JPH04187421A - Method and apparatus for manufacturing thermoplastic rolled film, and manufacture of laterally uniaxially stretched reticulated material - Google Patents

Abstract

PURPOSE:To efficiently obtain a good rolled film by suppressing the generation of rolling wrinkles or rolling irregularity by forming slits to the rolled film obtained by rolling a film after at least one edge part of a flattened cylindrical film composed of a thermoplastic resin is cut in the laterial direction of the film and stretching the slitted film in the lateral direction. CONSTITUTION:Both edge parts 2a, 2a of a flattened film 2 are cut off by laser cutters 10, 10. Next, the film 2 is fed to a preheating roll 4 through a guide roll 3 to be preheated by the preheating roll. 4. Next, the preheated film 2 is introduced into the nip of a pair of rolling rolls 6, 6 equal in outer peripheral speed through a guide roll 5 to be rolled. The rolled film 2 thus obtained is supplied to a slit forming apparatus to form slits intermittent in a zigzag pattern to the film in the laterial direction and the slitted film 2 is stretched in the lateral direction by a lateral stretching machine.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method and apparatus for manufacturing a rolled film by rolling a flattened cylindrical film made of a thermoplastic resin, and a method for transverse uniaxial stretching from this rolled film. The present invention relates to a method of manufacturing a reticular body.

[Prior Art] Conventionally, a method is known in which a cylindrical film made of a thermoplastic resin is flattened and then rolled in the vertical axis direction in a solid state.

Such a method eliminates the use of expensive and complicated three-layer dies.
-A-B three-layer structure film (a film in which the middle layer is made of resin A and both outer layers are made of resin B) can be obtained, which is useful. In other words, if such a method is used, a cylindrical A-
Flatten the A resin layers of the B two-layer structure film (cylindrical film formed by laminating A resin and B resin) so that they are in contact with each other, and roll this to form one B-A-B three-layer structure film. Obtainable.

Furthermore, when a crystalline resin film is oriented at a low magnification, it is generally difficult to achieve uniform orientation due to the necking phenomenon during stretching. In such cases, rolling is used. The films and sheets thus obtained have good mechanical properties and
It has a smooth surface, good transparency, and good airtightness, making it widely used. As for this rolling method, it is known that rolling is easier if the circumferential speeds of a pair of rolling rolls are made different (Japanese Patent Publication No. 31725/1983).

In addition, when forming a slit in the transverse axis direction (width direction) in a film made of thermoplastic resin and then stretching it in the transverse axis direction to produce a transversely uniaxially stretched network, if this film is rolled in advance, It is known that good slits can be easily obtained (Japanese Unexamined Patent Publication No. 59-227422).

[Problems to be Solved by the Invention] By the way, in the method of manufacturing a rolled film from a cylindrical film as described above, the cylindrical film is usually flattened and the flattened film is directly introduced into a rolling machine and rolled. In order to do this, rolling was sometimes carried out with air accumulated inside the cylinder or with uneven stress being applied to the film. If rolling is carried out under such conditions, rolling wrinkles and rolling unevenness will occur during rolling.
A situation often arises in which a good rolled film cannot be obtained.

Furthermore, if a slit is formed in the transverse direction of a rolled film having the aforementioned rolling wrinkles or uneven rolling, and the slit is stretched in the transverse direction, even if the rolling wrinkles are slight, they will become a trigger. There is a problem that stretching breaks easily occur due to the stretching, and a good transversely uniaxially stretched network cannot be obtained.

Furthermore, by rolling a pair of rolling rolls at different circumferential speeds, it is possible to easily produce a film in good condition with slight pressure. Then, there is a problem that stretching breakage is likely to occur.

The present invention has been made in view of the problems of the prior art, and provides a method for producing a thermoplastic resin rolled film that can suppress the occurrence of rolling wrinkles and rolling unevenness and efficiently obtain a good rolled film. The purpose is to provide such equipment.

Another object of the present invention is to provide a method for producing a transversely uniaxially stretched network in which almost no stretch breakage occurs when slits are formed in a rolled film in the transverse direction and the slits are stretched in the transverse direction. do.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides a method for manufacturing a rolled film by rolling a flattened cylindrical film made of a thermoplastic resin. This method is characterized in that at least one edge of the film is cut.

