JPH0260506B2 - - Google Patents

Description

Detailed Description of the Invention [Field of the Invention] The present invention relates to a T-die for molding a film from synthetic resin such as polyethylene resin, and more specifically, the present invention relates to a T-die for molding a film from synthetic resin such as polyethylene resin. By dividing the side plate that supports the deck and inner deck rod into upper and lower parts above the inner deck rod, it is easy to remove the oxidized resin that has adhered to it, improving workability and productivity, and The present invention relates to a T-die which prevents the occurrence of film edge height regardless of the type of film.

[Prior Art] There are two methods for forming polyethylene and polypropylene films: an inflation method and a T-die method. Among these, the T-die method is used to extrude and mold a film such as polyethylene, and then layer it on metal foil, cellophane paper, kraft paper, etc. while it is still hot, pressurize it with a roll, and laminate it to make fertilizer bags, moisture-proof bags, etc. It is also widely used in packaging paper for medicine packaging, food packaging, etc.

Various attempts have been made to improve this T-die and efficiently produce suitable films. for example,
Utility Model Application Publication No. 54-152274 and Utility Model Application Publication No. 57-1989, which belong to the present inventor.
No. 24488, Utility Model Publication No. 128423, 1983, etc. Films obtained by these proposals generally have excellent transparency, have a uniform thickness, and do not have edge heights (edge balls formed at both ends of the obtained film), making it possible to obtain a nearly satisfactory product.

However, there are various resins used, such as high, medium, and low density polyethylene, polypropylene (PP), and ethylene vinyl acetate (EVA), and the characteristics of the resins also differ depending on the manufacturing method such as the autograte method and the tubular method. Depending on the type of resin used, there is still a problem in that edge heights occur at both ends of the film. For example, a film using a resin obtained by the autograde method does not have a relatively high edge height, but a film using a resin obtained by the tubular method tends to have a high edge height, and polyethylene has a relatively high edge height. Although this does not occur, polypropylene and ethylene vinyl acetate have a problem in that they tend to have high edges. Furthermore, the resin used is not always the same, and when changing the type of resin, it is necessary to remove the oxidized resin attached to the lower part of the round part and the lip part, but it is difficult to remove the attached oxidized resin. This required a lot of time, significantly impairing productivity and workability.

[Object of the Invention] The present invention has been made in order to solve these drawbacks, and is capable of quickly and easily removing attached oxidized resin, and also preventing the occurrence of edge height at both ends of the film, regardless of the type of resin. The purpose is to provide a T-die that makes it possible to

[Structure and operation of the invention] The above object of the present invention is achieved by providing a downward facing flag at the tip of the inner deck rod and further dividing the side plate into upper and lower parts.

That is, the present invention is a film molding machine that uses synthetic resin as a raw material, and has a T die that has a manifold part, a round part, and a lip part, and whose width is regulated by an inner deckle and an inner deckle rod.
The T-die is characterized in that a downward flag is provided at the tip of the inner deck rod.

The present invention will be specifically described below with reference to the drawings.

Fig. 1 is an explanatory diagram of a T-die showing an embodiment of the present invention, Fig. 2 is an enlarged explanatory diagram of the side plate portion of Fig. 1, and Fig. 3 is a partially cutaway cross-section of the side plate portion of Fig. 2. Figures are shown respectively.

In FIGS. 1 to 3, the main body of the T-die 1 consists of a manifold part 2, a round part 3, and a lip part 4.
The rod 5 supported and connected by the inner deckle 6 is the T
Manifold part 2 similar to that used for the die
The T-die 1 of the present invention is not limited to the position or shape of the rod 5, although a die having the same cross-sectional shape as the rod 5 and having the rod 5 in contact with the inner circumferential surface of the manifold portion 2 is used. Further, in the present invention, the inner deckle 6 supported and connected by the rod 5 is positioned from the upper end to the lower end of the round part 3, and is 0.1 to 0.3 mm from the inner deckle rod 7 located at the lowest end of the round part 3. It is desirable to arrange them with a certain amount of space between them. The lower surface of the inner deck 6 may be a straight line parallel to the rod 5, but it is better to provide a recess with a semicircular cross section, and the recess has a gap in the upper semicircle of the inner deck rod 7. It is preferable to position it. In addition, this inner deck 6 is also available in Japanese Patent Application No. 8434/1986 (Japanese Patent Application No.
As described in Japanese Patent Publication No. 167523), it is desirable that the inner deck be divided into upper and lower parts, an embedded inner deck part 6a and an inner deck part with a flag 6b.
By dividing the inner deckle 6 into upper and lower sections in this manner, the embedded inner deck portion 6a and the flagged inner deckle 6b can be individually adjusted, and the width of the resin can be smoothly regulated. moreover,
In order to obtain a good film, it is desirable that the tip of the lower part of the flagged inner deckle part 6b is rounded so that the lower part of the flagged inner deckle part 6b comes into close contact with the inner deckle rod 7.

