JP2014000772A - Method of producing molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an efficient method of producing a molded article which, when producing a molded article having an uneven shape such as holes, does not require trimming and the like after molding or reduces at least operation of trimming or the like.SOLUTION: In a method of producing a molded article where raw materials are blown into the internal space of a hollow shaping die 7 having a first bottom wall 1, side walls, and a second bottom wall to produce the molded article, the first bottom wall 1 is provided with a projection 9 projecting to the internal space side, the side surface of the projection 9 is formed with air holes 11, and when the raw materials are blown and supplied into the internal space, sucking is performed from the air holes 11.

Description

  The present invention relates to a method for manufacturing a molded article. More specifically, the present invention does not require trimming after molding when manufacturing a molded product with irregularities such as holes, or at least an efficient molded product that reduces the work such as trimming. It relates to a manufacturing method.

  Conventionally, for the purpose of heat insulation, sound insulation, cushioning, etc., in the field of vehicle interior materials such as floor silencers, floor carpets, roof trims, door trims, and building materials such as floors, ceilings, walls, and carpets of buildings. For example, a fiber-shaped product such as a sheet is used. Such a fiber molded article is manufactured by various methods. For example, a mixed raw material of a binder fiber and a resin foam chip is blown into a hollow mold, heated, and then cooled (see FIG. 6, the broken line arrow in the mold 19 in FIG. This represents the direction in which the supplied raw material 17 is blown from the mouth N). As a method of blowing the raw material into the mold in this way, when a treatment material in which a fibrous binder and a chip such as flexible urethane foam are mixed is blown into the mold, the increase in resistance is detected and the blown air volume is adjusted. A method for manufacturing a soundproof material is known (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2001-60091

When a molded product with unevenness such as a hole (for example, a molded product 23 having a hole 21 as shown in FIG. 7) is to be molded by blowing a raw material into a mold as shown in Patent Document 1, 8 and 9, the first bottom wall 25, the side wall 27, the second bottom wall 29, and a protrusion 31 that is formed on the first bottom wall 25 and protrudes toward the inner space S (cavity) side. It is conceivable to use the molding die 33 (FIG. 9 is an exploded view of the molding die 33 with the second bottom wall 29 removed).
However, when there is a protrusion 31 for forming the hole 21 (see FIG. 7) in the molding die 33, when the raw material is blown in and supplied in the direction of the arrow as shown in FIG. The raw material is difficult to be supplied to the region X that is not directly hit but is behind the protrusion 31 (that is, the region that is on the leeward side with respect to the raw material supply direction in the internal space). Therefore, a trimming step near the hole is essential after molding. Furthermore, there is a possibility that a predetermined hole cannot be formed.

  The present invention has been made in view of the above circumstances, and does not require trimming after molding, or at least trimming or the like is reduced when manufacturing a molded product having irregularities such as holes. It is an object of the present invention to provide an efficient method for producing a molded product.

In order to solve the above problem, the invention described in claim 1 is a molding in which a raw material is blown into an internal space of a hollow mold having a first bottom wall, a side wall, and a second bottom wall to produce a molded product. A method for manufacturing a product,
The first bottom wall is provided with a protrusion protruding toward the inner space side,
A vent hole is formed on the side surface of the protrusion,
When the raw material is blown into and supplied to the internal space, the gist is drawn from the vent hole.

The gist of the invention described in claim 2 is that, in claim 1, the vent hole is formed in a shaded area where the flow of the raw material is not directly applied.
A third aspect of the present invention is the method according to the second aspect, wherein a part of the region in which the vent hole is formed is a first region,
When the other part of the region where the vent hole is formed is the second region,
The gist of the first region and the second region is that, when the distance from the region where the flow of the raw material directly hits is longer, the opening rate per unit area by the vent hole is larger. To do.

According to the method for producing a molded product of the present invention, when the raw material is blown in and supplied, the material is sucked from the vent hole formed in the protrusion, so that the flow of the raw material does not directly hit the region behind the protrusion. The raw material can be supplied sufficiently. Therefore, it is possible to perform uneven processing of the hole or the like in the molding die, and operations such as trimming after molding are not required or at least reduced, and a molded product can be manufactured efficiently.
In addition, when the vent is formed in a region that is not directly exposed to the flow of the raw material, the raw material is more reliably supplied to the region that is not directly exposed to the flow of the raw material and is behind the protrusion. be able to.
Furthermore, the raw material can be supplied more homogeneously and reliably when the opening rate per unit area by the air vent is increased as the distance from the region where the raw material flow directly hits is increased.

