JP2012071443A - Slot die apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slot die apparatus capable of increasing a flow rate of a molten resin discharged from a slot at its edge side of the horizontal direction and improving an uneven film thickness of a molded resin film around its edge side.SOLUTION: A molding room of a slot die 2 has a manifold 3 and a slot 4. A second inner deckle 12 is positioned at the downstream side of the slot 4 to control a size of the slot 4 in a horizontal direction of the downstream side. A surface 12a of the second inner deckle 12 (guide) has a first enlarging part 31 which is spread in the width direction as approaching an exhaust port 5 at the upstream side in the vicinity of the exhaust port 5, and a second enlarging part 32 which is connected to the downstream end of the first enlarging part 31, and reaches the exhaust port 5 while being spread in the width direction. The spread degree of the first enlarging part 31 in the width direction of the exhaust port 5 is larger than a degree at which the second enlarging part 32 approaches the exhaust port 5.

Description

  The present invention relates to a slot die device for forming a resin film, and more particularly to a slot die device that suppresses film thickness unevenness at an end portion of a resin film.

Conventionally, when a resin film is produced using a slot die, an end portion of the molded resin film becomes thick, and this end portion is cut off. Then, it suppresses that the edge part of a resin film becomes thick, and reduces the amount of resin cut off.
For example, in Patent Document 1, molten resin is supplied from a manifold portion formed on a die body, extruded from a lip outlet through a die land portion and a lip land portion, and a sheet or film widened to a target width is formed. In the T-die for extrusion molding, the lip outlet end is disposed on the inner surface of a pair of inner deckles that are slidably disposed in the manifold portion, die land portion, and lip land portion of the die body, and can be adjusted to be spaced apart from each other. There is disclosed an extrusion-molding T-die provided with an edge-squeezing part that restricts the resin flow rate at the edge part.
According to this extrusion forming T-die, the flow rate of the resin at the edge portion of the resin film is reduced by the edge drawing portion, and the left and right edge portions of the resin sheet have a circular cross section when discharged from the lip outlet. Suppresses swelling.

  Patent Document 2 includes a die body in which a lip forming an opening of a resin discharge slot is provided along a longitudinal direction, and a deckle mechanism that is attached to the lip and defines an opening width of the slot. In the extrusion die for film forming, the deckle mechanism is composed of a pair of left and right deckle components that move toward and away from each other along the lip, and each deckle component has an inner surface that is in contact with the front end surface of the lip. An extrusion die for forming a film is clearly shown, which is composed of a kel and a plate-shaped inner deckle that is raised substantially vertically from the inner surface of the outer deckle and is packaged in a slot.

JP 2002-192594 A JP 2001-030330 A

However, in the slot die apparatus according to Patent Documents 1 and 2, the flow rate of the molten resin discharged from the slot on the end side in the width direction is slower than the center portion, so the film thickness is near the target value in the vicinity of the end portion in the width direction. As a result, it became thin, and at the end in the width direction, it was easy to shrink toward the center in the width direction where the flow velocity was fast, and the thickness was likely to increase.
Patent Document 1 also reduces the resin discharge flow rate at the edge portion of the resin film by providing an edge stop portion for reducing the resin flow rate at the lip outlet edge portion on the inner surface of the inner deckle. Although it is described that the resin is gathered at the edge of the resin film by narrowing the lip outlet edge, the edge of the resin film bulges into a circular cross section and becomes thicker.

  The present invention has been made in view of the above-described circumstances, and can increase the flow velocity on the end side in the width direction of the molten resin discharged from the slot, so that the film thickness is near the end of the molded resin film. An object of the present invention is to provide a slot die device that can suppress the thickness from becoming thinner and the thickness at the end.

