JP2003326568A - Method for in-mold decorating injection-molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a decorative sheet laminate-bonded to the surface of a product from being released from the surface of the product by a pulling action caused following the ejection of a runner part, in ejecting a runner and the product from a mold respectively by ejector pins, in a method for in-mold decorating injection-molding. <P>SOLUTION: In obtaining a decorative molded product by clamping a mold, then injecting a fluidal resin into a cavity and hardening it after inserting the decorative sheet into between a pair of male/female molds and decorating the surface of a resin molded product with the decorative sheet simultaneously with injection molding, the runner part is released later than the product part by ejecting the ejector pin 1 for the runner which ejects the runner part from a mold later than the ejector pin 2 for the product which ejects the product part from the mold after opening the mold. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a method of laminating a decorative sheet on the surface of a resin molded product and decorating it simultaneously.
The present invention relates to a method of simultaneous injection molding. In particular, the present invention relates to an injection molding simultaneous decorating method in which a decorating sheet is also adhered to a runner portion during molding. 2. Description of the Related Art Conventionally, an injection molding simultaneous decorating method (Japanese Patent Publication No. 50-19132) using a decorative sheet and decorating a resin molded product by providing a pattern or the like on its outer surface. Publications and the like) are performed in various modes. In addition, the decorative sheet used in the simultaneous injection molding method includes a transfer type and a laminate type. Compared with the transfer type, the laminate type laminates the base sheet of the decorative sheet on the surface of the resin molding. Therefore, it is easy to impart surface strength and a feeling of painting to the decorative molded product. By the way, in the injection molding simultaneous decorating method (injection molding simultaneous lamination decorating method) using a laminate type decorative sheet, depending on the mode (construction method), a resin may be used. At the time of mold opening after injection, the product (decorated molded product) obtained by solidifying the resin and the runner are connected by a decorative sheet inserted on the same parting line as the runner. This state is shown in the conceptual diagram of FIG. That is, the decorative sheet S is laminated and bonded to the product part 12 and the runner part 11 in the fixed mold 26 that is a male mold, and the product part 12 is opened by the decorative sheet S when the mold is opened. Runner part 1 located away from
No. 1 also becomes an integrated object that is bridged and connected by the decorative sheet S between them. Then, as shown in FIG.
The runner portion 11 is removed from the mold by protruding with an ejector pin. The product portion 12 protrudes from the product ejector pin 2 and the runner portion 11 protrudes from the runner ejector pin 1. However, when the runner part is released before the product part, the product part is pulled by the decorative sheet connected to the runner part, and the decorative sheet laminated on the product surface peels off from the end of the product. In some cases, molding defects occur. FIG. 6 is a conceptual diagram conceptually showing this situation. The ejector pins 1 and 2 for runners and products are used.
It is a figure of the state which protruded. In FIG. 6, the upper half of the drawing shows the case of “NG” in which a molding defect e has occurred, and the lower half of the drawing is designed to prevent a molding defect from occurring.
“K” is also shown on one mold at the same time for easy comparison. As shown in the figure, the decorative sheet S laminated on the outer surface of the resin molded product in the product portion 12 is peeled off at the end portion of the product. Accordingly, the object of the present invention is to laminate and bond the runner part and the product part to the surface of the resin molded product at the product part when the runner part and the product part are ejected with an ejector pin in the injection molding simultaneous decorating method. It is to prevent the decorative sheet from being pulled off from the surface of the resin molding by being pulled by the protrusion of the runner portion. Accordingly, in order to solve the above-described problems, in the simultaneous injection molding decorative method of the present invention, a decorative sheet is inserted between a pair of male and female molds in an open state. After that, both molds are clamped, the resin in a fluid state is injected into the cavity formed by both molds, filled and solidified, and the surface of the resin molding is decorated with a decorative sheet simultaneously with the injection molding. In the injection molding simultaneous decorating method to obtain a decorative molded product, the runner ejector pin that projects the runner part out of the mold is ejected later than the product ejector pin that projects the product part out of the mold. I was going to release later. By adopting the injection molding simultaneous decorating method having such a configuration, a time difference is provided between the timing of protrusion of the runner portion and the protrusion of the product portion, and the runner portion is separated from the mold later than the product portion. Therefore, it is possible to avoid peeling of the decorative sheet laminated on the surface of the resin molded product in the product portion. As a result, it is possible to avoid molding defects due to peeling of the decorative sheet when the runner portion and the product portion are projected. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of an injection molding simultaneous decorating method according to the present invention will be described below with reference to the drawings. First, FIG. 1 is an explanatory view for explaining the timing of protrusion of a runner part and a product part by an ejector pin in the injection molding simultaneous decorating method of the present invention. FIG. 1A shows a state before ejection, FIG. 1B shows a state in which the product ejector pin 2 is projected first, and FIG. 1C shows a state in which the runner ejector pin 1 is subsequently projected. FIG. 1 is a diagram for explaining the concept of operating the ejector pin with a time difference that the timing protrudes later than the product portion of the runner portion. In order to make the operation of this time difference easy to understand. In addition, the specific structure and operation mechanism around the ejector pin, the mold structure, and the like can be appropriately simplified by adopting a conventionally known structure and operation mechanism depending on the shape and size of the molded product. It is explanatory drawing drawn in abbreviated form. Thus, for example, the parting line PL of the illustrated mold
In the injection molding simultaneous decorating method, the cavity surface portion is usually a convex shape in the product portion, but is drawn as a straight line (plane) including the runner portion and the product portion in the drawing. Moreover, illustration of the runner part which is a resin solidified material, a product part, and a decoration sheet is abbreviate | omitted. First, FIG. 1 (A) before ejection will be described. In the state before ejection in FIG.
