JP3708290B2 - Molding method and molding apparatus for different color plastic skin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for molding a different color plastic skin and a molding apparatus therefor, and more particularly, to a method and apparatus for obtaining a plastic skin having different color portions with a single mold.
[0002]
[Prior art]
For example, a skin made of a soft plastic may be used as a skin material that covers the surface of a foam molded product. Such an outer skin uses a powder plastic molding apparatus comprising a bucket containing plastic powder and a molding die having a mold surface. The plastic powder is contained in the bucket and rotated in combination with the molding die. It is often molded by a known powder slush molding method in which plastic powder is attached to a heated mold surface to form a film having a predetermined shape.
[0003]
By the way, when obtaining plastic skins that are color-coded in different colors, for example, plastic films of the respective colors are molded independently and their joining edges are bonded together, or as shown in FIG. The joint edges 53 and 54 of the films 51 and 52 are formed in a flange shape bent toward the back surface of the film, and a fastener portion 55 including a concave portion and a convex portion that can be fitted to each other is provided on the edge edges 53 and 54. At the time of foam molding, there is a method in which the plastic films 51 and 52 are joined to form a single skin by fitting the fastener portion 55 when the skin is placed on the foam molding die surface.
[0004]
However, in any of the methods, it is necessary to slush-mold the coatings for each color and join them together, which takes a lot of time and labor to produce a single skin. It was. In addition, since the plastic film is very soft, it is difficult to correctly position and bond and bond the films together. Furthermore, in the latter method, there is a possibility that the film cannot be securely fitted unless the convex part and the concave part are accurately formed. In particular, when used in the above-described foam molding, the skin is often placed in the foam mold while fitting the fastener portion. In this case, the foamed material sometimes leaked from the joint portion.
[0005]
[Problems to be solved by the invention]
The present invention has been proposed in view of such problems, and it is possible to easily and reliably obtain plastic skins having different colors with a single mold, and a method for molding different color plastic skins and its A molding apparatus is to be provided.
[0006]
[Means for Solving the Problems]
That is, according to the method for molding a different color plastic skin of the present invention, a bucket in which plastic powder is accommodated and a mold having a mold surface are combined and rotated, and the plastic powder in the bucket is heated by the mold during the rotation. In a method of forming a plastic skin by powder slush molding, which is moved to a surface to form a molten plastic film on the mold surface, and then cooled and cured to remove the mold, a partition plate is erected on the bottom surface of the bucket. While storing a plurality of plastic powders of different colors in a plurality of storage portions partitioned by a partition plate, the mold surface is provided with a ridge that abuts the tip of the partition plate at a position corresponding to the partition plate, The mold surface is partitioned by the ridge, and an unevenness is formed on either the tip of the abutting partition plate or the edge of the ridge to project the gap due to the unevenness. And forming a molten plastic film with different colors on the mold surfaces on both sides of the ridges by rotating the bucket and the mold, and forming gaps due to the unevenness. In this case, the molten plastic films having different colors on both sides of the ridge are arranged in series with each other, and then different color plastic skins are obtained by color-cooling and cooling.
[0007]
The molding apparatus for different color plastic skin according to the present invention is a powder plastic molding apparatus comprising a bucket for containing plastic powder and a molding die having a mold surface, and a partition plate is erected on the bottom surface of the bucket. A plurality of plastic powder containing portions partitioned by a partition plate are provided in the bucket, and a protrusion that contacts the tip of the partition plate is provided on the mold surface at a position corresponding to the partition plate. In addition to partitioning the mold surface, an unevenness is formed on either the tip of the abutting partition plate or the tip of the ridge, and a gap due to the unevenness is formed between the ridge and the partition plate.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
1 is a sectional view showing an example of the molding method of the present invention, FIG. 2 is a sectional view taken along the arrow 2, FIG. 3 is a sectional view showing a state where the molding die of FIG. 1 is rotated, and FIG. FIG. 5 is a perspective view showing a main part of the obtained skin, and FIG. 6 is a view showing the AA sectional view and the BB sectional view of FIG. 5 side by side.
[0009]
According to the method for molding a different color plastic skin of the present invention, the plastic powder is moved to a heated mold surface of the mold by rotating a bucket containing the plastic powder and a mold having a mold surface. This is preferably carried out in a known powder slush molding in which a molten plastic film is formed on the mold surface and then cooled and cured. An example is shown in FIG. In the figure, reference numeral 10 denotes a bucket, and 20 denotes a mold. In addition, about the molding apparatus of the different color plastic skin of this invention, it demonstrates simultaneously in the case of description of the said shaping | molding method.
[0010]
The bucket 10 is formed in a container shape having an upper opening as shown in the figure, and a partition plate 11 is erected on the bottom surface thereof. The partition plate 11 is for forming a plurality of plastic powder containing portions in the bucket 10 according to the number of colors of the plastic skin to be color-coded, and is provided along the shape of the color-coding. In the present embodiment, one partition plate 11 is provided at substantially the center of the bottom surface of the bucket, and two accommodating portions 12 and 13 are formed on both sides thereof. Note that an appropriate number of partition plates 11 can be provided according to the number of colors of the plastic skin. In the accommodating portions 12 and 13, plastic powders P1 and P2 of different colors are accommodated.
