JPS62108019A - Method and apparatus for molding multi-color synthetic resin molding and product thereof - Google Patents

Abstract

PURPOSE:To obtain synthetic resin moldings having integrally combined different color portions and other portions without delamination at low cost on a mass- production basis by a method in which decorating layers in the first and second cavities are transferred to the synthetic resin molding and at the same time both the synthetic resins are integrally hot-bonded to each other. CONSTITUTION:A synthetic resin 29 melted in the first cavity 28 is injected and packed from the first gate 20 through the first path 22, whereby a film 24 in the cavity 28 is transferred to a decorating layer 27. A synthetic resin 31 tinted with a different color, having compatibility with the resin 29, is injected into the second cavity 30 through the second path 23 and the second gate 21. Whereupon, the resin 31 and the resin 29 are completely hot-bonded to each other and at the same time the decorating layer 27 in the cavity 30 is transferred to the resin 31. A multi-color synthetic resin molding can thus be obtained with good efficiency by only one cycle process without the needs for opening the molds on the way by using a single mold.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for molding a multi-colored synthetic resin molded product, a molding device, and a molded product thereof, and more specifically,
The present invention relates to a method and apparatus for obtaining a molded article with a different appearance by combining synthetic resins colored in different colors, and a molded article having partially different colors.

(Conventional technology) Multi-colored molded products mainly have the advantage of improving decorative effects, and are used in daily necessities such as cosmetic containers and exterior panels of various devices. The so-called double rotational molding method is known. The former involves inserting a part previously formed by injection molding into a mold, and then injecting a synthetic resin colored in a different color from that of the part to integrally mold it, but this method is only inefficient. However, since the injected resin shrinks and inserts parts that have already shrunk, the molded product often warps or cracks, so it cannot be applied to molded products with extremely limited shapes. There were drawbacks. The latter method was proposed to overcome these drawbacks, and uses a two-part injection molding machine to inject resin from one injection tube into the cavity space in the mold to form the primary molded product. Then, leave this in either the core mold or the cavity mold of the rigging mold and release the other mold, and then combine the remaining mold of the molded product with another cavity mold or core mold and combine it with the molded product. The secondary molding part is integrally molded by injecting resins of different colors from the other injection tube into the space defined between them, but since it requires multiple molds, Problems were pointed out such as high cost and low productivity due to the two-cycle molding process in which the mold is opened once midway through.

In addition, it is widely used to apply patterns, etc. to the surface of molded products using a transfer film, and in this case, the transfer film is placed in the mold in advance, and the transfer film is transferred using the heat and pressure of the resin during injection molding. It is easy to do. however,
Conventionally, this method was limited to cases where the resin was monochromatic, and could not be applied to the above-mentioned molding method for multi-colored products. So, above
In order to apply a pattern or the like to the multicolored molded product obtained by the method (e), secondary processing after molding is required, which is extremely complicated.

(Problems to be solved by the invention) The present invention has been made in view of the above-mentioned circumstances.
The purpose is to efficiently and beautifully injection mold multi-colored synthetic resin molded products of a desired shape in one cycle using a single mold, and to transfer patterns etc. from a transfer film at the same time as injection molding. methods and devices that can be used;
In addition to having a pattern transferred from the transfer film during injection molding on the surface, the desired part is formed in a different color, and the different color part and other parts are completely integrated, so there is no risk of peeling etc. To provide a multicolored synthetic resin molded product that can be mass-produced at low cost.

