JPH11221845A - Apparatus for extrusion-molding film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of a seal material even when the width of a film is changed repeatedly by forming a seal part replaceably in a support part with a discharge width changing means set in a die part. SOLUTION: In constitution in which a change bolt held freely rotatably by a support frame body mounted on the lower surface of the end part of a die is screwed in a screw hole of a moving member, the axial position of the discharge opening of the moving member can be changed to an optional position by rotating the change bolt. Accordingly, a seal material 5 can be replaced simply by a process in which, after the moving member being separated from the openings of lips 9, 10 by loosening a fitting bolt with the moving member installed in a die, the seal material 5 is inserted and extracted with its grip part gripped along the fitting groove of the seal material 5 formed in the central part of the moving material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film extrusion apparatus capable of adjusting a die width, that is, a film width to be formed, and more particularly, to a widthwise movable seal at one or both ends of a die lip. The present invention relates to an improvement in a film extruding apparatus which is provided with a die width changing means comprising means for changing the width of extruding a molten polymer from a die.

[0002]

2. Description of the Related Art In film formation, it is necessary to form a film with a die having a width corresponding to a required film width.
Conventionally, every time the width of the film is changed due to a brand change, a method of interrupting the operation and replacing the die 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, it is necessary to own dies corresponding to each brand, which causes a problem that the number of dies is large and the equipment cost is high.

On the other hand, a film extrusion molding apparatus having a discharge width changing means for adjusting a die width so that a film having a plurality of widths can be formed with one die has already been proposed. That is, JP-A-51-145566 discloses a discharge width changing method in which the discharge width adjusting plate of the sealing means is slid from the side in the length direction of the discharge slit portion, that is, in the width direction of the die, to change the die width dimension. In Japanese Patent Application Laid-Open Nos. 8-142158 and 9-24535, when sliding, the band-shaped wedge piece of the sealing means and the slide deckle are retracted from the lip to define the position. There has been proposed a method of changing a discharge width in which a band-shaped wedge piece and a slide deckle are pressed against a lip.

[0005]

However, the width regulating device disclosed in Japanese Patent Application Laid-Open No. 9-24535 has a structure in which the band-shaped wedge piece and the width regulating fitting for setting the band-shaped wedge piece are independent, and each member is moved to the width changing position. Need to be
It takes time to change, and it is difficult to always keep the moving amount, that is, the sealing pressure constant.

On the other hand, in the width regulating device disclosed in Japanese Patent Application Laid-Open No. 8-142158, the slide deckle and the seal block have an integral structure. However, since the seal block is pressed against the lip by two cam lavers, a uniform seal is not always required. There is a problem that pressure does not always occur. Therefore,
This problem has been solved by using a resilient body for the seal portion in contact with the lip surface to absorb a small amount of nonuniform sealing pressure and maintain the sealing performance.

However, in any case, if the width change is repeated many times over a long period of time, the sealing material of the sealing portion is deteriorated and the sealing property is impaired. Problems arise that require work.

Accordingly, the present invention provides a film extrusion molding apparatus having a discharge width changing means capable of solving the above-mentioned problems.
In addition to this, a film extruder having a discharge width changing means capable of changing the width in a short time and constantly generating a uniform sealing pressure is also provided.

[0009]

The above object is achieved by the present invention described below. That is, the present invention provides a discharge width changing means for changing a discharge width by moving a predetermined length of sealing means for closing an opening of a die lip along the opening and closing an end of the opening for a set length. Wherein the sealing means comprises a seal portion and a support portion thereof, and the seal portion is provided on the support portion so that the discharge width changing means can be replaced with the discharge width changing device installed on the die portion. A film extrusion molding apparatus characterized by the following.

In the present invention, a mounting groove is provided at a seal mounting portion of the support portion, and the seal portion is inserted into the mounting groove so as to be replaceable from the outside. It consists of a holding material that holds this,
The holding member having a grip end protruding from the mounting groove is preferably used from the viewpoint of operation and cost.

