JP2776249B2 - Continuous winding method for resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously winding a resin film, such as a soft vinyl chloride resin, which does not bulge at an intermediate portion of an end face of a wound resin film roll.

[0002]

2. Description of the Related Art In the production of a resin film or when rewinding a preliminarily wound resin film, the resin film is generally wound around a core to form a resin film roll. For example, when a film is continuously produced from a soft vinyl chloride resin by a method such as a calendering method, the film is usually trimmed to a fixed width and wound around a core to form a wound resin film roll. Also, when the pre-wound wound resin film roll is adjusted to a desired film length or the like, it is unwound by a method of winding around a winding core to form a new resin film roll. As described above, the resin film is wound at a high speed in order to improve the production efficiency when producing or rewinding the film, and while applying a certain amount of tension to the film in order to smooth the outer peripheral surface of the wound resin film roll. This tension acts in the direction of shrinking the resin film, and turns into a tightening force in the direction of the core in the wound resin film roll. As a result, the middle part of the end face of the film roll expands in the width direction due to compression deformation. Happens.

That is, although the change in the film width near the core is small, the film is widened by the tightening force as the film is wound, and the film tightening force becomes weaker as approaching the outer periphery of the film roll. The change in the width is small, and eventually the film roll is deformed into a convex state in which the end face swells at the position of 1/6 to 1/3 of the film lamination thickness from the winding core. In the winding state, the end film near the winding core in the portion that is widened by the tightening force and swells to the maximum has a drawback that the end film is bent inward (to the winding core side). This causes troubles such as film breakage when the film roll is released, and also causes quality abnormalities that impair the lay flatness (flatness) of the released film.

[0004] As measures to prevent these troubles and abnormal quality, the tension at the time of winding the film is reduced, and the contraction force of the film is reduced to reduce the swelling (deformation) of the end face of the film roll due to the tightening of the film. Although a method of preventing bending of the end film has been adopted, production efficiency is reduced, and air is easily trapped between the wound films due to a decrease in tension at the time of winding the film. Was causing it. Conventionally, a great deal of labor has been spent on adjusting the tension in order to eliminate this drawback.

[0005]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies on a winding method that does not cause swelling of the resin film roll end surface even when the film is wound at a high speed. By winding onto the core while trimming both ends sequentially or intermittently by trimming both ends, it is possible to prevent convex deformation occurring at the intermediate portion of the end face of the film roll and bending of the end film of the roll film, and winding at high speed. We have found what we can do and completed the present invention. That is, the object of the present invention is:
It is an object of the present invention to provide a method for continuously winding a resin film in which an end film of a film roll is prevented from being deformed in a convex shape generated at an intermediate portion of an end face of the film roll.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a method of continuously winding a resin film around a winding core by sequentially or intermittently narrowing a width of a supply film at an initial stage of winding. A feature is a method for continuously winding a resin film. The present invention will be described in detail.

The resin film, which is an essential component of the present invention, includes various types such as a vinyl chloride resin film, a vinylidene chloride resin film, a polyethylene film, a polypropylene film, an ethylene-vinyl acetate copolymer film, and a polystyrene film. However, in the present invention, the effect is particularly great for films such as flexible soft vinyl chloride resin, low-density polyethylene, and ethylene-vinyl acetate copolymer film.

Although these films may be produced by any molding method, they are usually produced by a calendering method, an extrusion molding method, an inflation molding method or the like. The method of the present invention is particularly effective when applied to a calendering method in which a soft resin can be formed into a film at a high speed and a high-speed winding machine is provided. The method of the present invention is also effective in the step of rewinding the once wound film roll to adjust the film length and winding form and winding it around another winding core. The method of the present invention resides in a method of continuously winding a film around a core at the time of film formation or film rewinding as described above.

In order to carry out the method of the present invention, a resin film continuously supplied from a film forming device or a film rewinding device is fed to a pair of film trimming devices (trimming cutters) provided upstream of a winder. Take up the core at high speed while trimming. In the initial stage of winding, the supply film is wound sequentially or intermittently with a trimming cutter while reducing the width of the supply film. The pair of trimming cutters are configured to move symmetrically. The width of the film to be wound may be reduced sequentially or intermittently by moving a pair of trimming cutters inward until the winding is completed. The movement of the trimming cutter may be stopped, and the winding may be completed while maintaining the narrowed constant width.

