JPH06322651A - Method for forming nonwoven fabric and its formed product - Google Patents

Abstract

PURPOSE:To form a formed product making the most of air permeability, bulkiness or diverse appearances or touches, etc., possessed by nonwoven fabric as they are by superposing a flexible airtight sheet on nonwoven fabrics, bringing the sheet into close contact therewith and then vacuum forming the resultant laminate. CONSTITUTION:Nonwoven fabrics made from fiber such as paper pulp or thermoplastic fiber as a main raw material are vacuum formed. In the process, plural nonwoven fabrics 11 to be formed are superposed and a flexible airtight sheet 12 composed of a plastics or rubber is then superposed thereon and brought into close contact therewith and the resultant laminate is subsequently placed on a female die 3 communicating with a vacuum-producing source 2. The laminate is then heated with a heater 9 and a cylinder in a pressing part is subsequently operated to press a clamping part 4. A vacuum pump in the vacuum-producing source 2 is then operated to attract the nonwoven fabrics 11 together with the airtight sheet 12 to the female mold 3. Thereby, the forming is carried out. Otherwise, a plug having a male die approximate to the female die 3 is pressed to perform auxiliary forming. The vacuum forming as described above is then carried out. After releasing from the female die 3, the airtight sheet 12 is peeled to afford the prescribed formed product.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for vacuum forming a nonwoven fabric containing paper pulp, fibers or the like as a main raw material, a vacuum forming machine used in the forming method, and a molded product produced by the method. Three

[0002]

2. Description of the Related Art As is well known, a nonwoven fabric is a fabric which has not been subjected to the process of spinning and weaving. It has a long history, and it is said that felt, paper, etc. have been used by mankind before the usual cloth was made. Currently, only those using fibers for spinning and weaving are often called non-woven fabrics, but recently, by mixing plastic fibers etc., it is possible to make cloth-like paper with excellent water resistance. Let's call these papers a non-woven fabric.

Nonwoven fabrics have the following excellent properties. Bulky and light. Wide intensity range. Highly breathable. It is possible to make things with various appearances and touches. The cost is low because the spinning and weaving process is not required. This is the greatest feature. Therefore, it can be conveniently used for disposable or similar applications.

However, when using this non-woven fabric to make an article having a three-dimensional shape such as a hat, cutting and stitching steps are required, and the stitching step can be replaced with gluing and heat bonding steps. However, in any case, it requires a lot of trouble, and the above-mentioned greatest feature of low cost is diminished by this, and it is inevitable that textile products that have undergone the textile weaving process that ancient humans have loved can not compete. It was the current situation.

A vacuum forming method is conveniently used as a method for forming a sheet-like material made of plastic or the like into a three-dimensional shape. According to this method, the cutting described above,
Since the step of stitching is unnecessary, an object having a three-dimensional shape can be supplied at a low cost. However, since the nonwoven fabric has excellent air permeability, which is an excellent characteristic, it has not been possible to perform vacuum forming in the past.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned situation regarding nonwoven fabrics, and an object thereof is to inexpensively supply molded products of nonwoven fabrics having a three-dimensional shape. .

[0007]

The present invention has achieved the above object by developing the following vacuum forming method. That is, the first method is a vacuum forming method of a non-woven fabric including a compressed air type, in which a female mold or a male mold whose inside communicates with a source of vacuum and a molding for the female mold or the male mold. Clamp part that attaches and holds materials airtightly,
A heater for heating the molding material, and a pressing mechanism for pressing a plug having a male or female mold whose convex or concave shape is similar to that of the female or male concave or convex surface to the molding material. Using a vacuum forming machine,
A method of forming a non-woven fabric, characterized in that auxiliary molding is performed by a female mold or a male mold communicating with the vacuum generation source, and the degree of vacuum of the vacuum generation source communicating with the female mold or male mold is increased to perform vacuum molding. Is. The second method comprises a female die whose inside communicates with a vacuum source, a clamp portion for hermetically attaching and holding the molding material to the female die, and a heater for heating the molding material. Using a vacuum forming machine, a method for forming a non-woven fabric is characterized in that an airtight sheet made of a flexible material is brought into close contact with the surface of the forming material opposite to the surface facing the female mold and vacuum forming is performed. Is.

According to this method, it is possible to easily form not only a non-woven fabric whose main raw material is fibers for spinning and weaving, but also a non-woven fabric whose main raw material is paper pulp. It is also possible to replace a part of the non-woven fabric with a sheet mainly made of thermoplastic fiber. The main products that can be molded by this molding method include seedling pots for plants, dough for daruma, sanitary masks, brassieres, safety hats, bags, hats, food containers, etc. It is also clear 5 that this can be easily molded by this molding method.

