JPH04278334A - Manufacture or resin molded body - Google Patents

Abstract

PURPOSE:To effectively reutilize foamed styrol by filling a box-shaped body obtained by the foam molding of foamed polystyrene beads with ground small pieces formed by grinding foamed polystyrene and closely bonding them under heating to form a core body. CONSTITUTION:EPS (foamed polystyrene) formed into various shapes by foam molding is ground by a grinder to form small pieces with a particle size of 20-40mm and these small pieces are subjected to volume decrease treatment under heating to be reduced to 1/50 or more in volume. Next, a core mold 31 and a recessed mold 32 forming a cavity having a predetermined shape is filled with separate EPS beads having a foaming agent added thereto and foamed preparatorily and the EPS beads are subjected to foam molding under heating to form a hollow box-shaped body 33 having an opening. The box- shaped body 33, cleaned of the mold 32 is filled with ground small pieces 34 obtained by adding a binder or EPS beads to the EPS small pieces after volume decrease and these small pieces 34 are closely bonded under heating to form a core body 40 and a resin molded body wherein the core body 40 is covered with the box-shaped body 33 and a lid body 37 is obtained.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for manufacturing a resin molded article by recycling used styrofoam.

0002

[Technical background of the invention] Expanded polystyrene
ed Poly-Styrol (hereinafter referred to as EPS) is a product made by adding a foaming agent to polystyrene resin, injecting it into a specified mold, heating and softening it, and at the same time generating gas to create a foam mold. It has excellent heat insulating properties and compressive strength, so it is widely used as heat insulators and cushioning materials for packaging. Such EPS foam molding involves injecting pre-expanded polystyrene beads into a predetermined mold.
There is an in-mold foaming method that creates a foam with a predetermined density by heating and cooling, or a foaming agent is injected and mixed into molten polystyrene under high pressure to create a fluid gel, which is extruded into the atmosphere to rapidly produce a foam. This is done using an extrusion foaming method that involves expanding and molding.

[0003] EPS, once foam-molded into a predetermined shape, lacks versatility and is therefore a so-called "disposable" material, and after use, it must be disposed of by incineration or melting and then incineration. is common.

[0004] However, there are problems in that carrying out such a disposal process is complicated and that it is expensive to transport to a disposal site due to the large volume occupancy. Furthermore, it is necessary to reuse resources as much as possible from the perspective of effective use of resources.

[0005]

[Object of the Invention] The present invention was made in view of the above-mentioned circumstances, and an object thereof is to provide a method for manufacturing a resin molded product that can effectively reuse a polystyrene foam molded product. .

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the method for producing a resin molded article according to the present invention heats and foams expanded polystyrene beads in a concave mold to form a hollow box-like body having an opening. A binder or expanded polystyrene beads are added to the crushed pieces obtained by crushing the foamed polystyrene that has been formed and once foam-molded, and the crushed pieces are filled into the box-shaped body, and the crushed pieces to which the additive has been added are added. A core body is formed by heating to bring them into close contact with each other, and at the same time, or at the same time, a lid body for sealing the opening of the box-shaped body is formed by heating and foaming with expanded polystyrene beads. It is characterized by manufacturing a resin molded body that covers a core body.

[0007] Furthermore, in the method for producing a resin molded article according to the present invention, foamed polystyrene beads are heated and foam-molded in a concave mold to form a hollow box-like body having an opening, and the foamed polystyrene beads that have been foam-molded are A lid body that stores a core body formed by adding a binder or expanded polystyrene beads to crushed pieces of crushed polystyrene and molding the mixture in a mold in the box-shaped body, and seals the opening of the box-shaped body with the expanded polystyrene beads. It is characterized in that it is heated and foam-molded to produce a resin molded body in which a core body is covered with a box-shaped body and a lid body.