The present invention will be further described in the following detailed description with reference to the drawings referred to, with reference to non-limiting examples of exemplary embodiments according to the present invention. Similar parts are shown throughout the several figures.
It is typical explanatory drawing of a shaping | molding die. It is a typical disassembled perspective view of a shaping | molding die. It is typical explanatory drawing showing the manufacturing method of a molded article. It is typical explanatory drawing showing the manufacturing method of a molded article. It is typical explanatory drawing showing the manufacturing method of a molded article. It is typical explanatory drawing showing the manufacturing method of the conventional molded article. It is typical explanatory drawing of a molded article provided with a hole. It is typical explanatory drawing of a shaping | molding die provided with the protrusion for forming a hole part. It is a typical disassembled perspective view of a shaping | molding die provided with the protrusion for forming a hole part. It is typical explanatory drawing explaining the flow of the raw material blown in in a shaping | molding die.

Hereinafter, the present invention will be described in detail with reference to the drawings.
The items shown here are for illustrative purposes and exemplary embodiments of the present invention, and are the most effective and easy-to-understand explanations of the principles and conceptual features of the present invention. It is stated for the purpose of providing what seems to be. In this respect, it is not intended to illustrate the structural details of the present invention beyond what is necessary for a fundamental understanding of the present invention. It will be clear to those skilled in the art how it is actually implemented.

  The method for producing a molded product according to the present invention is a molded product for producing a molded product by blowing a raw material into an internal space S of a hollow mold 7 having a first bottom wall 1, a side wall 3, and a second bottom wall 5. This is a manufacturing method (see FIGS. 1 and 2). Further, the first bottom wall 1 is provided with a protrusion 9 protruding toward the internal space S side. Further, a vent hole 11 is formed on the side surface of the protrusion 9. Then, when the raw material is blown into and supplied to the internal space S, it is sucked from the vent hole 11.

[1] Mold Die 7 is hollow and has a first bottom wall 1, a side wall 3, and a second bottom wall 5. The first bottom wall 1 is formed with a protrusion 9 that protrudes toward the internal space S (see FIGS. 1 and 2). The shape of the internal space S of the mold 7 is substantially the same as the outer shape of the molded product to be manufactured.
Although the material of this shaping | molding die 7 is not specifically limited, Considering ease of handling, heat resistance, etc., it is preferable that it is metal. The type of metal is not particularly limited, but stainless steel, aluminum, or the like can be used. If it is made of stainless steel, it is possible to obtain a mold 7 having sufficient strength and hardly rusting. Moreover, if it is a product made from aluminum, while having sufficient intensity | strength, it can be set as the lightweight shaping | molding die 7. FIG.

A vent hole 11 is formed on the side surface of the protrusion 9 (see FIGS. 1 to 3). The shape and the number of the vent holes 11 are not particularly limited. For example, the shape may be a circle, an ellipse, a polygon such as a triangle or a quadrangle, and the like. The size of the vent hole 11 is not particularly limited as long as the supplied raw material does not leak from the vent hole 11.
The air holes 11 are preferably formed on the side of a region that is not directly exposed to the flow of the raw material (see the arrow (solid line) in FIG. 3) when the raw material is blown into the mold 7 (see FIG. 10 in region X). In this case, by blowing the raw material while sucking through the vent hole 11, the raw material can be sufficiently supplied to the area behind the projection 9 without being directly exposed to the flow of the raw material.
In addition, in other words, the region which is not directly hit by the flow of the raw material is a shadow region (the right side in FIG. 3) of the side surface of the protrusion 9 with respect to the raw material supply direction in the internal space S. ). In addition, this region is a region where a vortex or the like (Karman vortex, twin vortex, turbulent flow) can be formed behind the projecting portion having the same shape in which the vent hole 11 is not formed in the raw material flow. is there.

