JP2000334761A - Foamed molding excellent in design effect - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a foamed molding having a smooth outer surface fitted to flocking processing, printing and the mounting of a label or decorative skin or the application of a design and excellent in design effect. SOLUTION: Slits 7a, 7b exposed to both end parts in a cavity 4 for forming a foamed molding are arranged along the parting line part of a pair of combined molds 51, 61 not provided with vent holes surrounding the cavity 4 at a time of mold closing so that the opening width of each of the slits is smaller than the particle size of supplied raw material beads. The discharge of gas or the supply of steam is enabled through mold passages 91a, 91b being the passages communicating with exclusive service ports 93a, 93b and mold spaces 92a, 92b and the raw material beads charged in the cavity 4 are heated to melting temp. or higher through the molds 51, 61 and a foamed molded object is produced by foam molding while providing difference in the fusion degree of a surface layer and an intermediate layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed molded article having a surface layer with improved properties and excellent design properties, and more particularly to flocking, printing, attaching a label, attaching a cosmetic skin, or the like. The present invention relates to a foamed molded article having an outer surface suitable for design and excellent in design.

[0002]

2. Description of the Related Art Here, an outline of a foam molding method as a background of the present invention will be described. As shown in a schematic sectional view of FIG. The movable mold 31 and the fixed mold 21 are arranged to face each other so as to form the cavity 1 to be molded. Fixed mold 21
Is usually fixed to a gantry, but the movable mold 31 is
As shown in FIG. 2, the movable body is horizontally moved (to the right in FIG. 2) from the state in which the cavity 1 is formed together with the fixed mold 21 so as to be able to take out the molded foam. A large number of vent holes 22 and 32 are provided in both of the concave and convex molds 21 and 31 so that utilities such as heating steam described later can pass therethrough.

A fixed side chamber 2 and a movable side chamber 3 to which utilities such as steam, air and cooling water are supplied are formed on the back side of the dies 21 and 31. At the approximate center, a raw material bead filling device 26 for filling the raw material beads into the cavity 1 is disposed so as to penetrate the fixed side chamber 2. In this case, a heating steam,
Upper utility ports 24 and 34 for supplying pressurized air and the like are provided, and lower utility ports 25 and 35 are provided at a lower portion, and are connected to a pressure reducing pump or a drain pipe.

[0004] Using such a mold apparatus for foam molding,
In order to manufacture an expanded molded article, first, foamed raw material beads made of a predetermined expandable polystyrene or polyolefin resin or the like from a raw material bead container (not shown) are filled in the cavity 1 through a raw material bead filling device 26. And filled. Next, the heating steam is fed into the chambers 2 and 3 and is fed between the raw material beads filled through the vent holes 22 and 32 and heated.
The raw material beads are fused together and integrated. After that, it is cooled and solidified, and is taken out in the order of taking out as a foam molded article.

[0005] By the way, as described above, the mold apparatus used in such a foam molding method is provided with a vent hole for feeding utilities such as heating steam, exhaust air, air supply and water supply into the cavity. Are provided innumerably, on the surface of the obtained foam molded body, traces of countless tip portions of core vent members, and projections formed from raw material bead portions pushed into the vent holes thereof may be up to 1 mm. It was unavoidable to survive up to a diameter × length of 1 mm.

[0006] As described above, since the surface of the conventional foamed molded article has the core vent traces and the projections formed by the vent holes all over the surface, the outer surface itself does not have an aesthetic appearance, and the printed surface is not printed. In addition, a clear printing result cannot be obtained even when the method is carried out, and when a label or a cosmetic skin is attached, unevenness is generated, resulting in insufficient adhesion or poor aesthetic appearance. Furthermore, the presence of traces of core vents and the like for applying designs such as flocking, painting or coloring has become an extremely inappropriate cause.

[0007] In particular, in the case of flocking, there has been a problem that the unevenness of the finished appearance is remarkably exhibited due to the projection on the trace of the conventional core vent. In other words, since the adhesion rate of the flocked material is significantly different between the protruding portion and the other flat surface, the protrusions at the core vent marks, for example, tend to cause uneven shading of the finished color and spot-like unevenness, indicate the quality of the flocking process. Has a significant effect on

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is intended to provide an aesthetic appearance to the outer surface itself of a foam molded article. If necessary, when performing printing, flocking, painting, labeling, applying cosmetic skin, or other designs, foam molding with a smooth outer surface suitable for processing such as printing, with excellent design properties Provide body.