(Means for solving the problems) In order to achieve the above object, the molding method according to the present invention includes:
A mold having a core mold and a cavity mold, a sliding block disposed inside either the core mold or the cavity mold, and first and second openings communicating with an injection molding machine. A transfer film having a decorative layer is placed between the core mold and the cavity mold, and then the mold is closed to define a first cavity and tee space, into which molten resin is injected from the first opening. to transfer the decorative layer in the first cavity space.
, then 1r i) Slide the J block to the first
defining a second cavity space connected to the cavity space of the synthetic resin, and injecting a synthetic resin that is compatible with the synthetic resin and colored in a different color from a second sprue into the second cavity space. The molding apparatus according to the present invention is characterized in that the decorative layer in the second cavity space is transferred and both synthetic resins are integrally welded. an injection mold having a means for supplying a transfer film between the core mold and the cavity mold; A sliding block is arranged between a first position in contact with the other and a second position spaced apart from the other through a driving means, and when the sliding block is in the first position, the two positions are defined. First
a first cavity opening into the cavity space; and a first cavity defined by being closed when the sliding block is in the first position and connected to the first cavity space when the sliding block is slid to the second position. and a second sprue opening to the second cavity space, and the first and second sprues are each connected to injection means for synthetic resin colored in different colors. be. Furthermore, the synthetic resin multicolored molded article according to the present invention has a main body portion formed of a synthetic resin injected from a first sprue within a first cavity space defined in an injection mold. , in a second cavity space defined by sliding of a sliding block disposed in the mold and connected to the first cavity space, a mold that is compatible with the synthetic resin and has a different color. It consists of a different color part formed by injecting colored synthetic resin from the second opening, and the main body part and the different color part are integrally welded together during molding of the different color part, and the main body part and the different color part are It has a decorative layer on its surface that is transferred from a single transfer film during each injection molding process.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the illustrated embodiment, the shape of the molded product is a flat U-shape, but the present invention is not limited to this, and can of course be applied to molded products of any shape.

FIG. 1 shows a mold of a molding apparatus according to an embodiment of the present invention. This mold 1 has a cavity mold 2 and a core mold 3, and the lower peripheral edge of the core mold 3 has a molded product. A stripper plate 4 for releasing the mold is attached, and a runner mold 6 for attachment to an injection molding machine (not shown) is disposed above the core mold 3 via a receiving part 5. A sliding block 8 is placed in the space 7 formed by passing the core mold 3 and the receiving part 5 through.
is arranged, and this block 8 is slidable in the vertical direction in the figure via a drive means.

In FIG. 1, this block 8 is at the lower limit position (first position), and in this state, the flange 10 of the block 8 fitted into the recess 9 of the receiving part 5 is in contact with the upper surface of the core mold 3. The lower end of the block 8 protrudes from the lower surface of the core mold 3 by an amount approximately corresponding to the thickness J9 of the molded product, and a gap 12 is defined between it and the runner mold 6 by the protrusion.

The driving means of the block 8 in this embodiment is of the core type 3
It consists of a slide rod 14 that fits into a groove 13 formed on the top surface, and a piston member 15 that reciprocates the slide rod in the left-right direction in the figure, and this piston member is connected to a power source (not shown). has been done. The slide rod 14 has a downwardly inclined slope 16 at its inner end, and a hole 17 corresponding to this slope is formed in the block 8, so that the slide rod 14 can be moved from the position shown in FIG. When the block 8 is driven inward, the block 8 is moved upward. Further, the entrance portion 18 of the hole 17 is formed to have a sufficiently large diameter so as to allow the block 8 to move up and down.

A ring-shaped space 19 is provided between the core mold 3 and the stripper plate 4, and this space 19 cooperates with the recess 11 of the cavity mold 2 to define a cavity space to be described later. A first sprue 20 is opened on the bottom surface of the core mold 3, and a second sprue 21 is opened on the bottom surface of the block 8. The first runner 22 formed by penetrating the receiving part 5 and the runner mold 6 is
Further, the second sprue 21 is connected to each injection cylinder of a two-part injection molding machine (not shown) through a second runner 23 formed in the block 8 and the runner mold 6. A known machine can be used as this injection molding machine, and synthetic resins colored in different colors are supplied from each injection tube. The second runner 23 is cut off by the gap 12 when the block 8 is at the lower limit position in FIG.

A transfer film 24 is stretched between the cavity mold 2 and the core mold 3, and this film 24 is transferred from a conveyance roller 25 arranged on one side (left side in the figure) of the mold to a take-up roller on the other side (right side). 526 for each cycle of injection molding, which will be described later. On the upper surface of the transfer film 24, decorative layers 27 including a printed layer such as a pattern, a metal vapor deposition layer, etc., and an adhesive layer are formed at predetermined intervals.
7 is formed to have an area approximately equal to the surface area of the recess 11.