Further, in the present invention, from the viewpoint of supplying the raw material uniformly and surely into the mold 7, the opening rate per unit area by the vent hole 11 can be adjusted according to the flow of the raw material. Specifically, as shown in FIGS. 4 and 5, a part of the region where the vent hole 11 is formed in the protrusion 9 is defined as a first region Y (see FIG. 5), and the vent hole 11 is formed. In the case where the other part of the formed region is the second region Z (see FIG. 5), the first region Y and the second region Z have a longer distance from the region where the material flow directly hits (FIG. 5). In this case, Y is equivalent), but the opening rate per unit area by the air holes 11 can be increased.
The hole area ratio per unit area in the protrusion 9 can be controlled by the number and size of the air holes. 4 and 5 are examples in which the size of the air holes 11 is controlled, and the holes are arranged in order of increasing distance from the region where the flow of the raw material directly hits, that is, in order of the air holes 11A, 11B, and 11C. It is formed to be smaller.

The side wall 3 of the mold wall of the mold 7 has air permeability. The side wall 3 may be provided with a side wall vent, or the side wall may be formed using a material having air permeability. When the side wall vents are provided, the number and shape thereof are not particularly limited. For example, the shape may be a circle, an ellipse, a polygon such as a triangle or a quadrangle, and the like. The size of the side wall vent is not particularly limited as long as the supplied raw material does not leak from the side wall vent.
Further, it is preferable that the side wall air holes are provided substantially evenly on the entire side wall of the mold 7. In this case, a homogeneous molded product can be manufactured.

[2] Supply and forming of raw material The method of supplying the raw material by blowing it from the raw material supply port N is not particularly limited. For example, a method is adopted in which a raw material is flowed together with an airflow using a blower or the like from a container (not shown) containing the raw material, air-fed, and blown. 1 and 2, the first bottom wall 1 is illustrated as a bottom wall on the lower side of the drawing, but the first bottom wall 1 may be an upper side bottom wall. In addition, the raw material supply port may be formed only in one place, and may be formed in several places.
Further, when the raw material is supplied, suction is performed by a suction means (not shown) through the vent hole 11 formed in the protrusion 9 in the first bottom wall 1. By this suction, the raw material is sucked into the vent hole 11, and the raw material can be supplied uniformly to the area behind the protrusion 9 without being directly exposed to the flow of the raw material.
The suction means is not particularly limited, and a known suction means can be used. Specifically, a vacuum pump or the like can be used.

The raw material that is blown into the mold 7 and supplied usually contains a heat-sealing component that melts by heating and fuses the fibers of the raw material, particles, and the like. In this heating step, by heating the preformed product, the heat-sealing component is melted and the raw material fibers and particles are joined. Then, a molded article is manufactured by cooling.
The heating temperature should be a predetermined temperature that takes into consideration the material of the raw material, the melting point of the thermal fusion component, etc., and the non-thermal fusion component does not melt at all, but only the thermal fusion component melts and functions as a binder. it can.
In addition, the heating time is not particularly limited depending on the material of the raw material, the heating temperature, etc., but as long as the entire heat fusion component is melted and between the fibers of the raw material, between the particles, etc. are sufficiently joined, It is preferable to perform heating for a short time.

  The heating method described above is not particularly limited. For example, the mold 7 filled with the raw material can be heated by a method of allowing hot air to pass through. Further, the mold 7 filled with the raw material can be heated by a method of passing through a heating furnace, standing in the heating furnace for a predetermined time, or heating with a far infrared heater or the like. Thereby, a heat-fusion component can be softened and melted. Thereafter, the molded product can be manufactured by cooling by using a method of allowing the mold to pass a room temperature or low temperature wind, a method of cooling the mold from the outside, a method of forcibly cooling the mold with cold air, cold water, or the like.

According to the method for manufacturing a molded product of the present invention, for example, a molded product having unevenness such as a hole used as an interior material for a vehicle is performed in the mold 7 including uneven processing such as a hole. Can do. Therefore, after molding, work such as trimming in the vicinity of the concavo-convex portion is unnecessary or at least reduced.
In addition, the molded product can be manufactured as a molded product having a predetermined shape using a molding die having an internal space having a predetermined shape. Furthermore, by molding into a flat plate shape having a concavo-convex portion, and then pressing a flat plate-shaped preform that has been heated in advance to a predetermined temperature with a molding die that is cooled to the ambient temperature or, if necessary, the predetermined temperature, A molded product having a predetermined shape may be used. In addition, by using a molding die, placing a flat preform having a concavo-convex portion in a die controlled to a predetermined temperature, heating, pressurizing, and then cooling, a molded product having a predetermined shape It can also be.