In order to achieve the above object, in the invention according to claim 1 of the present invention, molten resin is supplied from the supply port of the slot die main body to the molding chamber and is expanded in the width direction in the molding chamber to be discharged from the molding chamber. In the slot die apparatus that is molded into a film by being discharged from, an inner deckle having a guide portion that contacts and guides the molten resin that passes therethrough is provided at both ends in the width direction of the molding chamber, The guide part is connected to a downstream side end of the first widened part at the upstream side in the vicinity of the discharge port and widens in the width direction as it goes to the discharge port. The degree to which the first widened portion spreads in the width direction as it goes to the discharge port is greater than the degree to which the second widened portion spreads in the width direction as it goes to the discharge port. A slot die apparatus wherein.
In other words, the present invention relates to a slot die device in which molten resin is supplied to a manifold, passes through a slot provided in a downstream portion of the manifold, and is formed into a film shape. Is provided with an inner deckle that guides in contact with the molten resin passing therethrough, and the inner deckle has a shape that gently spreads in the width direction in the vicinity of the discharge port and greatly expands in the width direction in the upper portion of the discharge port. This is a feature of a slot die device.

According to a second aspect of the present invention, in the slot die apparatus according to the first aspect, the guide portion extends in a width direction from the supply port side toward the discharge port side.
In other words, in the invention according to claim 2, the inner deckle has a contact surface with the molten resin that is widened so that the downstream side is inclined more outward than the upstream side in the width direction of the manifold and the slot. 2. A flow is formed at the end in the width direction along the inner deckle, from the upstream side toward the downstream side, and incline and widen outwardly in the width direction of the manifold and the slot. It is a slot die apparatus of description.
According to a third aspect of the present invention, the molding chamber includes a manifold connected to the supply port and a slot connected to a downstream portion of the manifold, and the inner deckle includes the manifold and the slot. A first inner deckle provided at both ends in the width direction of the upstream portion; and a second inner deckle provided at both ends in the width direction of the downstream portion of the slot; The slot die device according to claim 1, wherein the portion and the second widened portion are provided in a guide portion of a second inner deckle.
In the invention according to claim 4, the degree to which the guide portion of the second inner deckle spreads in the width direction toward the discharge port is such that the guide portion of the first inner deckle moves toward the discharge port. 3. The slot die device according to claim 2, wherein the degree of spreading in the width direction is greater as the length increases.
Moreover, in the invention which concerns on Claim 5, the said 1st widening part and the said 2nd widening part are formed in the curve shape which mutually continues, The any one of Claims 1 thru | or 4 characterized by the above-mentioned. It is a slot die device.

  In the present invention, the inner deckle has a contact surface with the molten resin that is widened so that the downstream side is inclined more outward than the upstream side in the width direction of the manifold and the slot. In addition, a flow is formed along the inner deckle from the upstream side to the downstream side and is inclined and widened outward in the width direction of the manifold and the slot.

  And it can suppress that the edge part of the width direction of the molten resin discharged | emitted from the slot by this flow shrinks in the width direction, and becomes thick. Therefore, the amount of the end portion of the resin film to be cut can be reduced, and cost reduction and waste reduction can be realized.

(A) is a figure which shows an example of the slot die apparatus by embodiment of this invention, and is the sectional view on the AA line of (b), (b) is the sectional view on the BB line of (a). (A) It is a cross-sectional view of the conventional inner deckle provided in the slot die apparatus. (B), (c) It is a cross-sectional view of the inner deckle of the present invention. (A) shows the relationship between the flow rate of the molten resin discharged from the slot die device having the inner deckle in the present embodiment range and the slot die device having the inner deckle outside the present embodiment range and the distance from the width center. The compared figure and (b) are the elements on larger scale of (a). (A) is a result explanatory view at the time of adopting an inner deckle outside the present embodiment range, (b) is a result explanatory view at the time of employing an inner deckle inside the present embodiment range.

  Hereinafter, a slot die device according to an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1A and 1B, a slot die apparatus 1 according to this embodiment includes a slot die body 2 and a manifold 3 that is formed inside the slot die body 2 and is supplied with a molten resin R1. The slot 4 is formed in the slot die body 2 so as to communicate with the manifold 3, and the molten resin R 1 in the manifold 3 passes through the film 4 and is formed into a film shape, and the molten resin R 1 on the film that has passed through the slot 4 is formed. A discharge port 5 for discharging, and an inner deckle mechanism 6 for defining the length in the width direction of the manifold 3 and the slot 4 are provided.

