JPH1177796A - Film extrusion molding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a film extrusion molding apparatus equipped with an ejection width altering means arranged at the lower part of the single or both end parts of a lip and capable of altering the width of a die within a short time and closing the die under uniform seal pressure. SOLUTION: In a film extrusion molding apparatus equipped with an ejection width altering means closing the end part of the opening part of the lip of a die over predetermined length, the ejection width altering means includes the support frame 1 attached to a die main body 14 guiding a moving member 2 along the opening part of the lip, a moving member 2 attached to the support frame 1 so as to be capable of being moved and positioned in the lateral direction of the die and having the opposed surfaces parallel to the lip surfaces on both sides of the opening part, the seal member 16 attached to the opposed surface of the moving member 2 in a movable manner in the normal line thereof so as to come into contact with and separate from the lip surface and pressed to the lip surface to close the end part of the predetermined length of the opening part and the drive member provided on the opposed surface of the moving member 2 and operated in the lateral direction of the die to bring the seal member 6 into contact with the lip surface and separate the same therefrom.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film extrusion molding apparatus capable of adjusting a die width, and more particularly to a discharge width changing means provided at one or both ends of a die lip.
The present invention relates to a film extruder for extruding a molten polymer from a die at a width set by a discharge width changing means to form a film.

[0002]

2. Description of the Related Art In film formation, the required film width varies depending on the brand, and it is necessary to form the film using a die having a width corresponding to the width. Conventionally, every time the width of a film is changed due to a brand change, a method of interrupting the operation and replacing the film with a die corresponding to the width of the film has been adopted.

[0003] Therefore, a long-time operation loss is caused every time the die is exchanged, thereby deteriorating productivity. In addition, there is a problem that the number of dies is large and that the equipment cost is high because the dies corresponding to each brand are owned.

On the other hand, there has already been proposed a film forming apparatus provided with a discharge width changing means for adjusting the width of a discharge port of a die so that a film of a plurality of widths can be formed with one die. For example, Japanese Patent Application Laid-Open No. S51-145566 discloses a method of changing the die width by freely moving the deckle in the width direction. Also, Japanese Patent Application Laid-Open No. 8-142215
No. 8 discloses a slide deckle in which the seal bar is kept away from the lip when it is slid, the position of the seal bar is defined, and the seal bar is pressed against the lip. Further, Japanese Patent Application Laid-Open No. 9-24535 discloses that the width-regulating metal fitting, the band-shaped wedge piece, and the moving metal can be moved in the width direction. There has been proposed a configuration in which a width-restricting bracket or a band-shaped wedge piece is pressed against a lip at the set position via a moving bracket.

[0005]

However, in the discharge width changing means disclosed in Japanese Patent Application Laid-Open No. 9-24535, the width regulating bracket and the band-shaped wedge piece are independent structures, and it is necessary to move each member to the width changing position. In addition, there is a problem that it takes time to make the change, and it is difficult to constantly maintain a constant sealing pressure, and thus a constant sealing pressure, due to the positional relationship between the moving metal fitting, the width regulating metal fitting and the band-shaped wedge piece.

On the other hand, in the discharge width changing means disclosed in Japanese Patent Application Laid-Open No. 8-142158, since the frame and the seal block have an integral structure, the seal bar is pressed against the lip by two cam lavers, so that the uniform seal pressure is not necessarily uniform. There is a problem that does not always occur, and there is a problem in terms of cost due to a complicated structure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a discharge width changing means which is capable of changing the width of a die in a short time and installed at a lower portion of one or both ends of a lip and closing with a uniform sealing pressure. An object of the present invention is to provide a film extrusion molding apparatus provided with the same.

[0008]

The above object is achieved by the present invention described below. That is, the present invention relates to a film extruder including discharge width changing means for changing a discharge width by closing an end of an opening of a lip of a die for a predetermined length, wherein the discharge width changing means comprises an opening of the lip. Moving member having a support frame attached to a die body for guiding the moving member along the portion, and a facing surface parallel to the lip surfaces on both sides of the opening mounted on the supporting frame so as to be movable and positionable in the die width direction. And a seal member mounted on the facing surface of the moving member so as to be movable in the normal direction so as to be able to approach and separate from the lip surface, and pressed by the lip surface to close an end of a predetermined length of the opening. And a drive member provided on the opposite surface of the moving member and operating in the die width direction to move the seal member toward and away from the lip surface. Hereinafter, the present invention will be described in detail with reference to the drawings.

