JPH10156935A - Method and equipment for vacuum forming of air-permeable material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and equipment for vacuum forming of an air- permeable material wherein the vacuum forming is applied to a face-like material having air permeability. SOLUTION: A clamp frame 2 holding a face-like material W and made up of an upper frame 2a and a lower frame 2b is provided above a die mounting table 1, a non-air-permeable sheet 5 of rubber or the like which is vacuum- sucked onto a die 7 and elastically deformable is stretched and fitted on the upper frame 2a, and construction is so made that the face-like material can be processed by a suction deforming pressure of the non-air-permeable sheet 5 to the die 1. In some cases, a heater 6 heating the non-air-permeable sheet 5 is provided and the face-like material W is heated thereby through the non-air- permeable sheet 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a vacuum forming method and a vacuum forming apparatus for a gas-permeable material such as a non-woven fabric, a foamed resin sheet, and a porous film.

[0002]

2. Description of the Related Art In a vacuum forming method, a sheet material of a heat-meltable resin such as a soft polyvinyl chloride film, a polyethylene film, an impact-resistant polystyrene sheet or the like is suctioned to a mold surface by a vacuum pressure to perform processing. You. For the general process, the sheet material is held by a clamp frame,
It is softened by heating, molded by vacuum suction on the mold surface, cooled and released.

[0003]

According to the conventional vacuum molding as described above, one mold is sufficient and the efficiency of the molding is very good. It is necessary to use a film or sheet or the like that does not have air permeability as the shape-like material, and there is a problem that the material is restricted in that respect, and a product having air permeability cannot be formed.

Therefore, conventionally, in order to process the air-permeable planar material, pressure molding (press molding) sandwiching the upper and lower molds has been performed. In
Since two molds, an upper mold and a lower mold, are required, and high dimensional accuracy is required from the molds, the mold cost is abnormally high. In this regard, vacuum forming has an advantage that an inexpensive wooden mold can be used. Further, in the case of pressure molding, when the air-permeable material is a nonwoven fabric or the like, there is a problem that air permeability, cushioning property, and heat insulating property as properties are impaired by pressurization.

The present invention has been made in view of the above-described circumstances,
An object of the present invention is to provide a vacuum forming method of a gas permeable material that can effectively process a gas permeable sheet material.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides a method in which a planar material to be a molded article is suctioned to a mold surface by a vacuum pressure while heating the molded article, and the molded article is cooled. In the vacuum forming method of releasing from the mold, a material having air permeability is used for the sheet material, and a non-air permeable sheet such as rubber that can be elastically deformed is joined and covered on the upper surface of the sheet material, and the sheet material is passed through. Applying the vacuum pressure to the non-permeable sheet thereby indirectly sucking the sheet material, releasing the permeable sheet from the molded product, and then performing the cooling. A vacuum forming method for a conductive material was constructed.

[0007] In addition, in joining to a planar material,
It is more effective to heat the non-permeable sheet and to achieve the purpose.

Further, the present invention provides a vacuum forming apparatus provided with a clamp frame comprising an upper frame and a lower frame for holding a planar material as a molded product, above a mold mounting table.
A non-permeable sheet made of elastically deformable rubber or the like, which is vacuum-sucked to the mold, is attached to the upper frame, so that the sheet material can be processed by the suction deformation pressure of the non-permeable sheet with respect to the mold. Thus, a vacuum forming apparatus for a breathable material was constituted.

It is more effective to achieve the object if a heater for heating the non-permeable sheet is provided.

[0010]

The vacuum suction force is applied to the non-breathable sheet through the sheet material, and the non-breathable sheet is vacuum-sucked. Therefore, the sheet material is pressed by the non-breathable sheet, pressed by the mold, and moved along the surface. It is processed into a shape. Further, due to the pressure caused by the vacuum suction of the sheet, even if the sheet material is a nonwoven fabric, a foamed resin, or the like, the heat insulating property, the cushioning property, the air permeability, and the like are not hindered by the pressurization. Since the planar material is a material that can be molded by heating as a target of vacuum molding, molding is facilitated by heating the non-permeable sheet. After the molding, when the upper frame of the clamp frame supporting the air-impermeable sheet is opened relative to the lower frame, the mold is easily released from the molded product by the restoring action accompanying the elasticity of the air-impermeable sheet.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings.

The drawing shows an example of a vacuum forming apparatus, in which a clamp frame 2 and a heater 3 are provided above a mold mounting table 1 and a clamp frame 2 is provided.
Then, a non-breathable sheet 5 for stopping the ventilation of the sheet material W is attached, and the sheet material W is vacuum-sucked into the mold 7 together with the non-breathable sheet 5, so that the non-breathable sheet 5 can be processed. Will be applied.

In the illustrated case, a so-called drape molding method using a convex mold as the mold 7 is shown. However, in other molding methods (for example, a straight molding method, a plug assist molding method, an air blow molding method, etc.). Can be implemented by the same idea. The mold mounting table 1 is connected to a vacuum suction pipe 9, and the mold 7 is provided with a vacuum suction hole 11.

The crumb frame 2 includes an upper frame 2a and a lower frame 2b.
The upper frame 2a is provided with a non-breathable sheet 5 on the lower surface thereof and is tightly stretched. Join.

In this case, the heater 3 is an upper heater 3
a and a lower heater 3b, which can be retracted by driving an air cylinder (not shown). At the same time, the mold mounting table 1 is raised to perform molding.

