JPS5816493Y2 - container body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a container body, such as a can used, for example, to confine a pressurized fluid.

The technology for forming a container body is to form a composite paper tube by winding cardboard called a kraft liner in a spiral around the outer periphery of an inner paper tube whose side edges are polymerized and bonded. It is already publicly known.

However, in conventional container bodies, a method is adopted in which the side edges of the inner paper are overlapped and glued together, but this adhesive part (sealed part) protrudes, so the inner paper tube formed around the mandrel is When a container body is formed by wrapping and laminating cardboard (kraft paper) around the outer periphery of the container, the following problems occur.

(A) When forming the container body, when winding and laminating the inner paper layer and the cardboard layer, the cardboard and the endless sliding belt
The inner paper layer seal portion is pushed and protrudes inward, and this protruding seal portion comes into local pressure contact with the outer peripheral surface of the mandrel.

Therefore, there is a drawback that the inner surface of the seal portion that presses against the mandrel may be damaged due to a peeling phenomenon due to sliding friction with the mandrel, or the sealing performance of the inner surface paper may deteriorate.

The inner paper that comes into contact with the mandrel is generally a moisture-proof treated paper or a gas barrier treated paper, so due to the nature of that paper, it has a large frictional resistance with the mandrel and is softer than the cardboard that provides strength, resulting in the peeling phenomenon. It is easy to cause

(B) When the container body formed in this way is used especially for pressure fluid sealing, the inner paper white body may be subjected to moisture-proofing treatment, gas barrier treatment, etc., as necessary, as described above. , local friction between the mandrel and the seal may damage it, making it impossible to maintain the airtightness of the container cylinder.
Paper containers have serious drawbacks, and these problems have remained unresolved to this day.

The present invention was developed as a result of research into a method for preventing damage to the inner circumferential surface of an inner paper tube, especially the sealing portion, as described above, with sufficient consideration given to the properties of paper.

An important point of the present invention is that when the inner paper, the first cardboard, the second cardboard, and the front paper are wound spirally around the mandrel, the sealed portion of the inner paper layer (the strip of paper forming the inner paper layer) The thickness of the side edges of the first cardboard layer is warped to form a spiral groove so that the surface of the protrusion (formed by overlapping and gluing the side edges of the first cardboard layer) does not peel off due to local friction. However, by fitting the seal portion into this groove, the inner surface of the inner paper layer is made smooth.

Even when the inner paper layer slides against the mandrel under pressure, the sliding friction becomes uniform, so that the soft inner paper layer does not suffer damage such as surface peeling due to the sliding friction with the mandrel.

Next, an embodiment of the present invention will be described with reference to the drawings.The inner paper layer 1 is made by winding a strip of paper 2 in a spiral shape, the inner surface of which has been subjected to surface treatments such as moisture-proofing treatment and gas barrier treatment as required. It is formed into a tubular shape, and adjacent paper strips 2a, 2
By polymerizing and adhering the side edges of b, the airtightness of the inner paper tube 1 is maintained.

The sealing part 3 in which the side edges of the adjacent paper strips 2a and 2b are bonded together by polymerization is created by folding the overlapping part that protrudes by the thickness of the paper strip 2a outward of the inner paper layer 1, and then attaching the inner paper to the inner paper layer 1. layer 1
The inner circumferential surface of the paper strips 2 a and 2 b is configured to be smooth, and the ends of the paper strips 2 a and 2 b are not exposed to the inner surface of the cylinder.

The overlapping portion of the seal portion 3 is formed by simply polymerizing and adhering the side edges of the paper strips 2a and 2b, so that the outer side edges protrude outward with a crank-shaped cross section, and the inner side edges protrude outward. It may be arranged so that it is flush with the inner surface of the paper strip with the side edges located on the outside, but especially in containers containing swellable or permeable fillings, the inner surface of the paper strip may be placed flush with the inner surface as shown in FIG. The side edge of the paper strip 2a located on the outside is bent outward, and it is glued to the side edge of the paper strip 2b located on the outside, thereby forming the inner surface of the paper strip 2b located on the outside and the paper strip 2 located on the inside.
A configuration in which the inner surface of the bent side edge part a is smooth prevents damage such as curling of the paper edge, and is particularly effective when the paper strip 2 is subjected to the above-mentioned surface treatment.

On the outer periphery of the inner paper layer 1 configured as described above, a plurality of cardboard layers 4 formed into a tube shape by spirally winding cardboard such as kraft paper forming the main body of the paper tube are superposed.