[0009]

FIG. 1 is a sectional view of a main part of a film extrusion molding apparatus according to one embodiment of the present invention, as viewed from the side of a die, and a side view of a discharge width changing means installed thereon. FIG. 2 is a front view showing an installation state of the discharge width changing means of FIG. FIG. 3 is a plan view of the discharge width changing means as viewed from the die side. FIG. 4 is an explanatory diagram of each member shown in a cross-sectional view taken along line AA of the side surface of the discharge width changing unit in FIG.

As is apparent from the drawing, the discharge section of the film extrusion apparatus of this embodiment has the same configuration as that of a known apparatus.
That is, reference numerals 9 and 10 denote lips, and the opening between the tips serves as a discharge port. The distance between the openings of the lips 9 and 10, that is, the distance between the discharge ports can be changed by the differential bolts 11 and 12, as shown in the figure, so that the thickness of the discharged sheet can be adjusted. In addition, 13, 14
Is a die body, 15 is a side plate, and 16 is a seal portion made of a sealing material for sealing between the die body and the side plate.

The discharge width changing means having the following structure is provided on the lower surface of the end of the opening. That is, 1
Is a supporting frame that supports and guides a moving member 2 described later, and is formed of a pair of plate members of a predetermined length attached at predetermined intervals to both sides along openings on the lower surfaces of the lips 9 and 10, A guide groove is provided on the side surface.

A moving member 2 whose upper surface is parallel to the lower surfaces of the lips 9 and 10 is movably inserted into the guide groove of the support frame 1. As shown in FIG. 4, the moving member 2 is a plate-like body having a predetermined length provided with a guide groove 2a and a housing groove 2b in the width direction of the die along the center axis of the upper surface, and a screw is provided below the same in the same direction. A hole 2c is provided, and the change bolt 8 is screwed into the hole 2c. By rotating the change bolt 8, the position of the discharge port in the width direction can be changed to an arbitrary position. The change bolt 8 is rotatably fixed to a support frame 1 a attached to the outer end of the die of the support frame 1.

As shown in FIG. 4, on the upper surface of the moving member 2, a seal support 3, a seal member 5, a seal holding member, and a taper member 4 as a driving member thereof are provided as follows. . That is, the tapered member 4 is provided in the guide groove 2a of the moving member 2 so as to be movable in the width direction of the die. As shown in FIG. 4, the tapered member 4 has a tapered portion 4a having an upper surface inclined at a predetermined angle toward the front end in the drawing, and a predetermined screw which is screwed with a set bolt 7 provided at the rear end. It consists of a joining portion 4c having a long screw hole 4b, and can be advanced and retracted in the width direction of the die by rotating the set bolt 7. The set bolt 7 is rotatably fixed to a mounting member 2d provided on the outer end face of the die of the moving member 2. And moving member 2
The seal member is provided so as to come into contact with and separate from the distal end surfaces of the lips 9 and 10 as the tapered member 4 advances and retreats. The sealing member 5 is pressed against the lower surfaces of the lips 9 and 10, and a sealing material 5 for closing and sealing the opening thereof and a sealing material 6 for reinforcing the sealing material 5 are laminated and attached to the center of the sealing support 3. It has a configuration.

As shown in FIG. 4, the seal support 3 is a member of a predetermined length having a top-side portion and legs at both ends and having an inverted U-shaped cross section, and a taper member 4 is provided inside the center of the top-side portion. In the width direction of the die, which engages with the inclined surface of the tapered portion 4a, the lower surface has an inclined portion 3a inclined at the same angle as the inclined angle of the tapered portion 4a toward the outer end of the die. It has a configuration in which a mounting groove 3b for mounting a seal member for closing a long end is provided. Then, as shown in FIG. 4, the seal support 3 is accommodated in the storage groove 3b having substantially the same width as the width of the foot on the upper surface of the moving member 2 with its both legs fitted and accommodated, and the inclined portion 3a is tapered. 4 is inserted into the guide groove 2a so as to partially engage with the tapered portion 4a, and is movable only in the normal direction of the upper surface of the moving member 2.

