JPH10323879A - T-die and laminating method for thermoplastic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To laminate securely two kinds of thermoplastic resin of different fluidity all over in the width direction. SOLUTION: When two kinds of molten thermoplastic resin in the state of being laminated in the up and down direction and copolymerized are flowed into a manifold 16 through a resin inflow path 15 of a T-die, two kinds of resin are flowed along the width direction crossing orthogonally its inflow direction in the manifold 16, and then ejected out of a lip opening 19a. The width direction dimension of a resin flow zone in the lip opening 19a is smaller than the maximum width direction dimension of a resin flowing zone in the manifold 16, and when two kinds of thermoplastic resin of different fluidity are flowed into the manifold 16, the thermoplastic resin of high fluidity is flowed along the peripheral edge of the manifold 16 and laminated on the thermoplastic resin of low fluidity on the lip opening 19a and ejected out of the lip opening 19a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a T-die used for laminating two kinds of thermoplastic resins when manufacturing a sheet-like or film-like product, and a thermoplastic resin using the T-die. The present invention relates to a method for laminating a resin.

[0002]

2. Description of the Related Art A sheet-like product or a film-like product in which two kinds of thermoplastic resins are laminated is usually manufactured by using a T-die. The T-die is attached to a feed block that supplies two types of thermoplastic resins, and the two types of thermoplastic resins that merge so as to be stacked in the feed block are co-extruded into the T-die. It has become.

FIG. 6 is a schematic plan view showing the internal structure of a T-die. The T-die is provided with a lip opening 29a, which is sequentially discharged at a constant width in a state where two kinds of thermoplastic resins are laminated, along one side edge, and is shared from the feed block. In a state where the two kinds of extruded thermoplastic resins are vertically stacked, the lip opening 2 is formed.
The resin flows into the manifold 26 through a resin inflow path 25 provided at a side edge opposite to the side 9a and orthogonal to the lip opening 29a. Manifold 2
6 extends along a width direction orthogonal to the resin inflow passage 25, and the two types of thermoplastic resins flowing from the resin inflow passage 25 spread along the width direction to form a manifold 26.
Is filled in. The thermoplastic resin filled in the manifold 26 is connected to the lip opening 29a and the manifold 26.
Between the pre-land portion 27 and the flow rate adjusting groove portion 2
8. The ink passes through the lip land 29 in order and is discharged from the lip opening 29a. The two types of laminated thermoplastic resins discharged from the lip land portion 29 are cooled by cooling rolls through which cooling water flows,
It is a sheet or film product.

The width of the resin flow area in the manifold 26 is equal to the width of the resin flow area in the lip opening 29a.
The pre-land portion 27, the flow rate adjusting groove portion 28, and the lip land portion 29 provided between the lip opening 29 and the lip opening 29a have the same width in the resin flow area.
a) is equal to the widthwise dimension of the resin flow area.

[0005]

The resin inflow path 2 of the T-die
When the thermoplastic resin that is co-extruded in a vertically stacked state into the inside 5 flows into the manifold 26, it flows along the rear wall 26 a of the manifold 26 and spreads in the width direction. . In this case, when the fluidity of the two types of thermoplastic resins stacked vertically is completely the same, each resin is placed in the manifold 26.
Flows in the same state within. Therefore, the thermoplastic resin in a vertically stacked state flows in the manifold 26 at the same speed along the width direction and is filled in the manifold 26, so that the entire width of the resin flow area in the manifold 26 in the width direction is filled in the manifold 26. And the ink is discharged from the lip opening 29a in such a stacked state. As a result, each of the thermoplastic resin layers is discharged from the lip opening 29a in a state where the layers are laminated with a constant thickness over the entire width direction. The ratio of the thickness of each thermoplastic resin layer corresponds to the ratio of the amount of extrusion of each thermoplastic resin.

