JPH02208019A - Tubular body using resin based material as base body and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent buckling due to driving force in the axial direction of a tubular body by a method wherein a thick rigid layer is laminated onto one surface of an inwall sheet to constitute a laminate, which is spirally wound successively onto a mandrel to form a cylindrical body, while a driving force in the axial direction is applied, an outside surface is supplied with a molten resin and a resin coating is shaped, and the tubular body is formed. CONSTITUTION:An inwall sheet 2 has multilayer constitution in which the layers 2a, 2f of a resin material such as a polypropylene resin are shaped on both sides of a metallic foil 2c such as an aluminum foil. One edge 2g of the inwall sheet 2 is heated by a hot air heater 3, and forwarded on a roll 4, and the edge of the metallic foil 2c is wrapped with a film material at said edge 2g. Such a laminate is brought to the state in which edges are superposed, and wound spirally onto a mandrel 25, thus forming a cylindrical body 26. When the laminate is wound spirally on the mandrel, a rigid layer is cured sufficiently, and the laminate has rigidity only of resistance against driving force in the axial direction applied to the cylindrical body. Accordingly, the buckling of the cylindrical body by driving force and out-of-shape are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tubular body mainly composed of a resin material and a method for manufacturing the same. The present invention also relates to a can material mainly composed of a resin material and a can formed from the can material. Furthermore, the present invention relates to a method of manufacturing this can material.

[Prior art]

A sheet of resin-based material is wound spirally onto a mandrel so that the edges overlap to form a cylindrical body, and the cylindrical body is fed in the axial direction of the mandrel to the outside of the cylindrical body. A method of forming a tubular body by forming an outer layer is known, for example, from JP-A-59-214627.

In the method disclosed in this patent publication, a sheet having characteristics depending on the purpose of use is used as a sheet for forming the inner wall layer of the tubular body. That is,
In the example disclosed in this patent publication, this inner wall layer sheet has a structure in which resin layers are formed on both sides of metal foil,
This inner wall layer sheet is spirally wound around a mandrel. The outer side of the cylindrical body formed by spirally wrapping the inner wall layer sheet around a mandrel is coated with resin material and inorganic material while feeding the cylindrical body by applying a driving force in the axial direction of the mandrel. The mixture is molten and extruded to form a relatively thick, rigid layer. This rigid layer is for providing necessary rigidity to the active material formed from the tubular body. Additionally, if the edge of the metal foil included in the inner wall layer is exposed to the inner surface of the tubular body, the metal foil will be eroded by the contents of the can manufactured by the tubular body and eluted into the contents, contaminating the contents. Therefore, in the method disclosed in the above-mentioned published patent application, one edge of the inner wall layer sheet is folded back to the outside, and when the inner wall layer sheet is wound spirally around the mandrel, the other edge is folded over this folded edge. The edges overlap to prevent the edges of the metal foil of the inner wall layer from being exposed to the inner surface.

In the method for manufacturing a tubular body disclosed in this publication, a mixture of a resin material and an inorganic material forming a rigid layer is extruded in a molten state onto an inner wall layer on a mandrel, and the mixture is heated to a considerably high temperature. Therefore, there is a problem in that the formed tubular body is in a softened state on the mandrel, and when a propulsive force is applied in the axial direction, the propulsive force buckles and the tube shape collapses. In the manufacturing process of the tubular body, water is constantly supplied between the mandrel and the cylindrical body to cool the cylindrical body sent in the axial direction and to maintain lubrication between the mandrel and the cylindrical body. If the body is manufactured too quickly, there will be insufficient cooling to prevent the buckling described above.

Also, because one edge of the inner wall layer is folded outward and the other edge is superimposed on top of it, the edges of the inner wall layer must be folded back when the inner wall layer is helically wound around the mandrel. Therefore, it becomes necessary to provide means for folding back the edges, which increases manufacturing costs. Furthermore, since the other edge is overlapped on top of the folded edge,
A step is created at this edge, and it is necessary to devise ways to prevent the step from appearing on the outside.

[Problem to be solved by the invention]

One object of the present invention is to solve the problem in conventional methods of manufacturing a tubular body that the tubular body wound around a mandrel buckles due to axial thrust.

Yet another object of the invention is to solve the problems of conventional methods and tubular bodies due to the necessity of folding back the edges of the inner wall layer.