The above-mentioned rolling is preferably performed by roll rolling using a pair of rolls having the same peripheral speed.

Further, the present invention includes a cutting means for cutting at least one edge of a flattened cylindrical film made of a thermoplastic resin, and a rolling means for rolling the film from which the edge has been cut. This is a characteristic feature.

Furthermore, the present invention provides a method for forming a slit in the transverse axis direction in a rolled film obtained by cutting at least one edge of a flattened cylindrical film made of a thermoplastic resin and then rolling the film. It is characterized by stretching this in the transverse direction.

[Function] Makes it easier to discharge the air accumulated inside the cylindrical film, and makes it easier to shift the stacked films.

Further, the orientation of the film in the thickness direction is made uniform.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 in FIG. 5 indicates a cutting device (cutting means) for cutting both edges of a cylindrical film 2 made of thermoplastic resin and flattened by an inflation method. At the rear stage of this cutting device 1, a guide roll 3 that guides the film 2 with both edges cut, a preheating roll 4 that preheats the film 2, a guide roll 5 that guides the film 2, A pair of rolling rolls (rolling means) 6, 6 for rolling are provided in this order. The rolling rolls 6.6 are adapted to be driven at equal circumferential speeds.

As shown in FIG. 1, the cutting device 1 has a guide rail 7 disposed on one side of the film 2 in the width direction. A pair of sliders 8.8 are supported on the guide rail 7 so as to be slidable in the width direction. Further, each slider 7 is urged outward in the width direction by a spring 9.

Furthermore, a razor cutter 10 is fixed to each slider 7. This razor cutter 10 is hooked on the inside of the ears 2a, 2a of the cylindrical film 2, and as the film 2 is conveyed, the ears 2a are cut.

It is designed to cut through 2a. Note that the ear portion 2a is the portion that is formed when the cylindrical film 2 is folded and flattened.
It refers to the vicinity of the part where the film 2 is divided into an upper side and a lower part with the fold as a boundary, that is, the vicinity of both ends of the flattened film 2.

As shown in FIGS. 2 and 3, each razor cutter 10 includes a razor 11 that cuts the film 2, a first leather fixture 12 and a second razor fixture 13 that support this razor 11, and these. Leather fixing base 14 to fix
have. The first leather fixture 12 is an L-shaped thin plate and has a recess 15 in which the leather 11 is accommodated.

The second razor fixture 13 has an L-shaped thin plate shape corresponding to the first razor fixture 12, and has a thick plate portion 13a and a thin plate portion 13b. The first leather fixture 12 is placed over the thin plate portion 13b of the second leather fixture 13 with the leather 11 housed in the recess 15, and is fixed with screws 16. As a result, the blade of the razor 11 is exposed inside the apex of the L-shape of the razor fixture 12.13. Further, the first razor fixing device 12 and the thin plate portion 13b of the second razor fixing device 13 constitute a film guide portion 17. This film guide section 17
The inner contour portions 17a, 17b, and 17c have an inverted V-shaped cross section (see FIGS. 2 to 4).

As shown in FIGS. 3 and 4, the slider 7 has a housing 18 that fixes a fixing base 14.

A slit forming device (not shown) that forms slits in the rolled film 2 in a zigzag pattern in the transverse axis direction (width direction) and a film containing the slits are provided at the subsequent stage of the rolling roll 6.6. A transverse stretching machine (not shown) is provided to stretch the film in the transverse direction. The slit forming device is
A type that slits the film 2 while pressing it against a pedestal with a horizontal blade (Japanese Patent Publication No. 60-23104), a type that presses the film 2 between a rotary blade with a horizontal blade and a roll, and a type that slits the film 2 while pressing it against a holder under tension. A rotating triangular blade that cuts without a roll (Japanese Patent Publication No. 60-32573), a rotary heat blade and a receiver that cut with a roll (Japanese Patent Publication No. 61-11757), etc. may be used, but are limited to these. It is not something that will be done. Also,
Examples of the stretching machine include a tenter, a machine that introduces the film between a pair of pulleys, and stretches the film 2 along the outer periphery of the pulley so as to form a stretching axis trace that widens toward the end (Japanese Patent Publication No. 57-30368). may be used, but is not limited to these.

Next, a method for manufacturing a thermoplastic resin rolled film will be explained.

