JPS5828091B2 - Futatsukiyoukino Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a container with a lid, and more specifically, to a method for manufacturing a lid integrally at the same time when manufacturing a molded product such as a container by a vacuum forming method. be.

Conventionally, as a method for manufacturing molded products such as containers using a thermoplastic synthetic resin sheet as a raw material by vacuum forming, the thermoplastic synthetic resin sheet is held in a clamp frame, etc., and this sheet is heated using an electric heater, heated air, After softening by introducing into a heating furnace or applying hot air to a temperature equal to or higher than the heat deformation temperature, the thermoplastic synthetic resin sheet is held at a predetermined position in a vacuum mold, while This is done by sucking air from a molding die (or by applying a positive electric current).

However, when manufacturing molded products from thermoplastic synthetic resin sheets using such vacuum forming methods, the thermoplastic synthetic resin sheet softens during heating, causing a phenomenon (drawdown) in which the sheet sags downward due to its own weight. They tended to break when coming into contact with electric heaters, heating furnaces, etc., or break when coming into contact with vacuum molding molds.

Meanwhile, the container thus obtained is filled with the contents,
In the case of closing the container, it is necessary to go through a process of filling the contents and closing the lid of the filled container separately from the manufacturing process of the container, which is not preferable because the process becomes complicated and the cost increases.

The inventor of the present invention has conducted various studies in order to eliminate such drawbacks and provide an efficient method for manufacturing containers with lids, and as a result, the inventors have solved the above-mentioned problems by using a molding material with a special composition. The present invention was completed on the basis of this discovery.

That is, the gist of the present invention is to provide a thermoplastic synthetic resin sheet;
A perforated sheet that has ventilation holes communicating between the front and back sides and that does not undergo thermal deformation at the preheating temperature of this thermoplastic synthetic resin sheet is overlapped and heated, and the thermoplastic synthetic resin sheet is heated. A container with a lid, characterized in that vacuum forming is performed using a mold placed on the side of the synthetic resin sheet, and pressure applied during the forming adheres the contact surfaces of the thermoplastic synthetic resin sheet and the perforated sheet at desired points. The method of manufacturing

The present invention will be explained in detail below.

The thermoplastic synthetic resin sheet used in the present invention includes:
Examples include sheets made of styrene resin, vinyl chloride resin, olefin resin, polyamide, polycarbonate, and other thermoplastic synthetic resins by extrusion molding, calendar molding, or the like.

These thermoplastic synthetic resin sheets may be suitably used even if they are partially crosslinked or foamed.

In addition, perforated sheets to be used in combination with Atsumachi plastic composite resin sheets include paper, metal foils such as aluminum foil and copper foil, laminates of paper, metal foil, etc., and thermoplastic synthetic resin, and thermoplastic synthetic resin sheets. Examples include curable synthetic resin sheets, cloth, and nonwoven fabrics.

Each of these has ventilation holes that communicate with the front and back sides, and does not undergo thermal deformation at the temperature at which the thermoplastic synthetic resin sheet is preheated for vacuum forming, and is compatible with the thermoplastic synthetic resin sheet. It is required that the adhesive can be bonded by pressing when forming.

The perforated sheet may be provided with one ventilation hole at a location corresponding to the portion of the thermoplastic synthetic resin sheet to be vacuum formed, or a large number of fine holes may be provided over the entire surface of the perforated sheet.

Of course, if the perforated sheet itself is breathable, such as a nonwoven fabric, there is no need to provide additional ventilation holes.

Further, the perforated sheet and the thermoplastic synthetic resin sheet are bonded to each other by pressing during molding at required points on the contact surfaces between the thermoplastic synthetic resin sheet and the perforated sheet during molding of the thermoplastic synthetic resin sheet.

This bonding may be heat fusion bonding or bonding with an adhesive.

When using the heat fusion method, it is effective to provide a thermoplastic synthetic resin coating on the entire surface of the perforated sheet portion or only on the portion to be heat fused.

When bonding with an adhesive is performed, a pressure-sensitive adhesive, a heat-sensitive adhesive, or the like may be applied in advance to the portion of the perforated sheet or the thermoplastic synthetic resin or both that is to be bonded.

Next, the mode of implementing the method of the present invention will be explained in more detail with reference to the drawings, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Figures 1a and 1b are longitudinal cross-sectional views showing an example of a stacked state of a thermoplastic synthetic resin sheet and a perforated sheet used in the method of the present invention, and Figure 2 shows the sheet of Figure 1a FIG. 3 is a longitudinal sectional view of a portion showing the state in which it is installed in a molding die.
FIG. 2 is a vertical cross-sectional view showing the state in which the sheet shown in FIG. 2 is vacuum formed, and FIG. 4 is a vertical cross-sectional view of the container formed in FIG. 3.

