JP7329832B2 - extrusion die - Google Patents

Description

The present invention relates to an extrusion die used in manufacturing resin films.

2. Description of the Related Art Conventionally, extrusion dies have been used when producing resin films such as polyethylene and polypropylene. This extrusion molding die spreads the supplied molten resin in its width direction through a manifold , and extrudes the molten resin in the form of a film from between the opposed flat portions of the lower portion. For example, the extruded molten resin is bonded to a film substrate unwound from a raw roll, and the bonded state is pressed and solidified by a cooling roll to form a laminate film. Laminated films obtained in this manner are mainly used for packaging and moisture-proof applications, and are required to have high sealing properties. Therefore, it is desirable that the resin film produced using the extrusion die has a uniform thickness.

In the extrusion molding die, it is necessary to adjust the separation distance between the opposing flat portions in order to make the film thickness of the resin film to be manufactured uniform. Here, the thickness of the resin film can be adjusted by changing the lip width of the lip portion that is provided at the tip of the lower part of the extrusion die and that discharges the molten resin.

For example, in Patent Document 1, a plurality of die bolts provided at approximately equal intervals in the width direction of the die slit gap are pushed and pulled to bend the neck portion of the movable lip, and a part of the lip at the die bolt contact point is formed in an arc shape or A T-die for plastic molding in which a groove with a shape similar to this is provided to form a thin portion, the lip is deformed while reducing the rigidity between the die bolt contact points, and the die slit gap is adjusted. It is disclosed to determine According to the T-die for extrusion molding of Patent Document 1, bolts other than the bolts to be operated are not affected, and the mutual interference effect is weakened, thereby making it possible to mold fine and precise plastic films.

However, in the technique disclosed in Patent Literature 1, when adjusting the die slit gap, it takes a lot of labor to push and pull many die bolts. In addition, a plurality of die bolts must be adjusted one by one in order to adjust the clearance of the lip portion, and much time is spent on the adjustment work to make the film thickness of the resin film uniform.

In order to address such a problem, Patent Document 2 discloses a motor, a drive shaft driven by the motor, a plurality of worms provided on the drive shaft, and a plurality of worms provided near each of the worms. a lip width adjusting bolt driving shaft, a worm wheel provided at one end of the lip width adjusting bolt driving shaft, and a clutch for connecting and disconnecting the worm and the worm wheel at an arbitrary position. A die lip width adjusting device is disclosed (see claim 1 of Patent Document 2). According to the T-die lip width adjusting device of Patent Document 2, by changing the lip width using the driving force of the motor, the adjustment work of the film thickness of the resin film can be automatically performed in a short time and with high accuracy. is supposed to be possible.

JP-A-61-291117 JP-A-63-246223

However, the technique disclosed in Patent Document 2 cannot sufficiently protect the motor from the high heat generated from the T-die body. Patent Document 2 describes that the motors are spaced apart on both sides of the T die in the longitudinal direction (see the third page, lower left column, lines 1 to 9 of Patent Document 2). In this case, it is insufficient to stably operate the motor for a long time, and the size of the die is increased.

Therefore, the present invention is capable of adjusting the clearance of the lip portion more easily and quickly, and stably, uniformly and highly accurately controls the film thickness of the resin film for a long time without increasing the size of the die. It is an object of the present invention to provide an extrusion die capable of

As a result of intensive studies, the inventors of the present invention have achieved the above problems by adopting the following extrusion molding die.

Extrusion molding die according to the present invention: The extrusion molding die according to the present invention comprises a pair of blocks having flat portions, the flat portions facing each other and spaced apart from each other. Equipped with a lip portion that discharges the molten resin that has passed through the gap in the form of a film, and a lip width adjusting means that adjusts the lip width that is the separation distance between the flat portions, and adjusts the lip width from the lip portion An extrusion molding die for controlling the thickness of a resin film obtained by extrusion, wherein the lip width adjusting means applies a pushing and pulling load to the lip portion using the principle of leverage, and the block is An arm member that expands or reduces the width of the lip by causing elastic deformation, a motor that generates a driving force to rotate the arm member around a fulcrum, and a motor that is disposed between the motor and the block. and a heat insulating structure.

In the extrusion die according to the present invention, it is preferable that the heat insulation structure includes a member having a heat insulation function.

In the extrusion molding die according to the present invention, it is preferable that the heat insulation structure has a refrigerant passage.

In the extrusion molding die according to the present invention, the lip width adjusting means is provided with a lip width adjusting bolt that is rotated by the driving force of the motor and converts the rotating force at this time into the rotating force of the arm member. is preferred.