The runner ejector pin 1 and the product ejector pin 2 provided at 6 have their respective ends at the parting line P.
It is located in a state facing L. The lower end of the product ejector pin 2 is connected to the ejector plate 3. The ejector plate 3 is provided with a drive cylinder 4 by hydraulic pressure, pneumatic pressure or the like that performs an expansion / contraction operation with respect to the fixed mounting plate 5, and the ejector plate 3 protrudes the ejector pins 1 and 2 by the drive cylinder 4. It is installed to move freely in the direction. On the other hand, the lower end portion of the runner ejector pin 1 is connected to the runner dedicated plate 8. The runner dedicated plate 8 is pushed downward (rightward in the drawing) by the spring 9, but the lower position is restricted by the intermediate fixing plate 6 that is fixed in position. An opening is provided in a portion of the runner dedicated plate 8 corresponding to the lower end of the runner ejector pin 1. Further, the ejector plate 3 described above has a portion corresponding to the opening,
A timing block 6 that fits in the opening is attached.
There is a gap between the tip of the timing block 6 and the back surface of the runner dedicated plate 8, and this gap causes a time difference in the protrusion of the ejector pin 1 for the runner relative to the protrusion of the ejector pin 2 for the product. Let That is, as the ejector plate 3 moves, the timing block 6 comes into contact with the runner dedicated plate 8, and then the runner ejector pin 1 starts to move and protrudes the runner. After the protrusion, the runner ejector pin 1 is pushed by the spring 9 and returns to the original position as the ejector plate 3 moves backward. Next, FIG. 1B shows a state in which the product ejector pin 2 protrudes first. In this state, as the ejector plate 3 moves forward (toward the left side of the drawing) by driving the drive cylinder, the product ejector pin 2 connected to the ejector plate projects to project the product portion. At the stage shown in the figure, the tip of the timing block 6 is still in contact with the bottom surface of the runner dedicated plate 8, and the runner ejector pin 1 is not moved through the runner dedicated plate 8. FIG. 1C shows a state in which the runner ejector pin 1 also moves behind the projection of the product ejector pin 2 and projects the runner portion. FIG.
As the ejector plate 3 further moves forward from the state of (B), the tip of the timing block 6 attached to the ejector plate 3 comes into contact with the back surface of the runner-dedicated plate 8, and the runner-dedicated plate 8 is moved in the protruding direction. As a result, the runner ejector pin 1 connected to the runner dedicated plate 8 moves in the protruding direction, and the runner portion is protruded. The gap between the intermediate fixing plate 7 and the ejector plate 3 is the runner dedicated plate 8 and the timing block 6.
When the ejector plate 3 further moves in the protruding direction from the intermediate state shown in FIG. 1 (B), the movement is restricted by the intermediate fixing plate 7 and is used for the runner. The ejection of the ejector pin 1 and the product ejector pin 2 is not insufficient. In the above-described injection molding simultaneous decorating method of the present invention, the product ejector pin 2 is an ejector as a method of projecting the runner ejector pin 1 for the runner portion slowly with respect to the product ejector pin 2. The runner ejector pin 1 is connected to the plate 3 and directly protruded, and the runner ejector pin 1 is connected to the runner dedicated plate 8, and the runner dedicated plate is connected to the ejector plate 3.