[3] Raw material The raw material is not particularly limited. Usually, the raw material 17 containing the heat-fusible fiber 13 used as a binder and the resin foam particle 15 is used (refer FIG. 6).
As the heat-fusible fiber 13, various synthetic fibers can be used. Synthetic fibers include polyester fibers such as polyethylene terephthalate fibers and polybutylene terephthalate fibers, polyamide fibers such as nylon 6 fibers and nylon 66 fibers, polyolefin fibers such as polyethylene fibers and polypropylene fibers, and acrylic fibers such as polymethyl methacrylate fibers. Is mentioned. As the heat-fusible fiber 13, only one type of these fibers may be used, or two or more types may be used in combination.

  The heat-fusible fiber 13 is preferably a low-melting-point polyester fiber or a polyolefin fiber that can be melted at a relatively low temperature to bond the resin foam particles 15 and the like. Moreover, as the heat-fusible fiber 13, a core-sheath fiber comprising a low-melting-point sheath and a high-melting-point core that does not melt at the temperature at which the sheath melts can be used. As such a core-sheath fiber, the following are mentioned, for example. That is, the sheath is made of polyester having a relatively low melting point, the core is made of polyester having a relatively high melting point, the sheath is made of polyethylene, the sheath is made of polyethylene, and the sheath is made of polypropylene. Can be mentioned. Furthermore, as the heat-fusible fiber 13, a side-by-side fiber such as a side-by-side fiber of polypropylene and polyethylene can be used.

As the resin foam particles 15, various resin foam particles such as polyurethane foam and polyolefin foam can be used. As the resin foam particles 15, only one kind of these particles may be used, or two or more kinds may be used in combination.
In addition, as the resin foam particles 15, unused foam particles may be used, and waste materials can be reused as long as a molded product of a predetermined quality can be obtained. For example, the shredder dust of the vehicle can be reused from the crushed material contained in the residue excluding metal, glass, wire harness and other dust, and the end material generated by trimming when manufacturing the interior material for the vehicle. it can.

  The shape of the resin foam particles 15 is not particularly limited, and may be any shape. For example, the crushed material and the end material are indefinite. The dimensions of the resin foam particles 15 are not particularly limited, and the resin foam particles 15 having a maximum dimension of 8 to 18 mm, particularly 10 to 14 mm can be used. The maximum size of the resin foam particles 15 is preferably set to an appropriate size depending on the thickness of the molded product.

  Furthermore, the mass ratio between the heat-fusible fiber 13 and the resin foam particles 15 is particularly limited as long as the resin foam particles 15 can be joined so that the heat-fusible fibers 13 do not easily fall off. Not. When the total of the heat-fusible fiber 13 and the resin foam particles 15 is 100% by mass, the heat-fusible fiber 13 can be 5 to 70% by mass, and is 25 to 45% by mass. It is preferable. Thereby, a molded article provided with sufficient strength and the like can be manufactured more easily. In addition, it is preferable that the heat-fusible fiber 13 and the resin foam particles 15 are sufficiently uniformly dispersed and mixed. If the dispersion and mixing are sufficiently uniform, the resin foam particles 15 can be joined so as not to easily fall off even if the amount of the heat-fusible fiber 13 is smaller.

  The raw material may contain various additives as required. Such additives include, for example, antioxidants, ultraviolet absorbers, lubricants, flame retardants, flame retardant aids, softeners, inorganic or organic to improve the impact resistance and heat resistance of the fiber structure, etc. Various fillers, antistatic agents, colorants, plasticizers and the like. Moreover, these additives can be contained in the molded product by blending into the heat-fusible fiber 13 and / or the resin foam particles 15.