As shown in FIG. 1A, the slot die body 2 has a supply port 2a for the molten resin R1 at the top, and the supply port 2a is connected to an adapter (not shown) that supplies the molten resin R1.
The slot die body 2 is formed in an outer shape elongated in the width direction of the resin film R2 to be molded.
The manifold 3 is formed in a cylindrical shape over the width direction of the slot die body 2, and the supply port 2a of the slot die body 2 is connected to the upper part of the intermediate portion in the width direction, and the molten resin R1 is supplied from the supply port 2a. Supplied.

As shown in FIGS. 1A and 1B, the slot 4 is formed on the lower side of the manifold 3 over the width direction of the slot die body 2.
The discharge port 5 is formed at the lower end of the slot die body 2 and is located at the lower end of the slot 4.
That is, the molding chamber of the slot die main body 2 has a manifold 3 connected to the supply port 2 a and a slot 4 connected to the downstream portion of the manifold 3.

The inner deckle mechanism 6 includes a pair of first and second inner deckles 11 and 12 and a throttle member 13 provided at both ends in the width direction of the manifold 3 and the slot 4. The first and second inner deckles 11 and 12 and the diaphragm member 13 are arranged in this order from top to bottom.
The first and second inner deckles 11 and 12 and the throttle member 13 can move in the width direction within the manifold 3 and the slot 4, and the manifold 3 and the slot 4 can be moved on the surfaces (guide portions) 11 a, 12 a, and 13 a. The dimension in the width direction is defined. The molten resin R1 supplied to the slot die body 2 is guided by the surfaces (guide portions) 11a, 12a, and 13a and passes downward.

The first inner deckle 11 is located on the upper side of the manifold 3 and the slot 4 and defines the dimension in the width direction on the upper side of the manifold 3 and the slot 4. The surface (guide portion) 11a of the first inner deckle 11 is inclined or curved so as to increase the dimension in the width direction of the manifold 3 and the slot 4 from the upper side to the lower side.
Further, the second inner deckle 12 is located on the downstream side of the slot 4 and defines the dimension in the width direction on the downstream side of the slot 4. The surface (guide portion) 12a of the second inner deckle 12 is inclined or curved so as to increase the dimension in the width direction of the slot 4 from the upper side to the lower side.
The throttle member 13 is positioned at the lower end portion of the slot 4, and the width direction dimension of the discharge port 5 is defined by defining the width direction size of the lower end portion of the slot 4.

The first and second inner deckles 11 and 12 and the throttle member 13 are such that their surfaces (guide portions) 11a, 12a and 13a expand the dimensions in the width direction of the manifold 3 and the slot 4 from the upper side to the lower side. The position is shifted. That is, the surfaces (guide portions) 11a, 12a, and 13a expand in the width direction from the supply port 2a side toward the discharge port 5 side.
The degree to which the surface (guide portion) 12 a of the second inner deckle 12 extends in the width direction toward the discharge port 5 is such that the surface (guide portion) 11 a of the first inner deckle 11 extends toward the discharge port 5. Greater than the degree of spread in the direction.

Next, a method for forming a resin film by the slot die apparatus having the above-described configuration will be described.
First, the molten resin R1 is supplied to the slot die body 2 from the supply port 2a. The molten resin R1 flows into the manifold 3, spreads in the width direction of the manifold 3, and flows into the slot 4 below. The molten resin R1 passes through the slot 4 and is formed into a film having a predetermined thickness.
Then, the molten resin R1 formed into a film shape in the slot 4 is discharged from the discharge port 5, and while passing through the air, the molten resin R1 is cooled and gradually solidified to be in the state of the molten film R2, Rolling is performed by a roller (not shown) provided below (downstream side) the slot die apparatus 1. The roller is rotated at a speed faster than the speed at which the resin film R2 is discharged.
At the time when the resin film R2 is discharged from the discharge port 5, the resin film R2 is not completely solidified and is cooled and solidified by a roller portion or the like.

  At this time, since the resin film R2 discharged from the discharge port 5 is not completely solidified, the end portion R2a shrinks in the width direction, and the end portion R2a of the resin film R2 becomes thick. Later, the thickened end R2a is cut away to provide a resin film R2 having a uniform thickness.

