JPH0643089B2 - T-die - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a T-die for molding a film from a synthetic resin such as polyethylene resin, and more specifically, to a taper portion that contacts an inclined upper surface of a lip portion on an inner deckle rod. And a thin plate portion extending from the lower end thereof into the resin extrusion port of the lip portion.

[Prior Art] As a method for molding a polyethylene or polypropylene film, there are an inflation method and a T-die method. Of these, the T-die method is used to extrude a film such as polyethylene and press it with a metal foil, cellophane paper, kraft paper, etc. while hot and laminate it by laminating to make a fertilizer bag, moisture-proof bag, etc. In addition, it is widely used for packaging papers such as medicine packaging and food packaging.

Various attempts have been proposed to improve this T-die and efficiently produce a suitable film. For example, utility model registration No. 1726281, utility model registration No. 1603083 according to the present inventor,
Utility model registration No. 1777587, Japanese Patent Publication No. 1-56648, JP-A-62
-53812 etc. The films obtained by these proposals are generally excellent in transparency and have a uniform thickness,
Almost satisfactory products can be obtained without generating ear height (eardrops generated at both ends of the obtained film).

5 to 7 show an example of a conventional T die described in JP-A-62-53812. FIG. 5 is a front view of the T die, FIG. 6 is an enlarged front view of the vicinity of the side plate of the T die of FIG. 5, and FIG. 7 is an enlarged sectional view of a lower portion of the Y die of the T die of FIG. Is.

In FIGS. 5 to 7, the T-die 1'main body comprises a manifold portion 2 ', a round portion 3', and a lip portion 4 '. The inner deckle 6'supported and connected by the rod 5'is located from the manifold portion 2'to the lower end of the round portion 3'and is fixed to the inner deckle rod 7'located at the lowermost end of the round portion 3 '. It is arranged with a gap. The inner deckle 6'is divided into an embedded inner deckle portion 6a 'and a flagged inner deckle portion 6b' at the top and bottom.

In FIG. 5, the arrow indicates the flow of resin, and the extruder A '
The more extruded resin flows into the round section 3'through the manifold section 2 ', and the inner deckle 6'determines the flow width of the resin, and finally the inner deckle rod 7'determines the precise resin width. Then, the film is formed from the lip portion 4 '.

However, in the conventional T-die, the inner deckle rod is a columnar rod, or as shown in FIGS. 5 to 7, the inner deckle rod is provided with a downward flag. Therefore, conventionally, the resin accumulated in the inner portion B '(see FIG. 6) of the inner deckle 6'of the round portion 3'leaks from between the inner deckle rod 7'and the inclined upper surface 4a' of the lip portion 4 ', Adhesion of leaked resin to the film occurred. The frequency of occurrence was high at least once every 3 to 5 minutes, resulting in deterioration of product quality and yield.

Further, in the conventional T die, the above-mentioned oxide of leaked resin is a portion C ′ sandwiched between the lower portion of the round portion 3 ′ and the resin extrusion port 4b ′, particularly the inner deckle rod 7 ′ and the lip portion 4 ′. (See FIG. 7). Therefore, the inner deckle rod 7'sticks to the lip portion 4 ', and it takes a lot of time to change the lot.

Furthermore, if the above-mentioned oxide resin is left to stand, the transparency or thickness of the product becomes non-uniform, so it is necessary to remove the oxide resin. Therefore, conventionally, it is necessary to remove the inner deckle rod 7 ′ every time the lot is changed and to remove the oxide resin by using a resin removing tool (not shown) described in the utility model registration No. 1393119 by the present inventor. was there. The work requires a considerable amount of time, which not only impairs the productivity and workability but also involves the risk of being burned by the high temperature resin.

The present invention has been made to solve the above-mentioned drawbacks of the prior art, and prevents the leaked resin from adhering to the film, and further facilitates the lot changing work and the oxide resin removing work and improves the safety. The purpose is to provide a T-die.

[Means and Actions for Solving the Problems] The above object of the present invention is to provide an inner deckle rod with a tapered portion that abuts an inclined upper surface of a lip portion and a thin plate portion that extends from a lower end thereof into a resin extrusion port of the lip portion. It is achieved by providing.

