A pattern or other design is formed and cut into a predetermined size. In addition, this sheet (b) has a mounting portion for mounting to the mounting pin (c) to the mold.
Holes, crosses and other cuts, a combination thereof, and the like are formed at predetermined positions.

The sheet (b) is made of polycarbonate resin,
Polysulfone resin, acrylic resin, other transparent and has heat resistance equal to or higher than that of resin for injection molding,
Particularly, a polycarbonate resin is preferable. In addition, the thickness is usually selected from the range of 0.1 to 2.0 mm, preferably 0.2 to 1.0 mm, and when integrated only around the resin and the sheet to be injection-molded, a relatively thick one is often preferable. Things.

These sheets (b) are cut into a predetermined size in advance for mounting the mold, and the sheet (b) is formed as a mounting section for mounting the pins for mounting the mold as described in detail below. Used in the invention.

The pin (c) of the present invention has a function of mounting the sheet (b), holding the sheet (b) in a predetermined portion of the mold cavity, and preventing the sheet from moving from a predetermined position due to the resin flow of the molten resin to be injection molded. Have

First, the seat (b) mounting portion may be the same as a conventionally known seat mounting pin. However, the seat (b) is mounted more firmly so that the sheet (b) does not drop or shift during movement. It is preferable to use a shape in which the tip portion has a slightly larger diameter than the mounting portion. In addition, it is possible to prevent the seat (b) mounted from being out of order and becoming difficult to fit in a predetermined position by flattening the shape of the pin or the like, but it is possible to more reliably prevent such a trouble from occurring. From a viewpoint, it is preferable to use at least two pins (c).

When the mold is opened, the pin (c) is advanced to about the parting surface of the mold or to a position protruding therefrom for mounting the sheet (b). The sheet (b) is retracted slightly earlier and put into operation at a predetermined position in the mold cavity. If the distance between the forward and backward movements is too large or the opening on the parting surface is relatively large due to the shape of the molded product, the range where the forward movement position can be mounted is slightly retracted from the mold padding surface. The retracting operation of the pin (c) can be performed simultaneously with the mold closing operation. The hydraulic movement, hydraulic pressure,
It is performed by cylinder driving such as air pressure, electric driving using a linear motor, a motor, an electromagnet or the like, and further using an ejector mechanism used for separating an injection molded product from a mold.

〔Example〕

 Next, embodiments will be described with reference to the accompanying drawings of the present invention.

FIG. 1 is a perspective view of an example of the molded article of the present invention, and FIG. 2 is a cross-sectional view of the mold for explaining a mold for manufacturing the molded article of FIG.

In FIG. 1, a molded article [1] has an injected opaque molten resin for injection molding injected through a sprue [4] and a gate [3], and a periphery of a transparent sheet [2] and a mold cavity. The meter design is printed on the transparent sheet 2 in advance.

The numbers in FIG. 2 are respectively 3: gate, 2, 2 ': seat, 4: sprue, 5: movable pin, 5': pin driving hydraulic cylinder, 6: ejector pin, 7: fixed side template, 8 : Moving side template, 9: standing wall of molded product dent, 10: parting surface.

When the mold is opened, that is, when the space between the fixed mold plate 7 and the movable mold plate 8 is opened, the movable pin 5 advanced to a position protruding from the parting surface 10 of the movable mold plate 8. To
The sheet 2 'is mounted using the fixing holes formed in advance.
Next, the movable pin 5 is retracted to the concave portion of the mold to obtain the sheet 2 mounted at a predetermined position. The mold is closed at the same time as or after the retracting operation of the movable pin, and the molten opaque injection molding material is injected into the mold cavity through the sprue 4 and the gate 3, and corresponds to the tip of the wall 9 of the recessed portion of the molded product. The sheet 2 is bonded to the molten resin at a portion corresponding to the periphery of the sheet 2, that is, a portion corresponding to the periphery of the sheet 2, and integrated. After cooling for a predetermined time, the mold is opened, and the molded article is projected from the mold with the ejector pin 6 to obtain a desired molded article. By repeating the above-mentioned cycle again, a molded article is manufactured continuously.

The present invention is described by taking the above-described example as an example. However, the present invention is not limited to this example, and various applications can be made as long as it is easy to fix the sheet using movable pins. It is possible.

[Action and Effect of the Invention]

From the above detailed description and Examples, the manufacturing method of the present invention uses the movable pin (c), advances the pin (c), attaches the sheet (b) to the movable pin (c), and removes the pin (c). By retreating and mounting or governing a sheet at a desired portion of the mold cavity, a desired sheet can be efficiently mounted at the bottom of a relatively deep recess or a narrow recess in the vertical cavity.

Since the method of the present invention has good productivity and workability, a molded product in which a sheet having a desired function and design is integrated with a desired portion of the molded product, which was conventionally difficult in terms of sheet mounting. Printing,
The present invention can provide a more inexpensive and highly reliable molded product by omitting painting and other post-treatment steps, and its industrial objection is extremely high.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an example of a molded article of the present invention, and FIG.
The figure is a sectional view of a mold for explaining a mold for producing the molded article of FIG. The numbers in the figure are 1: molded product, 2, 2 ': sheet, 3:
Gate, 4: Sprue, 5: Movable pin, 5 ': Hydraulic cylinder for driving pin, 6: Ejector pin, 7: Fixed-side template, 8: Moving-side template, 9: Molded product recessed wall, 10: Show the parting surface.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 45/00-45/84

Claims (1)

(57) [Claims] 1. A method of manufacturing a molded article, comprising: mounting a thermoplastic resin sheet (b) having a predetermined shape in a mold cavity recess (a) with a pin (c); and injection-molding a thermoplastic resin molding material. The pin (c) is made movable, and when the mold is opened, the pin (c) is advanced to at least substantially the mold parting surface, and the sheet (b) is mounted on the pin (c) at the mounting portion. A method of manufacturing a sheet-integrated molded product, wherein the pin (c) is retracted by the time the mold is completely closed and is seated in a desired portion by fitting the pin (c) into the concave portion (a) of the mold.