Attachment groove 3 outside the top side of seal support 3
As described above, the seal holding member 6 and the seal member 5 are attached to the layer b in this stacking order.

With the above configuration, the discharge width changing means of the present embodiment operates as follows. Side plate 15 or die body 1
The width of the discharge port of the die is changed by the moving member 2 being moved by the change bolt 8 in the support frame 1 installed in each of the support frames 3 and 14. The seal support 3, the taper member 4, and the set bolt 7 are provided on the moving member 2, and the change bolt 8
Is moved together with the moving member 2 by the
The width of the discharge port is determined only by the above operation.

The seal support 3 is moved between a sealing position for sealing the lower surfaces of the lips 9 and 10 of the extrusion die in close contact with each other and a moving position away from the lip surface when moving for changing the width. In this embodiment, the sealing member 5 is pressed against the lower surfaces of the lips 9 and 10 when the tapered member 4 provided on the moving member 2 is advanced by the set bolt 7 as described above. The seal support 3 is configured to move to a position away from the lower surfaces of the lips 9, 10 when retracted to the position, specifically, when pulled back. At this time, both sides of the seal support 3 are fitted into the storage grooves 2b of the moving member 2 as described above, and specifically, the storage grooves 2b of the moving member 2 And the taper member 4 is located just below the gap between the lips 9 and 10, that is, just below the discharge port. In other words, it is possible to move the upper surface of the lips 9 and 10 in parallel with the lower surface thereof, thereby making it possible to uniformly seal the opening having a predetermined length at the target end portion and to stably change the discharge width. Is realized.

At this time, the width of the sealing material 5 which is in close contact with the lower surfaces of the lips 9, 10 may be any width as long as it completely covers the lip opening to be closed, for example, a width of 10 to 15 mm is sufficient. As the material of the sealing material 5, lips 9, 10
It is preferable to use a material having a hardness smaller than that of the material forming the seal support 3. Usually, the material of the die is stainless steel, and the material of the seal support 3 is carbon steel or the like. In this case, aluminum is used for the seal material 5 and the seal holding material 6 is used.
May be omitted, but the sealability is improved by using aluminum for the seal holding member 6 and laminating an elastic body such as a fluororesin or rubber of the seal member 5. From this point, an elastic material having an elastic coefficient of 10 ⁵ to 10 ⁸ Pa is preferably used as the sealing material 5. Depending on the material, the sealing material 5 may be directly installed on the seal support 3. As the sealing material 5, various types of commercially available sealing materials other than those exemplified above can be used.

By the way, in the space between the lips 9 and 10 behind the opening of the lips 9 and 10 closed by the discharge width changing means, a dead space which does not become a flow path of the molten polymer is generated and stays there. There is a risk that the molten polymer is thermally degraded. For this, illustration is omitted,
Specifically, it is necessary to form pores leading to the outside of the die from the portion near the opening of the closed end of each of the dead spaces, specifically, the lips 9, 10, and to discharge a small amount of the molten polymer continuously or intermittently from the pores. Make sure it is valid.

In the above-described film extrusion molding apparatus,
With the discharge width set by the discharge width changing means as described above,
The molten polymer is continuously extruded from a film extrusion die into a film. Therefore, by setting the discharge width according to the brand by the discharge width changing means, one film extruder can cope with the film width of many brands. As is well known, the extruded film is rapidly cooled and solidified by a cooling means to form an unstretched film, and then subjected to necessary stretching treatment and the like to produce a film having desired characteristics.

The polymer is not particularly limited as long as it is a thermoplastic resin having a film forming ability. For example, aromatic polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyamides such as nylon-6, nylon-66 and the like. , Polyolefins such as polyethylene and polypropylene, and polycarbonates. Of these, aromatic polyesters are particularly preferred.

As the cooling means, those known as cooling means for film production can be used, and among them, a rotary cooling drum is particularly preferable. As described above, the unstretched film is further stretched to give a stretched film having desired characteristics, typically a biaxially stretched film. An example of film formation according to this example will be described below.