It is preferable that the supporting portion is movable along the opening and is provided so as to be able to contact and separate from the lip surface from the viewpoint of the stability of the seal. In addition, the stability of the seal,
From the viewpoint of reliability, at least the seal portion for sealing by contacting the lip surface of the sealing means is made of a material having a hardness smaller than that of the material forming the lip, and the sealing portion of the sealing means has a hardness higher than the material forming the lip. It is preferable to use a laminated structure in which a sealing material made of a material having a lower hardness than the holding material is stacked on a holding material made of a small material. In addition, from these aspects, specifically, it is preferable that the sealing portion that comes into contact with the lip of the sealing means is made of an elastic material having an elastic coefficient of 10 ⁵ to 10 ⁸ Pa.

In view of the long-term stable operation, it is preferable to provide a through hole for discharging the polymer from the space between the lips behind the closed portion of the opening of the lip closed by the discharge width changing means to the outside of the die. Hereinafter, the present invention will be described in detail with reference to the drawings based on specific examples. In addition,
The present invention is not limited to such embodiments,
Needless to say from the gist.

[0013]

FIG. 1 is a cross-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 therein. 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 of FIG. 1 as viewed from the die side. FIG. 4 is an explanatory view of each member of the discharge width changing means.
The lower drawing is an explanatory diagram of each member shown in a cross-sectional view taken along line AA of the upper drawing. FIG. 5 is a side view of the seal portion used in this example. FIG. 6 is a side view of a seal portion according to another embodiment.

FIG. 7 is a front view showing an installation state of a discharge width changing means of a film extrusion molding apparatus having a discharge width changing means according to another embodiment of the present invention. FIG. 8 is a sectional view of a support frame of the discharge width changing means of FIG. FIG. 9 is a sectional view of a moving member of the discharge width changing means of FIG.

As is apparent from FIG. 1, the discharge section of the film extruder of this embodiment has the same configuration as that of a known apparatus. That is, in the figure, reference numerals 9 and 10 denote lips, and the openings between the tips (lower ends in the figure) serve as discharge ports. Lip 9, 1
The distance between the openings 0, that is, the distance between the discharge ports can be changed by the differential bolts 11 and 12 as shown in the figure.
Thereby, the thickness of the discharged sheet can be adjusted. In addition, 13 and 14 are die main bodies, 15 in FIG. 2 is a side plate, and 16 is a packing material for sealing between the die main body and the side plate.

A discharge width changing means having the following configuration is provided on the lower surface of the end of the opening. That is, the support frame 1 is a support frame that supports and guides a moving member 2 described later, which is a support portion of the sealing means.
A pair of plate-like bodies having a predetermined length are attached along the opening on the lower surface of the “0” on both sides thereof at predetermined intervals, and a guide groove with which the moving member 2 is engaged is provided on the inner side surface.

A movable 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 formed of a plate-like body having a predetermined length provided with a guide groove 2a and a storage groove 2b on the upper surface along the center axis thereof in the width direction of the die. A screw hole 2c is provided in the same direction.
As shown in (1), the change bolt 8 is screwed in, and by rotating the change bolt 8, the width direction position of the discharge port can be changed to an arbitrary position. The change bolt 8 is rotatably fixed to a trapezoidal support frame 1a attached to an end of the support frame 1 on the outer side of the die.

As shown in FIG. 4, a seal portion is provided on the upper surface of the moving member 2 as follows. That is, the seal portion made up of the seal material 5 and the seal holding material 6 used as needed is inserted into the seal pressing body 3 of the support portion, and the guide groove 2 a and the storage groove 2 b are provided near the top end of the upper surface of the moving member 2. The movable member 2 is provided so as to be movable in the normal direction of the upper surface of the moving member 2, that is, the direction in which the moving member 2 comes into contact with or separates from the lip surface. A taper member 4 of a driving member for driving the seal pressing member 3 is provided in the guide groove 2a near the rear end of the moving member 2 so as to be movable in the die width direction.