[Means to solve the problem]

In order to solve the above problems, in the present invention, a rigid layer is formed on the outer surface of the inner wall layer before the inner wall layer is spirally wound around the mandrel, and the resulting laminate is spirally wound around the mandrel. A tubular body is formed by winding the tube around the tube. In addition, in order to eliminate the need to fold back the edges of the inner wall layer, the edge of the metal foil is wrapped with a resin material at least on one edge of the inner wall layer, and the other edge is wrapped so as to overlap this edge. Forms a tubular body. The edge of the inner wall layer may be treated by heating the edge of the inner wall layer to melt or soften the resin of the inner wall layer, and wrapping the green of the metal foil with the melted or softened resin, or by heating the edge of the inner wall layer. A resin layer may be applied at the time of formation, or before or after the formation of the rigid layer, and a portion of this resin layer may wrap around the edges of the metal foil of the inner wall layer.

That is, the method for manufacturing a tubular body according to the present invention involves laminating a relatively thick rigid layer to provide necessary rigidity on one side of an inner wall sheet that has the characteristics required for the inner wall depending on the purpose of use. A laminate is formed, the laminate is sequentially wound spirally on a mandrel with overlapping edges, and the overlapping edges are adhered to each other to form a cylindrical body, and the cylindrical body is In the process of forming the cylindrical body, a driving force is applied to the cylindrical body in the axial direction of the mandrel to send the cylindrical body in the axial direction of the mandrel, and a molten resin is supplied to the outer surface of the cylindrical body to form a resin coating. Characterized by forming a body.

The inner wall sheet can be made of a metal foil with resin layers formed on both sides, and the rigid layer can be made of a mixture of an inorganic material and a resin material. In this case, the laminate is provided with an outer layer of resin-based material on the outside of the rigid layer before being wound around the mandrel, the outer layer being formed to wrap around the edge of the inner wall sheet at at least one edge of the laminate; When the laminate is wound around the mandrel, one edge is overlapped to be inside the other edge. As another method, a resin layer is provided between the rigid layer of the laminate and the inner wall sheet, and the resin layer is formed so as to wrap around the edge of the inner wall sheet at at least one edge of the laminate. When the body is wrapped around the mandrel, the one edge may be overlapped so that it is inside the other edge. Still another method is to form the inner wall sheet by heating the resin layer on at least one edge and covering the edge of the metal foil with a melted or softened resin before forming the inner wall sheet into a laminate. When winding the laminate around a mandrel, overlap the laminate so that the one edge is inside the other edge.

Further, the tubular body according to the present invention has an inner wall layer in which a resin layer is formed on both sides of metal foil, and a laminate in which a relatively thick rigid layer is formed on the outside of the inner wall layer, with the edges overlapped. It has a configuration in which it is wound in a spiral shape with the inner wall layer inside,
The inner wall layer is characterized in that at least one edge of the metal foil is covered with resin, and this one edge is overlapped with the other edge so as to be on the inside.

[For production]

In the method for manufacturing a tubular body of the present invention, before the inner wall sheet is spirally wound around the mandrel, a rigid layer is formed on the outer surface of the inner wall sheet to form a laminate, so that the laminate is wound around the mandrel in a spiral manner. When wound into a shape, the rigid layer is sufficiently hardened and has sufficient rigidity to withstand the axial thrust applied to the cylindrical body. Therefore, in the manufacturing process of the tubular body, the problem that the tubular body buckles due to the axial propulsive force applied to the tubular body and loses its shape does not occur. In addition, in the case where the inner wall sheet has a metal foil in the middle layer, one edge of this metal foil is wrapped in a resin material and the other edge is overlaid on this edge, so that the metal foil has a tubular shape. No more exposure to the inside of the body.

Therefore, there is no need to fold back the edges of the inner wall sheet, the manufacturing process is simplified, and there is no fear that steps due to folding will appear on the outer surface of the manufactured tubular body.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an inner wall sheet 2 used in the method of the present invention.
As shown in cross section in FIG. 2, the inner wall sheet 2 is made of a metal foil 2c such as aluminum foil.
It has a multilayer structure in which layers 2a12f of a resin material such as polypropylene resin are provided on both sides, and a resin adhesive layer 2b such as a urethane adhesive is provided between the layer 2a and the metal foil 2C. Layer 2a is glued to metal foil 2C. Between the metal foil 2C and the layer 2f, a modified polypropylene resin layer 2d and a polypropylene layer 2e are arranged from the metal foil 2C side.
is arranged to bond between the metal foil 2C and the layer 2f.

To give an example of the thickness of each layer in the inner wall sheet 2, layer 2
a is about 30 μm, metal foil 2C is about 9 μm, layers 2d and 2e
, 2f are 3 μm, 112 μm, and 160 μm, respectively.