Furthermore, in the method for producing a resin molded article according to the present invention, a foamed polystyrene plate that has been heat-foamed is placed on the bottom of a mold, and the foamed polystyrene that has been foam-molded is crushed into small pieces. A core formed by adding a binder or expanded polystyrene beads and molding in a mold is placed on the expanded polystyrene plate at the bottom of the mold, and expanded polystyrene is filled in the space between the mold and the core. The method is characterized in that a box-shaped body is formed by filling the beads with heat and foaming, thereby producing a resin molded body in which a core body is covered with a foamed polystyrene plate and a box-shaped body.

[0009] In this way, in any of the present inventions,
It has a reused core inside, and the periphery of this core is made of new EPS, so the molding accuracy is higher than that of normal EPS.
It can be secured to the same level as PS, and can be applied to members that require high precision. Moreover, since most of the core material among the raw materials is made from used expanded polystyrene, this expanded polystyrene can be effectively reused, resulting in significant cost reductions and energy savings. It is also possible to make effective use of.

0010

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below based on embodiments shown in the drawings. 1 to 3 are the first embodiment of the present invention.
FIG. 4 is a cross-sectional view of the resin molded body manufactured according to the example, and FIG. 5 is a perspective view showing a crushing device according to the example.

First, in manufacturing the resin molded article according to the first embodiment, EPS foam-molded into various shapes by the conventional in-mold foaming method or extrusion foaming method, etc. is crushed by a crushing apparatus as shown in FIG. Grind into small pieces. This crusher includes a crusher 15 that crushes used EPS compacts to a particle size of 20 to 40 mm, and a fine crusher that further finely crushes the EPS crushed by the crusher 15 to a particle size of about 1 mm. 16 are connected to each other via a small piece guide duct 17, and each of the crushers 15 and 16 has an input port 18 into which used EPS molded bodies are input, and this input port 18 is equipped with a crushing cutter. A rotating drum 19 is rotated by a motor 20 (only the crusher 15 is shown). Further, the EPS finely crushed by the fine crusher 16 is stored in a silo 22 via a small piece guide duct 21. "2
3" is a blower for sending small pieces of EPS from the fine grinder to the silo. The small pieces referred to here have a particle size of 0.1 mm.
The size can be selected as appropriate, but is preferably 1 to 10 mm, more preferably 3 to 7 mm.
mm, most preferably around 5 mm.

[0012] Next, this small piece of EPS is subjected to volume reduction treatment by heating and shrinking. However, this volume reduction treatment is optional, and the next molding step may be performed without performing this volume reduction treatment, or the next molding step may be performed after this volume reduction treatment.

[0013] As heating means in this volume reduction treatment,
It is preferable to use a heating means that causes non-melting heating and contraction, such as a far-infrared heater. When heating with such a far-infrared heater is adopted, the volume can be reduced by non-melting, which not only prevents the heating device from getting dirty but also makes maintenance easier.The unique action of far-infrared rays also makes it possible to quickly heat the inside of the EPS. This can shorten processing time.

[0014] Furthermore, since the heat treatment with far infrared rays is carried out in a low temperature range (glass transition temperature Tg of polystyrene = 82°C, heat distortion temperature = 64-93°C), destruction of the polymer structure due to thermal decomposition may occur. This makes it suitable for reusing EPS. Specifically, this heating step is carried out by carrying crushed pieces of EPS on a belt conveyor or the like and continuously transporting them through a heating furnace equipped with a far-infrared heater.

[0015] In this volume reduction process, the volume of the small piece is reduced to 1/5
It is reduced to 0 or more, preferably 1/30 or more, and more preferably 1/10 or more. In addition, if the above-mentioned crusher and heating furnace are installed in a used EPS collection vehicle and the EPS is crushed and heat-shrinked during collection, collection and the above two steps can be performed at the same time. At the same time, volume reduction processing is performed during collection, which significantly increases the amount collected by collection vehicles. Furthermore, instead of installing both a crusher and a heating furnace in the collection vehicle, only the crusher may be installed.