Next, a method for forming a multicolor molded product using the apparatus configured as described above will be described. First, while the slide rod 14 is moved backward to maintain the block 8 at the first position, the roller 25 is
．． When the mold 1 is closed from the state shown in FIG. 1 in which the decoration layer 27 of the transfer film 24 is set in a predetermined position by rotating the transfer film 26, the lower end surface of the block 8 is inserted into the recess of the cavity mold 2 with the film 24 in between. 11, and this block 8
A first cavity space 28 is defined in a ring shape by the recess 11, the core mold 3, and the stripper plate 4 (FIG. 2). While the first sprue 20 opens into this space 28, the second sprue 21 is closed by the cavity mold 2 via the film 24. Further, as a result of the film 24 being pressed by the block 8, the decorative layer 27
is confined within the space 28 in a curved or bent state.

In this state, the molten synthetic resin 29 supplied from one injection cylinder 32 of the injection molding machine is injected and filled into the cavity space 28 from the first sprue 20 via the first runner 22 (the third figure). This causes the film 24 in the space to
is pressed against the bottom surface of the recess 11 by the pressure of the resin, and the decoration layer 27 is transferred by the heat of the molten resin. Next, before the resin 29 completely solidifies, the piston member 15 is actuated to move the slide rod 14 inward,
When the block 8 is slid to the upper limit position (second position) where its upper surface abuts the lower surface of the runner mold 6, a second A cavity space 30 is defined, into which the second sprue 21 opens. Thereafter, as shown in FIG. 4, a synthetic resin 31 that is compatible with the resin 29 and colored in a different color is introduced into the space 30 from the other injection tube 33 of the injection molding machine. When the resin 31 is injected through the second runner 23 and the second sprue 21, the heat and pressure of the resin 31 completely fuses the resin 29 with the resin 29, and the decoration inside the second cavity space 30 is created. Layer 27 is transferred onto resin 31. After that, one cycle is completed by waiting for the resin to cool and solidify, then opening the mold and removing the molded product.

The next cycle can then be started by advancing the film 24 and setting the next decorative layer 27 in place, thus allowing the decorative layers transferred from a single film to be applied to multiple areas of each color. Color molded products can be continuously molded.

FIG. 5 shows a multicolor molded product molded as described above, and in this molded product 40, the main body 4 is made of resin 29.
1 and a disk-shaped different-colored portion 42 made of resin 31 are integrally welded together, and a decorative layer 27 is continuously formed on the upper surface of these. The decorative layer 27 may have any pattern, or may have metallic luster, pearlescent luster, or the like. Furthermore, the boundary between the main body part 41 and the different color part 42 may be linear as shown in FIG. 5, but depending on the type and combination of resins employed, it may A non-linear boundary is preferred from the standpoint of increasing the welding surface and further ensuring the integrity of the two. Incidentally, such a non-linear boundary can be obtained by forming the lower end peripheral portion of the block 8 defining the first cavity space into a predetermined shape.

Next, FIG. 7 shows a molding apparatus according to another embodiment of the present invention, and the difference from the embodiment described above is that the first sprue 20
A is disposed on the side of the first cavity space 28, which is a so-called side gate type. Correspondingly, the first runner 22a is provided from the core mold 3a to the stripper plate 4a. The configuration of the pond is similar to that described above.

8 and 9 show an example of a case where a decorative layer 27 is provided on the back side of a plate-shaped molded product, and in this mold, first and second cavity spaces 28b and 30b are defined. A recess is formed in the core mold 3+1 for the main 11 bitty mold 2b when the block 8 is in the first position.
The decorative layer 27 is in contact with the upper surface of the decorative layer 27 . film 2
4 and the decorative layer 27 are held linearly between the core mold 3b and the cavity mold 2b, and molding and transfer are performed by injecting and filling the resins 29b and 31b in the same procedure as in the above case. However, these resins are colored or non-shield-colored and translucent, so that the decorative surface 27 on the back side can be seen through.

Further, FIGS. 10 and 11 show other examples of drive means for the block 8, and in the one shown in FIG. 10, a cylinder member 15a is connected to the block 8 to directly move it up and down. There is. The driving means shown in FIG. 11 includes a rack 50 connected to the cylinder member 15b, a pinion 51 that meshes with the rack 50, and a rack of the block 8 that meshes with the pinion 51 and is located on the opposite side of the rack 50. 52, rack 5
The vertical movement of 0 causes the block 8 to be activated in the opposite direction.