For the second of these forming methods, a conventional vacuum forming machine can be used as it is. Also the first
The following may be used, with some modifications made to the conventional vacuum forming machine. That is, it has a female die whose inside communicates with a vacuum source, a clamp portion for hermetically attaching and holding a molding material to the female die, a heater for heating the molding material, and a convex surface (concave surface) thereof. Is a vacuum forming machine having a pressing mechanism for pressing a male die (female die) having a shape similar to that of the concave (convex) surface of the female die (male) to the molding material. . In some cases, the above-mentioned molded products need to be produced in various small quantities, and in such a case, using a machined metal mold may increase the cost. On the other hand, if a thin metal plate is plastically processed and cement is filled as a reinforcing material, or if a ceramic mold is used, the cost can be reduced.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic structure of a vacuum forming machine according to the present invention. In the figure, a vacuum source 2 mainly composed of a vacuum pump is provided in the lower part near the center of the molding machine body 1.
Is built in, and the female mold 3 is installed above it. A frame-shaped clamp portion 4 is provided above the female die, and an upper portion thereof serves as a pressing portion 5. The pressing portion is provided with a cylinder 6 that operates hydraulically or pneumatically.

FIG. 2 is a sectional view showing the main part of this vacuum forming machine. In the figure, the lower part of the female mold 3 is a part 1 of the molding machine body.
It is airtightly attached to a via a seal ring 7,
The space formed by the seal ring, the lower part of the female mold, and a part of the molding machine body is a vacuum chamber 8. A through hole 3b is bored between the lower part of the female mold and the inside 3a thereof. The vacuum chamber 8 and the vacuum generation source 2 (not shown) are connected by a pipe 2a. 6

First, a conventional method of forming a plastic sheet or the like using this vacuum forming machine will be described. A plastic sheet or the like is placed on the female mold 3 (in FIG. 2, two sheets are placed, but this is the case of the present invention described later, and in the conventional method, one sheet such as a plastic sheet is placed. Only is placed.), Heated by the heater 9, and then the cylinder 4 of the pressing part is used to clamp the part 4.
After pressing and holding the plastic sheet etc. in an airtight manner and operating the vacuum pump, the inside 3a of the female mold becomes a vacuum through the vacuum source 2, the pipe 2a, the vacuum chamber 8 and the through hole 3b. A plastic sheet or the like is attracted to a female mold to be molded.

Next, the second molding method of the present invention will be described. As shown in FIG. 2, the nonwoven fabric 11 is placed on the lower side, and a flexible and airtight sheet 12 made of plastic, rubber or the like is placed on the nonwoven fabric 11 and placed on the female mold 3.
Then, it is heated by the heater 9. Although not shown, in some cases, if the heater is heated not only from the upper side but also from the lower side, more excellent molding can be performed. Similar to the above-mentioned conventional example, the clamp portion is pressed by the cylinder 6 of the pressing portion, the nonwoven fabric 11 and the airtight sheet 12 adhered to the nonwoven fabric 11 are airtightly attached and held, and then the vacuum pump is operated to generate a vacuum. A vacuum is applied to the inside 3a of the female mold through the source 2, the pipe 2a, the vacuum chamber 8 and the through hole 3b, and the action of the airtight sheet causes the nonwoven fabric and the airtight sheet to be attracted together to the female mold. The molding is completed by taking out from the female mold and peeling the airtight sheet from the nonwoven fabric. Since the airtight sheet is flexible, it can be repeatedly used.

FIG. 3 is a view showing a main part of a vacuum forming machine used in the first forming method of the present invention. As described above, in the second molding method of the present invention, the conventionally used vacuum molding machine can be used as it is, but in the first molding method, some modification is required. That is, in the figure, a male die 21 is attached above the female die 3 so as to be able to move up and down by the cylinder 6 of the pressing portion. The shape 7 of the male convex surface 21a is similar to the shape of the female concave surface, but is slightly simpler and shallower than that.

In the case of the first molding method, only the nonwoven fabric 11 is placed on the female mold as shown in the figure. After heating and mounting and holding as in the second molding method, the cylinder 6 is operated and the nonwoven fabric 11 is pressed by the male mold to perform pre-molding. Then, when the vacuum pump is operated, the non-woven fabric is attracted to the female mold to be molded. Although the nonwoven fabric is highly breathable, when air passes through the nonwoven fabric, frictional resistance naturally occurs, which causes a pressure difference between both surfaces of the nonwoven fabric. This pressure difference is not so large, but the pressure difference is sufficient to attract the non-woven fabric that is preformed by the male mold and has a shape similar to the female mold to the female mold, and the molding is extremely good. To be done.