The taper member 4 has the following structure, and is provided in the guide groove 2a provided at the center of the upper surface of the moving member 2 so as to be movable in the width direction of the die as described above.
That is, as shown in FIG. 4, the tapered member 4 is screwed into a tapered portion 4a having an upper surface inclined at a predetermined angle toward the front end and a set bolt 7 provided at the rear end. 4c formed with a predetermined length screw hole 4b
Consists of Then, as shown in FIG. 3, a set bolt 7 rotatably fixed to a mounting member 2d provided on an end surface of the moving member 2 on the outer side of the die is provided with a screw hole 4b of the joint 4c.
To the tapered member 4 by the rotation of the set bolt 7.
Can move in the width direction of the die.

On the other hand, as shown in FIG. 4, the seal pressing body 3 is a member having a predetermined length of a U-shaped cross section composed of a top part and feet at both ends thereof, and a tapered member inside the center part of the top part. 4
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, and an opening outside thereof Is provided with a mounting groove 3b for inserting and attaching a sealing material 5 or the like for closing an end portion of a predetermined length.

Then, as shown in FIG.
Is a storage groove 2 having substantially the same width as the width of the foot on the upper surface of the moving member 2.
b, and both of the legs are inserted into the guide groove 2a such that the inclined portion 3a partially engages with the tapered portion 4a of the tapered member 4, and moves only in the normal direction of the upper surface of the moving member 2. It is free. Therefore, the seal portion can be brought into contact with and separated from the lip surface via the tapered member 4 by operating the set bolt 7, and can be pressed against the lip surface with a predetermined pressure.

As shown in FIGS. 5 and 6, the seal member 5 of the seal portion can be easily removed from the outside of the die. The example of FIG. 5 has a laminated structure in which a seal member 5 that presses the seal portion against the lower surfaces of the lips 9 and 10 to close and seal the opening thereof and a seal holding material 6 that holds the seal member 5 are stacked. In addition, an inverted L-shaped grip portion 6a is provided at the rear end of the seal holding member 6, and the holding portion is provided with a reinforcing member 6b.
It is a crank type configuration reinforced with. Then, the mounting groove 3b provided on the upper surface of the seal pressing body 3 is formed in a C-shaped rope-shaped cross section, and the seal holding material 6 is gripped by the gripping portion 6a and inserted into the mounting groove 3b from the outside of the die. It is to be attached by. Therefore, it can be removed simply by gripping and pulling out the gripping portion 6a, and it can be easily replaced. This laminated configuration has an advantage that various sealing materials can be applied to the sealing material 5.

FIG. 6 shows an example where the hardness of the sealing material 5 is smaller than the hardness of the material of the die and has sufficient strength.
This is a configuration in which the gripping portion 5a is provided at the rear end of the sealing material 5 and the reinforcing material 5b is provided behind the sealing surface, and the seal holding material 6 can be omitted, and there is an advantage that the configuration is simplified. The reinforcing members 6b and 5b shown in FIGS. 5 and 6 are used to reinforce the mechanical strength. The same material as the reinforcing member or a structural material such as stainless steel is used. This is not necessary when a material is used.

FIG. 7 shows another embodiment of the present invention provided with another discharge width changing means. The discharge width changing means of this example has the following configuration. That is, reference numeral 21 in FIG.
As shown in FIG. 8, a supporting frame for supporting and guiding the moving member 22 is a U-shaped cross-section frame having a concave portion for accommodating the moving member 22 in the center portion. The configuration is such that two guide rails 21a for guiding are provided. The die is attached to the lower surfaces of the lips 9 and 10 by mounting bolts 23 via mounting bolt holes 21b so that the recess faces the openings on the lower surfaces of the lips 9 and 10.

As shown in FIG. 9, the movable member 22 has a guide groove 22a on the lower surface for engaging with the guide rail 21a of the support frame, a mounting groove 22b for the sealing material 5 on the upper surface, and a screw hole 22c in the middle. Is formed in a plate-like body having a predetermined length provided in the width direction of
As shown in FIG. 7, the sealing material 5 is attached so as to face the openings on the lower surfaces of the lips 9 and 10. That is, when the mounting bolts 23 of the support frame 21 are tightened, the sealing member 5 of the moving member 22 is in close contact with the opening, and further pressed by a predetermined pressure. Conversely, when the mounting bolt 23 is loosened, the moving member 22 is moved from the opening. You can move away.

