JPS6228733B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a cylindrical body made of a synthetic resin sheet, and more specifically to a method and apparatus for manufacturing a cylindrical body made of a synthetic resin sheet, which is used as a material for shrink-wrapped packaging such as glass bottles, or for molding such as a pot. The present invention aims to provide a cylindrical body which can be formed by winding and joining in a shape efficiently and reliably, and which also has a good finish.

In recent years, the synthetic resin sheet cylindrical body has been used to cover glass bottles with a cylindrical body made of a shrinkable sheet for protective packaging of glass bottles.
It has begun to be used by heat-shrinking it and integrally joining it to a glass bottle, and for this reason the demand for the above-mentioned cylindrical body is increasing.

However, the method for manufacturing the above-mentioned cylindrical body requires a step of folding and winding a sheet cut to a predetermined length into a cylindrical shape, and a step of joining both ends of the sheet by heat fusion. In the process, handling of the sheet is very complicated and difficult to mechanize or automate. Moreover, it is easy to damage the sheet or apply excessive force during the above-mentioned handling, and there are inconveniences when shrink-covering the formed cylindrical body. There were cases where this occurred.

Therefore, in this invention, we have developed a method and apparatus suitable for solving the above-mentioned conventional drawbacks and efficiently manufacturing cylindrical bodies of excellent quality.
The method is to form a cylindrical body from a synthetic resin sheet of a predetermined length, in which a cylindrical mandrel is provided with a heat-sealed part on one side, and a sheet is formed on the opposite side of the heat-sealed part. After the center is abutted and fixed, air is blown from the back side of the sheet to bend the sheet at right angles along the cylindrical mandrel, and then air is blown from the right and left directions perpendicular to the air blowing direction to bend the sheet into a cylindrical shape. Fold the sheet further along the mandrel toward the heat-sealed area, then blow air alternately from the right and left diagonal directions of the heat-sealed area, fold both ends of the sheet toward the heat-sealed area, and then fold again. A heating tool is pressed against both ends of the sheet to heat-seal and bond the ends of the sheet.

Next, embodiments of the present invention will be illustrated below with reference to the drawings.

Reference numeral 1 denotes a cylindrical mandrel, which has a substantially cylindrical shape and has a part of its circumferential side surface cut off linearly to form a flat heat-sealed portion 10 . Reference numeral 2 denotes a presser bar, which is movably provided on the opposite side of the cylindrical mandrel 1 from the heat-sealed portion 10, so that it can be pressed against the cylindrical mandrel 1. After feeding the synthetic resin sheet S cut into a predetermined length between the cylindrical mandrel 1 and the presser bar 2, the presser bar 2 is moved and the center of the sheet S is placed between the cylindrical mandrel 1 and the presser bar 2.
(Fig. 1 to Fig. 2).

Next, reference numeral 3 denotes a front air nozzle, which is installed at the back side of the presser bar 2 and blows air over the entire sheet S from the back side to the cylindrical mandrel 1 side, so that the sheet S is moved around the circumference of the cylindrical mandrel 1. Bend it along the shape to the right angle direction (Figures 2 and 3).

Next, reference numeral 4 denotes a side air nozzle, which is provided at the left and right side positions of the cylindrical mandrel 1 in a direction perpendicular to the front air nozzle 3. Air is blown from the back side of each sheet, and the sheet S is further bent along the circumferential shape of the cylindrical mandrel 1 until both ends of the sheet S are located approximately in the vicinity of the heat-sealed portion 10 (Figs. 3 to 3). Figure 4).

Next, 5 is an air nozzle for folding, which is provided at diagonal positions on the left and right sides of the heat-sealed part 10 of the cylindrical mandrel 1, and can blow air to the heat-sealed part 10 from an oblique direction. folded sheet S
Blow air from the back side of both ends of the sheet
Both ends are bent and brought into contact with each other by folding them onto the flat heat-sealed portion 10. By alternating the timing of air blowing by the left and right folding air nozzles 5, 5, the ends of the sheet S can be folded over each other (Figs. 4 to 5).
figure).