However, when the MFR (melt flow rate, JIS K6760) of each resin co-extruded into the resin inflow passage 25 of the T-die is different, each thermoplastic resin layer has a width in the width direction. In the state where one thermoplastic resin layer is not laminated at all, it is not laminated at a constant thickness throughout, and at each side edge in the width direction,
There is a possibility that the ink is discharged from the lip opening 29a. That is, since the thermoplastic resin having a large MFR and a large fluidity has a high degree of freedom of flow, when flowing into the manifold 26, it is easily propelled in the width direction orthogonal to the flowing direction. On the other hand, a resin having a small MFR and a small flowability has a small degree of freedom of flow, and therefore has a weak propulsive force in a width direction orthogonal to the inflow direction, and is easily along the width direction. Does not spread. As a result, as shown by the two-dot chain line in FIG. 6, the resin having a high fluidity that has flowed into the manifold 26 wraps around the peripheral portion of the manifold 26 before the resin having a small MFR and a small fluidity. The small resin cannot reach the periphery of the manifold 26 as shown by the broken line in FIG.

As a result, the periphery of the manifold 26 is filled with only a resin having high fluidity,
The peripheral portion of the manifold 26 is not filled with the resin having low fluidity at all, and the thermoplastic resin layer 32 having low fluidity is formed from the lip opening 29a as shown in FIG. Are not laminated at all, and only the thermoplastic resin layer 31 having high fluidity is provided at each side edge in the width direction. Usually, when the MFR of each thermoplastic resin has a difference of 3 times or more,
There is a possibility that a thermoplastic resin having a small MFR is not laminated on each side edge in the width direction.

[0008] As described above, if each side edge in the width direction is a single layer, a single-layered sheet-like product or a film-like product having a two-layer structure is required. It is necessary to cut off and remove each side edge of the. Therefore,
If the portion of the single layer is wide, the cut portion is also large, the yield of the sheet-like product or the film-like product is deteriorated, and the economic efficiency may be greatly impaired.

The present invention solves such a problem, and an object of the present invention is to provide a T-die capable of reliably laminating two types of thermoplastic resins having different fluidities over the entire width direction. Is to do. Another object of the present invention is to provide a method of laminating thermoplastic resins that can be discharged from a T-die in a state where two types of thermoplastic resins having different fluidities are laminated over the entire width direction. is there.

[0010]

According to the T-die of the present invention, two kinds of thermoplastic resins having different fluidities flow into the manifold in a laminated state, and flow along a width direction orthogonal to the flowing direction. A T-die that is to be discharged from a lip opening extending along the width direction after being filled in the manifold by performing the above operation. It is characterized in that it is smaller than the maximum widthwise dimension of the flow zone.

The method of laminating thermoplastic resins according to the present invention is a method of laminating two kinds of thermoplastic resins having different fluidities over the entire widthwise direction using a T-die, and laminating the same in a manifold of the T-die. After flowing each thermoplastic resin flowing in the state along the width direction orthogonal to the inflow direction and filling the manifold, the T-die is used in a state where the width direction dimension of the flow region of each thermoplastic resin is narrowed. Is discharged from the lip opening.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing an example of an embodiment of a T-die according to the present invention as seen through the inside. This T-die is used for manufacturing a sheet-like product or a film-like product in which two layers of thermoplastic resins are laminated, and two types of thermoplastic resins which are combined in a laminated state in a feed block. Are attached to the feed block so that they are co-extruded. T die is lower mold 1
The upper mold 12 and the upper mold 12 are abutted with each other, and a slit-shaped lip opening 19a through which the laminated thermoplastic resin is discharged is provided at one side edge. It is provided between the upper die 12. The laminated thermoplastic resin is sequentially discharged from the lip opening 19a with a constant thickness and width. The discharged thermoplastic resin in a laminated state is discharged with a widthwise dimension equal to the widthwise dimension of the resin flow area in the lip opening 19a.

A slit-shaped resin inlet 15a through which two types of thermoplastic resins co-extruded from the feed block flows is provided on a side edge of the T die opposite to the side edge provided with the lip opening 19a. Is provided. The resin inlet 15a is provided in parallel with the lip opening 19a, facing the center of the lip opening 19a. The two types of laminated thermoplastic resins flowing from the resin inflow port 15a pass through the resin inflow path 15,
It flows into the manifold 16.

