JP2934234B1 - Thermoplastic resin sheet, welding cutting method thereof, and welding cutting device - Google Patents

Abstract

An olefin resin sheet is formed into a desired shape.
Its production efficiency is also improved. SOLUTION: Two olefin resin sheets 2 are superposed and interposed between an ultrasonic horn 6 and a die cut roll 5 having a cutting blade portion. By giving the amplitude, the sheet pressure contact surface is caused to generate frictional heat to weld the sheets together, and after the sheet welding, the ultrasonic horn 6 is stopped and the sheet 2 is welded.
Is transported, and the flat roll 7 on the downstream side in the rotation direction of the die-cut roll 5 and the cutting blade section press the sheet to cut the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for welding and cutting a plurality of thermoplastic resin sheets, particularly olefin resin sheets, which are effective when they are welded to each other to form a desired shape. The present invention relates to a thermoplastic resin sheet formed by the above method.

[0002]

2. Description of the Related Art As a method of welding and cutting a thermoplastic resin sheet, there are known a method of welding and cutting the sheet by internally generating heat by high frequency induction heating, and a method of welding and cutting the sheet by conduction heating by heating a mold. ing.

[0003]

However, among the thermoplastic resin sheets, especially olefin resin sheets such as polypropylene and polyethylene, when the induction heating method is employed, internal heat generation hardly occurs, and welding and cutting into a desired shape are performed. There were difficulties that could not be applied when doing so.

[0004] If a conduction heating method is adopted for welding and cutting such an olefin resin sheet, the mold is pressed against the resin, melted, and then cut.
Not only skill is required to control the heating temperature, but also depending on the heating temperature, the molten resin adheres to the mold side, which requires time and effort to remove the resin, and furthermore, a good-looking sheet cutting edge cannot be obtained. There were difficulties. In addition, when the mold is released after welding and cutting the sheet, it must be performed after the sheet is cooled and becomes stable.However, when the conduction heating method is adopted, it takes time to cool the sheet and the mold, There was a drawback that it was not suitable for mass production of sheets.

At present, there is a demand for a sheet welding / cutting method which is most suitable for welding / cutting an olefin resin sheet and which is excellent in productivity, by solving the problems of the conventional method.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventor has conducted intensive studies on measures for welding and cutting a thermoplastic resin sheet into a desired shape and shortening the molding time. Instead of induction heating or conduction heating, a method of heating and melting the superposed sheets by frictional heat is adopted. As a means, multiple thermoplastic sheets are placed between the ultrasonic horn and the die cut roll facing it. By sandwiching the resin sheet and fusing the sheet by frictional heating with a minute amplitude perpendicular to the sheet surface and welding it, it does not take time to release the mold after welding and cutting as in the conventional conduction heating method, In addition, it has been found that welding and cutting can be easily performed even with a thermoplastic resin sheet, particularly an olefin resin sheet.

Further, after welding of the sheet, the sheet is conveyed by utilizing the rotation of the die cut roll, and a flat roll having a smooth surface is arranged downstream of the ultrasonic horn in the direction of rotation of the die cut roll. If the method of cutting the sheet between the die roll and the die cut roll is adopted, the welded sheet is cooled and stabilized before it is conveyed to the flat roll, and the subsequent cutting is performed smoothly. It has been found that it can be performed continuously and that productivity is improved. Moreover, even after welding, the resin sheet is pressed and cut between the flat roll while being held by the cutting blade portion of the die cut roll, so that the welded / cut portion does not shift in position and has a good appearance. The knowledge that it becomes a cut surface was obtained.

The die-cut roll in this case is a drum-shaped roll that rotates around an axis, and its surface structure can be of various shapes depending on the welding cut shape of the thermoplastic resin sheet. What has at least the welding part projected from the roll surface and the cutting blade part should just be used. Specifically, a die-cut roll provided with a ring-shaped welded part on the surface and a cutting blade part also formed in a ring shape on the outer peripheral side thereof can be exemplified.

The projecting height of the welded portion may be about 0.1 mm with respect to the roll surface. Further, the cutting blade portion may be at the same height or different height in relation to the welding portion, but in order to cut the hard-to-cut olefin resin sheet, it is desirable that the cutting blade portion is higher than the welding portion, A form in which a height difference of about 0.1 to 0.3 mm is maintained is preferable.

The welding portion and the cutting blade portion may be formed by directly processing a metal plate material wound or wound on the surface of a die cut roll. The processing method may be a cutting method, an electrolytic processing or an electric discharge processing. Either a forming method or a forming method by corrosion processing can be adopted.

Further, the tip of the cutting blade portion has a tapered pointed shape, which is 0.2 to 0.2 times smaller than when the pointed edge is sharp (R is zero).
An R shape of about 0.3 mm is more preferable. If it is sharper than that (less than 0.2 mm), there is a possibility that the sheet may be cut by the cutting blade during welding or before welding when the resin sheet is pressed by the ultrasonic horn and the die cut roll. Because there is.