In the figure, 1 is a thermoplastic synthetic resin sheet to be subjected to vacuum forming, 2 is a perforated sheet, 3 is a through hole, 4 is a synthetic resin coating layer, 5 is a vacuum forming mold, 6 is an air suction port, 7.8 indicate clamps, respectively.

The thermoplastic synthetic resin sheet 1 is superimposed on the perforated sheet 2, and its surroundings, if necessary, the parts of the superimposed thermoplastic synthetic resin sheets that are not to be vacuum formed, are fixed with clamps, and the usual vacuum forming technique is used. As is known in the art, the thermoplastic synthetic resin sheet is introduced into an electric heater, heating furnace, heated air, etc., and heated to a temperature higher than the thermal deformation temperature of the thermoplastic synthetic resin sheet, and as shown in FIG. position.

In this case, the positional relationship between the thermoplastic synthetic resin sheet 1 and the molded material must be such that the molded material is always located on the thermoplastic synthetic resin sheet side.

The thermoplastic synthetic resin sheet 1 and the perforated sheet 2 held in a predetermined position in the vacuum mold 5 are strongly pressed by the clamps 7.8, so that the pressed portions can be bonded together.

In the case illustrated in the drawing, the synthetic resin coating layer 4 serves as an adhesive.

On the other hand, if an adhesive is applied to the portion to be bonded instead of the coating layer 4, the bonding can be achieved by preheating and pressing.

Next, the air suction port 6 provided in the vacuum molding mold 5
Then, by applying a vacuum to suck the air inside the mold 5, the thermoplastic synthetic resin sheet 1 is molded into a container shape, as shown in FIG.

Of course, during this molding, air may be blown from the perforated sheet 2 side through the through holes 3 and the thermoplastic synthetic resin sheet 1 may be pressed against the mold, or both may be used in combination. It is.

At this time, the thermoplastic synthetic resin sheet 1 is softened because it is heated to a temperature higher than the heat deformation temperature by preheating during vacuum forming, and the perforated sheet 2 has a property that it does not undergo heat deformation at this preheating temperature. Therefore, only a thermoplastic synthetic resin sheet is molded by vacuum forming, and since the perforated sheet 2 is provided with through holes 3, air flows in through the through holes. The perforated sheet 2 maintains its flat shape.

The molded product thus obtained is cut into a suitable size to form a product container, as shown in FIG.

Such a product container is reinforced with a perforated sheet 2, and this perforated sheet 2 can also be used as a lid, and after filling the contents through the provided through hole 3, the through hole 3 is closed. By sealing with a sealant or the like, it can be made into an airtight container.

As described above, according to the method of the present invention, a strong container that is not reinforced by the perforated sheet 2 and a container with a lid can be manufactured very easily and simply.

Therefore, the industrial utility value of the method of the present invention is extremely limited.

[Brief explanation of the drawing]

Figures 1a and 1b are longitudinal cross-sectional views showing an example of a state in which a thermoplastic synthetic resin sheet used in the method of the present invention and a perforated sheet are overlapped, and Figure 2 is a longitudinal sectional view of the sheet of Figure 1a. FIG. 3 is a vertical cross-sectional view showing a part of the sheet mounted in a vacuum forming mold. FIG. 3 is a vertical cross-sectional view showing the sheet shown in FIG. 2 after being vacuum formed. FIG. FIG. 3 is a longitudinal cross-sectional view of the container. 1 is a thermoplastic synthetic resin sheet, 2 is a perforated sheet, 3 is a through hole, 4 is a synthetic resin coating layer, 5 is a vacuum mold, 6 is an air suction port, and 7 and 8 are clamps, respectively.

Claims (1)

[Claims] 1. A thermoplastic synthetic resin sheet and a perforated sheet that has ventilation holes communicating between the front and back sides and which does not undergo thermal deformation at the preheating temperature of this thermoplastic synthetic resin sheet are heated by superimposing them, and the above-mentioned thermoplastic synthetic resin sheet is heated. The resin sheet is vacuum-formed using a mold placed on the side of the thermoplastic synthetic resin sheet and the perforated sheet is bonded at the required points of the contact surface between the thermoplastic synthetic resin sheet and the perforated sheet by pressure during this molding. A method for manufacturing a container with a lid, characterized by: