JPS61146520A - Method and apparatus for preparing film - Google Patents

Abstract

PURPOSE:To effectively remove mist without interrupting a film manufacturing process, by wiping off the surface of a cooling roll by a wiping material and removing the liquid adhered substance on the surface of the cooling roller absorbed with the wiping material without detaching said wiping material. CONSTITUTION:A mist sucking apparatus 3 mainly consists of the wiping material 4 provided at a position capable of being contacted with a cooling roll 2 and a suction chamber 6 having a suction port 5, and is equipped with the holder 7 holding the wiping material 4 to the suction port 5. Because the wiping material absorbs mist in such a state that the leading end thereof is contacted with the cooling roll 2, said wiping material pref. has not only a property capable of absorbing and holding the oil component such as the plasticizer being the component of mist but also abrasion resistance. A suction blower or vacuum pump, is operated to evacuate the suction chamber 6 in the holder 7 to reduce the pressure therein. Mist is sucked to the suction chamber 6 through suction holes 9 and discharged out of the system from a liquid sump 6A through a mist discharge port.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a film manufacturing method and an apparatus thereof, and more specifically, in T-die extrusion molding of thermoplastic resin, liquid adhesion that condenses and adheres to the surface of a cooling roll is produced. The present invention relates to a method and apparatus for producing a film that can efficiently remove kimono (mist generated from a plasticizer added to a thermoplastic resin, etc.).

[Prior Art] In the case of T-die extrusion molding of thermoplastic resin, especially soft vinyl chloride containing a large amount of plasticizer, a large amount of liquid deposits (hereinafter referred to as "mist") are formed when the molten resin is discharged from the T-die. ) occurs.

This mist is cooled and condensed by a cooling roll located immediately after the T-die, becomes liquid, and adheres to the surface of the cooling roll.

However, if excessive mist condenses on the cooling roll, the mist will be transferred to the surface of the film that has been cooled and solidified by the cooling roll, causing wrinkles to occur in the subsequent film winding process and preventing normal winding. Another problem is that most of the components of the mist are plasticizers, so the mist transferred to the film acts as an adhesive, and the film roll fills.

There is a problem in that the film comrades are fused together, making it impossible to rewind the film. In addition, surface contamination caused by additives may degrade the quality of the film, and it also poses hygiene problems, especially when the film is used for food packaging.

Conventionally, in order to remove mist adhering to a cooling roll, wool felt was manually pressed against the surface of the cooling roll to absorb the mist.

[Problems to be Solved by the Invention] However, this conventional method cannot be used continuously for a long time, so film production must be temporarily interrupted to replace the wool felt that has absorbed the mist and is saturated. However, there were disadvantages in that the production efficiency was poor and a large amount of wool felt waste was generated.

Therefore, the present invention aims to remove the striped mist that adheres to the surface of the cooling roll.
It is an object of the present invention to provide a method and apparatus for producing a film that can be removed efficiently and effectively without interrupting the film production process.

[Means for Solving the Problems] In order to achieve the above object, the inventor has made extensive studies. C,
We have finally arrived at the present invention.

That is, the method for producing a film according to the present invention is a method for producing a film in which a synthetic resin is melted and extruded through a T-die, and then cooled and solidified on a cooling roll, in which the surface of the cooling roll is wiped with a wiping material, and the material is absorbed into the wiping material. The film manufacturing apparatus according to the present invention is characterized in that liquid deposits on the surface of the cooling roll are removed without removing the wiping material, and the film manufacturing apparatus according to the present invention melts and extrudes a synthetic resin using a T-die, and then cools and solidifies the film using a cooling roll. The manufacturing apparatus is characterized in that a wiping material for wiping off liquid deposits on the surface of the cooling roll is fixed at a position where it can come into contact with the cooling roll, and a device is provided for removing liquid deposits absorbed by the wiping material. .