That is, the present invention is a film forming machine using a synthetic resin as a raw material, which has a manifold portion, a round portion, a lip portion, and an inner deckle arranged from the manifold portion to the lower end of the round portion and from the lower end of the round portion. In a T-die in which the resin width is regulated by an inner deckle rod arranged over the lip portion, the inner deckle rod contacts the inclined upper surface of the lip portion and the maximum width is 0.8 of the width of the resin passage in the round portion. ~ 1.0 times the tapered portion, and a thin plate portion extending from the lower end of the tapered portion into the resin extrusion port of the lip portion and having a thickness of 0.8 to 1.0 times the width of the resin extrusion port It is in the T-die.

Hereinafter, the present invention will be specifically described with reference to the drawings.

FIG. 1 is a front view of a T-die showing an embodiment of the present invention, and FIG.
1 is an enlarged front view of the vicinity of the side plate of the T die of FIG. 1, FIG. 3 is a sectional view of the T die of FIG. 1 taken along the line XX, and FIG. 4 is an enlarged sectional view of the lip portion of FIG. Is.

1 to 4, the main body of the T-die 1 comprises a manifold portion 2, a round portion 3 and a lip portion 4. And the rod 5 supporting the inner deckle 6 is the utility model registration No. 17
Similar to the one used in the T-die disclosed in No. 77587, the one having the same cross section as the manifold portion 2 and having the rod 5 in contact with the inner peripheral surface of the manifold portion 2 is used. However, the T die 1 in the present invention is not restricted by the position and shape of the rod 5. In the present invention, the inner deckle 6 supported and connected by the rod 5 is also used.
Is preferably positioned from the inside of the manifold portion 2 to the lower end of the round portion 3, and is preferably disposed with a gap of about 0.1 to 0.3 mm with the inner deckle rod 7 located from the lower end of the round portion 3 to the inside of the lip portion 4. Further, as described in Japanese Patent Publication No. 1-56648, it is desirable that the inner deckle 6 be divided into an upper and lower embedded inner deckle portion 6a and a flagged inner deckle portion 6b. By thus dividing the inner deckle 6 into upper and lower parts, the embedded inner deckle portion 6a and the flagged inner deckle portion 6b can be individually adjusted, and the regulation of the width of the resin can be facilitated.

In the T-die 1 of the present invention, the inner deckle rod 7
Further, a tapered portion 7a that abuts the inclined upper surface 4a of the lip portion 4 and a thin plate portion 7b that extends from the lower end thereof into the resin extrusion port 4b of the lip portion 4 are provided. In this way, the taper part 7a and the thin plate part
By providing 7b, the leakage of the resin retained in the inner portion B (see FIG. 2) of the inner deckle 6 of the round portion 3 is completely prevented. Therefore, the leakage resin does not adhere to the film, and the product quality and the yield are improved.

Moreover, since the taper portion 7a and the thin plate portion 7b prevent resin from entering between the inner deckle rod 7 and the lip portion 4, the inner deckle rod 7 is prevented from sticking. Furthermore, since the adhesion of the oxide resin between the inner deckle rod 7 and the lip portion 4 is prevented, it is not necessary to remove this oxide resin. Therefore, in the T-die 1 of the present invention, the labor and time for changing lots are significantly reduced.

Further, the inner deckle rod 7 according to the present invention also has a function as a resin removing device. That is, the inner deckle rod 7 is moved along the resin extrusion port 4b in a state where the tapered portion 7a is in contact with the inclined upper surface 4a, so that the oxide resin adhered to the resin extrusion port 4b and the lower portion of the round portion 3 is completely removed. It can be removed. Therefore, it is not necessary to remove the oxide resin by using the resin removing tool after the inner deckle rod is pulled out when changing the lot as in the conventional case, and the removal of the oxide resin becomes extremely easy.
Further, in the T-die 1 of the present invention, the inner deckle rod 7 can be operated from the outside of the side plate 8 to remove the oxide resin, so that there is less risk of burns due to high temperature resin at that time, and the resin removal Work safety is improved.