The inner wall sheet 2 thus formed is first edge-treated as shown in FIG. That is, as shown in FIG. 3(a), one H2g of the inner wall sheet 2 is heated by the hot air heater 3, and the resin material in this portion is softened.

The edge 2g of the heated inner wall sheet 2 is pressed by the nip roll 5 disposed opposite to the roll 4 while the sheet 2 is being fed over the roll 4, as shown in FIG. 3(b). As shown in FIG. 3(C), the edge of the metal foil 2C at the cough edge 2g is wrapped with a resin material. In this example, the other 'ff12h of the inner wall sheet 2 is not processed, and this m
At 2h, the metal foil 2C is in an exposed state.

In the next step shown in FIG. 4, this edge-treated inner wall sheet 2 is laminated with a rigid layer 6 to form a laminate. In this example, the rigid layer 6 is formed in two steps.

That is, first, a mixture of polypropylene and an inorganic material is melted and extruded onto the surface of the inner wall layer 2 on the 12a side to form the first rigid layer 6a. This first rigid layer 6a
are formed in the inner part closer to the inside than the edges 2g and 2h on both sides of the inner wall sheet 2. Next, a mixture of polypropylene and an inorganic material is extruded in a molten state onto the first rigid layer 6a to form a second rigid layer 6b. As shown in FIG. 4, the second rigid layer 6b has an edge 2g of the inner wall sheet 2.
The first rigid layer 6a extends from the edge of the first rigid layer 6a toward the other edge 2h of the inner wall sheet 2, and extends beyond the edge 2h to further protrude outward in the width direction from the inner wall sheet 2.

Simultaneously with the step of forming the second rigid layer 6b, polypropylene resin is extruded in a molten state to the outside of the second rigid layer 6b to form the resin layer 7.

The resin layer 7 covers the edge 2g of the inner wall sheet 2 on the one hand;
On the other hand, it is formed so as to cover the edge on the edge 2h side of the second rigid layer 6b.

FIG. 5 shows an outline of the apparatus used in the tubular body manufacturing method of the present invention. The inner wall sheet 2 is pulled out from the roll 1, and while passing around the roll 4, one edge is heated as described above by the heater 3, and the heated part is pressurized by the pinch roll 5 to perform edge treatment. Ru. roll 4
．． The sheet 2 that has passed through the 50 mm is guided from a guide roll 10.11 provided in the second extruder 9 to a guide roll 12 to a first extruder 13. The first extruder 13 is provided with guide rolls 14, 15, 16, 17, and the sheet 2 is passed through these guide rolls to a pair of rolls 18.
．． Passed through 19 nips.

A first extrusion nozzle 20 is arranged opposite the nip of the rolls 18, 19, and from this first extrusion nozzle 20,
A mixture of an inorganic material and polypropylene for forming the first rigid layer 6a is extruded toward one side of the sheet 2 in a molten state.

The roll 19 has a forming groove (not shown), and the extruded mixture is formed into the shape of the first rigid layer 6a shown in FIG. 4 by the forming groove of the roll 19.

The sheet 2 with the first rigid layer 6a formed on one side is rolled into a roll 1.
9 and returns to the second extruder 9 via the guide roll 21. In the second extruder 9, the sheet 2 is passed through the nip of a pair of rolls 22,23. roll 2
A double extrusion nozzle 24 is provided opposite the nip of 2.23, and from this double extrusion nozzle 24 a mixture of inorganic material and polypropylene for forming the second rigid layer 6b and for forming the outer resin layer 7 are provided. of polypropylene resin are simultaneously extruded in layers. Due to the nozzle shape of the second extrusion nozzle 24 and the surface shape of the roll 230,
The extruded mixture has the shape shown as the second rigid layer 6b in FIG. 4, and the resin layer 7 on the surface has the shape shown in FIG.

The thus formed laminate 8 is spirally wound onto a mandrel 25 with its edges overlapped to form a cylindrical body 26. A feeding device 27 is placed on the mandrel 25.
is located. As shown in FIG. 6, this feeding device 27 consists of a pair of rotating spindles 27a, 2 which are arranged on both sides of the mandrel 250 with their positions slightly shifted in the length direction.
7b and a bell) 27C wound around these rotating spindles 27a and 27b. As shown in Figure 6,
The belt 27C passes from the spindle 27a over the cylindrical body 26 formed by winding the laminate 8 around the mandrel 25, goes around the lower side of the cylindrical body 26, and returns to the cylindrical body 26 on the front side in the feeding direction. and reaches the other spindle 27b,
passing around the spindle 27b, and passing around the spindle 27a.
It is wound so that it returns to . Therefore, spindle 2
When 7a and 27b are rotated in the direction of the arrow in FIG. 6, due to the frictional force between the bell 27C and the cylindrical body 26,
A propulsive force in the feeding direction is applied to the cylindrical body 26 .