[Example of Film Forming] In the above-described film extrusion molding apparatus of the present example, the lip opening width at the time of design is determined by the discharging width changing means employing aluminum as the seal holding material 6 and Teflon packing as the sealing material 5. In other words, a polyethylene terephthalate film was formed using a die modified to have a discharge width of 85% of the discharge width in the case where there was no closure. At that time, a small amount of the molten polymer was continuously leaked from the thin through-hole formed through the seal portion 16 and the side plate 15, and as a result, stable film formation was possible without foreign matter generation and breakage even in the film formation for about 2 days. there were. Thereafter, the discharge of the resin is stopped, the taper member 4 is pulled to open the seal, the moving member 2 is moved by the changing bolt 8 to 70% of the designed lip opening width, and then the taper member 4 is pushed in. The sealing material 5 was pressed against the lower surface of the lip and brought into close contact therewith. During this time, it takes about 5 minutes, and then the resin is discharged again for about 3 minutes.
The film was formed for one day, and stable film formation was possible without generation of foreign matter and breakage.

After the film was formed, the die was cooled and disassembled, and the inside of the die in the dead space upstream of the lip opening closed by the discharge width changing means was examined. Did not.

[0025]

According to the present invention, the discharge width changing means is provided with a seal member on the lip-facing surface of the movable member movable in the die width direction so as to be movable in the normal direction by an integral driving member. Since the seal member comes in contact with and separates from the lip surface by a simple operation, the width of the film can be changed easily and in a short time without causing resin leakage, and the brand change time can be reduced. Further, by providing a through-hole for polymer outflow from the dead space upstream of the closed lip opening to the outside of the die, it is possible to prevent the polymer from deteriorating.

As described above, the present invention provides a film extruding apparatus which can stabilize film formation in a short time without polymer deterioration and which can cope with various brands whose discharge width can be changed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a film extrusion molding apparatus according to an embodiment of the present invention, as viewed from the side of a die, and a side view of a discharge width changing unit installed therein.

FIG. 2 is a front view showing an installation state of a discharge width changing unit in FIG. 1;

FIG. 3 is a plan view of a discharge width changing unit as viewed from a die side.

FIG. 4 is an explanatory diagram of each member shown in a cross-sectional view taken along line AA of a side surface of the discharge width changing unit in FIG.

[Description of Signs] 1 Support frame 2 Moving member 3 Seal support 4 Taper member 5 Seal material 6 Seal holding material 7 Set bolt 8 Change bolt 9, 10 Lip 11, 12 Differential bolt 13, 14 Die body 15 Side plate 16 Seal Department

Claims (7)

[Claims] 1. A film extruder comprising discharge width changing means for changing the discharge width by closing an end of an opening of a lip of a die for a predetermined length, wherein said discharge width changing means comprises an opening of said lip. A supporting frame attached to a die body that guides the moving member along, and a moving member having a facing surface parallel to the lip surfaces on both sides of the opening that is movable and positionable in the die width direction on the supporting frame. A seal member mounted on the facing surface of the moving member so as to be movable in the normal direction so as to be able to approach and separate from the lip surface, and pressed by the lip surface to close a predetermined length end of the opening; And a drive member provided on the opposite surface of the moving member and operating in the die width direction to move the seal member toward and away from the lip surface. 2. The method according to claim 1, wherein the driving member is a tapered member having a predetermined inclined surface, and the sealing member is provided with an inclined surface which engages with the inclined surface of the tapered member, and moves the tapered member in the die width direction. The film extrusion molding apparatus according to claim 1, wherein the sealing member is brought into contact with and separated from the lip surface and pressed against the lip surface. 3. The film extrusion molding apparatus according to claim 1, wherein at least the seal portion for sealing by contacting the lip surface of the seal member is made of a material having a hardness smaller than that of the material forming the lip. 4. The film extrusion molding apparatus according to claim 3, wherein the sealing portion of the sealing member has a laminated structure in which the sealing material is laminated on a holding material made of a material having a lower hardness than the material constituting the lip. 5. The sealing part of the sealing member has an elastic coefficient of 10
⁵ -10 either film extrusion device according to claim 1 made of an elastic material is ⁸ Pa. 6. The film extrusion molding apparatus according to claim 1, wherein a through-hole for discharging the polymer is provided from the space between the lips behind the opening of the lip closed by the discharge width changing means to the outside of the die. 7. The film extrusion molding apparatus according to claim 1, wherein the moving member and the driving member are moved by bolt screws screwed to the moving member and the driving member.