In the T-die 1 of the present invention, a downward flag is provided at the tip of the inner deck rod 7. By providing a flag pointing downward in this way, a film with no edge height can be obtained regardless of the type of resin. For example, it is possible to obtain a film with no edge height, regardless of the type of resin. Even when used, the film does not have an edge height. Further, not only when polyethylene is used, but also when polypropylene or ethylene vinyl acetate is used, the film does not have an edge height.

In Figure 1, arrows indicate the flow of resin,
The resin extruded from the extruder A flows into the round part 3 via the manifold part 2, the flow width of the resin is determined by the inner deckle 6, and finally the exact width of the resin is determined by the inner deckle rod 7. The film is formed from the lip portion 4.

In the present invention, when changing the type of resin, T
In order to efficiently heat or cool the inside of the die 1,
a heat insulating cover (not shown) surrounding the upper part of the T-die 1;
Cooling means (not shown) may also be provided.

Further, the embedded inner deck part 6a and the flagged inner deck part 6b are held by pieces fixed to the side plate 8 with bolts, but it is preferable that each is held by separate pieces. Individual adjustments can be made easily, and replacing the inner deckle 6, which conventionally took about 30 minutes, can now be done in 5 to 6 minutes.

In the T-die 1 of the present invention, in order to quickly and easily remove the oxidized resin attached to the lower part of the round part 3 and the lip part 4, the side plate 8 supporting the inner deckle 6 and the inner deckle rod 7 is attached to the inner deckle. The upper side plate 7 is vertically divided into an upper side plate 8a and a lower side plate 8b. As described above, by dividing the side plate 8 into upper and lower parts, the inner deck rod 7 can be removed by simply removing the lower part 8b of the side plate, as disclosed in Japanese Utility Model Publication No. 55-53388 by the present inventor. The described resin removal instrument (not shown) can be used conveniently, and the removal of attached oxidized resin can be accomplished quickly and easily. At this time, the piece 10 that holds the inner deckle part 6b with the flag and the inner deckle rod 7 is also attached to the piece upper part 10a and the piece lower part 1.
By dividing it into upper and lower parts, the attached oxidized resin can be removed more quickly.

Further, in the present invention, as described in Japanese Patent Application No. 60-8434, the inner deck 6 is divided into the embedded inner deck 6a and the flagged inner deck 6b. Resin remains in the inner portion of the deck 6a, causing clogging. For this reason, a resin punch hole 9 is provided in the side plate 8 inside the inner deck 6.
It is desirable to remove the resin inside the inner deck 6, particularly inside the embedded inner deck portion 6a. A plug is usually inserted into the resin extraction hole 9, and when the resin is extracted, the plug is removed, and after the resin is extracted, the plug is inserted again.

[Effects of the Invention] According to the present invention as described above, regardless of the type of resin or the manufacturing method of the resin, the resulting film does not have an edge height, and the attached oxidized resin can be easily removed. . Therefore, by using the T-die of the present invention, workability and productivity are significantly improved, a product with no selvage height can be obtained, the resulting laminate can be easily wound, and there is no need to cut the selvage height. Since there is no waste, there is an effect that there is less waste of raw material resin.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a T-die showing one embodiment of the present invention, Fig. 2 is an enlarged explanatory diagram of the side plate portion of Fig. 1, and Fig. 3 is a partial cutout of the side plate portion of Fig. 2. Cross-sectional view. A: Extruder, 1: T die, 2: Manifold part, 3: Round part, 4: Lip part, 5: Rod, 6: Inner deckle, 6a: Embedded inner deckle part, 6b: Inner deckle with flag Part, 7: Inner deck rod, 8: Side plate, 8a: Upper side plate, 8b: Lower side plate, 9: Resin punch hole, 10: Piece, 1
0a: Upper piece, 10b: Lower piece.

Claims (1)

[Scope of Claims] 1. A film molding machine using synthetic resin as a raw material, in which the inner A T-die characterized by a downward facing flag at the tip of the stick. 2. The T-die according to claim 1, wherein the inner deckle and the side plate supporting the inner deckle rod are divided into upper and lower parts above the inner deckle rod. 3. The T-die according to claim 1 or 2, wherein the inner deckle is divided into an embedded inner deckle portion and an inner deckle portion with a flag located below the embedded inner deckle portion. 4. Claims 1 and 2, wherein the lower end of the flagged inner deckle part is R-shaped so that the lower part of the inner deckle part is in close contact with the inner deckle rod.
The T-die according to item 1 or 3.