JP2011213083A - Slot die device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slot die device which can accelerate the flow velocity on the end part side in the width direction of a molten resin to be discharged from a slot, and also can inhibit the thickening of the end part of a molded resin film.SOLUTION: This slot die device is structured as follows: first, the molten resin is supplied to a manifold, passing through a slot formed in the downstream part of the manifold, and is molded in the form of film. In addition, an inner deckle for guiding in contact with the molten resin passing through, is arranged at both end parts in the width direction of the manifold and the slot. The angle at which the inner deckle comes into contact with the upper part of the manifold, falls within the range of not less than 45° to not more than 75°.

Description

  The present invention relates to a slot die device for molding a resin film, and more particularly to a slot die device that suppresses an increase in the end 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, since the flow rate of the molten resin discharged from the slot is slower than the center portion in the width direction, the end portion in the width direction is the center in the width direction where the flow velocity is high. It was easy to shrink to the side, and its thickness was easy 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 speed on the end side in the width direction of the molten resin discharged from the slot, and the end of the molded resin film becomes thicker. It is an object of the present invention to provide a slot die device that can suppress the above-described problem.

  In order to achieve the above object, in the invention according to claim 1 of the present invention, the molten resin is supplied to the manifold, passes through a slot provided in the downstream portion of the manifold, and is formed into a film shape. The inner deckle that guides in contact with the molten resin passing therethrough is provided at both ends in the width direction of the manifold and the slot, and the angle of the inner deckle that is in contact with the upper portion of the manifold is 45 degrees or more and 75 degrees The slot die apparatus is characterized by being in the following range.

  Further, in the invention according to claim 2, in the inner deckle, the corner facing the manifold central portion at the lower portion of the inner deckle is a chamfered shape. Device.

  Further, in the invention according to claim 3, 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. 3. A flow that extends from the upstream side toward the downstream side and inclines toward the outer side in the width direction of the manifold and the slot along the inner deckle is formed at the end portion in the width direction. It is a slot die apparatus as described in above.

  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). It is a cross-sectional view of the inner deckle provided in the slot die device. (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).

  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.

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 in the manifold 3 and the slot 4, and the surfaces 11 a, 12 a and 13 a can move in the width direction of the manifold 3 and the slot 4. The dimensions are specified. The molten resin R1 supplied to the slot die body 2 is guided by the surfaces 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 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 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 arranged with their positions shifted so as to widen the dimensions in the width direction of the manifold 3 and the slot 4 from above to below.

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 second inner deckles 11 and 12 and the surfaces 11a, 12a and 13a of the throttle member 13, a flow spreading in the width direction is formed in the molten resin R1 as it flows downward. 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 first inner deckle 11. Looking at the same plane as FIG. FIG. 2 shows the shape of the first inner deckle 11 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.

  This time, the contact angle with the upper part of the manifold 3 becomes the angle 14 with the upper part of the manifold of the first inner deckle. The difference in the angle 14 greatly changes the flow situation. When the angle of the inner deckle is small, the space through which the molten resin flows at the end of the manifold is narrowed. Since a large force is required to flow the fluid in a narrow place, the molten resin does not flow to the end portion, but flows downward toward the end portion. For this reason, the flow velocity at the end portion decreases. If the flow rate is small, the flow rate is small, so that the film thickness is thin in the vicinity of the end portion, resulting in a defective product. Moreover, since the neck-in amount becomes larger as the flow velocity is slower at the end, the end becomes thicker.

  On the other hand, when the angle is made flat at 90 degrees, the flow velocity hardly decreases in the width region and becomes constant. It can be said that it is a good condition if it is a normal fluid, but with a normal resin, no matter how much the flow rate is increased, the neck-in amount can be reduced, but it is not possible to completely prevent the neck-in. As a result, the end portion rises and becomes thicker. For this reason, it is necessary to set the conditions so that the flow velocity distribution falls moderately in the width direction at an appropriate angle.

  The lower part of the first inner deckle is usually flat, but in this case, the molten resin has a larger component in the vertical downstream direction along the angle of the inner deckle surface rather than spreading in the width direction. For this reason, neck-in occurs due to a decrease in the end flow velocity, and the thickness of the end increases.

  The chamfered portion is attached to the lower part of the first inner deckle as shown in Fig. 2 so that the inner deckle surface can be oriented toward the end and the chamfered shape is used to remove the liquid. The possibility of accumulating in the part is low, and the molten resin can be easily flowed to the end part.

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 angle 14 with respect to the manifold upper portion of the first inner deckle 11 shown in FIG. 2 is 45 ° and 75 ° of the slot die apparatus 1 of the present embodiment, and the first inner deckle 11 shown in FIG. The relationship between the position in the width direction of the molten resin of the slot die apparatus 1 whose angle 14 with respect to the upper portion of the manifold is 30 ° outside the scope of the present embodiment 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 11 according to the present embodiment is employed and when the inner deckle 11 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 11 according to the present embodiment is faster than the inner deckle outside the range, and is about 10% faster. I understand that.
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 11a, 12a ... surface R1 ... molten resin R2 ... resin film 14 ... first inner deckle manifold Angle with upper part 15 ... Chamfered part of lower part of manifold of first inner deckle

Claims (3)

In 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,
Inner decks that are in contact with and guide the molten resin passing therethrough are provided at both ends in the width direction of the manifold and the slot, and the angle of the inner deck that is in contact with the upper part of the manifold is 45 degrees or more and 75 degrees or less. A slot die device characterized by being within a range.   2. The slot die apparatus according to claim 1, wherein a corner of the inner deckle that faces the central portion of the manifold below the inner deckle has a chamfered shape.   3. The slot according to claim 1, wherein the inner deckle is widened such that a contact surface with the molten resin is inclined more outward than the upstream side in the width direction of the manifold and the slot. Die equipment.

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