The extrusion molding die according to the present invention can adjust the gap of the lip portion more easily and quickly, and the film thickness of the resin film can be stably, uniformly and with high accuracy for a long time without increasing the size of the die. can be controlled to

1 is a diagram showing a configuration of an extrusion molding die as a first embodiment to which the present invention is applied; FIG. FIG. 6 is a diagram showing the configuration of an extrusion molding die as a second embodiment to which the present invention is applied;

FIG. 1 is a diagram showing the configuration of an extrusion molding die as a first embodiment to which the present invention is applied. FIG. 2 is a diagram showing the configuration of an extrusion molding die as a second embodiment to which the present invention is applied. The extrusion die according to the present invention will be described below with reference to the drawings.

The extrusion molding dies 1 and 30 according to the present invention are configured by arranging a pair of blocks 2, 3, 31, and 32 (T-die bodies) having flat portions so that the flat portions face each other and are spaced apart from each other. Lip portions 4 and 33 for discharging molten resin (not shown) passing between the spaced flat portions in a film form, and lip width adjusting means 8 for adjusting the lip width W, which is the separation distance between the flat portions. , 37 to control the thickness of the resin film (not shown) discharged from the lip portions 4 and 33 by adjusting the lip width W. As shown in FIG.

As shown in FIGS. 1 and 2, the pair of blocks 2, 3, 31, and 32 have a shape that becomes thinner as they approach the lip portions 4 and 33 located at the bottom, so that the lip width adjusting means 8 and 37 Elastic deformation of the lip parts 4 and 33 is facilitated, and the lip width W can be finely adjusted. The thickness of the obtained resin film correlates with the amount of molten resin discharged from the lip portions 4 and 33 .

Here, by providing notch portions (hereinafter referred to as "thickness reduction slits 6 and 35") at least in the lower portions of the blocks 2 and 31 that are elastically deformed, the lip portions 4 and 33 by the lip width adjusting means 8 and 37 Elastic deformation can be made easier. As a result, the thickness of the molten resin discharged from the lip portions 4 and 33 can be stably made uniform. Incidentally, in the present invention, the shapes of the blocks 2, 3, 31, 32 are not limited to those shown in FIGS. Also, there are no particular restrictions on the type of molten resin to be used and the material of the lip portions 4 and 33 .

Next, the lip width adjusting means 8, 37 of the present invention will be explained. By including the arm members 9, 38, the motors 17, 46, and the heat insulating structure, the lip width adjusting means 8, 37 of the present invention can exhibit the effects of the present invention described above. The lip width adjusting means 8, 37 of the present invention will be described below for each component.

Arm member: The arm members 9 and 38 of the present invention use the principle of leverage to apply a pushing/pulling load to the lip portions 4 and 33, causing the blocks 2 and 31 to elastically deform and widening the lip width W. or attenuation. Since the arm members 9 and 38 of the present invention elastically deform the lip portions 4 and 33 using the principle of leverage, the gap between the lip portions 4 and 33 can be changed with a small force, and the lip width W can be adjusted. can be done accurately. Incidentally, in the present invention, the shapes of the arm members 9 and 38 are not limited to those shown in FIGS. Also, the material of the arm members 9 and 38 to be used is not particularly limited.

As shown in FIGS. 1 and 2, the arm members 9 and 38 of the present invention are fixed by fitting one end in the longitudinal direction into the mounting grooves 7 and 36 formed near the lips 4 and 33 of the blocks 2 and 31. preferably. In this state, when the arm members 9 and 38 are rotated in the direction in which a load is applied to the lip portions 4 and 33, one end of the arm members 9 and 38 is supported by the blocks 2 and 31, and the blocks 2 and 31 are reduced. It rotates around the part where the thick slits 6 and 35 are formed as a fulcrum. Therefore, the lip width W can be easily adjusted by the principle of leverage. Incidentally, the lip width W of the arm members 9 and 38 decreases when rotated in the X direction in FIGS. 1 and 2, and the lip width W increases when rotated in the Y direction in FIGS. do.

Here, if it is desired to further increase the amount of adjustment of the lip width W, the distance between the fulcrum of the arm members 9 and 38 and the point of force should be increased to increase the rotational force applied to the arm members 9 and 38. good. By doing so, the lip portions 4 and 33 can be more easily deformed, and the force applied to the lip portions 4 and 33 can be adjusted more accurately. preferable. Furthermore, in this case, the motors 17 and 46 can be separated from the blocks 2, 3, 31 and 32 to suppress the heat generated from the blocks 2, 3, 31 and 32 from being transferred to the motors 17 and 46.