[4] Use of molded product, etc. The use of the molded product of the present invention is not particularly limited. It can be used in a wide range of products such as vehicles and building materials, and is particularly useful as an interior material for vehicles. Examples of the vehicle interior material include various interior materials such as a floor silencer, a floor carpet, a roof trim, and a door trim. Since the molded product is used in these various applications, the thickness is not particularly limited, and can be set to an appropriate thickness depending on the application. The thickness of the molded product is usually 5 to 75 mm, particularly 5 to 65 mm, and more preferably 30 to 65 mm. If the thickness of the molded product is 5 to 75 mm, it can be suitably used as a relatively lightweight member while having sufficient strength and the like in many applications.

Hereinafter, the present invention will be described specifically by way of examples.
Manufacture of molded products (Example 1)
(1) Raw materials The following materials were used as the heat-fusible fibers and resin foam particles as raw materials. As the heat-fusible fiber, the core-sheath short fiber (Toray) whose core is made of polyethylene terephthalate (melting point: 260 ° C.) and whose sheath is a copolymer polyester resin (melting point: 110 ° C.). (Trade name “T9611”, average fineness; 2.2 decitex, average fiber length; 10 mm). Further, as the resin foam particles, granular polyurethane foam, which is a crushed product obtained by crushing a lump-like soft polyurethane foam, was used (density: 0.015-0.030 g / cm ³ , maximum dimension: 15 mm). . Further, when the total of the heat-fusible fiber and the resin foam particles was 100% by mass, the heat-fusible fiber was 25% by mass.

(2) Feeding and molding of raw material As shown in FIG. 1, a molding die is being sucked by a suction means (not shown) through a vent hole 11 formed in a projection 9 in the first bottom wall 1. The raw material was blown into the internal space S of No. 7 through the raw material supply port N in the direction of the arrow to supply a total amount of 3500 g of the raw material. In addition, this raw material consists of the mixture which carried out the dry blend of the above-mentioned heat-fusible fiber and a granular polyurethane foam.
Thereafter, hot air at 200 ° C. was made to pass through the mold 7 to soften and melt the heat-fusible fiber, and the heat-fusible fiber and the resin foam particles were joined. Next, a room-temperature air was made to pass through and cooled to room temperature, and a flat plate-shaped molded article having a hole portion, which was used as a part of a floor part that is an interior material of a passenger car, was manufactured.

(3) Effect of Example In the molded product thus manufactured, there was no abnormality in the shape of the hole and its vicinity, and trimming was not necessary.

  It should be noted that the above description is for illustrative purposes only and is not to be construed as limiting the invention. Although the invention has been described with reference to exemplary embodiments, it is to be understood that the language used in the description and illustration of the invention is illustrative and exemplary rather than restrictive. As detailed herein, modifications may be made in the embodiments within the scope of the appended claims without departing from the scope or spirit of the invention. Although specific structures, materials, and embodiments have been referred to in the detailed description of the invention herein, it is not intended to limit the invention to the disclosure herein, but rather, the invention is claimed. It covers all functionally equivalent structures, methods and uses within the scope.

  The present invention can be used in a wide range of product fields such as vehicles and building materials. Molded products with irregularities such as holes produced by the method of the present invention do not require trimming after molding, have high productivity, and various members in the above-described product field, particularly the product field of vehicle interior materials Useful in.

  DESCRIPTION OF SYMBOLS 1; 1st bottom wall, 3; Side wall, 5; 2nd bottom wall, 7: Mold, 9; Protrusion, 11; Vent hole, 13; Heat-sealable fiber, 15; Raw material, N: Raw material supply port, S: Internal space.

Claims (3)

A method for manufacturing a molded product, in which a raw material is blown into an internal space of a hollow mold having a first bottom wall, a side wall, and a second bottom wall,
The first bottom wall is provided with a protrusion protruding toward the inner space side,
A vent hole is formed on the side surface of the protrusion,
A method for producing a molded product, wherein the raw material is sucked from the vent hole when supplied to the internal space.   The method for producing a molded product according to claim 1, wherein the air hole is formed in an area where the flow of the raw material is not directly applied but is shaded. A part of the region where the vent is formed is a first region,
When the other part of the region where the vent hole is formed is the second region,
In the first region and the second region, the opening rate per unit area by the vent hole is increased when the distance from the region where the flow of the raw material directly hits is longer. The manufacturing method of the molded article of description.

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