In the illustrated embodiment, the different color portion is formed approximately at the center, but it goes without saying that the position and shape of the different color portion is not limited to this.

(Effects of the Invention) As described above, according to the molding method of the present invention, multicolor synthetic resin molding can be carried out extremely efficiently using the mold A and in a single cycle process without the need to open the mold midway. In addition, the decorative layer on the transfer film can be transferred to a desired part at the same time as injection molding, and there is no need for complicated secondary processing as in the past. Furthermore, the apparatus according to the present invention makes it possible to carry out the above method reliably and efficiently.

Furthermore, in the multi-colored molded product according to the present invention, not only is there no risk that the main body portion and the different color portion will peel off from each other, but there is also no risk of the decorative layer slipping or peeling off at the joint between the two. Moreover, it has the advantage of being suitable for a low-cost and efficient spacer, and is particularly suitable for containers for cosmetics that require decorative properties.

[Brief explanation of drawings]

1 to 4 are cross-sectional views showing a mold of a molding apparatus according to an embodiment of the present invention, and FIG. 5 is a partially cutaway perspective view of a multicolored molded product according to an embodiment of the present invention. Figures 6a) to 6) are partially enlarged sectional views showing other examples of the welding surface of the molded product,
FIG. 7 is a sectional view showing a mold of a molding apparatus according to another embodiment of the present invention, FIGS. 8 and 9 are sectional views of a mold according to still another embodiment, and FIGS. The figures are sectional views showing other examples of the driving means. 1...Mold 2.2b...Cavity mold 3, 3a, 3't+...Core mold 8...
...Activity block 20.20a...First sprue 21...Second sprue 24...Transfer film 27...Decoration layer 28.28b...First cavity space 29
, 29b, 31.31b...Synthetic resin 30.30b.
... Second cavity space 40 ... Molded product 41 ... Body part 42 ... Different color part Patent applicant Yoshida Kogyo Co., Ltd. Representative Patent attorney − Irokanosuke Figure 5 2) Figure 6

Claims (5)

[Claims] (1) It has a core mold and a cavity mold, a sliding block is disposed inside either the core mold or the cavity mold, and first and second sprues communicating with the injection molding machine are provided. A transfer film having a decorative layer is disposed between the core mold and the cavity mold, and the mold is closed to define a first cavity space. A molten synthetic resin is injected from the first sprue to transfer the decorative layer in the first cavity space, and then the sliding block is slid to form a second sprue connected to the first cavity space. A synthetic resin having compatibility with the synthetic resin and colored in a different color is injected into the second cavity space from the second sprue into the second cavity space. A method for molding a multicolored synthetic resin molded article, which comprises transferring the decorative layer in the cavity space and welding the two synthetic resins together. (2) includes an injection molding mold having a core mold and a cavity mold, having means for supplying a transfer film between the core mold and the cavity mold, and having a means for supplying a transfer film between the core mold and the cavity mold; Inside, there is a sliding block that is slidable via a driving means between a first position in which it comes into contact with the other of the core mold and the cavity mold via the transfer film, and a second position that is spaced apart from the other. a first sprue opening to a first cavity space defined when the sliding block is in the first position; and a first sprue that is closed when the sliding block is in the first position. and a second sprue opening to a second cavity space defined by connection with the first cavity space when the sliding block slides to the second position, 1. A molding apparatus for a multicolored synthetic resin molded product, wherein the first and second sprues are respectively connected to injection means for synthetic resin colored in different colors. (3) The apparatus for molding a multicolored synthetic resin molded product according to claim 3, wherein the second sprue is formed in the sliding block. (4) A main body formed of synthetic resin injected from a first sprue within a first cavity space defined within an injection mold, and a sliding block disposed within the mold. In a second cavity space defined by sliding of the resin and connected to the first cavity space, a synthetic resin that is compatible with the synthetic resin and colored in a different color is applied. The main body part and the different color part are integrally welded during molding of the different color part, and the main body part and the different color part are formed by injection from the respective injection sprues. A multicolored synthetic resin molded product characterized by having a decorative layer on its surface transferred from a single transfer film during molding. (5) The multicolored synthetic resin molded product according to claim 4, wherein the main body portion and the different color portion are welded together at a non-linear interface.