JPH04191021A - Manufacture of molding integrated with sheet - Google Patents

Abstract

PURPOSE:To install a sheet efficiently, easily and securely by using a movable pin, moving forward the sheet almost to a mold parting face at the time of mold opening, moving back the pin by the time of completion of mold closing and storing the pin in a recessed section of a mold. CONSTITUTION:When an area between a fixed side template 7 and a movable side template 8 is opened, a sheet 2' is installed on the movable pin 5 moved forward to the position protruded more than a parting face of the movable side template 8 by utilizing a fixing hold formed preliminarily. The movable pin 5 is moved back to a recessed section of a mold and said sheet is installed on the given position as a sheet 2. The mold is closed simultaneously with or after the backward movement of the movable pin, and a molten, opaque injection molding material is injected into a mold cavity through a sprue 4 and a gate 3, and the sheet 2 is bonded with molten resin onto the section corresponding to the end of a molded product recessed section standing wall 9 corresponding to the periphery of the sheet 2 and integrated. The mold is opened after cooling, and a molded product is ejected by an ejector pin 6 and the desired molded product is thus manufactured.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is suitably used in a method for manufacturing a molded product to which a design such as a character or a mark has been added, and in particular, a desired design part is This makes it possible to apply the coating easily and with high productivity even when the mold has a rather deep recess.

[Conventional technology and its problems]

Designs can be created by attaching a thermoplastic resin sheet or film (hereinafter referred to as a "sheet") with a design in advance to a mold, and integrating it with the film or sheet by injection molding a thermoplastic resin molding material. Methods for manufacturing molded articles by imparting are known.

The methods for attaching this sheet to the mold include the electrostatic method,
There are vacuum adsorption methods, pin fixation methods, magnet methods, etc.

However, with the electrostatic method and vacuum adsorption method, if the mold cavity surface on which the sheet is attached is not smooth and clean, a gap will form between the sheet and the cavity surface, weakening or eliminating the fixing force, and making it difficult to close the mold. Problems such as falling off or misalignment are likely to occur during operation.One way to solve these problems is to optimize the timing of vacuum suction, but this increases the complexity of the mold. In addition, there is a problem in that additional equipment is required and the molding operation itself becomes complicated. In addition, in the case of the pin fixing method, once the device is attached to the pin, there are virtually no problems such as falling off or misalignment. However, in order to fix the bottle, it is necessary to previously form fixing holes or inscriptions on the sheet, and these holes and inscriptions remain on the molded product. Furthermore, if the pin is large or deep, a hole will remain in the molded product, and especially if the molded product is thin, a new problem arises in that it becomes a through hole. Furthermore, in the case of the magnet identification method, it is essential to attach a magnetic metal piece for fixation to the sheet in advance, and since this attached part becomes unusable due to its appearance, a part to be removed is provided. It was necessary to devise ways to attach the molded product, and there were restrictions on the shape of the molded product.

Conventionally, considering the shape of the molded product, etc.
The method used was to attach the sheet by appropriately selecting the best method for each molded product.

However, if the seat is installed in a recessed part of the mold cavity, especially if it is relatively deep or relatively narrow in length and width, none of the above methods can efficiently and easily attach the seat. It was difficult to attach the seat securely.

[Failure to solve the problem]

The inventors of the present invention have arrived at the present invention as a result of intensive studies on methods for solving the above problems.

That is, in the present invention, in the mold cavity recess (a),
A thermoplastic resin sheet (b) shaped into a predetermined shape is attached to a pin (C).
A method for manufacturing a molded article by injection molding a thermoplastic resin molded Hl, the pin (C) being movable,
When the mold is opened, the pin (C) is moved forward until the mold birch ink surface is slightly advanced, and the sheet (b), which forms the attachment part to the pin, is attached to the pin (C) until the mold is closed. This is a method for manufacturing a sheet-integrated molded product, which is characterized in that the sheet is attached to a desired part by retracting the pin (C) and placing it in the recess ta+ of the mold.

The configuration of the present invention will be explained below.

First, the molded product of the present invention is a molded product made by integrating a sheet with a desired design such as letters, marks, or patterns and injection-molded resin on the periphery or the entire surface of the sheet. It is suitably used for manufacturing molded products in which the seat mounting position in the mold cavity is located at the bottom of a relatively deep recess (the bottom of an Al or the bottom of a narrow four part).