The resin film roll wound by these methods has a shape in which the width of the resin film is gradually reduced from the winding core toward the outer periphery, or the film near the winding core is expanded by the tightening force. The resin film is wound so that the width of the resin film keeps the same width from the winding core toward the outer circumference, or gradually narrows from the middle toward the outer circumference. The initial stage of the beginning of winding in the method of the present invention refers to a timing at which the film is wound at least 1/6, preferably 1/3 from the core side of the film lamination thickness of the wound resin film roll. This value differs depending on the hardness of the resin film.

In the method of the present invention, it is preferable that the width of the pair of trimming cutters is widened immediately before the completion of the winding to widen the width of the supplied resin film to the width of the film at the beginning of winding.
By increasing the film width immediately before winding is completed, it has the effect of protecting the wound resin film roll,
It prepares to change to the next core and enables continuous winding work. The moving speed of the trimming cutter varies depending on the winding speed (tension), film thickness, film roll winding diameter, etc., but the end face shape of the film roll previously wound at a constant tension, film thickness, and winding diameter is used. By storing the relationship between the time from the start of the picking and the amount of deformation of the end face in the trimming cutter moving device, the control can be easily performed. The control of the moving speed of the cutter is not limited to the above-described method. For example, during continuous winding, the shape of the end face of the film roll is detected by a laser sensor, and the shape of the cutter is adjusted to a predetermined shape stored in advance. May be moved.

[0012]

According to the method of the present invention, even when the film is continuously wound around the core at a high speed, no convex deformation due to the tightening force occurs at the intermediate portion of the end face of the film roll. It was possible to prevent the end film from being bent, which eliminated the problem of film breakage during unraveling, and the lay flat property of the unraveled film was also good, which was necessary for adjusting the tightening force. There is no labor required, and production efficiency can be improved.

[0013]

Next, the method of the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples unless departing from the gist of the method.

EXAMPLE A soft vinyl chloride resin composition containing 100 parts by weight of a vinyl chloride resin and 50 parts by weight of a plasticizer was calendered by a calendering machine equipped with a center winder to a thickness of 0.1 mm.
A film having a width of 140 cm was formed, and was wound 1500 m around a winding core having an outer diameter of 90 mm at a winder speed of 120 m / min. A pair of trim cutters were intermittently moved by 1 mm every 5 seconds for a period of 70 seconds from the start of winding to reduce the film width. Thereafter, the trim cutter was wound at a constant width without moving the trim cutter. Immediately before the winding was completed, the trim cutter was returned to the winding start position. The film roll manufactured in this manner had no deformation such as swelling on its end face. Then, there was no breakage of the film at the time of the release.

Comparative Example A film roll was manufactured in the same manner as in the example except that the trim cutter was not moved. In this film roll, the most bulged convex deformation occurred at a position 1/5 of the film lamination thickness from the winding core on the end face. This position was 140 m from the beginning of film winding. Also,
The end film swelled on the end face of the roll film was bent toward the core.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-50-20174 (JP, A) JP-A-2-55654 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B65H 19/28

Claims (5)

(57) [Claims] 1. A method for continuously winding a resin film around a winding core, wherein the width of a supply film in an initial stage of the beginning of winding is narrowed sequentially or intermittently. 2. The continuous winding method for a resin film according to claim 1, wherein the width of the supply film is reduced sequentially or intermittently until winding is completed. 3. The continuous winding method for a resin film according to claim 1, wherein the width of the film, which has been reduced during the winding, is maintained. 4. The method according to claim 1, wherein the width of the supply film is widened to the width of the film at the beginning of winding immediately before the completion of the winding.
The method for continuously winding a resin film according to claim 3. 5. A resin film roll continuously wound around a core, wherein the resin film roll is wound in such a manner that the width of the resin film is gradually reduced from the core toward the outer periphery.