  In the present embodiment, the molten resin R1 passing through the manifold 3 and the slot 4 is arranged in a first position that is shifted from the upper side to the lower side so as to widen the dimension in the width direction of the manifold 3 and the slot 4. Since it flows along the surfaces (guide portions) 11a, 12a and 13a of the second inner deckles 11 and 12 and the throttle member 13, a flow spreading in the width direction is formed in the molten resin R1 as it flows downward. Is done. And since molten resin R1 is discharged | emitted by this flow as resin film R2 from the discharge port 5, the edge part of resin film R2 is compared with the conventional form from which the edge part of resin film R2 is discharged | emitted in a perpendicular direction. R2a can be prevented from shrinking in the width direction.

  Next, the inner deckle shape, which is a feature of the present invention, will be described with reference to FIG.

  FIG. 2 is a cross-sectional view of the second inner deckle 12. Looking at the same plane as FIG. FIG. 2 shows the shape of the second inner deckle 12 on the left side. As described above, as it flows from the upper side to the lower side, the manifold 3 and the slot 4 are inclined to the outside in the width direction and widened.

  An existing second inner deckle 12 that is generally available is shown in FIG. At a position close to the diaphragm member 13, the space in which the resin flows is suddenly widened in the width direction.

The 2nd inner deckle 12 of this invention becomes FIG.2 (b), (c). Although the cross section is arcuate, the space where the resin flows is widened in the width direction at a position far from the diaphragm member 13.
More specifically, the surface (guide portion) 12a of the second inner deckle 12 has a first widened portion 31 that expands in the width direction toward the discharge port 5 at a location on the upstream side in the vicinity of the discharge port 5, and a first A second widened portion 32 connected to the downstream end of the widened portion 31 and extending in the width direction to reach the discharge port 5.
The degree to which the first widened portion 31 extends in the width direction as it goes to the discharge port 5 is greater than the degree to which the second widened portion 32 extends in the width direction as it goes to the discharge port 5.
In the present embodiment, in the second inner deckle 12 shown in FIG. 2B, the first widened portion 31 and the second widened portion 32 are formed in curved shapes that are continuous with each other.
In the second inner deckle 12 shown in FIG. 2C, the first widened portion 31 and the second widened portion 32 are formed in a curved shape, and the first widened portion 31 and the second widened portion 32 are formed. In between, the linear part 33 extended linearly toward the discharge port 5 without changing a width | variety is provided.

  In the shape of the existing inner deckle 12, it spreads rapidly in the width direction in the vicinity of the discharge port 5. Therefore, the molten resin that flows down from the top has a shape that is difficult to flow along the inner deckle surface, so the amount of molten resin that is discharged near the end decreases, so that the vicinity of the end of the film is It will be thinner.

  There is a neck-in phenomenon in which the molten resin contracts in the width direction after the discharge from the die until the film is formed. As a feature of this phenomenon, the slower the discharge flow rate, the greater the length of contraction in the width direction. In addition, the molten resin that shrinks in the width direction is almost laminated at the end, so that even if the discharge flow rate is small from the end of the die discharge port 5, that is, even if the flow rate is slow, the film end is not always thin, rather In many cases, the resin is collected by neck-in, and the film ends are considerably thick.

  On the other hand, in the shape of the inner deckle 12 according to the present invention, the surface (guide portion) 12 a of the second inner deckle 12 includes a first widened portion 31 and a second widened portion 32, and is located above the discharge port 5. It spreads in the width direction. Therefore, there is a distance until the molten resin that flows down from the top flows to the end of the discharge port, and the time for flowing to the end can be earned. Since the amount of the molten resin discharged near the end can be increased, the phenomenon that the film thickness becomes thin near the end can be improved.

  Regarding the end film thickness, the discharge flow rate increases, so it is likely to be thick. However, considering the neck-in phenomenon, the amount of contraction in the width direction decreases as the flow rate increases, so it cannot be said that the film thickness increases.

