JPH07304096A - Device for correcting film strain in molding of blown film - Google Patents

Abstract

PURPOSE:To promote stabilization and cooling of bubbles with a low-cost material by forming a bubble stabilization board of at least one kind selected from among paperboard, corrugated board, nonwoven fabric, felt board, cork board and rubber board. CONSTITUTION:A bubble stabilization board 17 is formed of at least one kind selected from among paperboard, corrugated board, nonwoven fabric, felt board, cork board and rubber board and performs stabilization and cooling of bubbles 11. When the center hole of the bubble stabilization board 17 and the annular discharge port 13 of a die are offcenter, a supporting rod 22 is extended and contracted and also the bubble stabilization board 17 is turned around the axis 20 of rotation at a slight angle. The off-center state is corrected by regulating the horizontal position of the bubble stabilization board 17. When a frost line L is fluctuated, a screw rod 22 is rotated and a vertically moving body 23, a supporting rod 24 and a supporting frame 25 are vertically moved in accordance with fluctuation thereof. Height of the bubble stabilization board 17 is regulated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for correcting film distortion in inflation film molding.

[0002]

2. Description of the Related Art An apparatus of this type is disclosed in JP-A-61-2.
There is a device described in Japanese Patent No. 35129. In this publication, a porous cylinder extending from the upper surface of the housing of the air ring to a position above the frost line is arranged. Inside the upper end of the porous cylinder, there is a concentric space with the porous cylinder and a slight gap therebetween. In addition, an inflation film located above the frost line and a bubble stabilizing ring that comes into contact with the inner surface are detachably installed to suppress the vibration of bubbles above the frost line and to prevent uneven thickness, small wrinkles, etc. on the formed inflation film. I try not to occur.

[0003]

However, the bubble stabilizing ring described in the above-mentioned publication has a cylindrical shape that hangs from the height position of the upper end of the porous cylindrical body (claim 2
Item) or an inwardly-facing flange that projects from the height of the upper end of the porous cylindrical body to the inside of the upper end of a cylindrical inner cylinder (claim 4), and its structure is complicated, When changing the diameter of the formed inflation film, the bubble stabilizing ring has to be removed upward from the porous cylinder and the porous cylinder itself must be replaced, which is one of the reasons for increasing the cost. Therefore, an object of the present invention is to provide on the market a film distortion straightening device which simplifies the structure of the bubble stabilizing ring and allows an inflation film to be formed at low cost without distortion.

[0004]

In order to solve the above-mentioned problems, a film distortion correcting device in an inflation film molding which is a specific invention is equipped with an air ring having an annular air outlet around a die annular ejection port, In an inflation molding apparatus for expanding a bubble discharged from an outlet to a desired diameter, a thin bubble stabilizer having a center hole slightly larger than the outside diameter of the expanded bubble is frosted around a tubular film having a desired diameter. The bubble stabilizer is provided above the line and is characterized by being made of at least one of a paper plate, a cardboard plate, a non-woven fabric, a felt plate, a cork plate, and a rubber plate.

In order to solve the above problems, a related invention, a film distortion correcting device in inflation film molding, is provided with an air ring having an annular air outlet around a die annular ejection port, and a bubble ejected from the annular ejection port. In an inflation molding apparatus that expands and forms a desired diameter, a thin bubble stabilizer having a center hole slightly larger than the expanded bubble outer diameter has a desired diameter around a tubular film, which is located downstream of the frost line. The bubble stabilizer is provided so as to surround the bubble portion, and the bubble stabilizer is made of at least one of a paper plate, a cardboard plate, a non-woven fabric, a felt plate, a cork plate, and a rubber plate. It is possible to adjust the movement in the horizontal direction between the use position and the retracted position, which are located directly above the discharge port. There the film straightening device in inflation film molding to.