Next, using the crushed EPS pieces (which may or may not have been subjected to a volume reduction process), the process shown in FIG. 4 is carried out by the steps shown in FIGS. 1 to 3. A resin molded body 30 is manufactured.

First, as shown in FIG. 1, in a core mold 31 and a concave mold 32 having a cavity of a predetermined shape, a foamed material which is pre-foamed by adding a foaming agent different from the crushed EPS pieces is placed. Filled with polystyrene beads and heated and foamed. As a result, a hollow box-like body 33 having an opening is formed. After this molding, the core mold 31 is removed. The foaming conditions in this case may be substantially the same as the normal EPS foaming conditions, and the molding cycle may also be substantially the same. Further, the shape of the box-like body 33 is not limited to a cube or a rectangular parallelepiped, but may be of various shapes depending on the purpose.

Next, as shown in FIG. 2, a binder or expanded polystyrene beads are added to the pulverized EPS pieces (which may or may not have undergone a volume reduction process). , and the crushed pieces 34 to which these have been added are filled into the box-shaped body 33.

[0019] Here, the binder is for adhering the crushed pieces to each other, and includes a vinyl acetate adhesive, starch glue, a synthetic viscosity modifier, CMC (carboxymethyl cellulose),
Examples include synthetic resin paints, paste sol, and rubber latex. Among these, vinyl acetate adhesives are preferably used.

[0020] The expanded polystyrene beads are also for adhering the crushed pieces to each other, and unlike the crushed EPS pieces mentioned above, they are new expanded polystyrene beads that have been pre-foamed with the addition of a foaming agent.

Thereafter, as shown in FIG. 3, the crushed pieces 34 to which the binder or expanded polystyrene beads have been added are heated, and the crushed pieces 34 are adhered to each other by the binder or expanded polystyrene beads.
The core body 40 is formed by closely fixing the core body 40. Simultaneously with the heating of the crushed pieces 34, pre-foamed polystyrene beads are injected into the molds 32, 35 closed by the lid mold 35 through the gate 38 and are heated and foamed. Thereby, the lid body 37 that closes the opening of the box-like body 33
A resin molded body 30 can be formed in which a core body 40 is covered with a box-shaped body 33 and a lid body 37.

As mentioned above, the heating of the crushed pieces 34 and the molding of the lid 37 may be performed at the same time, but the invention is not limited to this; after heating the crushed pieces 34, the lid 37 is then formed.
You may also perform molding. Furthermore, the foaming conditions for the lid body 37 may be substantially the same as the normal EPS foaming conditions, and the molding cycle may also be substantially the same.

[0023] The resin molded article formed in this way is
As shown in Figure 4, although the specific gravity becomes heavier, the basic E
It does not impair the properties of PS in any way, and therefore, like normal EPS, it is lightweight, has excellent heat insulation properties, and has excellent compressive strength, so it can be used as insulation material for packaging, cushioning material, buried material, etc. . Furthermore, the core body 40 is reused inside.
A box-like body 33 and a lid body 37 made of new EPS.
Since the core body 40 is coated, the molding accuracy can be ensured on a par with that of normal EPS, and it can be applied to members that require high precision. Moreover, since most of the raw materials for the core body 40 are made of used expanded polystyrene, it is possible to effectively reuse these expanded polystyrenes, which in turn can significantly reduce costs. Effective use of energy can also be achieved.

Further, the outer dimensions and shape of the resin molded body 30 are not particularly limited. However, the ratio of the core body 40 to the resin molded body 30 is 50 to 90% of the outer dimension of the resin molded body 30.
%, preferably about 80%. However, since the shapes of the resin molded body 30 and the core body 40 do not necessarily have to be similar, the ratio of the core body 40 to the resin molded body 30 can be arbitrarily selected depending on the purpose and shape. The core may have, for example, a spherical shape, a disk shape, or other irregular shapes, and a plurality of these may be used.