Specifically, in an automobile rear finisher (rear decorative plate), a molded product with a width of 250m+++ and a length of 800mm has two grooves parallel to the longitudinal direction, each 30mm wide and 15mm deep.The design is applied to the back side of the groove. A molded product made by integrating sheets printed with: 120 for automotive tachometers
Open in the center of the mm square with a depth of 50 mm [1 part 100 mmφ
, a molded product that integrates a sheet with a dial pattern formed on a convex spherical surface with a bottom diameter of 85 mm and a radius of 300 E; the inner lens of the lamp has a U-shaped spherical convex lens pattern on the entire bottom plate with a width of 800 mm and a length of 250 m + n. The indicator panel has a convex curved surface with a width of 65 m+n, a length of 140 mIIl, and a radius of 200 mm toward the outside, and a groove for displaying the scale (Ii) of 10 mm. ,length】
An example is a molded product that integrates a sheet with a print that makes only the mark part transparent in the groove for displaying the scale of a molded product that has an opening for incorporating a button (40n++n, depth 5 cities) and an opening for incorporating a button. The injection molding material used to form the body of these molded products is E.
VA resin, acrylic resin; polystyrene resin (PS),
Styrene or copolymers using styrene such as Hl-PS, AS, ABS, PET, PBT,
PNT and other saturated polyester resins; polycarbonate resins (PC), polycarbonate resin-based resin compositions (PC/PET, PC/PBT, PC/AS,
polyphenylene ether resin (PPE)-based silk compositions (PPE/PS, PPE/H1-PS, PP)
E/ABS, PPE/PA, PPE/PBT, P
PE/PET.

polysulfone resins, etc.); these include fillers (materials), reinforcing materials, heat stabilizers, ultraviolet absorbers, plasticizers, mold release agents, and other known additives. For example, fillers or reinforcing materials include silica, alumina, titanium oxide, calcium sulfate powder, gypsum, gypsum whiskers, halium sulfate, talc, mica, asbestos, glass peas, glass flakes, and silicic acid. Calcium, carbon black, graphite, iron powder, copper powder, molybdenum disulfide, carbon fiber, silicon carbide, silicon carbide fiber, silicon nitride, silicon nitride fiber, brass fiber, stainless steel fiber, potassium titanate fiber or whisker, aromatic polyamide Examples include fibrous, plate-like, flake-like, or powdery fillers, which are specifically exemplified by fibers.

The thermoplastic resin sheet (b) of the present invention has surface gloss,
It has scratch resistance, ultraviolet resistance, infrared absorption, anti-glare, anti-fogging properties, and other properties, and is appropriately formed with desired designs such as letters, marks, and patterns. In addition, since it is integrated with the injection-molded molten resin, a material is selected that has good adhesion to the resin forming the main body of the molded article and is not deteriorated by the injection-molded molten resin.

Resins for such sheets include polycarbonate resins, polysulfone resins, acrylic resins, and other transparent thermoplastic resins, and usually have a thickness of 0.2 to 1. O
Select from the mrn range. In particular, in the present invention, those made of polycarbonate resin are suitable.

Further, in order to improve the adhesion with the injection molding resin, it is preferable to form an adhesive layer on one side of the thermoplastic resin sheet (b), that is, on the side facing the injection molding resin. For example, when using a polycarbonate resin sheet and using acrylic resin, ABS resin, AS resin, polystyrene resin, etc. as the injection molding material, use a polycarbonate resin sheet with an acrylic resin layer formed; PET, PBT, etc. as the injection molding material. When using polyester resin, use a polycarbonate resin sheet with a non-quality polyester resin layer, which is known for hot melt adhesives; When using other general-purpose resins, use a polycarbonate resin sheet with an EVA resin layer. can be mentioned.

(b) of the present invention has surface gloss, scratch resistance,
It has one or more of the following functions simultaneously: ultraviolet resistance, infrared absorption, anti-glare, anti-fog, photochromic, polarizing, metal plating, and other functions, and if necessary, it also has characters, marks, etc.
It is formed by forming a pattern or other design and cutting it to a predetermined size. In addition, this sheet (b) is formed with holes, crosses, other cuts, combinations thereof, etc. at predetermined positions as attachment parts for attachment to the attachment pins (C) to the mold.

The material for the sheet (b) is polycarbonate resin, polysulfone resin, acrylic resin, or other transparent resin that has heat resistance equal to or higher than that of injection molding resin, and polycarbonate resin is particularly suitable. Also, the thickness is
Usually 0.1 to 2.0 mm, preferably 0.2 to 1.0
If the thickness is selected from the range of mm, and it is integrated only around the resin to be injection molded and the sheet, a relatively thick one is often preferable.

These sheets (b) are cut in advance to a predetermined size for mounting on a mold, and are provided with mounting portions for mounting mold mounting pins as described in detail below. Used in inventions.

The pin (C) of the present invention has the function of attaching the sheet (b) and placing it in a predetermined part of the mold cavity to prevent the sheet from moving from the predetermined position due to the resin flow of the molten resin to be injection molded. It is something that you have.