FIG. 7 shows the overlapping state of the edges of the laminate 8 when forming the cylindrical body 26, and the arrow indicates the direction in which the cylindrical body is fed. The laminate 8 is wound onto the mandrel 25 so that the edge 2g that has been edge-treated is on the rear side in the feeding direction. During winding, the front edge of the laminate 8 to be wound next is overlapped with the rear edge of the previously wound part. Feeding device 27
At the position , the resin constituting the layers 6a, 6b, and 7 is in a softened state, so the laminate 8 is subjected to radial pressure by the belt 27c of the feeding device 27, changing from the shape shown in FIG. 4 to the shape shown in FIG. The surface is deformed into a relatively smooth cylindrical shape. However, since the mixture of the inorganic material and polypropylene forming the first rigid layer 6a and the second rigid layer 6b is extruded before the laminate 8 is wound around the mandrel 25,
The layer 6as6b has sufficiently cooled, and the cylindrical body 26
The resin of the cylindrical body 26 is not soft enough to cause buckling of the cylindrical body 26 due to the axial propulsive force applied to the cylindrical body 26 . Therefore, the cylindrical body 26 can be fed over the mandrel 25 without any problem.

Along the mandrel 25 a surface coating device 28,29 is arranged. The surface coating devices 28 and 29 are used to form a suitable resin coating 30 as shown in FIG. 8 on the surface of the cylindrical body to improve the appearance and enable printing.

In the surface coating devices 28 and 29, the resin forming the coating is extruded in a molten state, but since the amount of heat of this coating resin is relatively small, the resin of the cylindrical body 26 is not softened. In this way, the resin coating 30 is formed on the surface of the cylindrical body 260, and the tubular body 31 is constructed.

At the distal end of the mandrel 25 a cutting device 32 is provided. This cutting device 32 is disposed so as to be movable along the mandrel 25 in synchronization with the feeding speed of the tubular body 31. The cutting device 32 has a rotating cutting blade 32a, and this blade 32a
The tubular body 31 fed over the mandrel 25 is cut into a predetermined length.

In this way, one cylinder or can material 33 of a predetermined length as shown in FIG. 9 is obtained. A can bottom 34 and a lid 35 are attached to the ends of the can material 33 to form a can 36. By appropriately changing the cross-sectional shape of the tubular body 31,
It is also possible to manufacture cans of rectangular cross-section, as shown in FIG. 10, or of other shapes.

FIG. 11 shows another embodiment of the invention. In this embodiment, the inner wall sheet 2 is coated so that the mR2g is wrapped in the polypropylene resin forming the outer resin layer 7 and the metal i2c of the sheet 2 is not exposed, without completely processing the edge 2g. This configuration also prevents the metal foil 2C from being attacked by the contents of the can.

FIG. 12 shows still another embodiment of the present invention. In this example, polypropylene resin is extruded in a molten state onto one side of the inner wall sheet 2 to form the resin layer 38 . This resin layer 38 is formed so as to wrap one edge 2g of the sheet 2 so as not to expose the edge of the metal foil 2C. Furthermore, a rigid layer 39 is formed on the resin layer 38. This rigid layer 39 is a mixture of an inorganic material and a polypropylene resin, and is formed by extruding it in a molten state, as in the previous example. The rigid layer 39 extends in the other ff12h direction of the sheet 2 from a position closer to the inner side in the width direction than the edge 2g of the sheet 2, and extends beyond the m2h to the protrusion 39a.
arranged to form a

When forming a tubular body from the laminate thus formed, as shown in FIG. are stacked on top of each other and wound on a mandrel to form a cylindrical body. Then, as shown in FIG. 13, an outer resin coating 40 is formed on this cylindrical body.