Next, a method for manufacturing a resin molded body according to a second embodiment of the present invention will be described with reference to FIGS. 6 to 8. In this second embodiment, first, E
A small piece of PS or a small piece of EPS that has not been subjected to volume reduction treatment is injected into a mold having a predetermined shape and molded in the mold to form the core body 40. When performing this in-mold molding, a binder or expanded polystyrene beads are added to bond the pieces together. The preferred binder used for bonding the EPS is as exemplified in the first embodiment.

[0026] Furthermore, when molding a small piece of EPS in a mold, E
Compression molding may be performed by compressing small pieces of PS and applying heat.
Alternatively, in-mold molding may be performed by applying heat to the small piece without compressing the small piece. Furthermore, the molding conditions (temperature, etc.) for this in-mold molding may be the same as those for normal EPS.

On the other hand, similarly to the first embodiment, the core mold 3
1 and a concave mold 32, pre-foamed expanded polystyrene beads are heated and foam-molded to form a hollow box-shaped body 33.

Next, as shown in FIG. 6, the core body 40 solidified as described above is housed in the hollow box-shaped body 33. During this storage, in order to increase the degree of adhesion between the core body 40 and the box-shaped body 33, it is preferable to tighten the fit between the two, but the invention is not limited to this, and the fit between the two may be loosened. It's okay to have one.

Next, as shown in FIG. 7, a lid 37 is formed. That is, as in the first embodiment, both molds 32, 3
Expanded polystyrene beads are injected into the tube 5 through the gate 38 and heated and foamed. As a result, as shown in FIG. 8, a resin molded body 30 is completed in which the core body 40 is covered with the box-shaped body 33 and the lid body 37.

Similar to the first embodiment, the resin molded body 30 molded according to the second embodiment also has a reused core 40 inside, and this core 40 is covered. For,
It is possible to ensure molding accuracy equivalent to that of normal EPS,
It can be applied to members that require high precision, and since most of the core body 40 is made of used expanded polystyrene, it is possible to effectively reuse the expanded polystyrene. .

The dimensional ratio between the resin molded body 30 and its core body 40 according to the second embodiment is the same as that of the first embodiment. Next, a method for manufacturing a resin molded body according to a third embodiment of the present invention will be described with reference to FIGS. 9 and 10.

In this third embodiment, first, the core body 40 is molded in a mold as in the second embodiment. The specific in-mold molding method is the same as in the second embodiment. On the other hand, a foamed polystyrene plate 41 is heated and foam-molded using new foamed polystyrene beads, and placed on the bottom of a concave mold 32, as shown in FIG. This expanded polystyrene plate 41 may be any ordinary EPS, and is an EPS made of something other than the above-mentioned crushed EPS.

The core body 40 molded in the mold is placed on the expanded polystyrene plate 41 placed on the bottom of the concave mold 32.
is placed, and the lid mold 35 is closed with respect to the concave mold 32. Thereby, a predetermined space is defined between the core body 40 and the molds 32 and 35. Note that if there is a risk that the core body 40 may be displaced, it may be simply fixed with an adhesive or double-sided tape. Into the predetermined space, via the gate 38,
Inject new expanded polystyrene beads and heat foam molding. Thereby, it is possible to form a box-like body 33 arranged in the opposite direction to the box-like bodies of the first and second embodiments. As a result, a resin molded body 30 is completed in which the core body 40 is covered with the expanded polystyrene plate 41 and the box-shaped body 33.

Similar to the first and second embodiments, the resin molded body 30 molded according to the third embodiment can also ensure molding accuracy equivalent to that of ordinary EPS, and can also be used in cases where high precision is required. In addition, since most of the core body 40 is made of used expanded polystyrene, it is possible to effectively reuse the expanded polystyrene.