First, the attachment part for the seat (b) may be similar to the conventionally known seat attachment pins, but it should be attached more securely to prevent the seat (b) from falling or shifting during movement. A shape in which the distal end has a slightly larger diameter than the attachment part is preferably used. In addition, by making the shape of the pin flat, it is possible to prevent the installed seat (b) from becoming erroneous at an angle and becoming difficult to fit in the specified position, but it is possible to prevent such troubles from occurring more reliably. From this point of view it is preferable to use at least two pins (C).

In order to attach the sheet (b), the pin (C1) is advanced to the parting surface of the mold or to a position protruding from it when the mold is opened. The sheet (b) is operated to move backward quickly and fit the sheet (b) into a predetermined position in the mold cavity.Due to the shape of the molded product, if the distance of advance and retreat is too large or if the opening on the parting surface If the area is relatively wide, it is possible to set the forward position to a part that is slightly recessed from the mounting range or the mold padding surface.
) can be performed at the same time as the mold closing operation. 0 This pin advancement/retraction operation can be performed using cylinder drives such as hydraulics, water pressure, or pneumatics, or electric drives using linear motors, motors, electromagnets, etc. , further by utilizing an ejector mechanism used to separate the injection molded article from the mold.

〔Example〕

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

FIG. 1 is a perspective view of an example of the molded product of the present invention, and FIG.
The figure is a cross-sectional view of a mold for explaining the mold for producing the molded product shown in FIG. 1.

In FIG. 1, a molded product 51] has an opaque molten resin for injection molding that is injected into a sprue [4] and a Kate [3].
It is injected through the transparent sheet [2] and integrated within the mold cavity, and the transparent sheet 2 has a meter design printed on it in advance.

The numbers in Figure 2 are 3: Kate, 2.2': Sheet, 4. Sprue, 5: Movable pin, 5゛: Hydraulic cylinder for pin drive, 6. Ejector pin, 7 Fixed side template, 8
: Moving side template, 9: Standing wall of recessed part of molded product, IO birch ink surface is shown.

When the mold is opened, that is, when the space between the stationary template 7 and the movable template 8 is opened, the movable pin 5 is advanced to a position protruding from the parting surface 10 of the movable template 8. To,
Attach the sheet 2 using the pre-formed fixing hole,
Then, the movable pin 5 is retreated to the recessed part of the mold, and the sheet 2 is mounted in a predetermined position. At the same time as or after the movable pin retreats, the mold is closed, and the molten opaque injection molding material is injected into the mold cavity via the sprue 4 and the cage 3, and is applied to the tip of the standing wall 9 of the recessed part of the molded product. The sheet 2 is bonded and integrated with the molten resin at a corresponding portion, that is, a portion corresponding to the periphery of the sheet 2. After cooling for a predetermined period of time, the mold is opened and the molded product is ejected from the mold by an ejector turbine 6 to obtain a desired molded product. By repeating the above-described cycle again, molded products are continuously produced.

The present invention is not limited to the above-described example, but is applicable to various applications as long as the movable pin is used to facilitate sheet identification. It is possible.

[Operation and effects of the invention]

From the above detailed description and examples of the invention, the manufacturing method of the present invention uses a movable pin (C), moves the pin tc+ forward to attach the sheet (b) thereto, and moves the pin (C1 backward). By attaching or fixing the sheet to a desired portion of the mold cavity, it is possible to efficiently attach the desired sheet to the bottom of a relatively deep recess or the narrow four-part bottom of the mold cavity.

Since the method of the present invention has good productivity and workability, it is possible to integrate a sheet with a desired function and design into a molded product in a desired part of the molded product, which was previously difficult to attach to the molded product. Because it enables the production of molded products, it is possible to omit printing, painting, and other post-processing steps, and to provide cheaper and more reliable molded products.Therefore, industrial objections to this are extremely high.

[Brief explanation of drawings]

FIG. 1 is a perspective view of an example of the molded product of the present invention, and FIG.
The figure is a cross-sectional view of a mold for explaining the mold for producing the molded product shown in FIG. 1. The numbers in the figure are 1: molded product, 2, 2' sheet,
3 Gate, 4 Sprue, 5: Movable pin, 5° Hydraulic cylinder for pin drive, 6 Eject turbine, 7 Fixed side template, 8: Moving side template, 9. Standing wall of molded product recess,
10 Shows birch ink surface. . Patent applicant Mitsubishi Gas Chemical Co., Ltd.

Claims (1)

[Claims] A method for manufacturing a molded article, in which a thermoplastic resin sheet (b) having a predetermined shape is mounted in a mold cavity recess (a) with a pin (c), and a thermoplastic resin molding material is injection-molded, the method comprising: (C) is movable, and when the mold is opened, the pin (C) is advanced to at least approximately the mold parting surface, and the sheet (b) is attached to the pin (C) at the attachment part, and when the mold is closed, Retract the pin (c) until it reaches the recess (a) of the mold.
A method for manufacturing a sheet-integrated molded product, characterized in that the sheet is attached to a desired part by fitting the sheet into a molded product.