EMBODIMENT OF THE INVENTION Hereinafter, one embodiment of the manufacturing apparatus for carrying out the film manufacturing method of this invention is demonstrated based on an accompanying drawing.

FIG. 1 is a side view showing one embodiment of the present invention, FIG. 2 is a front view of the same, and FIG. 3 is a sectional view taken along the line ■--■ in FIG. 2.

In each figure, 1 is a T-die for discharging and supplying the molten resin A, and 2 is a cooling roll for cooling and solidifying the molten resin A supplied from the T-die I.

The cooling roll 2 is disclosed in Japanese Patent Application No. 59-228762.
It is preferable to take measures to prevent neck-in as described in the specification.

When the molten resin A is cooled and solidified by the cooling roll 2, a synthetic resin film 1 is formed. During this film forming process, some of the plasticizers and additives contained in the molten resin A volatilize, resulting in a large amount of Mist is generated. A part of this mist is also cooled by the cooling roll 2 and condenses on the surface of the cooling roll 2. If this condensed mist adheres to the film, it may interfere with the film winding process or cause a decrease in the quality of the film, but according to the present invention, this mist can be easily removed. That is, in the figure, 3 is a mist suction device for suctioning and removing the above-mentioned mist, and 1 is preferably provided above the cooling roll 2 as shown in the figure, but it is not necessarily limited thereto.

Although the mist suction device 3 is not particularly limited,
It mainly consists of a wiping material 4 provided in a position where it can come into contact with the cooling roll 2, and a suction chamber 6 having a suction port 5 (see Fig. 3), and a holder that holds the wiping material 4 in the suction port 5. 7
and, for example, a suction blower or a vacuum pump (not shown) connected to the holder 7 with a suction pipe 8.
Note that the means for holding the wiping material 4 in the holder 7 is arbitrary, and it is conceivable to make it so that it can be inserted or fitted as described later, or to provide a separate fixing means.

Since the tip of the wiping material 4 comes into contact with the cooling roll 2 and absorbs the mist, it is not only able to absorb and retain oil such as plasticizer, which is a component of the mist, but also has abrasion resistance. Preferably, for example, wool felt, polypropylene nonwoven fabric, paper (edible synthetic paper), cotton cloth, etc. are used. These may be used alone or
Two or more types may be used in combination, for example, one wiping material 4
It is also preferable that the other wiping material 4 covers the wiping material 4. Further, the width of the wiping material 4 may be as wide as shown in the drawing, or it may be formed narrower than that shown in the drawing.

The means for connecting the suction pipe 8 to the holder 7 is not particularly limited as long as suction is possible, but from the viewpoint of uniform suction, it is possible to gradually gather a plurality of suction pipe branches as shown in FIG. You can do as you like.

The means for holding the wiping material 4 in the holder 7 is as shown in FIG. It is preferable that a suction hole 9 is provided, and the surface on which the suction hole 9 is formed is preferably sloped, for example, as shown in the figure, in order to facilitate the flow of the mist into the liquid reservoir 6A formed in the suction chamber 6.

When holding the wiping material 4 on the holder 7 as described above,
In the front part X and the rear part Y of the wiping material 4, since the mist is absorbed from the front part Therefore, there is a risk that mist suction cannot be performed efficiently. For this purpose, the rear portion Y may be provided with means for regulating air suction.

Furthermore, in order to suction and remove the mist uniformly in the width direction of the cooling roll, especially when the width of the cooling roll is wide, it is preferable to divide the suction chamber 6 into small sections.

IO is a mist outlet for discharging the mist accumulated in the liquid reservoir 8A.

To explain a method of suctioning mist using the suction device configured as described above, first, a suction blower or a vacuum pump is operated to suction the suction chamber 6 in the holder 7 to reduce the pressure. The mist is sucked into the suction chamber 6 through the suction hole 9, and is discharged from the liquid reservoir 8A to the outside of the system via the mist discharge port IO.