The ultrasonic horn has a well-known structure for striking a sheet with a small amplitude in a direction perpendicular to the sheet surface, and the amplitude can be appropriately selected in a range of about 0.05 to 0.1 mm. .

The gap between the ultrasonic horn and the die cut roll is a gap that allows the sheet to be pressed into contact with the ultrasonic horn, and may be set within a range in which the cutting blade does not hit the ultrasonic horn due to vibration perpendicular to the sheet surface. The interval is also changed by the sheet thickness. For example, when two sheets having a thickness of 0.2 mm and a thickness of 0.2 mm from the welded portion to the cutting blade are overlapped and welded and cut (the sheet thickness is 0.4 mm),
When the proximity distance between the cutting blade and the ultrasonic horn is set to 0.3 mm, the amplitude of the ultrasonic horn is set to 50 μm to 100 μm.
Even if it is set to μm, it does not hit the tip of the cutting blade at the bottom dead center of vibration of the horn. The reason why the cutting blade is set so as not to hit the ultrasonic horn is because the vibration of the ultrasonic horn causes damage to the horn when the cutting blade hits and loss of the cutting blade, shortening the service life. is there.

The flat roll is a drum having a smooth surface and, unlike an ultrasonic horn, is arranged so as to be pressed against a die cut roll. in this case,
Since the high-frequency vibration is not performed unlike the ultrasonic horn, there is little possibility that the cutting blade portion is damaged, and the sheet can be cut reliably.

The number of sheets interposed in this case is not limited as long as it is a number of sheets that are welded by frictional heat generated by high-frequency vibration, and the concept of the sheet includes a thin film. Although the olefin resin sheet has been described above, the present invention can be applied to other thermoplastic resin sheets.

Further, the thermoplastic resin sheet must be cooled until it becomes stable between the welding and cutting, but in the case of this method, unlike the conduction heating method, the high frequency vibration If the ultrasonic horn is stopped after welding the sheet, there is no residual heat such as conduction heating, so it is cooled instantly, and the sheet is transported to the flat roll by the rotation of the die cut roll. The sheet can be cut in a stable state because it is cooled until the sheet is cooled, and the molding time for welding and cutting the sheet into a desired shape can be reduced.

[0017]

An embodiment of the present invention will be described below with reference to the drawings. 1 is a schematic cross-sectional view of a welding and cutting apparatus for a resin sheet, FIG. 2 is an enlarged cross-sectional view showing a relationship between an ultrasonic horn and a die cut roll, and FIG. 3 is an enlarged cross-sectional view showing a welded portion and a cutting blade of the die cut roll. FIG.

As shown in the figure, a welding and cutting apparatus 1 for a thermoplastic resin sheet welds and cuts a plurality of superposed olefin resin sheets 2 by frictionally heating a press-contact surface of the olefin resin sheets 2. Unwinding roll 3 to send out,
A pair of upper and lower pinch rolls 4 disposed on the feed side of the unwind roll 3, a die cut roll 5 disposed downstream of the pinch roll 4, and an ultrasonic horn disposed facing the die cut roll 5. 6, a flat roll 7 disposed downstream of the ultrasonic horn 6 in the rotation direction of the die cut roll 5, and a winding for winding the sheet 2 discharged from between the flat roll 7 and the die cut roll 5. A take-up roll 8 and a pair of upper and lower transport rolls 9 disposed between the flat roll 7 and the take-up roll 8 are provided.

Since the unwinding roll 3, the pinch roll 4, the transport roll 7 and the winding roll 8 have a well-known structure, the description thereof is omitted, and the die cut roll 5, which is a main part of the present embodiment, is omitted. The configuration of the ultrasonic horn 6 and the flat roll 7 will be described.

The die cut roll 5 conveys the sheet,
A metal drum for welding and cutting into a desired shape, as shown in FIG. 3, a stainless steel plate material 10 is wound around the surface, and a welding portion 11 is formed on the plate material 10 in accordance with a welding area of the resin sheet 2. The cutting blade portion 12 protruding from the outer peripheral portion of the welded portion 11 according to the shape (cutting line) is formed by corrosion processing.

The welded portion 11 is formed about 0.1 mm higher than the surface base 13 (base thickness 0.2 mm) of the plate material.
Knurling is appropriately performed according to the shape of the welding region of the sheet. The cutting blade portion 12 is set so that its height is about 0.2 mm higher than the welding portion 11, and
In order to prevent the sheet from being cut at the time of welding or before welding, the tip is formed into an R-shaped tapered shape with a tip of about 0.2 to 0.3 mm.

The ultrasonic horn 6 has a well-known structure that vibrates at a small amplitude (50 μm to 100 μm) in a direction perpendicular to the sheet surface, and is arranged in close proximity to the die cut roll 5 to strike the sheet 2. It generates frictional heat.

The distance between the cutting blade portion 12 of the die cut roll 5 and the ultrasonic horn 6 is set to 0.2 mm when two sheets having a thickness of 0.2 mm are overlapped. The gap is such that the cutting blade 12 does not hit the tip of the horn due to the vibration.

