JPH0444910A - Sealing method for container - Google Patents

Abstract

PURPOSE:To make it possible to seal a container at a low cost without making the bonding power too strong or too weak by a method wherein on an antifog layer of a lid forming sheet, the antifog layer on the spots to come into contact with a container main body is melt-removed by applying an adhesive, and then, the lid is bonded to the container. CONSTITUTION:For a lid 2, at a part on the periphery, which comes into contact with a mouth edge 11 of the above mentioned container main body 1, a flat collar 22 is formed. On the rear surface of the lid 2, an antifog agent layer B made of a higher fatty acid ester resin is applied and formed in order to prevent wet fog on the lid rear surface due to entrance of moisture from a content A such as food. At the collar 22 spot on the rear surface of the lid 2, the antifog agent layer B is melt-removed by the application of an adhesive, and a bonding layer F is formed. By heat-melting the bonding layer F by a hot mold N, the lid 2 and the container main body 1 are well bonded.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a method for sealing a container.

<Prior art> Conventionally, when it comes to containers for storing meat, seafood, and various other foods, simply placing a lid on the container body has caused the lid to break during transportation due to manufacturing errors or warping of the container. There was a risk that it would come off the container body and the stored items would flow out of the container.

Therefore, it is generally done to prevent the lid from coming off the container body by wrapping it with cling film or using rubber bands, tape, or staples.

However, all of these container sealing methods are troublesome and costly, and are inconvenient when a large number of containers must be sealed in a short period of time.

Therefore, a bonding layer is formed by applying an adhesive to the back surface of the lid where it comes into contact with the container body, and the adhesive action of this bonding layer connects the lid to the container body. A method of sealing a container to prevent contents from flowing out of the container has been devised and implemented.

The container sealing method using the adhesive action of the bonding layer formed on the back of the lid where it contacts the container body is convenient because it can easily seal a large number of containers in a short time at low cost. .

<Problems to be Solved by the Invention> However, when a lid made of a transparent or translucent material is used as the lid of the above-mentioned food packaging container, a high-grade material is coated on the back of the lid to prevent fogging. The antifogging agent layer made of fatty acid ester resin inhibits the formation of a bonding layer, and even if the lid is bonded to the container body, sufficient bonding strength with the container body cannot be obtained, resulting in vibrations during transportation. This has caused problems such as the lid detaching from the container body and the stored items flying out.

Note that the anti-fogging agent should be prevented from adhering to the contact area of the lid by pasting tape, etc. in advance on the back of the lid where it contacts the container body, or by printing in place. It is also possible to apply adhesive and form a bonding layer, but
The work of applying and peeling off the tape or the work of printing in position is troublesome, the cost is relatively high, and there are also disadvantages such as the bond between the lid and the container body being too strong.

Therefore, the present invention aims to provide a container sealing method that allows the lid to be attached to the container body with sufficient bonding force and that facilitates sealing operations.

Means for Solving the Problems> In order to achieve the above object, the container sealing method of the present invention is characterized in that the antifogging agent layer formed on the side of the lid forming sheet that contacts the container body is The part that comes into contact with
After applying an adhesive and melting and removing it and forming a bonding layer with the adhesive at the contact points, this sheet is molded to form a lid, and the lid is then placed over the container body. The method consists in melting the bonding layer by pressing a heating mold against the bonding layer from a position above the body, and bonding the lid to the container body by the adhesive action caused by the heating and melting of the bonding layer.

According to the invention configured as described above, an adhesive is applied to the portion of the antifogging agent layer of the lid forming sheet that will come into contact with the container body, and the applied adhesive is Since the antifogging agent layer is melted and removed at the contact points to form a bonding layer on the sheet, the molded lid can be bonded to the container body without weakening the adhesive force due to the antifogging agent. A bonding layer that maintains an appropriate bonding force can be formed at the abutting portion, and the lid can be bonded to the container body by the adhesive action of the bonding layer by heating and melting.

