JP3898566B2 - Injection molding simultaneous decoration method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a simultaneous injection molding decoration method in which a decorative sheet is laminated and decorated simultaneously with the molding of a resin molded product. 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.
[0002]
[Prior art]
Conventionally, various types of injection molding simultaneous decoration methods (see Japanese Examined Patent Publication No. 50-19132, etc.) in which a decorative sheet is used to decorate a resin molded product by providing a pattern or the like on its outer surface It is done in 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.
[0003]
[Problems to be solved by the invention]
By the way, in the injection molding simultaneous decoration method (injection molding simultaneous lamination decoration method) in a form using a laminate type decorative sheet, depending on the mode (construction method), the resin is solidified at the time of mold opening after resin injection. The finished product (decorative molded product) 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. The runner portion 11 located at a position away from the bridge is also formed as an integral unit by being bridged by the decorative sheet S between them.
[0004]
Then, as shown in FIG. 5, the product part 12 and the runner part 11 are taken out from the mold by being ejected by 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.
[0005]
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. Defects sometimes occurred.
FIG. 6 is a conceptual diagram conceptually showing this situation, and shows a state in which the ejector pins 1 and 2 for runners and products protrude. In FIG. 6, the upper half of the drawing shows the case of “NG” in which molding failure e has occurred, and the lower half of the drawing also shows the case of “OK” in which molding failure does not occur so that the comparison is easy for convenience. Shown simultaneously on one mold. 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.
[0006]
Accordingly, an object of the present invention is to provide a decorative sheet in which a runner part and a product part are ejected by an ejector pin and released from an ejector pin in the injection molding simultaneous decorating method. However, it is to be pulled by the protrusion of the runner portion and not peeled off from the surface of the resin molded product.
[0007]
[Means for Solving the Problems]
Therefore, in order to solve the above problems, in the injection molding simultaneous decorating method of the present invention, after inserting a decorative sheet between a pair of male and female molds in the mold open state, both molds are clamped, Injecting and filling the fluidized resin into the cavity formed by solidifying by solidification and decorating the surface of the resin molding with a decorative sheet simultaneously with injection molding to obtain a decorative molded product In the method, the runner ejector pin that projects the runner portion from the mold is ejected later than the product ejector pin that projects the product portion from the mold, so that the runner portion is released later than the product portion.
[0008]
By adopting the injection molding simultaneous decorating method with such a configuration, there is a time difference between the protrusion of the runner part and the protrusion of the product part, and the runner part is separated from the mold later than the product part. The peeling of the decorative sheet laminated on the surface of the resin molded product in the product portion can be avoided. 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.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the injection molding simultaneous decorating method of the present invention will be described with reference to the drawings.
[0010]
First, FIG. 1 is explanatory drawing explaining the timing of the protrusion by the ejector pin of a runner part and a product part in the injection molding simultaneous decorating method of this 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. Therefore, for example, the cavity surface portion of the parting line PL of the illustrated mold may be usually a convex shape in the product portion in the injection molding simultaneous decorating method, but the runner portion is also a product in the drawing. It is drawn as a straight line (plane) including the part. Moreover, illustration of the runner part which is a resin solidified material, a product part, and a decorating sheet is abbreviate | omitted.
[0011]
First, FIG. 1 (A) before ejection will be described. 1A, the runner ejector pin 1 and the product ejector pin 2 provided on the fixed die 26 are positioned in a state where their tip portions face the parting line PL. 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.
[0012]
On the other hand, the lower end 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 is provided with a timing block 6 that fits in the opening at a portion corresponding to the opening. 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.
[0013]
Next, FIG. 1 (B) shows a state where 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.
[0014]
FIG. 1C shows a state in which the runner ejector pin 1 also moves behind the protrusion of the product ejector pin 2 and protrudes the runner portion. As the ejector plate 3 further moves forward from the state of FIG. 1 (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 The 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. Since the gap between the intermediate fixing plate 7 and the ejector plate 3 is larger than the gap between the runner-dedicated plate 8 and the timing block 6, the ejector plate is further removed from the intermediate state shown in FIG. When the 3 moves in the protruding direction, the movement is restricted by the intermediate fixing plate 7 and the runner ejector pin 1 and the product ejector pin 2 do not protrude sufficiently.
[0015]
In the above-described simultaneous injection molding decorating method of the present invention, the product ejector pin 2 is placed on the ejector plate 3 as a method of slowly projecting the runner ejector pin 1 with respect to the runner portion with respect to the product ejector pin 2. The runner ejector pin 1 is connected to the runner dedicated plate 8, and the runner dedicated plate is attached to the ejector plate 3, and is provided with a gap from the runner dedicated plate 8. This is performed by indirectly driving and protruding through the timing block 6.
[0016]
As described above, the runner portion is separated from the mold later than the product portion by providing a time difference between the runner portion ejection timing and the product portion ejection timing. 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.
[0017]
And, as a result of the above, even if the runner part is on the parting line where the decorative sheet is inserted, the runner part is connected with the decorative sheet when the mold is opened, In the process of ejecting the runner part and the product part by the ejector pin, it is possible to avoid the molding defect in which the decorative sheet laminated and adhered to the surface of the resin molded product in the product part peels off.
[0018]