As shown in FIG. 1, when the sheet material W is heated above the mold 7 as shown in FIG. 1, the heater 3 retreats, and as shown by a two-dot chain line in FIG. The frame 2 is closed, the sheet material W is joined to the air-impermeable sheet 5, the mold mounting table 1 is raised, and then the sheet material W and the air-impermeable sheet having the two dies 7 are joined together. 5 and the air is sucked from the pores 11, the suction effect is applied to the non-permeable sheet 5 through the sheet material W, and the sheet material W is subjected to vacuum forming as shown by a solid line in FIG. As a result, a molded product Wa is formed.

While the vacuum forming is performed in this manner, the two sheets are held together. In this state, when the clamp frame 2 is opened and the upper frame 2a is raised with respect to the lower frame 2b. The non-breathable sheet 5 is released from the molded product Wa by the action of restoring by elasticity. And
While the molded product Wa remains in the mold 7 (two-dot chain line in FIG. 3), the molded product Wa is cooled by blowing air, and after cooling, the mold mounting table 1 is lowered to separate the mold 7 from the molded product Wa. It is molded (solid line in FIG. 3). Thus, when the molded article Wa is removed from the lower frame 2b and the next sheet material W is placed on the lower frame 2b, the heater 3 arrives and molding is performed in the same manner.

As for cooling, means such as spray cooling and mold cooling can be employed in addition to air blowing, but a combined use of mold cooling is preferable. Further, in the above embodiment, the case where the sheet material W is formed individually is shown. However, as is often seen in vacuum forming, the sheet material W may be processed while being rewound from a roll. A vacuum forming apparatus may be provided which includes a heating step, a forming step, and a step of cutting a molded product after the roll loading apparatus.

Examples of the sheet material W include a nonwoven fabric in which heat-fusible short fibers are connected by heat welding, a nonwoven fabric in which a heat-fusible resin is used as a connecting material, a hot-melt foamed resin sheet having open cells, and a large number of holes. And a film or a sheet of a hot-melt resin provided in a dispersed manner. In a test, a non-woven fabric made of polyester short fiber was used, and a food tray could be easily and conveniently formed using a wooden mold. In this case, as the non-breathable sheet 5, an industrial rubber sheet having a thickness of 0.5 mm was used. Similar to the thickness, the type of the rubber cannot be specified by the conditions such as the shape and size of the molded product, the heating temperature, and the like, and a rubber suitable for the processing conditions is selected. Incidentally, chloroprene rubber, fluoro rubber, etc., which have relatively elasticity and tensile strength, and have heat resistance and durability, are considered to be suitable.

If the sheet material W is a non-woven fabric or a foam sheet having heat insulating properties, heating is not easy. Is promoted and the molding is facilitated. In FIG. 1, reference numeral 6 denotes the heater, and the air-impermeable sheet 5 is heated from above by the heater 6 and is thermally conducted to the sheet material W. Further, the impermeable sheet 5 may be heated by the upper heater 3a of the heaters 3.

[0021]

As described above, according to the present invention, vacuum forming is performed on a breathable sheet material such as a nonwoven fabric, a foamed resin sheet, or a porous resin sheet to obtain a molded article having a desired shape. A method and a vacuum forming apparatus have been successfully provided, and unlike the case of pressure forming using an upper mold and a lower mold, a simple mold is sufficient for vacuum forming, Since the material does not impair the cushioning, heat insulation and air permeability of the material, it has an excellent effect of being suitable for effective and inexpensive mass production, especially of molded articles whose use properties are valued.

In the case where the non-breathable sheet is heated (claims 2 and 4), the above-mentioned effect becomes more remarkable.

[Brief description of the drawings]

FIG. 1 is an explanatory view seen from a side of a vacuum forming apparatus for a breathable material according to the present invention.

FIG. 2 is an explanatory view showing a state before entering vacuum forming from a state of FIG. 1 by a two-dot chain line, and a state of entering the state by a solid line.

FIG. 3 is an explanatory diagram showing a state in which a non-breathable sheet is released from the state of FIG. 2 by a two-dot chain line, and a state in which a molded product is released by a solid line;

[Explanation of symbols]

 W Planar material Wa Molded product 1 Mold mounting table 2 Clamp frame 2a Upper frame of clamp frame 2b Lower frame of clamp frame 3 Heater 5 Non-breathable sheet 6 Heater 7 type

Claims (4)

[Claims] 1. A vacuum forming method in which a planar material to be a molded article is suctioned to a mold surface by vacuum pressure in a mold while being heated, and the molded article is cooled and then released from the mold. By using a material having, a non-permeable sheet such as rubber which can be elastically deformed is bonded and covered on the upper surface of the sheet material, and the vacuum pressure is applied to the non-permeable sheet through the sheet material to thereby apply the vacuum pressure. A vacuum forming method for a gas-permeable material, wherein the cooling is performed after the sheet material is indirectly sucked and the air-permeable sheet is released from the molded product. 2. The method according to claim 1, wherein the air-impermeable sheet is heated before joining to the sheet material. 3. A vacuum forming apparatus provided with a clamp frame comprising an upper frame and a lower frame for holding a planar material to be a molded product above a mold mounting table, wherein the upper frame is vacuum-sucked by a mold. A non-breathable sheet made of rubber or the like that can be elastically deformed is adhered, and the planar material is configured to be processed by suction deformation pressure of the non-breathable sheet with respect to the mold. Molding equipment. 4. The vacuum forming apparatus for a breathable material according to claim 3, further comprising a heater for heating the non-permeable sheet.