In the T die 1 of the present invention, the thickness of the thin plate portion 7b needs to be in the range of 0.8 to 1.0 times the width of the resin extrusion port 4b.
The above-mentioned resin leakage prevention and oxide resin removal can be performed more reliably. Further, it is also necessary that the maximum width of the tapered portion 7a is in the range of 0.8 to 1.0 times the width of the resin passage in the round portion 3. Further, it is preferable that the thin plate portion 7b projects downward from the lower end of the lip portion 4 to the resin extrusion port 4b.
It is preferable because the oxidized resin tends to be completely removed up to the lower end of.

Further, in the inner deckle rod 7 according to the present invention,
The taper portion 7a and the thin plate portion 7b are at least the T-die 1
It is preferable to provide it on the entire portion that may be present in the main body, because the above-mentioned prevention of resin leakage and prevention of fixing of the inner deckle rod 7 tend to be more complete.

In FIG. 1, the arrow indicates the flow of resin, the resin extruded from the extruder A flows into the round section 3 through the manifold section 2, and the inner deckle 6 determines the resin flow width, Then, the width of the resin is strictly determined on the inner deckle rod 7, and the film is formed from the lip portion 4.

In the present invention, in order to efficiently heat or cool the inside of the T die 1 when changing the type of resin, a heat insulating cover (not shown) surrounding the upper portion of the T die 1 and a cooling means (not shown) are provided. May be.

[Advantages of the Invention] As described above, in the T-die of the present invention, it is possible to completely prevent the leakage resin from adhering to the film by eliminating the leakage of the resin. Further, the inner deckle rod is prevented from sticking, and further, the oxide resin is prevented from adhering between the inner deckle rod and the lip portion. Furthermore, in the T-die of the present invention, it is possible to completely remove the adhered oxide resin simply by moving the inner deckle rod.

Therefore, by using the T-die of the present invention, the product quality, the yield and the work efficiency are remarkably improved, and particularly the lot changing work and the oxide resin removing work are facilitated and the safety is improved.

[Brief description of drawings]

FIG. 1 is a front view of a T-die showing an embodiment of the present invention, FIG. 2 is an enlarged front view of a side plate of the T-die of FIG. 1, and FIG. 3 is a T-die of FIG. It is sectional drawing of the XX cross section of a die, FIG. 4 is an expanded sectional view of the lip part of FIG. 3, FIG. 5 is a front view which shows an example of the conventional T die, and FIG. 5 is an enlarged front view of the vicinity of the side plate of the T die of FIG. 5, and FIG. 7 is an enlarged cross-sectional view of the lower portion of the Y-Y section of the T die of FIG. 1: T-die, 2: Manifold part, 3: Round part, 4: Lip part, 4a: Inclined upper surface of lip part, 4b: Resin extrusion port, 5: Rod, 6: Inner deckle, 6a: Embedded inner deckle part, 6b: Inner deckle part with flag, 7: Inner deckle bar, 7a: Tapered part, 7b: Thin plate part, 8: Side plate, A: Extruder, B: Inner part of inner deckle of round part.

Claims (3)

[Claims] 1. A film forming machine using a synthetic resin as a raw material, comprising a manifold portion, a round portion, and a lip portion,
In the T-die for regulating the resin width with the inner deckle arranged from the manifold portion to the lower end of the round portion and the inner deckle rod arranged from the lower end of the round portion to the lip portion, in the inner deckle rod,
A tapered portion that abuts the inclined upper surface of the lip portion and has a maximum width of 0.8 to 1.0 times the width of the resin passage in the round portion, and extends from the lower end of the tapered portion into the resin extrusion port of the lip portion and has a thickness. And a thin plate portion having a width of 0.8 to 1.0 times the width of the resin extrusion port. 2. The T-die according to claim 1, wherein the tapered portion and the thin plate portion are provided on the entire portion of the inner deckle rod that can exist in the T-die body. 3. The T die according to claim 1, wherein the thin plate portion projects downward from a lower end of the lip portion.