JP3225558B2 - T-die having gas discharge pipe and film forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a laminate for soft packaging which obtains good physical properties by using gas during film formation by extrusion molding, and more particularly, to a T-die having a gas discharge pipe. And a film forming method.

[0002]

2. Description of the Related Art Conventionally, in a method for producing a laminated body for soft packaging by an extrusion molding method, a gas such as oxygen or nitrogen is blown onto the surface of a molten resin flow film discharged from an extruder to adhere to another film. A method for improving the film quality and preventing oxidation of the film-forming surface has been adopted as necessary. The gas discharge pipe for blowing the gas was generally mounted in a movable form so that it can be mounted on or removed from the extruder body or T-die as needed. For example, a support table (50) having a gas discharge pipe (30) attached to the main body of the extruder as shown in FIG. 4, or a left and right side of a T-die (10) as shown in FIG. Gas discharge pipe (3
The holding plate (36) to which (0) was attached was attached to the attachment fulcrum (37) in a vertically movable manner. Furthermore, T-
As a method of attaching to a die, Japanese Patent Publication No. 60-51438
In some cases, an exhaust device and a gas blowing device are provided on the outside of the T-die disclosed in Japanese Patent Application Laid-Open Publication No. H11-209,878.

[0003]

However, in the case where the gas discharge pipe is attached to the main body of the extruder, it is necessary to remove the gas discharge pipe when exchanging the cooling roll (17). There has been a problem that misalignment tends to occur at times. In addition, in the case where the gas discharge pipe is attached to the T-die, as the holding plate to which the gas discharge pipe is attached moves up and down, a positional shift occurs due to loosening of the movable fulcrum,
There is a problem that the jig is deformed due to the heat radiation of the T-die. Further, in the case where the exhaust device and the gas blowing device are attached to the outside of the T-die, the gas is discharged from the exhaust device relatively quickly after blowing the gas upward from below on the molten resin flow film discharged from the lip. There was a problem that the effect of the gas became insufficient and the temperature of the molten resin had to be raised. The present invention solves the above-mentioned conventional problems as described above, forms a film by effectively utilizing the improvement of physical properties by gas, and manufactures a laminate for flexible packaging having good physical properties at a relatively low molten resin temperature. It provides a way to:

[0004]

SUMMARY OF THE INVENTION As shown in FIGS. 1, 2 and 3, both ends of a lip (11) of a T-die (10) connected to an extruder by an adapter (19). The outer deckle (2
0) is attached so as to close the lip, and a gutter-shaped gas discharge pipe insertion section (22) having a key groove (22) for fixing the gas discharge pipe (30) at the lower front and rear portions of the two outer deckles. 21) is provided in parallel with the lip, and a fixing key (31) and two gas discharge pipes having a plurality of gas discharge holes (32) are inserted into the gas discharge insertion portion and fixed. A plurality of gas discharge holes are T-
T having a gas discharge pipe fixed and provided in parallel so as to face the molten resin flow film (13) discharged from the die lip
Using a die and a T-die having this gas discharge pipe,
A film forming method in which the same, different or mixed gas (40) is sprayed onto the molten resin flow film from two gas discharge pipes provided in front and rear of the molten resin flow film discharged from the lip of the die to form a film. It is.

In the above description, the outer deckle for closing the unnecessary portion of the lip of the T-die is fixed to the both side walls at the tip end of the T-die from outside by fixing bolts (23) or the like so as to straddle the lip. It is attached.

Further, the hole-shaped gas discharge pipe insertion portion provided in the outer deckle covers and holds at least half of the outer circumference of the gas discharge pipe when the gas discharge pipe is inserted. .

The length of the fixing key (31) provided on the gas discharge pipe is such that when the gas discharge pipe is inserted into the gas discharge pipe insertion portion of the outer deckle, the gas discharge pipe is securely positioned. It only needs to be long enough to be fixed to

The positional relationship between the fixing key provided on the gas discharge pipe and the gas discharge hole is determined by inserting the fixing key of the gas discharge pipe into the key groove of the gas discharge pipe insertion portion of the outer deckle. When the discharge pipe is fixed at a fixed position, the direction of the gas discharged from the gas discharge hole is directed downward (rightward) of the molten resin flow film descending from the T-die (the traveling direction of the molten resin flow film). It is provided.