  Further, when the temperature can be controlled for each portion of the die, the shrinkage in the width direction due to neck-in may be suppressed by lowering the temperature of the end portion.

In the figure, the first and second inner deckles 11 and 12 are shown. However, as long as this claim is satisfied, there is no problem in this configuration even if there is only one inner deckle.
Further, even if the first and second inner deckles 11 and 12 have a shape in which the contact surfaces 11a and 12a with the molten resin R1 are concavely curved in an arc shape in the cross section in the horizontal direction, there is no problem in this configuration. .

  Here, the relationship between the position in the width direction of the molten resin of the slot die apparatus 1 of the second inner deckle 12 shown in FIG. 2 and the flow velocity thereof was verified by simulation. FIG. 3A shows the relationship between the position in the entire width direction and the flow velocity. In FIG.3 (b), the relationship between the position of the edge part side of the molten resin of Fig.3 (a) and the flow velocity is expanded and shown.

  As can be seen from FIGS. 3 (a) and 3 (b), molten resin is used when the inner deckle 12 according to the present embodiment is employed and when the inner deckle 12 according to a form outside the present embodiment is employed. The flow rate at the center of R1 is almost the same, but at the end, the inner deckle 12 according to the present embodiment is faster than the inner deckle outside the range, and is about 20% faster. I understand that.

  From the verification by the simulation, the inner deckle of FIG. 2B was created, and a resin film was created using the production apparatus. FIG. 4A shows an end film thickness result of a film generated using the existing inner deckle. FIG. 4B shows the end film thickness results of the film generated using the inner deckle of FIG.

As can be seen from FIGS. 4 (a) and 4 (b), when the inner deckle 12 according to the present embodiment is adopted and when the inner deckle 12 according to a form outside the present embodiment is adopted, end portions are used. The drop in film thickness is clearly improved.
Therefore, it can be seen that by using the inner deckle of the present claims, the phenomenon of thinning near the end and the neck-in at the end can be suppressed.

DESCRIPTION OF SYMBOLS 1 ... Slot die apparatus 2 ... Slot die main body 2a ... Supply port 3 ... Manifold 4 ... Slot 5 ... Discharge port 6 ... Inner deckle mechanism 11 ... 1st Inner deckle 12 ... second inner deckle 13 ... throttle member 31 ... first widened portion 32 ... second widened portion 11a, 12a ... surface R1 ... melted resin R2 ... Resin films

Claims (5)

In the slot die apparatus in which the molten resin is supplied to the molding chamber from the supply port of the slot die body, is expanded in the width direction in the molding chamber and is discharged from the discharge port of the molding chamber, and is molded into a film shape
Inner deckles having guide portions that contact and guide the molten resin passing therethrough are provided at both ends in the width direction of the molding chamber,
The guide portion is connected to a first widened portion that extends in the width direction toward the discharge port at a location on the upstream side in the vicinity of the discharge port, and is connected to a downstream end of the first widened portion and extends in the width direction. A second widened portion leading to the exit,
The degree to which the first widened portion spreads in the width direction as it goes to the discharge port is larger than the degree to which the second widened portion spreads in the width direction as it goes to the discharge port,
A slot die device characterized by that. The guide portion extends in the width direction from the supply port side toward the discharge port side.
The slot die apparatus according to claim 1, wherein: The molding chamber has a manifold connected to the supply port, and a slot connected to a downstream portion of the manifold,
The inner deckle is a first inner deckle provided at both ends in the width direction of the upstream portion of the manifold and the slot, and a second inner deckle provided at both ends in the width direction of the downstream portion of the slot. Is composed of Kell and
The first widened portion and the second widened portion are provided in a guide portion of a second inner deckle.
The slot die apparatus according to claim 1 or 2, characterized by the above-mentioned. The degree to which the guide portion of the second inner deckle extends in the width direction as it goes to the discharge port is greater than the degree to which the guide portion of the first inner deckle extends in the width direction toward the discharge port,
The slot die apparatus according to claim 3. The first widened portion and the second widened portion are formed in curved shapes that are continuous with each other.
The slot die apparatus according to claim 1, wherein the slot die apparatus is any one of claims 1 to 4.

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