[0016]

INDUSTRIAL APPLICABILITY According to the present invention, a nonwoven fabric is vacuum-formed by closely contacting with a flexible and airtight sheet, or is preformed by a male mold having a shape similar to that of a female mold, and then vacuum-formed. As a result, the following excellent effects are exhibited. It is possible to make a molded article having the same characteristics as a nonwoven fabric, such as being bulky and light, having a wide strength range, having large air permeability, having various appearances, and having various tactile sensations. Since the spinning and weaving process, which is the greatest feature of non-woven fabrics, is not required, it is possible to make low-cost molded products by taking advantage of the low cost. Recently, the demand type of molded products using non-woven fabric is changing from high-volume production type to high-mix low-volume production type, and the cost of die cost causes high cost. By using the cement-reinforced mold, it is possible to reduce the burden on the mold cost and reduce the product cost. Since it is possible to perform simultaneous molding by stacking multiple molding materials, the product cost can be significantly reduced. 8

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic structure of a vacuum forming machine according to the present invention.

FIG. 2 is a sectional view showing a main part of a vacuum forming machine and a first forming method of the present invention.

FIG. 3 is a diagram showing a main part of a vacuum forming machine used in a second forming method of the present invention and a forming method thereof.

[Explanation of symbols]

1 Molding machine main body 1a Part 2 Vacuum source
2a pipe 3 female 3a internal 3b through hole 4 clamp part 5 pressing part 6 cylinder 7 seal ring 8 vacuum chamber
9 Heater 11 Nonwoven 12 Sheet 21 Male 21
a convex

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location A45C 3/00 Z 2119-3B B29C 51/10 7421-4F B32B 25/10 27/12 8413-4F D04H 1/04 A 7199-3B // B29L 9:00 4F

Claims (19)

[Claims] 1. A vacuum forming method for a non-woven fabric including a pneumatic type, comprising a female mold or a male mold whose inside communicates with a vacuum source, and an airtight molding material for the female mold or the male mold. A plug having a male or female mold having a clamp portion mounted and held on a heater, a heater for heating the molding material, and a convex or concave shape of which is similar to the concave or convex shape of the female or male mold. Using a vacuum forming machine equipped with a pressing mechanism for pressing a material, a vacuum that is auxiliary formed by the plug and a female mold or a male mold communicating with the source of the vacuum and communicates with the female mold or the male mold A method for forming a non-woven fabric, which comprises vacuum forming by increasing the degree of vacuum of a source. 2. A female die, the inside of which communicates with a vacuum source, a clamp portion for hermetically attaching and holding the molding material to the female die, and a heater for heating the molding material. A method of forming a non-woven fabric, which comprises using a vacuum forming machine to bring an airtight sheet made of a flexible material into close contact with the surface of the forming material opposite to the surface facing the female mold and performing vacuum forming. 3. The method for forming a non-woven fabric according to claim 2, wherein the flexible material is plastic. 4. The method for forming a non-woven fabric according to claim 2, wherein the flexible material is rubber. 5. The method for forming a non-woven fabric according to claim 1 or 2, wherein a plurality of forming materials are superposed and simultaneously formed. 6. A molded article of a non-woven fabric, characterized by being molded using the molding method according to claim 1 or 2. 7. The molded article of the non-woven fabric according to claim 6, wherein the non-woven fabric is mainly made of a paper pulp material. 8. The molded article of the non-woven fabric according to claim 6, wherein the non-woven fabric is mainly made of fibers. Two 9. The non-woven fabric molded article according to claim 7, which is used as a pot for raising seedlings of a plant. 10. The molded article of the non-woven fabric according to claim 7 or 8, which is used as a cloth for a daruma. 11. The molded article of the nonwoven fabric according to claim 7, which is used as a sanitary mask. 12. The molded article of the non-woven fabric according to claim 7, which is used as a brassiere. 13. The molded article of the non-woven fabric according to claim 7 or 8, which is used as a safety cap. 14. The molded article of the non-woven fabric according to claim 7 or 8, which is used as a bag. 15. The molded article of the non-woven fabric according to claim 7, which is used as a hat. 16. The molded article of the non-woven fabric according to claim 7 or 8, which is used as a food container. 17. The molded article of the non-woven fabric according to claim 6, wherein a sheet containing a thermoplastic fiber as a main material is used as a part of the non-woven fabric. 18. The method for forming a non-woven fabric according to claim 1, wherein a ceramic mold is used as the female mold or the male mold. 19. The method for forming a non-woven fabric according to claim 1 or 2, wherein a metal thin plate is plastically worked as said female mold or male mold and cement is poured into the inside to reinforce the thin metal plate.