[0009]

The foam molded article of the present invention which has solved the above-mentioned problems is a foam molded article in which raw beads made of a thermoplastic resin such as a polystyrene resin or a polyolefin resin are fused together and integrated. It is characterized in that at least the surface directly exposed to the outside is not formed with protrusions composed of core vent traces or vent hole traces, has a smooth surface layer and is excellent in design. is there.

Furthermore, the surface layer of the foamed molded article of the present invention, which has excellent design properties, directly exposes foamed raw material beads made of a thermoplastic resin to at least the outside of a pair of heating dies. One of the molds for forming the surface is filled between molds having no vent hole, and can be embodied in a form formed by heating and fusing at a temperature higher than a fusing temperature. If necessary, the surface of the mold may be provided with design irregularities in advance, and the design based on the design irregularities may be embodied on the surface of the surface layer of the foam molded article.

[0011] The foamed molded article of the present invention having the above-described structure has a smooth surface free of molding traces such as core vent traces and vent hole traces on the surface, and therefore can be formed without applying a decorative or finishing process. It is suitably applied to members such as toys and display articles. In addition, when printing, flocking, painting, labeling, applying cosmetic skin, and other designs, the adaptability is extremely excellent.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the foam molded article of the present invention will be described. In the foamed molded article having excellent design properties according to the first preferred embodiment, the material is not limited to the above-mentioned heat insulating property, impact resistance, light weight, waterproof property, supply cost, availability, and the like. From, any thermoplastic resin of raw material beads composed of polyolefin resin and polystyrene resin, which are widely used, can be used, and among them, those having a low foaming rate to those having a high foaming rate depending on the application. Up to this point may be appropriately selected and applied.

[0013] A decorative article made of a foamed molded article in which the raw material beads made of these thermoplastic resins are fused and integrated with each other, and the feature of the present invention is that it is exposed at least to the outside. The surface is provided with a smooth surface layer without forming protrusions composed of core vent traces and vent hole traces which cannot be avoided by the conventional manufacturing method described above.

According to the present invention, the surface layer that is not directly exposed to the outside is provided with a projection formed of a core vent mark or a vent hole mark, or when the protrusion is not formed. Can also be embodied. Usually, on the surface that is not exposed to the outside, there is no need for design or design such as flocking, printing, etc., so there is no problem in design even in the form where protrusions such as vent hole marks are formed, and To
As described below, there is an advantage that a commonly used technique can be applied in the foam molding operation.

Further, in the second embodiment of the present invention, the surface layer on which no projections composed of core vent traces and vent hole traces are formed is a smooth surface densely fused,
In addition, the intermediate foamed layer inside can be embodied as a foamed molded article having an excellent design property in which the fusion ratio is a value in the range of 30% to 100%. In addition, the fusion rate is indicated by the ratio of the beads having an internal fracture, not the boundary fracture of the beads, in the fracture surface.

In the case of a conventional foamed molded article, smoothness was obtained from the front to the back of the foamed molded article by sufficiently fusing the raw material beads to each other.
In the case of the present invention, the smoothness is carried out as a layer in which the surface layer is densely fused, and the inner intermediate foam layer has a fusion rate in the range of 30% to 100%, more preferably 30%. % ~
It is a value within the range of 60%, and is characterized in that the tissue in this portion is in a relatively loose bond. The advantage of providing a difference in the degree of fusion between the surface layer and the intermediate layer will be described in connection with the following description of the manufacturing method.

Next, a third embodiment of the foamed molded article of the present invention will be described together with a method of manufacturing the foamed molded article of the present invention with reference to FIG. 1 showing a main part of a foam molding die apparatus. . The surface layer of the decorative article made of the foam molded article of the present invention is a foam molding raw material bead made of a polyolefin resin or a polystyrene resin, and a pair of heating molds.
At least, one of the molds for forming a surface exposed to the outside is filled between molds having no vent hole, and is heated to a fusion temperature or higher to be foamed and fused to be formed. Things. The case is shown below.

A foam molding die apparatus applicable to the present invention is a combination mold having no pair of vent holes formed so as to surround a cavity for forming a foamed molded product. A foam molding die device, characterized in that a slit exposed in a cavity is provided along a joint portion and a passage communicating from the slit to an external utility pipe is provided. A passage communicating from the slit to an external utility pipe can be embodied in a form formed from the cavity side to the outside along the joint portion of the combination mold.