FIG. 2A is a plan view showing a space between the lower die 11 and the upper die 12 of the T-die, and FIG. 2B is a cross-sectional view thereof. As shown in FIGS. 1 and 2, the manifold 16 provided continuously with the resin inflow path 15 extends along a width direction orthogonal to the direction in which the thermoplastic resin flows from the resin inflow path 15. The manifold 16
It has the same length in the width direction as the lip opening 19a,
The length in the vertical direction is gradually reduced toward the lip opening 19a. On the lip opening 19a side of the manifold 16, a pre-land portion 17 having a constant vertical interval is provided continuously, and furthermore, the pre-land portion 17 is provided with an upper portion along the width direction. Depressed flow control grooves 18 are provided continuously. A lip land 19 having a constant vertical interval is continuously provided in the flow rate adjusting groove 18, and a lip opening 19 a is provided at a side edge of the lip land 19. Each of the manifold 16, the pre-land portion 17, the flow rate adjusting groove portion 18, and the lip land portion 19 has a widthwise dimension equal to the widthwise dimension of the lip opening 19a.

The resin flowing into the resin inflow passage 15 flows along the rear wall 16a of the manifold 16 and spreads in the manifold 16 in the width direction. The rear wall 16a is inclined so as to sequentially approach the preland portion 17 as the distance from the resin inflow path 15 increases. The resin that has flowed into the manifold 16 is filled into the manifold 16 and is discharged from the lip opening 19a through the pre-land portion 17, the flow rate adjusting groove portion 18, and the lip land portion 19.

Side plates 13 are fitted to the longitudinal (widthwise) sides of the manifold 16, the pre-land portion 17, the flow rate adjusting groove portion 18, the lip land portion 19, and the lip opening portion 19a, respectively. . Each side plate 13 has a manifold 16, a pre-land portion 17 such that the width of the flow region of the thermoplastic resin in the manifold 16, the pre-land portion 17, the flow rate adjusting groove portion 18, the lip land portion 19, and the lip opening portion 19 a is reduced. , A flow adjustment groove 18, a lip land 19,
The inside of each side of the lip opening 19a is filled in a close contact state. The inner side edges of each side plate 13 that face each other are the lip openings 1.
9a, so that the manifold 16 and the pre-land portion 1 are gradually inclined toward each other.
7, the width dimension of the resin flow area in the flow rate adjusting groove 18, the lip land 19, and the lip opening 19a is
The size becomes smaller sequentially along the resin flow direction. Therefore, the widthwise dimension W1 of the resin flow area in the lip opening 19a is smaller than the maximum widthwise dimension W2 of the resin flow area in the manifold 16.

In such a T-die, two types of molten thermoplastic resins laminated in two layers from the feed block and coextruded are passed through the resin inlet 15a,
It flows into the resin inflow channel 15 and flows into the manifold 16 through the resin inflow channel 15. The resin that has flowed into the manifold 16 spreads in the width direction in the manifold 16, is filled in the manifold 16, passes through the pre-land portion 17, the flow rate adjusting groove portion 18, the lip land portion 19, and passes through the lip opening portion 19 a Is discharged from.

At this time, the two kinds of thermoplastic resins flowing into the manifold 16 are mixed with the rear wall 16 of the manifold 16.
2A, the thermoplastic resin having a large MFR and a high fluidity flows along the periphery of the manifold 16 as shown by a two-dot chain line in FIG.
The thermoplastic resin with low FR and low fluidity is shown in FIG.
As shown by a broken line in FIG. 3, the fluid flows inside the fluid region of the thermoplastic resin having high fluidity. The thermoplastic resin having high fluidity is guided along the side edge of each side plate 13 provided on each side of the manifold 16, flows into the pre-land 17, and flows into the flow control groove 18, Through the lip land 19, the lip opening 1
9a. Therefore, the thermoplastic resin having a high fluidity is guided along the side edge of each side plate 13 to the inside of the resin flow area, and when discharged from the lip opening 19a, the fluid flowing inside the lip opening 19a. It is in a state of being laminated on a thermoplastic resin having low properties.