In order to solve the above-mentioned problems, a film distortion correcting device in an inflation film molding which is a related invention is equipped with an air ring having an annular air outlet around a die annular ejection port, and a bubble ejected from the annular ejection port is discharged. In an inflation molding apparatus for expansion molding to obtain a desired diameter, a bubble downstream of the frost line around a tubular film having a desired diameter of a thin bubble stabilizer having a center hole slightly larger than the expanded bubble outer diameter. It is provided by surrounding the part, this bubble stabilizer is a paper board,
Composed of at least one of a cardboard plate, a non-woven fabric, a felt plate, a cork plate, and a rubber plate, the bubble stabilizer is movable and adjustable in the axial direction of the bubble,
Further, the bubble stabilizer is movable in the horizontal direction between a use position and a retracted position which are located right above the discharge port, and is a film distortion correcting device in inflation molding.

In order to solve the above problems, it is more preferable in terms of molding that the bubble stabilizing plate of the bubble stabilizing device in the film distortion correcting device in inflation film molding which is a related invention is at least a two-divided type.

[0008]

In the operation of the invention described in claim 1, when the film is inflation-molded, the bubbles extruded from the annular discharge port are expanded at the annular blowout portion of the air ring by the venturi effect of the airflow blown from this. At the same time, the bubble is cooled by the air flow flowing along its surface, and the outer peripheral surface of the expanded film is supported by the inner peripheral surface of the central hole of the bubble stabilizer in a non-contact state over its entire circumference and further downstream. Be taken over. At this time, the height position of the bubble stabilizer is set above the frost line. On the other hand, the airflow flowing along the outer peripheral surface of the bubble passes through the gap between the center hole of the bubble stabilizer and the outer peripheral surface of the bubble,
Above the frost line, the outer peripheral surface of the bubble is forcedly cooled and flows upward. The air flow forcibly cooling the outer peripheral surface of the bubble diffuses from the outer peripheral edge of the bubble stabilizing plate to the periphery so as to move away from the bubble.

According to the second aspect of the invention, in addition to the operation of the first aspect of the invention, the bubble stabilizer is further moved horizontally from the use position to the retracted position during maintenance and repair of the discharge port and the air ring. To be done. During molding, when the cores of the discharge port and the bubble stabilizer are misaligned,
This disc is moved and adjusted in the horizontal direction to correct this misalignment.

According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, when the frost line fluctuates, the height of the bubble stabilizer is changed and adjusted according to the fluctuation.

According to the invention of claim 4, claim 1
In addition to the effect of the invention according to claim 3, the attachment / detachment of the bubble stabilizer to / from the bubble is performed from the outside according to the bubble diameter.

[0012]

EXAMPLE A typical example of the invention described in claims 1 to 3 will be shown. In FIG. 1, 10 is a die, 11 is a bubble pushed out from an annular discharge port 13 of this die, and an air ring 15 having an annular air outlet 14 surrounding these bubbles 11 immediately after being pushed out. A bubble stabilizer 17 having a central hole 16 slightly larger than the expanded bubble outer diameter is provided surrounding the bubble portion downstream of the frost line L. The bubble stabilizer 17 is a cardboard plate. Consists of.

The bubble stabilizing plate 17 is not limited to a cardboard plate, and may be at least one of a paper plate, a non-woven fabric, a felt plate, a cork plate, and a rubber plate. Belong to the range. The bubble stabilizing plate 17 is movable and adjustable with respect to the bubble 11 in the horizontal direction between the use position and the retracted position, which are located right above the discharge port 13 (see FIG. 2). The bubble stabilizer 1
The position of bubble 7 is adjustable in the axial direction of bubble 11 (see FIG. 1).