Using high-density polyethylene and low-density polyethylene as thermoplastic resins, a cylindrical film 2 consisting of two layers, high-density polyethylene on the inside and low-density polyethylene on the outside, is cut into a cutting device 1 with the film 2 folded flat into a sheet. will be transported to.

This carried-in flattened film 2 has both ears 2a,
2a is cut with a razor cutter 10.10. That is, the cylindrical flattened film 2 is cut into a laser cutter 10.1.
0, the film guide 17.17 of the razor cutter 10.10 enters inside the ears 2a, 2a. Thereby, the cylindrical flattened film 2 is peeled off while being guided. The outer portions 17a, 17b, and 17c of the film guide portion 17.17 have an inverted V-shaped cross section, so that the film 2 that is folded and flattened
can be easily peeled off. At this time, the razor cutter 10
．． 10 are each urged outward in the width direction of the film 2, so that the film 2 is spread outward in the width direction and maintained in a flat state.

When the flattened film 2 guided by this guide part 17.17 reaches the razor 11, the ear part 2a.

2a comes into contact with the leather 11 and is torn into two leaves.

Next, this film 2 is carried to a preheating roll 4 via a guide roll 3, and is preheated by the preheating roll 4.

Next, the preheated film 2 is introduced via the guide roll 5 between a pair of rolling rolls 6.6 having the same peripheral speed and rolled, and thus the production of the rolled film 2 is completed.

Next, in the rolled film 2 thus obtained, slits are formed in a zigzag pattern in the transverse axis direction (width direction) using a slit forming device.

The film 2 with the slits is then stretched in the transverse direction by a transverse stretching machine, thus producing a transversely uniaxially stretched network.

According to the above configuration, both ear portions 2a of the film 2.

Since the film 2a is cut, the film 2 becomes bilobed, and the air accumulated inside the film 2 can be more smoothly discharged during rolling. Additionally, if uneven stress is applied to the film 2 during rolling, the two-leaf film 2 can shift in the direction to release such stress, which further prevents rolling wrinkles and rolling unevenness. can.

Furthermore, since the peripheral speeds of the pair of rolling rolls 6.6 are made equal, it is possible to produce a good transversely uniaxially stretched network having no unstretched portions or breaks such as stretching breaks.

Note that the method for cutting the cylindrical film 2 is not limited to the method using a laser cutter as described above, and for example, a thermal cutter or the like may be used. Further, in the above embodiment, the edges 2a, 2a of the film 2 are cut, but the edges may be slightly removed by applying a round blade, or cut by other methods without using a blade. You can also melt it or melt it. Furthermore, both ears 2a
.

Although 2a is cut, one of the ears 2a may be cut.

[Effects of the Invention] As explained above, according to the present invention, it is possible to obtain a rolled film in which the occurrence of rolling wrinkles and rolling unevenness is prevented as much as possible. Further, it is possible to produce a good transversely uniaxially stretched network body with almost no breakage such as unstretched parts or stretching breaks.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a cutting device according to the present invention, FIG. 2 is a plan view showing a laser cutter of the same device, and FIG.
FIG. 4 is a side view of the laser cutter, FIG. 4 is a bottom view of the same laser cutter, and FIG. 5 is a schematic diagram showing the cutting device, rolling device, etc. 1... Cutting means (cutting device), 2... Film, 2
a... Ear portion, 6... Rolling means (rolling roll). Old Figure 4 Figure 5

Claims (4)

[Claims] (1) When manufacturing a rolled film by rolling a flattened cylindrical film made of a thermoplastic resin, at least one edge of the film is cut before rolling. Method for manufacturing rolled film. (2) Claim (1) characterized in that the rolling is performed by roll rolling using a pair of rolls having equal peripheral speeds.
The method for producing a thermoplastic rolled film as described in . (3) It is characterized by comprising a cutting means for cutting at least one edge of a flattened cylindrical film made of a thermoplastic resin, and a rolling means for rolling the film from which the edge has been cut. Thermoplastic resin film manufacturing equipment. (4) After cutting at least one edge of a flattened cylindrical film made of thermoplastic resin, a slit is formed in the transverse direction of the rolled film obtained by rolling the film. A method for producing a transversely uniaxially stretched net-like body, which is characterized by stretching in the axial direction.