The runner-dedicated plate 8 is provided by being indirectly driven and protruded through a timing block 6 provided with a gap. As described above, the runner portion can be separated from the mold later than the product portion by providing a time difference between the protrusion timing of the runner portion and the protrusion timing of the product portion. On the other hand, at the timing of the time difference such that the product part moves away from the mold later than the runner part, the decorative sheet laminated and adhered to the resin molded product surface at the product part is pulled in a direction that makes it easier to peel off. It will be quite counterproductive. And as a result of the above, even if the runner portion is connected to the runner portion by the decorative sheet when the mold is opened in the mold having the runner portion on the parting line into which the decorative sheet is inserted, In the subsequent process of ejecting the runner part and the product part by the ejector pins, it is possible to avoid a molding defect in which the decorative sheet laminated and bonded to the surface of the resin molded product in the product part peels off. The specific method for providing a time difference in the protrusion and the mechanism thereof described with reference to the conceptual diagram of FIG. 1 is an example of the present invention. Other methods may be used. For example, the runner ejector pin 1 and the product ejector pin 2 are driven by their own drive cylinders, and are driven completely independently to provide a time difference in the drive itself of each drive cylinder. May be realized. Moreover, in FIG. 1, as a drive source of an ejector pin,
Although a drive cylinder is used, other known ejector pin drive sources such as a mold opening force may be used.
The ejector pin drive mechanism or the like may be a known ejector pin drive mechanism as appropriate. The injection molding simultaneous decorating method of the present invention is
As described above, except for providing a time difference between the ejector pins for the runner and the product,
Various forms of a conventionally known simultaneous injection molding decorating method can be taken as appropriate. For example, the decorative sheet may be preformed or not preliminarily formed. Further, the decorative sheet may or may not be preheated. In addition,
At the time of preforming, the decorative sheet is usually preheated. Of course, it is preferable to perform pre-forming when the decorative sheet has a large aperture. On the other hand, when the decoration sheet has a small aperture, the decoration sheet may be formed with the resin pressure of the injected resin in a fluid state. At this time, if the squeezing is shallow, the decorative sheet may be molded by the heat and filling pressure of the injection resin in a fluid state filled in the mold at the same time as the resin injection without preforming. In addition, the preforming of the decorative sheet can be performed by using an injection molding die that is also used as a vacuum molding die (inline pre-molding), before the decorative sheet is supplied between the molds. Preliminary molding (offline preliminary molding) in which the decorative sheet is vacuum-molded with a vacuum mold may be used. However, the pre-molding is preferably performed in the form of using both an injection mold and a vacuum mold because the decorative sheet can be laminated efficiently and accurately. However, when the preformed decorative sheet is manufactured in advance in another place, the preforming is preferably in the form of off-line preforming. In the description of the present invention, vacuum forming includes vacuum / pressure forming. Next, among the above, in particular, one embodiment of in-line pre-molding in which an injection mold is also used as a pre-mold is outlined with reference to the cross-sectional views of FIGS. First, FIG. 2 shows a movable mold 21 serving as an injection mold that also serves as a preforming mold for a decorative sheet. Accordingly, the movable mold 21 has a parting line P around the cavity surface 22 so that it can be preformed by vacuum forming.
A suction hole 23 opened to L is provided. This movable type 21
Is female. The decorative sheet S is pressed and fixed to the movable mold 21 by the sheet clamp 24 so that the air in the space sealed by the decorative sheet S and the movable mold 21 does not leak. Next, as shown in FIG. 3, the heater 25 is inserted between the molds from the retreat position outside the mold, the decorative sheet S fixed to the movable mold 21 is heated and softened, and the vacuum is drawn from the suction hole 23. Perform V and vacuum form. As a result, the decorative sheet S is formed into a shape that follows the shape of the cavity surface 22 of the movable mold 21. Next, as shown in FIG. 4, after the heater 25 is retracted outside the mold (not shown), the movable mold 2 is a female mold.