This movement is performed by the following configuration. The side plate 15 of the die is inserted into the screw hole 22c of the moving member 22.
A rotatable change bolt 25 is rotatably screwed into a support frame 24 attached to the lower surface of the end of the movable member 22. By rotating the change bolt 25, the width direction position of the discharge port of the moving member 22 is changed. It can be changed to any position.

The mounting groove 22b of the seal member 5 of the moving member 22 has a C-shaped steel cross section as in the above-described example, and the seal member 5 has a laminated structure with the seal holding member 6 of FIG. . Therefore, similarly to the previous example, the sealing member 5 is
After the moving member 22 is separated from the openings of the lips 9 and 10 by loosening the mounting bolt 23 in a state in which the mounting member 2 is set on the die, the mounting groove 22b of the sealing material 5 provided at the center of the moving member 22 is provided.
The sealing material 5 can be easily replaced by inserting and pulling out the gripping portion 6a while gripping the gripping portion 6a.

The width of the sealing material 5 in close contact with the lower surfaces of the lips 9 and 10 of the present invention may be any width as long as it completely covers the lip opening to be closed. As the material of the sealing material 5, it is preferable to use a material having a hardness smaller than the material forming the lips 9, 10. Usually the material of the die is stainless steel, carbon steel, etc.
Aluminum can also be used for the seal member 5, and in this case, the seal holding member 6 becomes unnecessary. However, the sealing material 5
In addition, when an elastic body such as a fluororesin or rubber is used and laminated on the seal holding member 6 made of a rigid material such as aluminum, the sealing performance is improved. 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. 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 film extruder provided with the above-mentioned discharge width changing means, when a predetermined end of the lip opening is closed by the discharge width changing means, dead space is generated in the lip land at this portion. There is a risk that the molten polymer staying here may be thermally degraded. On the other hand, though not shown, the side plate 15 and the packing material 16 of the die body and the side plate are provided with pores (communication holes in which the positions of the pores are aligned) from the dead space to the outside of the die. It has been confirmed that it is effective to form and continuously or completely discharge a small amount of the molten polymer from the pores.

According to the present invention described above, the molten polymer is formed into a film shape with the discharge width according to the brand from the film extrusion molding apparatus in which the width of the lip according to the brand is set by the discharge width changing means as described above. It is possible to provide a method for producing a film for a large number of brands, which can cope with a large number of brands in one series of an unstretched film which is rapidly solidified by extrusion and cooling by a cooling means.

The polymer is not particularly limited as long as it is a thermoplastic resin having a film-forming ability. Examples thereof include aromatic polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, and polyamides such as nylon-6 and nylon-66. , 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. The unstretched film can be further stretched to give a stretched film, particularly a biaxially stretched film. Hereinafter, an example of film formation according to the above-described embodiment of the present invention will be described.

[Example of Film Forming] In the above-described film extrusion molding apparatus of the present example, when the discharge width is designed by the discharge width changing means of FIG. 1 in which Teflon packing is used for the sealing material 5 and aluminum is used for the seal holding material 6. Was adjusted so as to be 75% of the discharge width, that is, the discharge width in the case where there was no closure, and a film was formed using polyethylene terephthalate as the polymer.
At that time, as a result of continuously leaking a small amount of molten polymer from the pores formed in the packing material 16 and the side plate 15,
Even in film formation for about 2 days, stable film formation was possible without generation of foreign matter and breakage.

Thereafter, the discharge is stopped, the taper member 4 is retracted by the set bolt 7, the seal is opened, and the seal holding material 6 on which the sealing material 5 is laminated is gripped by the gripping portion 6a and replaced with a new one. Then, after the moving member 2 is moved to 90% of the designed lip opening width by the changing bolt 8, the taper member 4 is pushed in, and the sealing material 5 is pressed against the lower surface of the lip so as to be brought into close contact therewith. Made changes. The time required for this change operation was about 7 minutes.

Thereafter, the discharge was started again, and a film was formed for about 3 days. Thereafter, every time the discharge width was changed in the same manner as described above, film formation was performed for 15 days while replacing the seal holding material 6 in which the seal material 5 was laminated with a new one. A membrane was possible.