Both ends of the sheet S bent and wound along the circumferential shape of the cylindrical mandrel 1 are joined together, and 6 is a heating tool;
The heating tool 6 is movably provided at the front position of the folded sheet S, and by pressing the heating tool 6 from the outside against the heat-sealing section 10 at both ends of the folded sheet S, and pressing the sheet S at the same time as heating. Both ends are heat-sealed to each other to be integrally joined. Note that the tip of the heating tool 6 is the heat-sealing part 10.
The sheet S is formed flat in the same way as the sheet S, and the heat-sealed area of the sheet S is sufficiently secured to increase the bonding strength. It is made so that it is not thicker than the other parts (Figure 6).

The cylindrical body A is formed as described above, but in order to extract the cylindrical body A from the cylindrical mandrel 1, a extracting tool 11 protruding from the outer periphery of the cylindrical mandrel 1 is provided so as to be movable in the axial direction. , the extracting tool 11 is brought into contact with the end of the cylindrical body A and is slid in the axial direction to extract it (FIG. 7).

The apparatus having the above configuration can sequentially perform each step to form the sheet S to the cylindrical body A (FIG. 8).

In addition, among the above devices, the presser bar 2 and the heating tool 6
As the moving mechanism, various known mechanisms such as a hydraulic/pneumatic cylinder or a cam mechanism may be used, and it is preferable that the sheet S be elastically pressed by a spring or the like. Further, each air nozzle 3, 4, 5 is connected to an air supply source as appropriate.
By automatically controlling the air supply to 4 and 5 and the operation timing of the presser bar 2 and heating tool 6 by appropriate means, it is possible to completely automate the entire apparatus.

Next, an example of an apparatus suitable for carrying out the method of the present invention more efficiently will be described.

That is, a plurality of cylindrical mandrels 1 are arranged at equal intervals along the circumferential direction on a rotatably provided table 7, and each cylindrical mandrel 1 is equipped with a presser bar 2, a side air nozzle 4, and a foldable mandrel. Layering air nozzle 5,
The heating tools 6 are each installed at a predetermined position. Note that each cylindrical mandrel 1 is installed radially so that the heat-sealing portion 10 side faces toward the center.

And only the front air nozzle 3 is on table 7.
It is fixedly installed independently on the outside of the table 7.
This allows air to be blown towards the center.

Reference numeral 8 denotes a feeding mechanism for the sheet S, which pulls out the rolled sheet S' with a roller 80 or the like, cuts it into a predetermined length by the action of a cutter roller 81, or the like, and then feeds the sheet one sheet at a time along a guide section 82 as appropriate. The sheets S can be sequentially supplied between the front air nozzle 3 and one cylindrical mandrel 1 facing each other on the table 7.

The sheet S supplied as described above is fixed in contact with the cylindrical mandrel 1 by the presser bar 2, bent by the front air nozzle 3, and then rotated as the entire table 7 rotates. Then, the step of forming the cylindrical body A progresses sequentially while performing the above-mentioned rotational movement, and after the completed cylindrical body A is extracted, the table 7 rotates exactly once, and the cylindrical mandrel 1 again supplies the sheet S. It will return to its position.

Therefore, by sequentially supplying the sheets S to a plurality of cylindrical mandrels 1 placed on the table 7, the cylindrical body A can be formed continuously, and the operating efficiency of each cylindrical mandrel 1 is extremely high. It is efficient, suitable for mass production, and requires less space and equipment cost for the entire device (FIG. 9).

In the illustrated device, the presser bar 2 is pressed against the cylindrical mandrel 1 side by the action of a spring or the like, and in order to release the presser bar 2, a regulating member 20 is placed along the outer periphery of the table 7. It is fixedly installed separately from the table 7, and as the presser bar 2 moves to the location where the regulating member 20 is installed as the table 7 rotates, the presser bar 2 moves along the regulating member 20 to the cylindrical mandrel 1. The device is forced to move in a direction away from the target. Immediately before the presser bar 2 returns to the sheet S supplying position again, the regulating member 20 disappears, and the presser bar 2 can press and fix a new sheet S to the cylindrical mandrel 1.