1 and the fixed mold 26, which is a male mold, are clamped and heated to soften the molding resin R, which is made into a fluid state, is injected and filled to decorate the surface of the resin molding simultaneously with the injection molding. A decorative molded product is obtained by decorating with a sheet. In addition, a sheet clamp will be in a half open state before mold opening, and a decorating sheet will be in a free state from a movable mold | type. And at the time of mold opening, the extra brim-like decorative sheet around the decorative molded product comes out of the sheet clamp frame due to its flexibility, (with brim)
The decorative molded product remains on the fixed mold side. Excess brim can be trimmed after taking out the decorative molded product. If the injection mold is not preformed (no off-line preforming or preforming), it is not necessary to seal the cavity, so that the sheet clamp as described above can be omitted. [Others] In the injection molding simultaneous decorating method of the present invention, as the decorative sheet to be used, a conventionally known decorative sheet may be appropriately used depending on the application. In addition, for the molding resin to be a resin molded product,
A conventionally known molding resin may be appropriately used depending on the application. The decorative sheet used in the injection molding simultaneous decorating method of the present invention is a laminating type. The laminate type here is a decorative sheet comprising at least a base sheet, and this base sheet. Is a decorative sheet such that a decorative sheet containing a laminate is laminated on a resin molded product. In addition, the decorative sheet including the base material sheet has a configuration in which a release sheet such as a protective sheet is laminated on the surface side so as to be peelable,
After laminating this decorative sheet on the surface of the resin molded product, the release sheet used as a protective sheet or the like is peeled off, and the decorative sheet including the remaining base sheet is laminated on the surface of the resin molded product. It may be a laminate-type decorative sheet as a decorative molded product. This decorative sheet is a transfer type in that the release sheet is peeled off, but it is thicker than a thin transfer layer formed by printing or coating in a so-called general transfer sheet. This is because it can be regarded as a laminate type. The term “decoration” as used in the present invention refers to an invisible pattern, a hard coating film, a conductor, or the like, in addition to simply giving a visible pattern such as a pattern, character, or figure to a molded product. It also includes providing functional layers such as layers and magnetic layers.
Therefore, a sheet having such a layer is used as the decorative sheet depending on the purpose. The visible pattern is, for example, a pattern layer formed by printing, a metal thin film layer formed by vacuum deposition, etc. Examples include a pattern printed with emitted fluorescent ink, a bar code printed with infrared absorbing ink, and the like. In addition, the resin in a fluid state to be injected is A
A heat-melted thermoplastic resin such as a BS resin or polypropylene, or a known one made of an uncured liquid material such as a two-component curable urethane resin or a thermosetting (or two-component reaction curable) resin such as an epoxy resin. Used. Next, the present invention will be described in more detail with reference to examples. [Embodiment] First, as described with reference to FIGS. 2 to 4, a decorative sheet S printed and decorated on a thermoplastic resin sheet in the form of in-line pre-molding in which an injection mold is also used as a pre-mold. Pre-formed. Next, the mold was clamped, and a thermoplastic resin was injection molded as a molding resin in the cavity. Next, after the mold is opened, the runner ejector pin 1 is ejected later than the product ejector pin 2 by the mechanism as shown in FIG. 1, and the runner portion and the product portion are separated from the fixed die. . In addition, the ejector pin 2 for the product is moved by the ejector pin 1 for the runner 1
At the time of projecting mm, it started to project. As a result, the runner portion is not removed from the mold earlier than the product portion, and the decorative sheet on the surface of the decorative molded product is not peeled off. According to the injection molding simultaneous decorating method of the present invention, the runner part protrudes from the mold later than the product part and is separated from the mold, so that the resin molding in the product part is performed. It becomes possible to avoid peeling of the decorative sheet laminated and adhered to the object surface. As a result, it is possible to avoid molding defects due to peeling of the decorative sheet when the runner portion and the product portion are projected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram conceptually explaining in one form the injection molding simultaneous decorating method of the present invention. FIG. 2 is a sectional view conceptually illustrating an embodiment in which an injection mold is also used as a preforming mold (part 1). FIG. 3 is a sectional view conceptually illustrating a mode example in which an injection mold is also used as a preforming mold (part 2). FIG. 4 is a sectional view conceptually illustrating an embodiment in which an injection mold is also used as a preforming mold (No. 3). FIG. 5 is a sectional view conceptually illustrating a state after the mold is opened and before being ejected by an ejector pin. FIG. 6 shows a state after ejecting with an ejector pin (NG
And OK is a cross-sectional view for conceptually explaining. [Description of Symbols] 1 Ejector pin for runner 2 Ejector pin for product 3 Ejector plate 4 Drive cylinder 5 Fixed mold mounting plate 6 Timing block 7 Intermediate fixed plate 8 Runner dedicated plate 9 Spring 11 Runner portion 12 Product portion 21 Movable die 22 Cavity Surface 23 Suction hole 24 Sheet clamp 25 Heater 26 Fixed mold e Defective part (sheet peeling) PL Parting line R Molding resin S Decorating sheet V Vacuum drawing

Claims (1)

[Claim 1] Between a pair of male and female molds in an open state,
After inserting the decorative sheet, both molds are clamped, the resin in the fluid state is injected into the cavities formed by both molds, filled and solidified, and the surface of the resin molding is decorated at the same time as injection molding In the injection molding simultaneous decorating method to obtain a decorative molded product by decorating with a sheet, the runner ejector pin that projects the runner part from the mold is ejected later than the product ejector pin that projects the product part from the mold. An injection molding simultaneous decorating method in which the runner part is released later than the product part.