〔effect〕

As is clear from the above description, in the present invention, when a laminate consisting of an inner wall sheet and a rigid layer is spirally wound around a mandrel to form a cylindrical body in one turn, the rigid layer is Before wrapping the material around the mandrel, the material is extruded onto the inner wall sheet to form a laminate, so that the rigid layer is sufficiently cooled by the time it is wound around the mandrel, and the material is rolled into a cylindrical body on the mandrel. This solves the problem that the cylindrical body buckles and becomes deformed due to the applied propulsive force. Furthermore, in the case where the inner wall sheet has a resin layer on both sides of the metal foil, the metal foil of the inner wall sheet can be configured so as not to be exposed to the inner surface of the tubular body without folding back the edges of the inner wall sheet. , the structure and manufacturing process are simplified, the unevenness appearing on the surface can be reduced compared to the conventional one, and the appearance is improved, which is an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a roll of the inner wall sheet used in the method of the present invention, Fig. 2 is a sectional view showing an example of the structure of the inner wall sheet, and Figs. 3 (a), (b), and (C) are FIG. 4 is a sectional view showing the structure of a laminate according to an embodiment of the present invention, and FIG. 5 is a process diagram showing an example of the total processing of the inner wall sheet.
A schematic diagram of an example of a tubular body manufacturing apparatus used in the embodiment shown in the figure, FIG. 6 is a perspective view of a feeding device for the tubular body on the mandrel, and FIG. 7 is an edge of the laminate inside the tubular body. 8 is a longitudinal sectional view showing the cross section of the tubular body, FIGS. 9 and 10 are perspective views showing the can obtained by the embodiment of the present invention, and FIG. 11 is the main body. FIG. 12 is a sectional view showing a laminate in another embodiment of the invention, FIG. 13 is a sectional view showing the overlapping state of the edges of the laminate in FIG. 12. It is a diagram. 2...Inner wall sheet, 2C...Gold, Manhaku,
6... Rigid layer, 8... Laminate, 9.
13... Extruder, 25... Mandrel, 26... Cylindrical body, 30
...Surface coating, 31...Tubular body. Figure 3 (a) (b) (C) Figure 1 Figure 2 Figure 9 Figure 10

Claims (10)

[Claims] (1) Construct a laminate by laminating a relatively thick rigid layer on one side of an inner wall sheet that has the characteristics required for the inner wall depending on the purpose of use to provide the necessary rigidity, and then place it on a mandrel. A cylindrical body is formed by sequentially winding the laminated body in a spiral shape with the edges overlapping and adhering the overlapping edges to each other, and in the process of forming the cylindrical body, the cylindrical body The tubular body is formed by applying a driving force in the axial direction of the mandrel to send the cylindrical body in the axial direction of the mandrel, and supplying molten resin to the outer surface of the cylindrical body to form a resin coating. , a method for manufacturing a tubular body using a resin material as a base. (2) In the method for manufacturing a tubular body according to claim 1,
The method for manufacturing a tubular body, wherein the inner wall sheet has a structure in which resin layers are formed on both sides of metal foil. (3) In the method for manufacturing a tubular body according to claim 2,
The method for manufacturing a tubular body in which the rigid layer is made of a mixture of an inorganic material and a resin material. (4) In the method for manufacturing a tubular body according to claim 3,
An outer layer of a resin-based material is formed on the outside of the rigid layer before the laminate is wound around a mandrel, and the outer layer is formed to wrap around an edge of the inner wall sheet at at least one edge of the laminate; A method for manufacturing a tubular body, characterized in that when the laminate is wound around the mandrel, the one edge is overlapped so that it is inside the other edge. (5) In the method for manufacturing a tubular body according to claim 3,
The laminate has a resin layer between the rigid layer and the inner wall sheet, the resin layer is formed to wrap around the edge of the inner wall sheet at at least one edge of the laminate, and the laminate has a A method for manufacturing a tubular body, characterized in that when being wound around the mandrel, the one edge is overlapped so as to be inside the other edge. (6) In the method for manufacturing a tubular body according to claim 2 or 3, before forming the inner wall sheet into the laminate, the inner wall sheet is made of a resin that is melted or softened by heating a resin layer on at least one edge. The edge of the metal foil is covered so that the edge of the metal foil is not exposed, and when the laminate is wound around the mandrel, the one edge is stacked on the inside of the other edge. A method for manufacturing a tubular body. (7) A method for producing a can material, which comprises producing a tubular body by the method according to any one of claims 1 to 6, and cutting the tubular body into a predetermined length to produce a can material. (8) A laminate having an inner wall layer in which a resin layer is formed on both sides of metal foil, and a relatively thick rigid layer formed on the outside of the inner wall layer is placed on the inner wall with the edges overlapped. The inner wall layer has a structure in which the inner wall layer is wound in a spiral shape, and the inner wall layer has at least one edge of the metal foil covered with resin, and the other edge is covered with resin so that the one edge is on the inner side. A tubular body characterized by overlapping edges. (9) A can material formed by cutting the tubular body according to claim 8 into a predetermined length. (10) A can in which a lid is attached to an end of the can material according to claim 9.