The dimensional ratio between the resin molded body 30 and its core body 40 according to the third embodiment is the same as in the first and second embodiments. The resin molded body 30 manufactured according to the first to third embodiments in this way is not particularly limited in its use, but can be used, for example, as a block for civil engineering. Examples of the civil engineering blocks include blocks for embankments on soft ground, blocks for embankments on steep slopes, blocks for backfilling structures, and blocks for upright retaining walls.

FIGS. 10 and 11 show examples of civil engineering work using civil engineering blocks made of resin molded bodies according to the present invention. FIG. 11 shows a block used as an embankment block on soft ground. In this example, a non-woven fabric 3a is laid on the soft ground 1, and this non-woven fabric 3a is made of the same material as the non-woven fabric 3b, which will be described later, and has the role of discharging water etc. that has passed through the waterproof layer, and also has a block part. It acts to separate the ground from the ground. A resin molded body 30 according to the present invention is laminated on this nonwoven fabric 3a. In addition, in the example of FIG. 11,
Although the resin molded bodies 30 are laminated to have a rectangular cross section, the present invention is not limited to this, and the cross section may be laminated to have a trapezoidal shape with a wide base.

The size of the resin molded body 4 used for civil engineering is as follows:
Although not particularly limited, it is determined to have a weight that can be easily carried by two people, and preferably has a rectangular parallelepiped shape ranging from several tens of cm square to a rectangular parallelepiped with a long edge of 10 m or less. For example, the outer dimensions of the resin molded body 4 are 50 x 100 x 20
0 (unit: cm). At this time, the outer dimensions of the core body 40 inside the resin molded body 4 are 25 x 50 x
100 (unit: cm) to 45 x 90 x 180 (unit: cm)
), and preferably the molded body is 40 x 80 x 160 (unit: cm). In the future, the outer dimensions of the resin molded body 4 will be
A large one measuring 100 x 200 x 600 (unit: cm) is preferable.

After the resin moldings 30 are stacked in a predetermined shape in this manner, the nonwoven fabric 3b is laid around the resin moldings 30. The nonwoven fabric 3b is made of, for example, polyester long fibers like the nonwoven fabric 3a described above. After this nonwoven fabric 3b is laid, asphalt is applied to this nonwoven fabric 3b by a coating method such as spraying to form a waterproof layer. Thereafter, the surface of this nonwoven fabric 3b is covered with a protective sheet 5. The protective sheet 5 is for protecting the waterproof layer and is made of polyethylene film, polyester film, or the like.

The road 2 is formed on the resin molded body 30 covered with the waterproof layer and the protective sheet 5 in the following manner, for example. First, a concrete plate 6 is laid on the protective sheet 5. Thereafter, roadbeds 7 and 8 are formed using gravel or the like, and a road surface layer 9 is formed thereon. After that, or at the same time as the above process, retaining walls 10 are covered with soil etc. on both sides.
Once the road is formed, the road will be completed. In addition, the retaining wall 10 can also be replaced with a simple wall surface protection material without using the covering soil.

As described above, when the resin molded body 30 of the present invention is applied to road construction, since a waterproof layer is formed around the laminated resin molded body 30, moisture such as rainwater is absorbed into the resin molded body. Therefore, the weight of the resin molded article does not increase. Moreover, since the resin molded body itself does not need to have water resistance, it is preferable to use a recycled EPS product like the resin molded body of the present invention described above.

FIG. 12 shows a specific example of constructing a road on steeply sloping ground using an embankment block made of a resin molded body according to the present invention. In this case, the resin molded bodies 30 are laminated along the sloped ground 12, and one side is covered with the wall surface protection material 11. This embodiment also has the same effects as those of the previous embodiment, has almost no adverse effect on the sloped ground, and can suppress the occurrence of road subsidence, slipping, etc.

[0042] The present invention is not limited to the above-mentioned embodiments, and can be variously modified within the scope of the present invention. In particular, the use of the resin molded article according to the present invention is not limited to the above-mentioned embodiments. Of course, it is not limited.