Further, the plurality of gas discharge holes provided in the gas discharge pipe are provided in a line at equal intervals in the width direction of the molten resin flow film.

The gas to be discharged may be an active gas such as ozone, an inert gas such as nitrogen, or a mixed gas thereof depending on the purpose. The gas supply is connected to a discharge pipe. This is performed from the gas supply pipe (35).

[0011]

The outer deckle is securely fixed to the side walls of the tip by bolts or the like across the lip of the T-die, and a gas discharge pipe provided at a lower part in front and rear of the outer deckle. The gas discharge pipe inserted into the insertion portion is securely held by the insertion portion inner wall, and further,
The gas discharge holes arranged in a line in the gas discharge tube always keep a constant angle with respect to the molten resin flow film discharged from the T-die by fitting the key of the tube and the key groove of the insertion portion. I have.

Also, the gas discharge pipe inserted into the gas discharge pipe insertion portion of the outer deckle attached to the molten resin discharge unnecessary portion at both ends of the lip of the T-die naturally has a gas discharge hole at the molten resin discharge unnecessary portion. Is closed by the inner wall of the insertion portion, so that the gas discharge width is regulated by the width of the molten resin flow film.

Since the lip of the T-die at the portion where the molten resin is not required to be discharged is completely covered with the outer deckle, it is possible to prevent the influence of corrosion by an active gas such as ozone.

Further, the gas blown downward from the gas discharge pipe at a right angle to the molten resin flow film descending from the lip of the T-die travels along the flow of the molten resin flow film, and effectively treats the gas. Therefore, it is possible to lower the resin temperature of the molten resin by 20 ° C. to 30 ° C. as compared with the conventional method.

[0015]

【Example】

<Embodiment 1> FIG. 1 is a cross-sectional view showing a state in which a flexible package laminate of an embodiment is manufactured by a film forming method using a T-die according to the present invention. FIG. 2 is a front view thereof. FIG. 3 is a perspective view of the outer deckle and the gas discharge pipe used in the embodiment of the present invention.

An outer deckle having a gas discharge tube insertion portion at the front and rear lower portions of the present invention is attached to a portion of the T-die where the molten resin is not required to be discharged, and a gas discharge tube is inserted into the gas discharge tube insertion portion. Fixed. The angle of the gas discharge hole with respect to the molten resin flow film was set at 20 °. Using a T-die according to the present invention, low-density polyethylene is applied between the surface of the 20 μm stretched polypropylene film anchor-coated with the polyurethane-based AC agent and the surface of the 12 μm stretched polyester film anchor-coated with ozone gas. Improve adhesion while spraying on both sides to form a film,
Laminate and make OPP (20μm) / LDPE (20μm)
m) / PET (12 μm). The temperature of the molten resin is 290 ° C.
The temperature was low from 0 ° C. to about 30 °. The take-off speed was 100 m / min.

In order to measure the adhesive strength between the layers of the three-layer film thus prepared, a sample having a width of 15 mm was prepared and measured at a descent speed of 200 mm / min using a Tensilon tensile tester. As a result of this evaluation, the adhesive strength between OPP / LDPE was 300 g / 15 mm or more, and the adhesive strength between PE / PET was 150 g / 15 mm or more. This is a value that is sufficient for practical strength and has no problem.

In the present invention, as the thermoplastic resin to be laminated on the base material, in addition to the above-mentioned low-density polyethylene, thermoplastic resins such as medium-density polyethylene, high-density polyethylene, polypropylene, nylon, vinyl chloride resin, ionomer, polyester, etc. Resin may be used,
As the base material, in addition to the above-mentioned polypropylene and polyester films, films of ethylene-vinyl acetate copolymer, nylon, vinylidene chloride and the like, cellophane, paper, aluminum foil, non-woven fabric, cloth and the like can be used.