The suction of the mist and the discharge of the suctioned mist may be performed continuously or intermittently, and the wiping material 4 may be replaced as necessary.

Further, in the present invention, suction of the mist and discharge of the suctioned mist can also be performed by an automated system.

Although the embodiments described above relate to the case where the mist is removed by suction, the means for removing the mist removed by the wiping material is not limited to this, and for example, it is possible to remove the mist using capillary action. . In this case, the material of the wiping material itself may have a capillary shape capable of discharging mist, or the mist may be discharged from the wiping material by structurally creating a capillary tube capable of discharging the absorbed mist. You can do it like this.

[Examples] The present invention will be further explained in detail with reference to Examples below, but the embodiments of the present invention are not limited thereto.

Example 1 In a T-die extrusion molding process of a soft vinyl chloride resin film, a film was manufactured under the following conditions using the mist suction device of the present invention.

A soft vinyl chloride resin containing 45fjL of plasticizer was used, the width of the T-die was 2250s layer, the width of the cooling roll was 2340mm, the diameter of the cooling roll was 250mm, and the rotation speed was 12Orp layer. The molten resin at about 200°C was cooled to 60 to 80°C by passing water through a cooling roll. The resin extrusion rate was 250 kg/hour. The width of the wiping material is 10
A wool felt with a thickness of 0 mm, a thickness of 10 mm, and a length of 2250 mm was used, and the top was covered with cotton cloth. The suction chamber of the mist suction holder is divided into 8 sections and 11 JIK sections in the width direction.

As a suction device, air volume 3.0 m''/min, wind pressure 2400 m
A suction blower with mAq was used.

In the above film production, the defective rate due to the replacement interval of the wiping material and the interruption of the production equipment was determined. The results are shown in Table 1.

Comparative Example 1 In Example 1, except that a 100 mm width, 10 mm thickness, and 2250 layers of woven wool felt covered with cotton cloth was used as the wiping material, and the suction device of the present invention was not used. A film was produced under the same conditions as in Example 1. The results are shown in Table 1.

Table 1 [Effects of the Invention] As described above, the present invention eliminates the need to frequently replace wool felt that has become saturated by suctioning mist as in the past, so there is no need to interrupt the film manufacturing process, and production efficiency is improved. It is possible to significantly improve the amount of industrial waste and reduce the amount of industrial waste, making a great contribution to industry.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the present invention, FIG. 2 is a front view of the same, and FIG. 3 is a sectional view taken along the line mm in FIG. 2. In the figure, l is a T-die, 2 is a cooling roll, 3 is a mist suction device, 4 is a wiping material, 5 is a suction port, 6 is a suction chamber, 8A is a liquid reservoir, 7 is a holder, 8 is a suction pipe, 9 is a suction pipe Suction hole, 1
0 is characterized by a mist outlet Patent applicant Mitsui Toatsu Chemical Co., Ltd. Agent Nobuaki Sakaguchi (and 1 others)
given name)

Claims (4)

[Claims] (1) In a method for producing a film in which a synthetic resin is melt-extruded through a T-die and then cooled and solidified using a cooling roll, the surface of the cooling roll is wiped off with a wiping material, and liquid deposits on the surface of the cooling roll that have been absorbed by the wiping material are removed. A method for producing a film, characterized in that the wiping material is removed without being removed. (2) The method for producing a film according to claim 1, characterized in that liquid deposits are removed by suction from the wiping material. (3) In a film manufacturing apparatus in which a synthetic resin is melt-extruded through a T-die and then cooled and solidified with a cooling roll, a wiping material is held at a position where it can come into contact with the cooling roll to wipe off liquid deposits on the surface of the cooling roll; A film manufacturing apparatus comprising a device for removing liquid deposits absorbed by the wiping material. (4) The film manufacturing apparatus according to claim 3, wherein the device for removing liquid deposits is a suction removal device having a wiping material held at the end of an air suction path.