Further, the lip width adjusting means 8, 37 according to the present invention are rotated by the driving force of the motors 17, 46, and the lip width adjusting bolt 18, which converts the rotating force at this time into the rotating force of the arm members 9, 38, 47 is preferably provided. By adopting a bolt type as means for rotating the arm members 9 and 38, the structure of the extrusion molding dies 1 and 30 can be simplified and maintenance can be facilitated. Furthermore, when a bolt type is adopted, the lip width W can be finely adjusted with high accuracy by reducing the pitch of the screw thread and making the spiral angle of the screw thread loose. The structure of the lip width adjusting bolts 18 and 47 of the present invention is not particularly limited, and conventionally known structures can be employed.

Incidentally, the lip width adjusting bolts 18, 47 preferably have at least part of their outer circumferences in contact with a load reducing member for reducing the load applied to the lip width adjusting bolts 18, 47 themselves. This is because, when the arm members 9 and 38 rotate, the fastening angle between the lip width adjusting bolts 18 and 47 and the mating fastening member changes, so that a load is applied to the lip width adjusting bolts 18 and 47 and the arm members 9 and 38 rotate. This is to prevent the inconvenience that the members 9 and 38 cannot rotate smoothly. Here, the nut members 22 and 51 having a columnar shape and capable of rotating in the rotating direction of the arm members 9 and 38 can be preferably used as the load reducing members. When the lip width adjusting bolts 18 and 47 are threadedly connected to the nut members 22 and 51, they are threaded through in a direction substantially orthogonal to the rotation outer peripheral surfaces of the nut members 22 and 51 so that the arm member 9 , 38 are absorbed, the load applied to the lip width adjusting bolts 18, 47 themselves can be reduced. When the nut members 22 and 51 are used as load reducing members, the extrusion molding dies 1 and 30 according to the present invention apply grease to the rotation outer peripheral surfaces of the nut members 22 and 51 in order to obtain the above effects for a long period of time. It is more preferable to have grease injection paths 23 and 52 for supplying.

When the lip width adjusting means 8, 37 according to the present invention are provided with the lip width adjusting bolts 18, 47, they are connected to the blocks 2, 31 via the connecting plates 12, 41 as shown in FIGS. By adopting such a configuration, it is possible to further suppress transmission of high heat generated from the blocks 2, 3, 31, 32 to the motors 17, 46. Therefore, this configuration is preferable for stably operating the extrusion die for a long period of time.

By the way, in the embodiment shown in FIG. 2, the lip width adjustment assisting bolt 53 is further provided as means for adjusting the lip width W, and both blocks 31 and 32 are provided with means for adjusting the lip width W. there is The extrusion molding dies 1 and 30 according to the present invention are provided with a lip width adjustment auxiliary bolt 53 in addition to the lip width adjustment bolts 18 and 47 so that the lip width W can be adjusted more finely and accurately. Become. Here, it is preferable that the lip width adjustment assisting bolt 53 has a structure in which the bolt is manually rotated for fine adjustment of the lip width.

Motor: The motors 17 and 46 of the present invention generate driving force for rotating the arm members 9 and 38 . The lip width adjusting means 8, 37 of the present invention rotate the arm members 9, 38 using the motors 17, 46 to adjust the lip width W in the direction of the force acting on the point of action of the arm members 9, 38. By performing, the adjustment of the lip width W can be performed in a short time and with high accuracy.

In addition, the lip width adjusting means 8 and 37 of the present invention can automatically adjust the lip width W by using the motors 17 and 46 to make the film thickness of the manufactured resin film uniform. Become. For example, a control means (not shown) for controlling the lip width W is provided, and the control means is based on the thickness value of the resin film after production measured by the film thickness detector. From the relationship between the film thickness and the lip width W, the lip width W can be motor-controlled so as to have a desired width. At this time, the control means can also individually operate the plurality of lip width adjusting bolts 18 and 47 . If the lip width W can be automatically adjusted using the motors 17 and 46, even if the thickness of the manufactured resin film deviates from a preset value, it can be quickly handled. The film thickness of the resin film can be made uniform over the longitudinal direction of the lip portions 4 and 33 with high accuracy.