In addition, the synthetic resin sheet S used in this invention
Materials include polystyrene, polyethylene,
In addition to foamed sheets or non-foamed sheets made of various resins such as polypropylene, it is also possible to freely use multilayer sheets in which a non-foamed film is laminated on one or both sides of the foamed sheet.

In the method of the present invention constructed as described above, the entire bending process of the sheet S is performed by blowing air without directly contacting the sheet S, and there is no need to apply excessive force to the sheet S or locally bend the sheet S. Since there is no deformation, it is possible to run the sheet S along the cylindrical mandrel 1 very smoothly, without damaging the sheet S or creating creases.
The quality of the formed cylindrical body A becomes extremely good.
Furthermore, since the device does not require a complicated operating mechanism or detailed mechanical parts, the device itself is easy to manufacture and the equipment cost is reduced.

Also, even if there is an error in the dimensions or thickness of the sheet S,
Since the bending is done by air blowing, it is not affected at all and can be operated without any problems, and there is no problem with the finish of the cylindrical body A. Also, when changing the type and shape of the material sheet S to be supplied or the diameter of the cylindrical body A, all that is required is to change the cylindrical mandrel 1, for example, without changing the mounting position of each air nozzle. It is highly flexible and can reduce the labor involved in recombining work and the cost of changing equipment.

[Brief explanation of the drawing]

The figures illustrate an embodiment of the present invention, and FIGS. 1 to 7 are operation process diagrams showing the order of operation, FIG. 8 is a perspective view of the manufactured cylindrical body, and FIG.
The figure is a schematic structural diagram showing an example of the entire device. 1... Cylindrical mandrel, 10... Heat fusion part, 2
...Press bar, 3...Front air nozzle, 4...
... air nozzle for side surfaces, 5 ... air nozzle for folding, 6 ... heating tool, 7 ... table, S ... synthetic resin sheet, A ... cylindrical body.

Claims (1)

[Claims] 1. A method for forming a cylindrical body from a synthetic resin sheet of a predetermined length, in which a cylindrical mandrel is provided with a heat-sealed portion on one side, and a cylindrical body is formed on the opposite side of the heat-sealed portion. After fixing the center of the sheet against the sheet, blow air from the back side of the sheet and bend the sheet at right angles along the cylindrical mandrel. The sheet is further folded along the shaped mandrel toward the heat-sealed part, and then air is blown alternately from the right and left diagonal directions of the heat-sealed part to fold both ends of the sheet toward the heat-sealed part. A method for manufacturing a cylindrical body made of synthetic resin sheets, characterized by pressing a heating tool against both ends of the stacked sheets to heat-seal and bond the ends of the sheets. 2 A device for forming a cylindrical body from a synthetic resin sheet of a predetermined length, in which a cylindrical mandrel is provided with a heat-sealed portion on one side, and a movable presser bar is pressed against the opposite side of the heat-sealed portion. A front air nozzle is provided at the back of the presser bar, a side air nozzle is provided at the left and right positions of the cylindrical mandrel, and the cylindrical mandrel is folded at diagonal positions on the left and right with respect to the heat-sealed part. 1. An apparatus for producing a cylindrical body made of a synthetic resin sheet, characterized in that an air nozzle is provided for the heat-sealing part, and a heating tool is provided in front of the heat-sealing part and is movable in pressure contact with the heat-sealing part. 3 A plurality of cylindrical mandrels are arranged along the circumferential direction on a rotatable table, and the heat-sealed part of each cylindrical mandrel is arranged toward the center, and each cylindrical mandrel has a A presser bar, a side air nozzle, a folding air nozzle, and a heating device are provided, and the front air nozzle is fixedly installed outside the table, and the front air nozzle is installed between the front air nozzle and the cylindrical mandrel on the table. An apparatus for manufacturing a cylindrical body made of a synthetic resin sheet according to claim 2, which is capable of supplying a sheet.