<Example> Next, an example of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an example of a container sealed by the sealing method of the present invention, in which the container body (1) is made of a heat-resistant synthetic resin foam sheet, such as a heat-resistant foamed polystyrene sheet.
S') is heated and softened and integrally formed into a sheet by vacuum forming, and a mouth edge (11) curved outward in an arc shape is formed on the upper edge of the side wall.

In addition, the lid opening is made of a heat-resistant synthetic resin sheet (S) such as a non-foamed heat-resistant transparent polystyrene sheet that is integrally formed into a sheet by vacuum forming as in the case of the container body (1). A flat-throated flange (22) is formed on the periphery of the container at a portion that comes into contact with the mouth edge (11) of the container body (1).

The back of the lid (2) is coated with an anti-fogging agent layer (made of higher fatty acid ester resin) to prevent clouding (caking) caused by the evaporation of moisture generated from stored items (A) such as food. B)
is formed by coating.

Then, at the flange (22) on the back side of the lid (2), the antifogging agent layer (B) is melted and removed by applying an adhesive to form a bonding layer (F). , bonding layer (
F) is heated and melted using a heating mold (N) to form a lid body C.
) and the container body (1) are fully joined (see Figures 2 and 3).

In addition, (24) shows the lid side piece of the non-joining part formed in the outer periphery of the said joining part.

As shown in Fig. 1, the container body (1) has a recess (23) for air discharge, etc. on the periphery of the lid (2) as a sealed container.
By molding a container with a non-bonded part, even if excessive steam pressure is applied inside the container due to microwave heating of stored frozen foods, steam can escape from this non-bonded part, The sealed container can be used as it is as a container for heating and cooking in a microwave oven or the like without transferring the article (A) to another container, making it convenient.

In addition, the above-mentioned non-joined portion includes the mouth edge of the container body (1) (
11) with four parts can also be molded to allow steam to pass through. In addition, instead of the non-joint parts such as the recesses (23) for air discharge, a hole is formed in a part of the lid body a, and the majority of this part is made of non-woven fabric with adhesive processing applied to one side. Even in the case where a breathable member is attached, excess steam due to heating of the stored article (A) can escape from the part of the breathable member, and a non-bonded part consisting of the recess (23) is formed. It can be made to work similarly. If the name of the food, the weight of the food, the price, or the manufacturer, etc. are printed on the other side of the breathable member which has been subjected to adhesive processing, it can be conveniently used as a display label.

The hole in the lid (2) is covered with an adhesive seal that has an adhesive layer that is weaker than the seal joint between the container body (1) and the lid (2), and the adhesive strength of the adhesive seal is weakened by heated steam. A gap may be created between the adhesive seal and the lid (2) to allow steam to escape from this gap.
Furthermore, cover the hole with an elastic piece whose one end is joined to the lid body 0,
The elastic piece may be lifted up by steam pressure to allow steam to escape. This adhesive sticker and elastic piece can also be used as a display label in the same way as the above-mentioned breathable material such as nonwoven fabric.

In the sealed container, in order to take out the stored article (A) from the container body (1) after cooking, grasp the lid side piece (24) of the non-joining part formed on the outer periphery of the joining part. The lid (2) can be easily peeled off from the container body (1) by pulling it off from the container body (1), which is very convenient (see Fig. 2).

In the above embodiment, since the container body (1) is made of a foamable synthetic resin sheet with excellent heat insulation properties, it is necessary to grasp the container body (1) side when taking out the container. If you do this, you can easily take it out with your bare hands.

Next, the method for sealing a container according to the present invention will be explained with reference to FIG. 3. First, an antifogging agent layer (B) is formed on the back surface that will be in contact with the molded container body (1). In a certain lid forming sheet (S), the part of the antifogging agent layer (B) that comes into contact with the molded container body (1), that is, the mouth edge of the container body (1) ( 11) Use a roller or the like to print and apply an adhesive component to the back side of the flange (22) of the lid body (2) that comes into contact with the top surface of the lid (2), and use this applied adhesive component to form an anti-fog agent layer ( B) is melted and removed to form a bonding layer (F) on the sheet (see Figure 3.
．． II). In addition, in the case of Figure 3, 4 is placed on the sheet (S).
This figure shows the case of multi-piece molding in which bonding layers are formed in different places.