The specific method for providing a time difference in the protrusion described with reference to the conceptual diagram of FIG. 1 and the mechanism thereof are examples of the present invention, and the method for providing a time difference in the protrusion is another method. It may be. 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. In FIG. 1, a drive cylinder is used as a drive source for the ejector pin. However, 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.
[0019]
The injection molding simultaneous decorating method of the present invention is the same as that described above except that there is a time difference between the ejection of the ejector pins for the runner and the product. Various forms of decoration methods can be taken as appropriate.
[0020]
For example, the form which performs the preforming of a decorating sheet or the form which does not perform may be sufficient. Further, the decorative sheet may or may not be preheated. Note that the decorative sheet is usually preheated at the time of preforming.
[0021]
Needless to say, when the decorative sheet has a large aperture, it is preferable to perform preforming. 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.
[0022]
Next, among the above, in particular, one form of in-line pre-molding in which the injection mold is also used as the pre-mold is outlined with reference to the cross-sectional views of FIGS.
[0023]
First, FIG. 2 shows a movable mold 21 serving as an injection mold that also serves as a preforming mold for a decorative sheet. Therefore, the movable die 21 is provided with a suction hole 23 that opens to the parting line PL around the cavity surface 22 so that it can be preformed by vacuum forming. The movable mold 21 is a female mold. 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.
[0024]
Next, as shown in FIG. 3, the heater 25 is inserted between the molds from the retracted position outside the mold, the decorative sheet S fixed to the movable mold 21 is heated and softened, and vacuuming V is performed from the suction hole 23. And vacuum forming. 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.
[0025]
Next, as shown in FIG. 4, the heater 25 is retracted to the outside of the mold (not shown), and then the movable mold 21 that is a female mold and the fixed mold 26 that is a male mold are clamped and softened by heating. If the molding resin R in a fluid state is injected and filled, the surface of the resin molded product is decorated with a decorative sheet simultaneously with the injection molding to obtain a decorative molded product. 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 excess brim-like decorative sheet around the decorative molded product slips out of the sheet clamp frame due to its flexibility, and the decorative molded product (with brim) remains on the fixed mold side. Excess brim can be trimmed after taking out the decorative molded product.
[0026]
In the case where the injection mold is not preformed (offline preforming or no preforming), the sealing of the cavity is unnecessary, and thus the sheet clamp as described above can be omitted.
[0027]
[Others]
In addition, what is necessary is just to use a conventionally well-known decorating sheet suitably as a decorating sheet to be used in the injection molding simultaneous decorating method of this invention according to a use. Similarly for the molding resin to be a resin molded product, a conventionally known molding resin may be appropriately used according to the application.
[0028]
Note that the decorative sheet used in the injection molding simultaneous decorating method of the present invention is a laminating type, but the laminate type here is a decorative sheet comprising at least a base sheet and a decorating sheet including the base sheet. It is a decorative sheet in which a decorative sheet is laminated on a resin molded product. In addition, the decorative sheet including the base sheet is laminated on the surface side so that a release sheet such as a protective sheet can be peeled off. Even if it is a laminate-type decorative sheet that peels the release sheet and laminates the decorative sheet containing the remaining base material sheet on the surface of the resin molded product as the final decorative molded product good. 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.
[0029]
In addition, “decoration” as used in the present invention refers to an invisible pattern, a hard coating film, a conductor layer, a magnetic layer, in addition to simply giving a visible pattern such as a pattern, character, or figure to a molded product. It also includes providing a functional layer such as a body layer. 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 heat-melted thermoplastic resin such as ABS resin or polypropylene, and a thermosetting (or two-component reaction curing) resin such as a two-component curable urethane resin or an epoxy resin. A known material made of a cured liquid or the like is used.
[0030]
【Example】
Next, the present invention will be described in further detail with reference to examples.
[0031]
〔Example〕
First, as described with reference to FIGS. 2 to 4, a decorative sheet S printed and decorated on a thermoplastic resin sheet was preformed in the form of in-line preforming in which an injection mold is also used as a preforming mold. Next, the mold was clamped, and a thermoplastic resin was injection molded as a molding resin in the cavity.
[0032]
Next, after the mold was opened, the runner ejector pin 1 was protruded later than the product ejector pin 2 by the mechanism described in FIG. 1, and the runner part and the product part were released from the fixed mold. The product ejector pin 2 starts to protrude when the runner ejector pin 1 moves and protrudes 1 mm. 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.
[0033]
【The invention's effect】
According to the injection molding simultaneous decorating method of the present invention, the runner portion protrudes from the mold later than the product portion and is separated from the molding die, so that the decoration is laminated and adhered to the surface of the resin molding in the product portion. Sheet peeling can be avoided. 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 illustrating, in one form, an 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 is a cross-sectional view conceptually illustrating a state (NG and OK) after ejection by an ejector pin.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ejector pin for runners 2 Ejector pin for products 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 type e Defective part (sheet peeling)
PL Parting line R Molding resin S Decorative sheet V Vacuum drawing

Claims (1)

After inserting the decorative sheet between the pair of male and female molds in the mold open state, both molds are clamped, and the resin in the fluid state is injected into the cavity formed by both molds and filled to solidify. In the simultaneous injection molding method of decorating the surface of the resin molding with a decorative sheet simultaneously with injection molding to obtain a decorative molded product,
An injection molding simultaneous decorating method, wherein a runner ejector pin for projecting a runner part from a mold is ejected later than a product ejector pin for projecting a product part from the mold, whereby the runner part is released later than the product part.

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