Further, the mounting structure of the bubble stabilizing plate 17 will be described in more detail. A pair of upper and lower brackets 19 are horizontally projected and fixed to one of the four vertical columns 18 at a position surrounding the bubble 11 formed by the inflation film forming machine.
A rotary shaft 20 parallel to the support column 18 is rotatably fixed by bolts 22 between the upper and lower ends of the rotary shaft 20, and arm rods 21 projecting in the radial direction are fixed to the pair. Between this arm rod 21 of this rotary shaft 20
An elevating feed screw rod 22 that is rotatable in parallel with and is immovable in the vertical direction is rotatably provided around its axis.
At one end of the feed screw rod 22, a handle 2 for rotating operation is provided.
7 is attached. A base of a telescopic support rod 24 is integrally fixed to a movable body 23 which is slidably and rotatably fitted to the rotary shaft 20 and screwed to a lifting feed screw rod 22. The bubble stabilizer 17 is attached to the tip of the support rod 24.
A support frame 25 having a rectangular shape in a plane is provided to support the bubble stabilizer 17. The bubble stabilizer 17 has a horizontal posture and is detachably screwed along the outer edge of the support frame 25 (see FIG. 2). It should be noted that the technical scope of the present invention can be achieved even if a clamp tool that can be opened and closed is used instead of the screw. By the rotation of the rotary shaft 20, the support rod 24, the support frame 25, and the bubble stabilizing plate 17 cause the axis line of the rotary shaft 20 in the horizontal plane between the use position and the retracted position located between the adjacent columns 18. The bubble stabilizer 17 is rotatable about its circumference, and the expansion and contraction of the support rod 24 allows the bubble stabilizing plate 17 to be adjusted in position in the horizontal direction with respect to the discharge port 13 (see FIG. 2). The rotation of the movable body 23 allows the bubble stabilizing plate 17 to move in the axial direction of the bubble 11 (see FIG. 1).

The operation of this embodiment will be described below. When the film is inflation-molded, the annular discharge port 13 is formed.
The bubble 11 pushed out further begins to expand due to the Venturi effect of the air flow blown from this at the annular outlet 14 portion of the air ring 15, and the bubble 11 is cooled by the air flow flowing along its surface and the expanded film is The outer peripheral surface is supported by the inner peripheral surface of the central hole 16 of the bubble stabilizing plate 17 over the entire circumference in a non-contact state, and is further drawn to the downstream side. At this time, the height position of the bubble stabilizing plate 17 is set above the frost line L. On the other hand, the airflow flowing along the outer peripheral surface of the bubble 11 is generated by the bubble stabilizer 17
Through the gap between the central hole 16 of the
Above the frost line L, the outer peripheral surface of the bubble 11 is further forcibly cooled and flows upward. This bubble 1
(1) The airflow forcibly cooling the outer peripheral surface diffuses from the outer peripheral edge of the bubble stabilizing plate 17 to the periphery so as to move away from the bubble 11.

Further, the center hole 16 of the bubble stabilizing plate 17
If the die annular discharge port 13 is misaligned, the support rod 24 is expanded and contracted, and the bubble stabilizing plate 17 is rotated at a slight angle around the rotary shaft 20 to move the bubble stabilizing plate 17 at a slight angle. By adjusting the horizontal position, this misalignment is corrected. When the discharge port 13 and the air ring 15 are maintained and repaired, the bubble stabilizing plate 17 is horizontally rotated from the use position to the retracted position by rotating the rotary shaft 20. When the frost line L fluctuates, the screw rod 22 is rotated and in accordance with this fluctuation,
The height of the bubble stabilizing plate 17 is adjusted by vertically moving the vertical moving body 23, the support rod 24, and the support frame 25.

Further, if necessary, the bubble stabilizer 17
May be divided into two (see FIG. 3), three or four (corresponding to the invention of claim 4). In this case, the split bubble stabilizing plate 17 is independently attached to the common support frame 25. When a bubble stabilizer 17 having a different inner diameter is used, or when the bubble stabilizer 17 is replaced with a new bubble stabilizer 17, the bubble stabilizer 17 attached to the support frame 25 is removed and attached again. At this time, since the weight of one bubble stabilizing plate 17 is about 1 kg at the maximum, the operator can manually perform the replacement work.

According to the apparatus invention of claim 1, the air flow flowing along the outer peripheral surface of the bubble is passed through the gap between the central hole of the film distortion correcting disk and the outer peripheral surface of the bubble, and further above the frost line. It is possible to flow upward while forcibly cooling the outer peripheral surface of. It is possible to forcibly cool the outer peripheral surface of the bubble and diffuse the airflow whose temperature has risen from the outer peripheral edge of the bubble stabilizer to the periphery so as to move away from the bubble. Since the bubble stabilizing plate is made of at least one of a paper plate, a cardboard plate, a non-woven fabric, a felt plate, a cork plate, and a rubber plate, it is possible to promote bubble stabilization and cooling with a low-cost material. In particular, such a thin bubble stabilizer is a paper board,
If the diameter of the inflation film to be molded is changed by using a material consisting of at least one of cardboard, nonwoven, felt, cork, and rubber, replace only the bubble stabilizer. Good, it can reduce the burden on the operator and can be easily replaced without using a lifting machine such as a crane.