As a result, as shown in FIG. 3, each of the thermoplastic resins 31 and 32 is discharged from the lip opening 19a in a state where the thermoplastic resins 31 and 32 are vertically stacked with a constant thickness over the entire width. . Two types of thermoplastic resin 31 discharged vertically from the lip opening 19a
And 32 are cooled by cooling rolls through which cooling water flows. As a result, a sheet-like product or a film-like product in which the thermoplastic resin layers 31 and 32 having different fluidities are laminated with a constant thickness over the entire width direction is obtained.

In the above-described embodiment, the side edge of each side plate 13 on the side of the resin flow region is set so that the width dimension of the thermoplastic resin in the flow region is successively narrowed by each side plate 13. The configuration is such that the respective portions are inclined linearly. However, the present invention is not limited to such a configuration. The widthwise dimension W1 of the resin flow area in the lip opening 19a is larger than the maximum widthwise dimension W2 of the resin flow area in the manifold 16. Should also be small. Therefore, for example, as shown in FIG. 4, the inner side of each side plate 13 may be such that the width dimension of the resin flow area of the manifold 16 is gradually reduced from the rear wall 16 a to the preland portion 17 side. Each side plate is formed such that the edges thereof are linearly inclined, and the pre-land portion 17, the flow rate adjusting groove portion 18, the lip land portion 19 and the lip opening portion 19a have a constant widthwise dimension of the resin flow area. 13 is a lip opening 19a.
And may be a linear shape orthogonal to.

Further, as shown in FIG.
The inner side edge of the side plate 13 located in the inner surface 6 is depressed in an arc shape, and the pre-land portion 17, the flow rate adjusting groove portion 18, the lip land portion 19 and the lip opening portion 19 are formed.
In a, the inner side edge of each side plate 13 may be linearly inclined so that the widthwise dimension of the resin flow region gradually decreases toward the lip opening 19a.

[0022]

【Example】

<Embodiment 1> In the T-die shown in FIG. 1 and FIG.
Assuming that the maximum width dimension W2 of the resin flow area in the manifold 16 is 600 mm, the width dimension W1 of the resin flow area in the lip opening 19a is 500 mm, and the set temperature of the T-die is 200 ° C., the MFR is 3.7 g / 10 min. LDP
E (low density polyethylene, manufactured by Mitsui Petrochemical Co., Ltd., trade name "Mirason 16") and MFR is 20 g / 1
EVA (ethylene-vinyl acetate copolymer, manufactured by Tosoh Corporation, trade name “Ultracene 633”) for 0 min at 50 kg / hr and 30 kg / hr, respectively,
LDPE and EVA were laminated so as to have a constant width dimension to produce a sheet-like product. The obtained sheet-shaped product has a width direction dimension of 480 mm, and each side edge in the width direction has a single layer of EVA,
DPE and EVA were in a state of being laminated over the entire width direction.

<Embodiment 2> Except that each side plate 13 is replaced so that the maximum width dimension W2 of the resin flow area in the manifold 16 is 600 mm and the width dimension W1 of the resin flow area in the lip opening 19a is 590 mm. Produced a sheet-like product in the same manner as in Example 1. The obtained sheet-shaped product has a width dimension of 565 mm.
And each side edge in the width direction has an EV
A was not laminated and a single layer of LDPE was formed,
Each length in the width direction was 20 mm.

<Embodiment 3> By mounting each side plate 13, the maximum widthwise dimension W2 of the resin flow area in the manifold 16 is 600 mm and the widthwise dimension W1 of the resin flow area in the lip opening 19a is 5 mm.
A sheet-like product was manufactured in the same manner as in Example 1 except that the thickness was set to 85 mm. The obtained sheet-shaped product had a width dimension of 565 mm, and a single layer of LDPE was formed on each side edge in the width direction without EVA being laminated. The directional length was 5 mm.