More specifically, referring to FIG.
This arrangement of the mold device surrounds the cavity 4 in which the foamed molded product is filled and molded, as in the conventional case described above,
The moving mold 61 and the fixed mold 51 are arranged to face each other. Frames 52, 62 and back plates 53, 63 are attached to the back side of these dies 51, 61, and fixed-side chamber 5 to which utilities such as steam are supplied.
And the moving side chamber 6 are formed. In this case, in the upper part of the frames 52 and 62, the upper
4 and 64, lower ports 55 and 65 are provided at the lower part, and valves to which steam for heating or the like are supplied are attached to the upper ports 54 and 64, respectively. A valve connected to a decompression pump, a drain pipe, or the like is attached to the ports 55 and 65.

A feature of this mold apparatus is that, when the mold is closed, a pair of combined molds 51 and 61 formed so as to surround the cavity 4 for forming a foamed molded product are provided with a conventional vent. Although no holes are provided, the slits 7a and 7b exposed at both end portions in the cavity 4 along the seam are made to have the opening width smaller than the particle diameter of the raw material beads supplied. It is arranged.

A passage connecting the utility holes 93a and 93b connected to external utility pipes from the slits 7a and 7b exposed at both ends in the cavity 4 is provided from the cavity side when the mold is closed. Mold 5 to the outside
The mold-to-mold passage 9 formed along the joint portion of 1, 61
1a and 91b, when the mold is closed,
a, 91b, which are provided with external utility ports 93a, 93b, and are formed in a state surrounded by joints of the frames 52, 62 to be sealed.
Is provided.

That is, since the molds 51 and 61 are not provided with vent holes, when the molds 51 and 61 are closed, the cavity 4 is airtightly isolated from each of the fixed side chamber 4 and the movable side chamber 6. The mold passages 91a and 91b, which are utility passages communicating with dedicated utility openings 93a and 93b provided on the frame (the frame 52 side in FIG. 1) of the mold apparatus, are formed in the mold state. Interspace 92
Through the holes a and 92b, pressurization, air supply and exhaust of decompressed air, and supply and discharge of heated steam can be performed from the slits 7a and 7b to the cavity 4.

Using such a mold apparatus, the slit 7
The raw material beads are filled from the raw material bead filling device 26 while the inside of the cavity 4 is evacuated using a and 7b. By heating as described above, the applied thermal energy is transmitted from the surface of the packed raw material bead layer to the inside, so that the fusion reaction of the surface portion precedes and the internal portion is departed. Thus, as in the present invention,
This is convenient for providing a difference in the degree of fusion between the surface layer and the intermediate layer of the foam molded article.

The advantage of providing a difference in the degree of fusion between the surface layer and the intermediate layer is that the time required for the heat fusion step can be shortened. The reason is that the intermediate layer can keep its fusion rate at a relatively low value such as at least 30%, while the surface layer can reach a tight fusion state. This is because the required amount of heat is theoretically satisfied with a small amount of 以下 or less as compared with the case where the whole is heated to a fusion state as homogeneous as possible.

In the above description, the mold 51,
In the present invention, at least one of the pair of fixed and movable heating dies 51 and 61 has at least a surface directly exposed to the outside. Therefore, it is sufficient to use a combination of molds in which one of the molds does not have a vent hole, and it is not always necessary that both molds have no vent hole. If the fixed mold 51 is provided with a vent hole, the slits 7a, 7
b can be used in the same manner, and the foam molding step can be performed without using b.

According to the manufacturing method described above, at least the exposed surface which is exposed to the outside is provided with a smooth surface layer as a whole on which no projections formed by vent marks and vent hole marks are formed. A foam molded article can be obtained. Further, by controlling the heating temperature or the heating time, the thickness of the surface layer of the obtained foamed molded article can be increased or decreased, so that the desired smoothness can be set according to the purpose. And besides being able to make the outer surface of these foamed moldings a sufficiently smooth surface,
If necessary, an advantage can be obtained in that the finished product is excellent without unevenness even if flocking for cosmetics, painting, sticking of a seal, and the like are performed.

The foamed molded article thus obtained having excellent design properties can be used as a member of a toy, a three-dimensional model, a display article, a decorative article, or a base member for mounting a cosmetic or decorative skin. Can be further,
Such a foamed molded article is formed so as to have a boot-like outer shape, and the surface thereof is subjected to flocking to be used as a souvenir or as a member of a container for small goods such as confectionery and small toys. Such a boot-shaped container is not only a function of simply putting confectionery, etc., but also a seasonal product for spring, summer, autumn and winter, for children with strong seasonality such as for Christmas, goods for young women or local tourism, various containers for events, Display supplies,
Alternatively, it is applied as a member having a design property to mascot-like applications.