In addition to the effect of the invention as set forth in claim 1, the invention as set forth in claim 2 is such that when the axial centers of the discharge port and the bubble stabilizer are decentered, the bubble stabilizer is decentered. Can be corrected by moving the bubble stabilizer in the horizontal direction,
Moreover, maintenance and repair of the discharge port and the air ring can be easily performed by retreating and moving the bubble stabilizer.

According to a third aspect of the present invention, in addition to the effects of the second aspect, when the frost line changes,
The height of this disc can be changed and adjusted according to the change.

In this embodiment, the support frame 25 supporting the bubble stabilizing plate 17 can change its distance to the bubble by the expandable support rod 24 and can rotate about the rotation axis 20. Therefore, the central axis of the bubble and the bubble stabilizer 17
The shaft center of the inner diameter of can be easily adjusted. Also, the bubble stabilizer 17 can be replaced by removing the bubble stabilizer 17 from the support frame 25, and since the weight thereof is light,
It can be done easily by hand. Further, even if the diameter of the center hole 16 of the bubble stabilizing plate 17 is arbitrary, the center hole 16 having an arbitrary diameter can be easily formed in the bubble stabilizing plate 17 by cutting the bubble stabilizing plate 17 with a knife or the like.

[Brief description of drawings]

FIG. 1 is a schematic front view of a first embodiment.

FIG. 2 is a schematic plan view of FIG.

FIG. 3 is a plan view showing another shape of a bubble stabilizing plate.

[Explanation of symbols]

 10 die 13 annular discharge port 14 annular outlet 15 air ring 17 bubble stabilizer

Claims (4)

[Claims] [Claim 1] An inflation molding apparatus, comprising: an air ring having an annular blowout port around a die annular ejection port; and expanding a bubble ejected from the annular ejection port to a desired diameter by expanding the bubble. A thin bubble stabilizer having a center hole slightly larger than the diameter is provided so as to surround a tubular film having a desired diameter above the frost line, and the bubble stabilizer is a paper plate, a cardboard plate, a non-woven fabric, or a felt. A film distortion correcting device in inflation film molding, comprising at least one of a plate, a cork plate, and a rubber plate. 2. An inflation molding apparatus, comprising an air ring having an annular blowout port around a die annular ejection port, and expanding and shaping a bubble ejected from the annular ejection port to a desired diameter. A thin bubble stabilizer having a center hole slightly larger than the diameter is provided around a tubular film having a desired diameter to surround a bubble portion downstream from the frost line. The bubble stabilizer is a paper plate or a cardboard plate. , A non-woven fabric, a felt plate, a cork plate, at least one of the rubber plate, the bubble stabilizer,
A film distortion correcting device in inflation film molding, which is capable of being horizontally moved and adjusted between a use position and a retracted position located right above the discharge port with respect to a bubble. 3. An inflation molding apparatus comprising an air ring having an annular blowout port around a die annular ejection port, and expanding and shaping a bubble discharged from the annular ejection port to a desired diameter. A thin bubble stabilizer having a center hole slightly larger than the diameter is provided around a tubular film having a desired diameter to surround a bubble portion downstream from the frost line. The bubble stabilizer is a paper plate or a cardboard plate. , A non-woven fabric, a felt plate, a cork plate, at least one of the rubber plate, the bubble stabilizer,
In inflation molding, the movement of the bubble stabilizer is adjustable in the axial direction of the bubble, and the bubble stabilizer is horizontally movable between a use position and a retracted position which are located right above the discharge port. Film distortion correction device. 4. A film distortion correcting device in inflation molding according to claim 1, 2 or 3, wherein said bubble stabilizer is of at least two-divided type.