The flat roll 7 is a die cut roll 5
A metal drum which faces the die-cut roll 5 on the downstream side in the rotation direction and press-cuts the sheet 2 between the die-cut roll 5 and the cutting blade portion 12 of the die-cut roll 5; 12.

Next, a method for welding and cutting a polypropylene sheet using the welding and cutting apparatus 1 will be described. As shown in FIG. 1, the ultrasonic horn 6 is used to weld two olefin resin sheets of a 0.2 mm-thick polypropylene sheet into a desired shape by laminating them.
And two die-cut rolls 5, two polypropylene sheets 2 are superposed and transported. Then, by applying a small amplitude in a direction perpendicular to the sheet 2 by the ultrasonic horn 6, the sheet pressing surface is beaten to generate frictional heat and weld the sheets. After the welding of the sheet 2, the ultrasonic horn 6 is stopped to cool the sheet 2. In this case, if the ultrasonic horn 6 is stopped, the horn itself is not generating heat, so that it is cooled instantaneously.

After the ultrasonic horn 6 stops, the die cut roll 5 rotates to convey the sheet 2 to the flat roll 7 side. Then, since the cutting blade portion 12 is pressed against the flat roll 7, the sheet 2 is cut at this portion, and the sheet 2 is finished in a desired shape. The sheet is cooled even during the sheet conveyance from the die cut roll 5 to the flat roll 7, so that the sheet can be cut in a stable state.

The cut sheet 2 is taken up by the transport roll 9 and wound up by the take-up roll 8. Such an operation is repeatedly performed, and the sheet 2 is continuously cut into a desired shape.

[0028]

As is clear from the above description, according to the present invention, the ultrasonic horn is vibrated at a small amplitude in a direction perpendicular to the surface direction of the sheet, so that the sheet is frictionally heated and welded, and die cutting is performed. Since the step of cutting into a desired shape by the cutting blade portion on the downstream side of the rotation of the roll is continuously performed,
The molding time can also be reduced. Further, since the cutting blade portion of the die cut roll is not in contact with the ultrasonic horn, there is an effect that the cutting blade portion can be prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an apparatus for welding and cutting a resin sheet according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a relationship between an ultrasonic horn and a die cut roll.

FIG. 3 is an enlarged sectional view showing a welded portion and a cutting blade portion of the die cut roll.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sheet welding cutting apparatus 2 Resin sheet 3 Unwinding roll 4 Pinch roll 5 Die cut roll 6 Ultrasonic horn 7 Flat roll 8 Takeup roll 9 Conveyance roll 11 Welding part 12 Cutting blade part

Continuation of front page (72) Inventor Kenjiro Nishikawa 1-9-2 Hannan-cho, Abeno-ku, Osaka-shi Maruni Co., Ltd. (56) References JP-A 1-257038 (JP, A) JP-A 3-126529 ( JP, A) Jikai Hei 6-9927 (JP, U) Jiko 62-26192 (JP, Y2) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 65/08 B29C 65/74 B65B 51/10-51/22

Claims (4)

(57) [Claims] 1. A method in which a plurality of thermoplastic resin sheets are stacked and conveyed on a rotating die-cut roll having a sheet welded portion and a cutting blade formed on a surface thereof, and are interposed between an ultrasonic horn facing the die-cut roll. The sheet is interposed and pressure-welded, the ultrasonic horn is made to have a very small amplitude in the direction perpendicular to the surface direction of the sheet, and the sheets are welded to each other by beating the sheet to generate frictional heat.
The ultrasonic horn is conveyed to the rotation downstream side of the die-cut roll, and is passed between the die-cut roll and a flat roll facing the same in a press-contact state, and between the cutting blade portion of the die-cut roll surface and the flat roll. A method for welding and cutting a thermoplastic resin sheet by cutting a part of the welded portion of the sheet. 2. The welding cutting method according to claim 1, wherein the thermoplastic resin sheet is an olefin resin sheet. 3. A thermoplastic resin sheet formed by the method according to claim 1. 4. A welding / cutting apparatus for a thermoplastic resin sheet for welding / cutting a press-contact surface of a plurality of laminated thermoplastic resin sheets by generating heat by friction, wherein one side of the sheet surface of the resin sheet is provided. An ultrasonic horn that is arranged and that generates frictional heat by beating the sheet with a small amplitude in a direction perpendicular to the sheet surface, and the other side of the sheet surface facing the ultrasonic horn so that the sheet can be conveyed. A die-cut roll having a welded portion and a cutting blade portion that is rotatably disposed on the surface and pressed against the sheet, and that faces the die-cut roll on the downstream side in the rotation direction of the die-cut roll, between the die-cut roll. A flat roll for press-cutting the sheet with the cutting blade, the cutting blade protrudingly formed on the ultrasonic horn side with respect to the welding part, and a tip of the cutting blade and an ultrasonic horn. Setting thermoplastic resin sheet welding and cutting device so as to retain the minute gap between the vibrating bottom dead center of.