The adhesive forming the bonding layer (F) has adhesive properties to both the container body forming sheet (S') and the lid forming sheet (S), and is applied to the back surface of the lid (2). Various known adhesives can be used as long as they can melt and remove the antifogging agent layer (B).

Then, the lid forming sheet (S), which has a bonding layer formed on the part that contacts the container body (1), is heated and softened using a heater (K), etc., and the heated and softened sheet is placed in a mold (1,). After vacuum suction is applied to the sheet to form a lid-like recessed portion on the sheet, trimming is performed using a Thomson blade (M) or the like to form a lid body (2) (Fig. 3 - ■).

As for the container body (1), similarly to the lid (2), the container body forming sheet (S') is heated and softened using a heater (K), etc., and the heated and softened sheet is placed in a mold (L). After vacuum suction is applied to the sheet to form a recess that will become the container, trimming is performed using a Thomson blade (M), etc., and the container body (1
) is formed (see Fig. 3 1'-■').

After the stored articles (A) are stored in the container body (1), the lid (2) is covered, and the lid (2) is placed on the area where the bonding layer (F) of the lid (2) is formed. From the upper position of the heating type (N
) is lowered, and the portion of the lid (2) where the bonding layer (P) is formed is heated and pressed.

By heating and pressing with this heating mold (N), the bonding layer (F) of the lid (2) is melted, and the container body (1) and the lid (Z) are sufficiently bonded by the adhesive action. (Fig. 3 ■～
■Reference).

In addition, as for the device (10) that lowers the heating mold (N) from above the lid (2), the container receiver is attached to the support shaft (14) against the upper surface of the base (12) provided with the stand (13). ) is installed upright, and two upper and lower arms (1, 5) (16) are attached to this support shaft (14).
The operating part 7) is connected to the stand (1) through a link mechanism consisting of
3), and a heating mold (N) is attached to the lower end of this operation part (17).

Upper and lower arms (15) of the above device (10) (1B
) is pivotally supported by the support shaft (14) and the operating part (17) at equal lengths, and when the operating part (17) is lowered, the heating mold (N) is positioned above the lid (2). This contact is perpendicular to the area where the bonding layer (F) is formed, so that uniform heating of the area of the bonding layer (F) can be performed.

In addition, as a device for carrying out the above container sealing method,
A lid body (2) and a container body (1) are formed from a sheet for forming the lid body and the container body, but a stock mechanism and a mechanism in which a plurality of receivers are formed on the disc-shaped body are used. For example, the receiver of the disc-shaped body is used for the process of supplying and placing the container body from the stock mechanism on the stand, the process of storing the contents in the container body placed on the stand, and the process of storing the contents in the container body that has stored the contents. If each process such as supplying the lid from the stock section, covering the lid, and sealing the container using the heating type (N) of the device (10) can be performed at the same time, the container sealing work can be done efficiently. It's very convenient.

- Specific Example A heat-resistant foamed polystyrene sheet was used as the sheet for forming the container body (S'), and a transparent, non-foamed, heat-resistant polystyrene sheet was used as the sheet for forming the lid (S). An antifogging agent layer (B
), and a molded lid body (2) with an air discharge recess (23) formed in the flange (22>) was used.

An adhesive made of acrylic resin (product name A-450A; Dainippon Ink Chemical Co., Ltd. (manufactured by Kogyo Co., Ltd.) was applied to form a bonding layer (F).

Then, the sheet for forming the lid (S) and the sheet for forming the container body (s') on which the bonding layer (P) was formed are sheet-molded to form the lid (2) and the container body (1), and then, Cover the container body (1) containing frozen food with the lid ■, lower the heating mold (N) from above the lid (2), and
) The bonding layer (F) forming portion was heated and pressed from the upper surface.