Of these cardboard layers 4, a first cardboard layer 4a that is directly superposed on the inner paper layer 1 has a spiral groove 5 formed on the inner surface facing the sealing part 3, into which the sealing part 3 is inserted. There is.

In order to form this spiral groove 5, as shown in FIG. The spiral groove 5 may be formed with the side edge of the cardboard layer 4a.

Now, in order to form the container body 7 constructed in this way, the paper strip 2 is wound spirally around a mandrel (not shown) while its sealing portion 3 is polymerized and bonded, and the first cardboard layer 4 is
One side edge of a is ground in advance with a grinder or the like to form a stepped portion, and this stepped portion is attached to the sealing portion 3 of the inner paper layer 1.
Wrap it spirally around its outer circumference.

Furthermore, during the winding operation, the first cardboard layer 4
A second cardboard layer 4b is formed by winding cardboard around the outer periphery of the first cardboard layer 4a with the side edges shifted by half a pitch.

Furthermore, a container body 7 is formed by winding a surface paper 6 which has been subjected to various surface treatments on the outer peripheral surface.

In this case, since the spiral groove 5 is a bottomed groove formed by the first cardboard layer 4a, the second cardboard layer 4 is formed on the outer periphery of the first cardboard layer 4a.
The container body 7 can be formed by simply winding the container body 7.

Therefore, there is an effect that the number of winding steps and material costs can be reduced.

During the forming operation of this container body 7, the inner paper layer 1 is
moves in the axial direction of the mandrel while sliding and rotating, and the inner paper layer 1 is inserted into the spiral groove 5 formed by the first cardboard layer 4a.
Since the sealing portion 3 is fitted and the inner circumferential surface of the inner paper layer 1 becomes smooth, the winding pressure of the inner paper layer 1 and each cardboard layer 4 does not act on the sealing portion 3.

Therefore, the inner peripheral surface of the inner paper layer 1 and the mandrel are in a state of uniform pressure distribution, and as a result, damage such as peeling of the inner paper layer 1 can be prevented.
When gas barrier treatment is applied, it has a remarkable effect of protecting it.

By cutting the container body 7 constructed in this way to a required length and sealing it by attaching metal lids 8 and 9 to both openings, a can for filling pressurized fluid such as liquid or gas can be manufactured. can.

In this case, since there is no protrusion on the inner surface of the container body 7 as in the conventional case, when the metal lids 8 and 9 are attached to the container body 7,
A can with good sealing performance can be manufactured without creating any gaps.

Therefore, even if the inner paper layer slides and rotates against the mandrel when forming the container body, the pressure of the inner surface against the mandrel becomes uniform, so the inner surface of the inner paper layer, which is soft and has high frictional resistance, The surface will not cause damage such as peeling.

As a result, even if the inner paper has been subjected to various surface treatments, it will not be damaged, so this container body is particularly effective when used in pressure vessels and the like.

In addition, since the inner peripheral surface of the container body is formed smoothly, even if a metal lid is wrapped around the container body or a cap is fitted, there will be no gap between them, and the sealing performance will be significantly improved. It has many advantages, such as being able to improve the performance.

Note that the inner surface paper that forms the inner surface of the container can be surface-treated paper that has undergone moisture-proofing or gas-barrier treatment, but in some cases, synthetic resin film or synthetic resin film laminated paper can also be used. In the above detailed description and the like, these are collectively referred to as a strip of paper or an inner paper layer.

In addition to bonding with an adhesive, heat sealing can also be used for the sealing part.

Furthermore, according to the present invention, in order to form a spiral groove by curving the wall thickness of the side edge of the first cardboard layer as described above, the size of the groove is adjusted according to the size of the seal portion. Since it can be easily determined, the inner surface of the inner paper layer can be made flush and smooth very well.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a partially cutaway front view, and FIG. 2 is an enlarged sectional view of the main part. 1... Inner paper layer, 2... Strip paper, 3.
...Seal part, 4゜4a, 4b, 4C・
...Cardboard layer, 5...Spiral groove, 6...
... Outer surface paper layer, 7... Container body.

Claims (1)

[Scope of utility model registration request] A first cardboard layer and a second cardboard layer are spirally wound around the inner paper layer in which the paper strip forming the inner surface is wound spirally, and the side edges of adjacent paper strips are polymerized and bonded to form a sealing part. In the container body in which the outer surface paper layer is further polymerized, the wall thickness of the side edge of the first cardboard layer is warped to form a spiral groove;
The container body is made by fitting the seal portion into this groove and smoothing the inner surface of the inner paper layer.