Further, in the above-mentioned mold apparatus, it is preferable to provide a design with irregularities on the surface of the mold so as to reproduce the design based on the irregularities on the surface on the surface layer of the foamed molded article. Since the desired design pattern can be given to the foamed molded article itself, which enhances the design properties, the molding and the patterning of the design irregularities can be performed simultaneously,
The advantage is that the total manufacturing cost can be significantly reduced.

Further, according to the mold apparatus, the following advantages can be obtained in addition to the advantage that the surface of the molded body is smooth and the appearance quality is excellent. 1) The cost of the mold material is reduced, and the cost of manufacturing and processing the mold can be reduced. 2) No special maintenance is required. 3) The thermal efficiency of heating and cooling is improved, which is effective for energy saving and shortening of cycle time. 4) The drying step can be omitted because the water content of the molded body is reduced.

[0030]

The foamed molded article of the present invention having excellent design properties is
Since it is configured as described above, it has a smooth aesthetic appearance itself, and furthermore, the cosmetic skin is directly attached to the smooth formed surface, or a flocking process as necessary. A desired design such as coloring, patterning, printing, labeling or painting can be clearly provided, and the aesthetic design can be particularly improved. Further, at this time, no undercoating treatment is required, so that productivity is remarkably improved and cost can be reduced.

In addition, since a foam molding method capable of saving heating energy can be adopted, there are excellent effects such as a reduction in molding cycle time and energy cost, and a foam molded article excellent in design can be provided. Therefore, the present invention has a very high industrial value as a foam molded article which has solved the conventional problems and has excellent design properties.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a mold apparatus for producing a foam molded article of the present invention.

FIG. 2 is a cross-sectional view of a main part of a mold apparatus for manufacturing a conventional foam molded article.

[Explanation of symbols]

26 Filler for raw material beads, 4 cavities, 5 fixed chamber, 51 fixed mold, 6 moving chamber, 61
Moving mold, 7a, 7b slit, 91a, 91b
Inter-model passage, 92a, 92b Inter-model space, 93a, 93b
Office entrance.

Continued on the front page F term (reference) 4F100 AK01A BA02 BA10A BA10B BA13 DE04A DJ01A DJ01B GB84 GB90 HB21A JB16A JD05A JK15 JL02 YY00B 4F212 AG03 AG20 AH67 UA01 UB01 UB30 UK02 UP02 UW41

Claims (8)

[Claims] 1. A decorative article comprising a foamed molded article in which raw beads made of a thermoplastic resin are fused together and integrated with each other, and at least a surface exposed to the outside is provided with a core vent mark or a vent hole mark. What is claimed is: 1. A foam molded article having an excellent design, wherein a smooth surface layer is provided without forming a projection. 2. The foam molded article having an excellent design according to claim 1, wherein a surface layer which is not exposed to the outside is provided with a surface layer having a projection formed of a core vent mark or a vent hole mark formed thereon. 3. The foamed molded article excellent in design according to claim 1, wherein a surface layer which is not exposed to the outside is provided with a surface layer on which no projection formed of a core vent mark or a vent hole mark is formed. 4. The design according to claim 1, comprising the densely fused non-permeable surface layer and an intermediate foamed layer having a fusion rate in the range of 30% to 100%. Molded foam with excellent properties. 5. The method according to claim 5, wherein the foam molding raw material beads made of a thermoplastic resin are made of at least one of a pair of heating dies having no vent hole for forming a surface exposed to the outside. The foam molded article having excellent design properties according to any one of claims 1 to 4, further comprising the surface layer formed by filling between the molds of the combination and heating and fusing at a temperature higher than a fusing temperature. 6. The foam molding having excellent design properties according to claim 5, wherein design irregularities are provided on the surface of the mold, and a design based on the design irregularities is formed on the surface of the surface layer of the foam molded article. body. 7. The article according to claim 1, wherein the foamed molded article is a member of a toy, a three-dimensional model, a display article, a decorative article, or a base member on which a cosmetic or decorative skin is mounted. Foam molded body with excellent design. 8. A foamed article according to claim 1, wherein the outer shape is formed into a boot shape, and the surface thereof is flocked for souvenirs, or for small goods such as confectionery and small toys. Container material.