As a result, although the antifogging agent layer (F) was formed on the back surface of the lid (2), the lid (2) was attached to the container body (1).
A sealed container in which 2) was sufficiently bonded was obtained.

The methyl ethyl ketone and toluene solvent components used for the polyacrylate, which is the main component of the adhesive forming the bonding layer (P), melt and remove the antifogging agent layer (F) on the back side of the lid (Z). This is thought to be because the antifogging agent layer (F) maintained an appropriate bonding force without being inhibited or too strong, and was adhered to the lid (2).

In addition, as a result of putting the above-mentioned container in a microwave oven and heating, thawing and cooking for the required time, a well-cooked product was obtained. Further, no deformation or the like was observed in the container, and it was found that the container could sufficiently withstand high-temperature heating in a microwave oven or the like.

Note that the container body forming sheet (S'
), in addition to the heat-resistant polystyrene sheets shown in the examples, foamed resin sheets made of a single or copolymer of various synthetic resins such as polypropylene, or mixed resins, and even non-synthetic resin sheets added to the foamed sheets mentioned above include A multilayer sheet made by laminating foamed film or the like can be used.

In addition, as the lid forming sheet (S), in addition to heat-resistant non-foamed polystyrene sheets, non-foamed resin sheets made of a single or copolymer of various non-foamed synthetic resins such as polypropylene, or mixed resins can be used. .

In the above embodiment, the lid body (2) is provided with non-jointed parts such as four air discharge parts in order to improve the anti-fogging effect, but it is also sufficient even if the lid body (2) is not provided. Can be implemented.

In addition, various design changes can be made without changing the gist of the invention.

<Effects of the Invention> According to the container sealing method of the present invention configured as described above, the lid is sealed by the adhesive action of the bonding layer formed at the portion of the lid forming sheet that comes into contact with the molded container body. Since the lid is joined to the container body, a large number of containers can be easily sealed in a short time at low cost.

The above-mentioned bonding layer is made of an adhesive component applied to the contacting portion of the antifogging agent layer of the lid forming sheet on which the antifogging agent layer is formed, at the portion that comes into contact with the molded container body. Because it is melted and removed, it can be easily formed, and the adhesive strength will not be weakened by the antifogging agent and will not be too strong (
, it is possible to form a bonding layer that is bonded to one body with sufficient bonding force. In addition, a heating mold is pressed against the bonding layer of the lid from above the lid covering the container body to melt the bonding layer, and the adhesive action of the heating and melting of the bonding layer allows the lid to be attached to the container body. Since the container is sealed with a lid, it is possible to easily obtain a container whose lid is joined with sufficient adhesive force.

Therefore, according to the sealing method of the present invention, a container can be obtained in which the lid is joined to the container body with sufficient joining force without being too strong or weak, through a series of simple steps, and the container can be transported. The lid does not come off from the container body due to vibrations during the process, and it exhibits various excellent effects not found in the past, such as being able to package stored items such as frozen foods in a good manner.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a sectional view of a molded container, FIG. 2 is a partially enlarged view of a previous container, and FIG. 3 is a schematic diagram showing a sealing process. (S)... Sheet for forming lid body, (S')...
... Container body forming sheet, (B) ... Antifogging agent layer, (F) ... Bonding layer (N) ... Heating type (^) ... ...Stored items, (1) ... Container body, (11) ... Mouth rim, (2) ... Lid, (22) ... ...
Flange (") Container body mouth rim Lid body Flange antifogging agent layer bonding layer Lid forming sheet heating type (W) Figure (V) (■)

Claims (1)

[Claims] 1. Of the antifogging agent layer formed on the side of the lid forming sheet that comes into contact with the container body, place the part that will come into contact with the container body,
After applying an adhesive and melting and removing it and forming a bonding layer with the adhesive at the contact points, this sheet is molded to form a lid, and the lid is then placed over the container body. A seal for a container, characterized in that a heating mold is pressed against the joining layer from above the body to melt the joining layer, and the lid is joined to the container body through the adhesive action of the heating and melting of the joining layer. Method.