[0011]
On the other hand, the molding die 20 is made of a known electroforming mold, and a protrusion 21 is provided on the die surface at a position corresponding to the partition plate 11 when the bucket 10 is attached. This ridge 21 is for partitioning the mold surface of the mold 20 in accordance with the color-coded shape. In this example, one ridge 21 is provided, and the mold is divided into two mold surfaces 22, It is divided into 23. In this example, the height of the protrusion 21 is about 8 mm and the thickness is about 1 mm.
[0012]
The mold surfaces 22 and 23 are heated to a predetermined temperature at which the plastic powder can be melted by a heater 24 attached to the outer surface side of the mold. The heating temperature of the mold 20 is appropriately set according to the type and composition of the plastic powder used. In this example, the temperature was 150 ° C.
[0013]
As shown in FIG. 2, comb-shaped irregularities 25 are provided at the tip of the protrusion 21. When the molding die 20 and the bucket 10 are bonded together, the irregularities 25 come into contact with the tip of the partition plate 11 as understood from FIG. In addition to partitioning the molding space for each plastic film, a gap 15 of a predetermined interval is formed between the protrusion 21 and the partition plate 11. In the gap 15, as shown in FIGS. 3 and 4, when the bucket 10 and the mold 20 are rotated, the plastic powder in the bucket 10 accumulates and melts to form a molten plastic film S3. The molten plastic film S1 formed on the mold surface and the molten plastic film S2 formed on the mold surface 23 are partially arranged in series. In the present embodiment, the irregularities 25 are provided at the tip of the protrusion 21, but may be provided at the tip of the partition plate 11 of the bucket 10 depending on the size and shape of the skin to be molded.
[0014]
The shape of the gap 15 is not particularly limited. However, if the gap 15 becomes too wide, the plastic powders of different colors accommodated in the accommodating portions 12 and 13 are rotated when the bucket 10 is rotated. There is a risk of mixing through the film 15 and causing color mixing in the film. If the gap 15 is too narrow, the plastic powder does not accumulate and it is difficult to form a series of films formed on the mold surfaces 22 and 23. Therefore, the shape of the unevenness 25 is determined by the bulk density and melt viscosity of the plastic powder used for molding. In this example, concave portions 26 having a depth of about 4 mm and a width of about 1 mm are formed at intervals of 2 mm. Furthermore, in order to immediately melt the plastic powder accumulated in the gap 15 and to reliably form the film S3, it is necessary to reliably control the protrusion 21 to a predetermined melting temperature of the plastic powder. Therefore, as shown in the figure, a protrusion temperature control heater 24a may be provided on the outer surface of the mold at the protrusion 21 portion.
[0015]
Next, the bucket 10 and the mold 20 are combined and closed. In this example, a cushion material 16 that abuts against the irregularities 25 is provided at the tip of the partition plate 11. The cushion material 16 prevents the uneven portion 25 from being damaged by the contact between the partition plate 11 and the tip of the uneven portion 25 when the mold is closed, and makes it difficult for heat of the uneven portion to be transmitted to the partition plate 11 to rotate the mold. This is to prevent sometimes the plastic powder from adhering to the partition plate 11. In addition, there is also an effect that the predetermined gap is surely formed by securely bringing the leading end of the partition plate 11 and the convex portion of the unevenness 25 into close contact. The cushion material 16 is made of a fluororesin or the like and is formed slightly thicker than the thickness of the protrusion 21.
[0016]
Thereafter, the bucket 10 and the molding die 20 are rotated in a combined state by an appropriate drive device (not shown), and the plastic powder P1 in the accommodating portion 12 of the bucket 10 is transferred to the mold surface 22 and the accommodating portion 13. The inner plastic powder P2 is moved to the mold surface 23, respectively. Since the mold surfaces 22 and 23 including the protrusions 25 are heated to a predetermined temperature by the heater 24, the plastic powders P1 and P2 are instantaneously melted and attached, as shown in FIGS. In addition, different color plastic films S1 and S2 are formed on the mold surfaces on both sides of the ridge 21 as a boundary. At that time, the plastic powders S1 and S2 accumulate and melt in the gap 15 to form a coating S3. Therefore, the plastic powders P1 and P2 do not mix through the gap 15. The rotation of the mold is continued an appropriate number of times until molten plastic films S1 and S2 having a certain thickness are formed on the mold surfaces 22 and 23.
[0017]
Thereafter, the mold 20 is cooled, and the molten plastic films S1 and S2 formed on the mold surfaces 22 and 23 are cured and removed from the mold. As shown in FIG. 5, the obtained plastic skin S is clearly divided into different colors when viewed from the surface.