After completion of the film formation, 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. Few were recognized.

[0037]

According to the present invention, the discharge width changing means is installed on the lip-facing surface of a supporting portion such as a moving member so that the seal portion can be replaced from the side of the die or the like while being installed on the die. The new seal member can be easily updated each time the discharge width is changed, so even if the film width is changed repeatedly, stable film formation without polymer leakage due to deterioration of the seal material can be achieved. It is possible. Also,
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 polymer from being degraded due to retention. As described above, the present invention provides a film extruder capable of coping with multiple brands that can change the discharge width in a short time without polymer leakage, can change the setting of the discharge width many times without polymer leakage. This greatly contributes to streamlining the film production process and improving productivity.

[Brief description of the drawings]

FIG. 1 is a cross-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 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 the complete die width changing device of FIG. 1 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.

FIG. 5 is an explanatory diagram of a sealing material used in an example.

FIG. 6 is an explanatory view of a sealing material according to another embodiment.

FIG. 7 is a front view showing an installation state of a discharge width changing means of a film extrusion molding apparatus according to another embodiment of the present invention.

FIG. 8 is a sectional view of the support frame of the embodiment of FIG. 7;

FIG. 9 is a sectional view of the moving member of the embodiment of FIG. 7;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 support frame 2 moving member 3 seal pressing member 4 taper member 5 seal material 6 seal holding material 7 set bolt 8 change bolt 9,10 die lip 11,12 differential bolt 13,14 die body 15 side plate 16 packing material 21 support frame 22 Moving member 23 Mounting bolt 24 Support 25 Change bolt

Claims (10)

[Claims] 1. A discharge width changing means for changing a discharge width by moving a predetermined length of sealing means for closing an opening of a die lip along the opening and closing an end of the opening for a set length. In the film extrusion molding apparatus provided, the sealing means comprises a seal portion and a support portion thereof, and the seal portion is provided on the support portion so that the discharge width changing means can be replaced with the die portion installed. Film extrusion molding equipment. 2. The film extrusion molding apparatus according to claim 1, wherein a mounting groove is provided at a seal mounting portion of the support portion, and the seal portion is inserted into the mounting groove so as to be exchangeable from outside. 3. The film extrusion molding apparatus according to claim 2, wherein the seal portion comprises a seal member for closing the opening and a holding member for holding the sealing member, and the holding member has a grip end protruding from the mounting groove. 4. A lip surface according to claim 1, wherein said support portion is movable along said opening and is capable of moving toward and away from said lip surface.
4. The film extrusion apparatus according to any one of the above items 3. 5. The moving member according to claim 4, wherein the supporting portion includes a moving member that moves along the opening, and a pressing member provided on an opposing surface facing the lip of the moving member so as to be able to approach and separate from the lip surface. The film extrusion molding apparatus according to the above. 6. A surface opposite to the lip surface of the pressing member is an inclined surface, and a tapered member having an inclined surface engaged with the inclined surface can move forward and backward in the width direction of the die on the opposing surface of the moving member. 6. The film extrusion forming apparatus according to claim 5, wherein the pressing member comes into contact with and separates from the lip surface as the taper member advances and retreats. 7. The film extrusion molding apparatus according to claim 1, wherein at least the seal portion of the sealing means for sealing by contacting the lip surface is made of a material having a hardness lower than that of the material forming the lip. 8. The sealing portion of the sealing means has a laminated structure in which a sealing material made of a material having a lower hardness than the material forming the lip is laminated on a holding material made of a material having a lower hardness than the material constituting the lip. Item 8. The film extrusion molding apparatus according to any one of Items 1 to 7. 9. The sealing material has an elastic modulus of 10 ⁵ to 10 ⁸ Pa.
9. The film extruder according to claim 8, which is made of an elastic material. 10. The film according to claim 1, wherein a through hole for discharging the polymer is provided outside the die from the space between the lips behind the closed portion of the opening of the lip closed by the discharge width changing means. Extrusion molding equipment.