<Embodiment 4> The side plate 1 shown in FIG.
3, the width dimension of the resin flow area in the manifold 16 was sequentially reduced so that the maximum width dimension W2 of the resin flow area was 600 mm and the minimum width dimension thereof was 550 mm. Then, the width dimension of the resin flow region from the pre-land portion 17 to the lip opening portion 19a was fixed at 550 mm. The other conditions were the same as in Example 1 to produce a sheet-like product. In the obtained sheet-shaped product, the dimension of the sheet in the width direction was 530 mm, and the LDPE and EVA were laminated over the entire width direction without the EVA being a single layer.

<Comparative Example 1> In Example 1, the manifold 16 was mounted without mounting the side plates 13.
The maximum widthwise dimension W2 of the resin flow area at 600 m
m, the width W1 of the resin flow area in the lip opening 19a was also set to 600 mm. Other conditions are as described in Example 1.
In the same manner as described above, when a sheet-shaped product was manufactured, the obtained sheet-shaped product had a width dimension of 570 mm, and an EVA was not laminated on each side edge in the width direction. The single layer portion was formed over 100 mm in the width direction.

[0027]

As described above, in the T-die of the present invention, since the width dimension of the resin flow area at the lip opening is smaller than the maximum width direction dimension of the resin flow area at the manifold, the fluidity of the T die is reduced. When two types of resins are extruded co-extruded into the manifold, even if the thermoplastic resin with high fluidity flows to the peripheral edge of the resin flow area, when discharged from the lip opening, the width direction At each side edge of
Since the thermoplastic resin having low fluidity is laminated on the resin having high fluidity, the two kinds of thermoplastic resins are laminated over substantially the entire width direction. Therefore, a sheet-like product or a film-like product in which thermoplastic resins are laminated can be manufactured with a high yield.

In the method for laminating thermoplastic resins according to the present invention, each thermoplastic resin, which has flowed in a state of being laminated in a T-die, is filled in the manifold by flowing in a direction perpendicular to the flowing direction. In order to discharge from the lip opening of the T-die in a state where the width dimension of the flow area of each thermoplastic resin is narrowed, each thermoplastic resin having different fluidity is spread over the entire width direction. Can be laminated. Therefore, a sheet-like product or a film-like product in which thermoplastic resins are laminated can be manufactured with a high yield.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an embodiment of a T-die according to the present invention in a state where the inside is seen through.

FIG. 2A is a schematic plan view of a main part showing an internal structure of the T-die, and FIG. 2B is a cross-sectional view thereof.

FIG. 3 is a cross-sectional view of a laminate of a thermoplastic resin discharged from the T-die.

FIG. 4 is a schematic plan view of a main part showing an internal structure in another example of the embodiment of the T-die of the present invention.

FIG. 5 is a schematic plan view of a main part showing an internal structure in still another example of the embodiment of the T-die of the present invention.

FIG. 6 is a schematic plan view of a main part showing an internal structure in an example of an embodiment of a conventional T-die.

FIG. 7 is a cross-sectional view of a laminate of a thermoplastic resin discharged from a conventional T-die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Lower mold | type 12 Upper mold | type 13 Side plate 15 Resin inflow path 15a Resin inflow port 16 Manifold 17 Pre-land part 19 Rip land part 19a Lip opening part 31 Resin layer 32 Resin layer

Claims (2)

[Claims] 1. After two kinds of thermoplastic resins having different fluidities flow into a manifold in a laminated state, and flow along a width direction perpendicular to the flowing direction, and are filled in the manifold, A T-die which is to be discharged from a lip opening extending along a width direction, wherein a width direction dimension of a resin flow area in the lip opening is smaller than a maximum width direction dimension of a resin flow area in a manifold. A T-die. 2. A method of laminating two kinds of thermoplastic resins having different fluidities over the entire width direction by a T-die, wherein each thermoplastic resin flowing in a laminated state into a manifold of the T-die is After filling the manifold by flowing along the width direction orthogonal to the inflow direction, the thermoplastic resin is discharged from the lip opening of the T-die in a state where the width direction dimension of the flow region of each thermoplastic resin is narrowed. Laminating method of thermoplastic resin.