[0043]

[Effects of the Invention] As explained above, according to the method for manufacturing a resin molded article according to the present invention, although the molded resin article has a higher specific gravity, the basic characteristics of EPS are not impaired in any way. Therefore, like normal EPS, it is lightweight, has excellent heat insulation properties, and has excellent compressive strength, so it can be used as a heat insulating material, a cushioning material, an embedding material, etc. for packages. In addition, it has a core that is recycled internally, and a new EP
Since this core body is covered with a box-like body and a lid body made of S, it is possible to ensure the same molding accuracy as normal EPS, and it can be applied to parts that require high precision. . Moreover, since most of the core material among the raw materials is made from used expanded polystyrene, this expanded polystyrene can be effectively reused, resulting in significant cost reductions and energy savings. It is also possible to make effective use of.

[Brief explanation of the drawing]

FIG. 1 is a process diagram for manufacturing a resin molded body according to a first embodiment of the present invention.

FIG. 2 is a process diagram for manufacturing a resin molded body according to the same example.

FIG. 3 is a process diagram for manufacturing a resin molded body according to the same example.

FIG. 4 is a sectional view of a resin molded article manufactured according to the same example.

FIG. 5 is a perspective view showing a crusher according to the same embodiment.

FIG. 6 is a process diagram for manufacturing a resin molded body according to a second embodiment of the present invention.

FIG. 7 is a process diagram for manufacturing a resin molded body according to the same example.

FIG. 8 is a sectional view of a resin molded article manufactured according to the same example.

FIG. 9 is a process diagram for manufacturing a resin molded body according to a third embodiment of the present invention.

FIG. 10 is a sectional view of a resin molded article manufactured according to the same example.

FIG. 11 is a longitudinal sectional view of an embankment road using a civil engineering block made of a resin molded body manufactured according to the present invention.

FIG. 12 is a longitudinal cross-sectional view of a road on a steep slope using a civil engineering block made of a resin molded body manufactured according to the present invention.

[Explanation of symbols]

30 Resin molded body 32 Concave mold 33 Box-shaped body 34. Small crushed pieces 37 Lid body 40 Core body

Claims (3)

[Claims] Claim 1: Expanded polystyrene beads are heat-foam-molded in a concave mold to form a hollow box-like body with an opening, and once the foam-molded expanded polystyrene is pulverized into crushed pieces, a binder or expanded polystyrene is added. Adding beads, filling the crushed pieces into the box-like body, heating the crushed pieces to which the additives have been added to bring them into close contact with each other to form a core, and simultaneously or then filling the crushed pieces with expanded polystyrene beads. A method for producing a resin molded body, comprising heating and foam-molding a lid that closes the opening of the box-shaped body, thereby producing a resin molded body in which a core body is covered with the box-shaped body and the lid. . 2. Expanded polystyrene beads are heat-foam-molded in a concave mold to form a hollow box-like body with an opening, and once the foam-molded expanded polystyrene is pulverized into crushed pieces, a binder or expanded polystyrene is added. A core formed by adding beads and molding in a mold is housed in the box-shaped body,
A resin molding characterized in that a lid body that closes the opening of the box-shaped body is heated and foam-molded with expanded polystyrene beads, thereby producing a resin molded body in which a core body is covered with the box-shaped body and the lid body. How the body is manufactured. 3. A foamed polystyrene plate that has been heated and foam-molded is placed on the bottom of a mold, and a binder or foamed polystyrene beads are added to the crushed pieces of the foamed polystyrene that has been foam-molded and molded in the mold. The core body made of
Placed on a foamed polystyrene plate at the bottom of the mold,
The space between the mold and the core body is filled with foamed polystyrene beads and heated and foamed to form a box-shaped body, whereby the core body is covered with the foamed polystyrene plate and the box-shaped body.Resin molding 1. A method for producing a resin molded body, the method comprising producing a resin molded body.