As shown in FIGS. 1 and 2, the motors 17 and 46 of the present invention are surrounded by covers 19 and 48, and the cool air circulation pipes 20 and 49 having cool air outlets 21 and 50 are covered with the covers 19 and 48. It can also be configured to be arranged inside. By adopting such a configuration, it is possible to more effectively suppress the malfunction of the motors 17 and 46 due to overheating.

Heat Insulation Structure: The heat insulation structure of the present invention is arranged between the motors 17,46 and the blocks 2,31. The blocks 2, 3, 31, 32 of the extrusion dies 1, 30 are subject to high temperatures because they hold heaters and the manifolds 5, 34 are supplied with hot molten resin. However, the lip width adjusting means 8, 37 of the present invention can protect the motors 17, 46 from the high heat generated from the blocks 2, 3, 31, 32 by providing a heat insulating structure. It is possible to suppress the occurrence of malfunctions. Moreover, the lip width adjusting means 8, 37 according to the present invention can prevent the extrusion molding dies 1, 30 from increasing in size by providing a heat insulating structure.

Here, it is preferable that the heat insulation structure includes heat insulation members 15 , 16 , 44 , 45 . The heat-insulating members 15, 16, 44, and 45 used in the heat-insulating structure of the present invention preferably have excellent heat resistance. ) or a chemically bonded ceramic member (for example, NICHIAS Corporation's product name "Neoark") can be suitably used.

Moreover, it is also preferable that the heat insulation structure includes refrigerant passages 11 , 14 , 40 , and 43 . Since the heat insulating structure of the present invention includes the refrigerant passages 11, 14, 40, and 43, it is possible to more effectively suppress malfunction of the motors 17 and 46 due to high heat. Water, air, or the like can be used as the coolant that flows through the coolant passages 11 , 14 , 40 , and 43 . These refrigerants can be passed through the refrigerant passages 11 , 14 , 40 , 43 via the refrigerant supply ports 10 , 13 , 39 , 42 . In addition, by providing a cooling device (not shown) in the path to the coolant passages 11, 14, 40, 43, the coolant can always be maintained at a temperature that protects the motors 17, 46 from heat. The arrangement of the coolant passages 11 , 14 , 40 , 43 is not particularly limited as long as it is between the motors 17 , 46 and the blocks 2 , 31 .

The extrusion molding dies 1 and 30 according to the present invention have been described above, but in the present invention, the lip width W can be adjusted by providing the arm members 9 and 38, the motors 17 and 46, and the heat insulating structure. This can be performed more easily and quickly, and the film thickness of the resin film can be stably, uniformly and highly accurately controlled for a long period of time without increasing the size of the extrusion molding dies 1 and 30 .

Since the extrusion molding die according to the present invention can produce high-quality resin films, it can be suitably used for producing resin films for various uses such as packaging and moisture-proofing.

1, 30... Dies for extrusion molding 2, 3, 31, 32... Blocks (T die body)
4, 33... Lip portions 5, 34... Manifolds 6, 35... Thickness reduction slits 7, 36... Mounting grooves 8, 37... Lip width adjusting means 9, 38... Arm members Refrigerant supply ports 11, 14, 40, 43 Refrigerant passages 12, 41 Connection plates 15, 16, 44, 45 Thermal insulation members 17, 46 Motors 18, 47 Lip width adjusting bolts 19, 48 Covers 20, 49 Cold air circulation pipes 21, 50 Cold air outlets 22, 51 Nut members (load reducing members )
23, 52 Grease injection path 53 Lip width adjustment assisting bolt W Lip width

Claims (3)

A pair of blocks having flat surfaces are arranged such that the flat surfaces face each other and are spaced apart, and a lip portion that discharges the molten resin that has passed between the spaced flat surfaces in the form of a film; and a lip width adjusting means for adjusting the lip width, which is the distance between the parts, and the lip width is adjusted to control the thickness of the resin film obtained by extruding from the lip part. hand,
The lip width adjusting means includes an arm member that applies a pushing/pulling load to the lip portion using the principle of leverage to elastically deform the block to increase or decrease the lip width;
a motor that generates a driving force for rotating the arm member about the fulcrum;
a lip width adjusting bolt that is rotated by the driving force of the motor and converts the rotational force at this time into the rotational force of the arm member;
a heat insulating structure disposed between the motor and the block for protecting the motor from heat emitted from the block ;
An extrusion die , wherein the motor and the lip width adjusting bolt are connected to the block via a connecting plate . 2. The extrusion die according to claim 1, wherein said heat insulating structure comprises a member having a heat insulating function. 3. The extrusion die according to claim 1, wherein the heat insulating structure has coolant passages.

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