Further, when viewed from the back surface, a flange portion F is formed on the back side in accordance with the shape of the protrusion 21 at the boundary between the plastic films S1 and S2. Then, as shown in FIG. 6 (A), the end of the flange portion F is intermittently connected in series with the molten plastic film S3 formed in the gap 15, and the molten plastic film S1 and S2 are connected in series. The plastic films S1 and S2 are formed on a single plastic skin S. Further, in the portion where the tip of the partition plate 11 and the tip of the concavo-convex portion 25 are in contact with each other, the mold surfaces 22 and 23 are completely partitioned by each other. Therefore, as shown in FIG. The molten plastic films S1 and S2 are divided without being connected.
In addition, although the plastic powder P1 and P2 of both colors may be mixed in the front-end | tip part of the flange part F which the said melted plastic membrane | film | coat S1, S2 becomes a series, since it is a back side part of an outer skin, There is no problem even if color mixing occurs.
[0018]
Furthermore, the different color plastic skin obtained by the molding method of the present invention can be suitably used as a foam skin material. The different color plastic skin is disposed on the mold surface of the foam molding die when foam is molded, and the different color plastic skin is injected onto the back surface of the different color plastic skin by foaming and curing. As a result, a foam-molded product in which is integrally formed can be obtained. At that time, since the different colored films are not separated from each other, the arrangement on the mold surface is easy and accurate without any deviation. Moreover, since the flange part F is pressed from both sides by the foaming pressure of the foaming raw material and is in close contact with the part where the molten plastic coatings S1 and S2 are divided, there is no particular risk of leakage of the foaming raw material. It is even more reliable if the separated flange portion F is integrally taped and joined by an adhesive member.
[0019]
【The invention's effect】
As illustrated and described above, according to the method for molding a different color plastic skin of the present invention, the partition plate standing on the bucket and the protrusion standing on the mold surface are brought into contact with each other, and the plastic powder container and In addition to partitioning the mold surface for each color, a gap is formed between the partition plate and the protrusions by unevenness, and the plastic films are arranged in series through the gap. Therefore, it is possible to easily obtain one plastic skin that is reliably color-coded. Moreover, because the coatings of both colors are connected to each other by the coating formed in the gaps at each color boundary, there is no need to mold the coatings separately according to the colors and join them later, forming a different color plastic skin Can be performed efficiently.
[0020]
In addition, since the device for molding a different color plastic skin according to the present invention is such that a gap is partially formed between the tip of the partition plate and the tip of the ridge, the accuracy for film bonding to the mold is improved. It is not necessary to provide a high concave portion or convex portion, the mold structure is not complicated, and it can be manufactured economically.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a molding method of the present invention.
FIG. 2 is a view taken in the direction of arrow 2.
FIG. 3 is a cross-sectional view showing a state where the mold shown in FIG. 1 is rotated.
FIG. 4 is an enlarged perspective view showing the main part.
FIG. 5 is a perspective view showing a main part of the obtained skin.
FIG. 6 is a view showing the AA sectional view and the BB sectional view side by side.
FIG. 7 is a diagram showing an example of a general joining method for a general different color plastic skin.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Bucket 11 Partition plate 12, 13 Housing | casing part 15 Crevice 20 Molding die 21 Projection line 22, 23 Mold surface 25 Concavity and convexity P1, P2 Plastic powder S1, S2, S3 Molten plastic film S Plastic skin

Claims (2)

A bucket containing plastic powder and a mold having a mold surface are combined and rotated, and during the rotation, the plastic powder in the bucket is moved to the heated mold surface of the mold to form a molten plastic film on the mold surface. In a method of forming a plastic skin by powder slush molding that is formed and then cooled and cured and demolded,
A partition plate is erected on the bottom surface of the bucket, and plastic powders of different colors are stored in a plurality of storage portions partitioned by the partition plate, while the partition surface is positioned at a position corresponding to the partition plate. A ridge that abuts against the tip of the plate is erected to partition the mold surface with the ridge, and an irregularity is formed on either the abutment partition plate tip or the ridge tip to form a gap between the projections and depressions. Formed between partition plates,
By rotating the bucket and the mold, plastic powders of different colors are attached to the mold surfaces on both sides of the ridge to form molten plastic films of different colors, and the colors on both sides of the ridge through the gaps due to the irregularities. A method for molding a different color plastic skin, characterized in that different molten plastic skins are arranged in series with each other to obtain a different color plastic skin colored by subsequent cooling and demolding. In a powder plastic molding apparatus comprising a bucket for containing plastic powder and a mold having a mold surface,
A partition plate is erected on the bottom surface of the bucket, and a plurality of plastic powder containing portions partitioned by the partition plate are provided in the bucket. On the mold surface, the partition plate is disposed at a position corresponding to the partition plate. While standing the ridge that contacts the tip and partitioning the mold surface with the ridge,
An apparatus for forming a different color plastic skin, wherein irregularities are formed on either the leading edge of the partition plate and the leading edge of the protrusion, and a gap due to the unevenness is formed between the protrusion and the partition plate.

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