<Example 2> Using a T-die having a gas discharge pipe according to the present invention, low-density polyethylene was flown, and the adhesive property was applied to the surface of the molten resin flow film discharged from the T-die to be laminated with the substrate. Ozone gas is blown from the gas discharge hole of the gas discharge pipe to improve the performance, and nitrogen gas of an inert gas is blown on the opposite side of the non-laminated surface to prevent oxidation due to deodorization. A molten resin film treated with ozone gas is laminated on the aluminum foil surface of a stretched polyester / aluminum foil laminated film anchor-coated with a polyurethane-based AC agent, and PET (12 μm) / AL foil (7 μm) / LDPE
A three-layer laminated film (20 μm) was prepared. The molding conditions were as follows: the temperature of the molten resin: 290 ° C., the take-off speed: 100 m / min, the gas spray angle to the molten resin flow film: 30 °, and the like. The result of measuring the adhesive strength between AL / LDPE of this laminated film was 15
It was 0 g / 15 mm or more. The oxidation odor of polyethylene was also small.

[0020]

According to the present invention, when a film is formed using a T-die having a gas discharge pipe according to the present invention to produce a laminate for flexible packaging, the following effects are obtained. The gas discharge pipe inserted into the gas discharge pipe insertion part of the outer deckle securely fixed to the T-die is securely fixed by the inner wall of the insertion part and the key, so that the gas discharge hole is formed in the molten resin flow film. On the other hand, since it can be held at a fixed angle, there is no need to worry about misalignment. The gas discharge pipe inserted into the gas discharge pipe insertion portion of the outer deckle has its gas discharge width regulated by itself and has little effect on gas treatment unnecessary surfaces such as the back surface of the molten resin flow film. Since the gas is blown from the gas discharge holes in the traveling direction of the molten resin flow film, the gas effect is good, and the resin molding temperature can be lowered. Since the portion of the lip of the T-die that does not need to be discharged with the molten resin is covered with the outer deckle, the influence of corrosion and the like by the active gas is small. The gas blowing angle can be changed by changing the position of the key groove at the gas discharge pipe insertion portion of the outer deckle.

[Brief description of the drawings]

FIG. 1 shows a film forming method using a T-die of the present invention.
It is sectional drawing which showed the state which is manufacturing the laminated body for flexible packaging.

FIG. 2 is a front view when the T-die of the present invention is attached to an extruder to produce a laminate for flexible packaging.

FIG. 3 is a perspective view of an outer deckle and a gas discharge pipe of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a laminate for flexible packaging is being manufactured by a conventional film forming method using a T-die using gas.

FIG. 5 is a perspective view of a T-die to which a gas discharge pipe is attached by a conventional method.

[Explanation of symbols]

 10 T-die 11 Lip 12 Molten resin flow path 13 Molten resin flow film 14, 15 Film 16 Laminated film 17 Cooling roll 18 Nip roll 19 Adapter 20 ... Outer deckle 21 ... Gas discharge tube insertion part 22 ... Key groove 23 ... Fixing bolt 30 ... Gas discharge tube 31 ... Fixing key 32 ... Gas discharge hole 33 ... Gas flow passage 34 ... Outer Part to be inserted into deckle 35 Gas supply pipe 36 Plate holding plate for gas discharge pipe 37 Mounting fulcrum 40 Gas 50 Support base

Continuation of the front page (56) References JP-A-54-71164 (JP, A) JP-A-56-25413 (JP, A) JP-B-60-51438 (JP, B2) JP-B-49-35816 (JP) , B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 47/00-47/96 B29C 63/02 B32B 31/30

Claims (2)

(57) [Claims] 1. An outer deckle is attached to portions of both ends of a lip of a T-die connected to an extruder where no molten resin is to be discharged so as to close the lips, and lower portions at the front and rear of the two outer deckles on the left and right sides. A gutter-shaped gas discharge pipe insertion portion having a key groove for fixing a gas discharge tube is provided in parallel with the lip, and the gas discharge insertion portion has a fixing key and a plurality of gas discharge holes having a plurality of gas discharge holes. The discharge pipe is inserted and fixed, and the plurality of gas discharge holes are formed at the time of extrusion molding.
A T-die having a gas discharge pipe, which is fixed and provided in parallel so as to face a molten resin flow film discharged from a lip of the die. 2. A T-die having a gas discharge pipe according to claim 1, which is the same as two gas discharge pipes provided in front and rear of a molten resin flow film discharged from a lip of the T-die. Alternatively, a film forming method characterized by spraying a different or mixed gas onto a molten resin flow film to form a film.