JPH053301Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field of the invention] This invention relates to a device for adjusting the fold width of a film formed by an inflation molding machine [Prior art and its problems] Conventionally, as a device for adjusting the folding width of the bubble, a damper is installed in the inner air supply pipe system that communicates with the inside of the bubble, and by controlling the degree of opening and closing of this damper, the amount of air supplied to the inside of the bubble is increased or decreased.
By adjusting the cooling rate of the bubble and changing the bubble expansion rate, the diameter of the bubble discharged from the annular outlet of the molding die of the inflation molding machine is controlled, that is, the folding width of the bubble is adjusted. One example is Japanese Patent Publication No. 52-46985.

In such devices that control the bubble diameter by increasing or decreasing the amount of air supplied to the inside of the bubble, the amount of air is adjusted using a single damper, so the adjustment is rough and the bubble fold width cannot be adjusted over a wide range. However, it is difficult to make fine adjustments over the entire range, and there is room for improvement in this respect, and a device that can make such fine adjustments has been eagerly awaited.

[Means for solving problems]

In response to the above-mentioned request, the present invention has developed an inflatable film molding machine that has an external cooling ring that surrounds the bubbles discharged from the annular discharge port of the molding die of the inflation film molding machine and cools the outer peripheral surface of the bubbles in order to enable fine adjustment. In the flasion film forming machine, a part of the air system of the cooling air supply blower of the external cooling ring includes a main damper for opening and closing the main suction port, which has almost the entire cross-sectional area of its passage, and An auxiliary damper for opening and closing the auxiliary suction port having a particularly narrow cross-sectional area is provided, and a reversible fine-movement drive source for opening and closing the auxiliary damper is connected to the auxiliary damper. It is a device.

Next, a typical embodiment of the present invention will be explained based on the drawings.

In FIGS. 1 and 2, 10 is a molding die of an inflation film molding machine A, and a molten bubble B discharged from an annular discharge port 11 of this die 10 is surrounded by an external cooling ring 12. , the outer peripheral surface of this bubble B is the external cooling ring 1
It is cooled by cold air from 2.

The external cooling ring 12 and the secondary side of the cooling air supply blower 13 communicate with each other through a pipe 14. Main suction port 1 which is the primary side of this blower 13
A manual main damper 16 for opening and closing the main suction port 15 is disposed at the main damper 5 .

Further, near the main suction port 15, near the secondary side, an elongated auxiliary suction port 17 having a suction area of 1/5 to 1/10 of the cross-sectional area of the main suction port 15 is formed. An auxiliary damper 18 that opens and closes the auxiliary intake port 17 by sliding it in the longitudinal direction is connected to a piston rod 20 of an air cylinder device 19, which is a type of variable drive source for opening and closing operation, and mechanically opens and closes the auxiliary intake port 17. The suction area can be adjusted.

The invention is the same even if a servo motor or an impulse motor is used in place of the air cylinder device 19 described above.

The blower 13 is preferably a blower whose rotation speed is varied by an inverter motor.

[Effect of invention]

The operation of the device configured as described above will now be explained.

Prior to inflation film forming, the main damper 16 is operated manually to open the main suction port 1.
5 and adjust the opening degree of the auxiliary damper 1.
At step 8, half of the opening area of the auxiliary suction port 17 is set to be closed.

In this state, the blower 13 is started as usual, cooling air is supplied to the external cooling ring 12 through the pipe 14, and is discharged from the annular outlet 11 of the die 10, guided to the upper pinch roll 19, and molded. Cool air is blown onto the outer peripheral surface of the bubble B from the nozzle of the cooling ring 12, and the molten bubble B is cooled and solidified to form an inflation film F with a predetermined fold width.
to be molded.

When it is desired to widen the fold width of the film F to be formed, the drive source 19 is driven in the forward direction to slightly move the auxiliary damper 18 in the opening direction, and the blower 13
By increasing the amount of cooling air supplied from the external cooling ring 12 to the external cooling ring 12 and increasing the cold air from the external cooling ring 12, the bubble B is rapidly cooled, the bubble expansion rate is reduced, and the frost line of the bubble B is 10 to reduce the folding diameter of bubble B, that is, the folding width.

Conversely, by slightly moving the auxiliary damper 18 in the closing direction and narrowing the opening area of the auxiliary intake port 17, the amount of cooling air supplied is reduced, and the external cooling ring 1
Bubble B by reducing the cold air from 2
delay the cooling rate of bubble B, increase the expansion rate of bubble B, raise the frost line of bubble B,
increase the fold width.

Furthermore, by changing the rotational speed of the blower 13, the amount of cooling air taken in by the blower 13 per unit time is adjusted, and the folding width of the bubble B is adjusted and changed over a wider range.

[Effect of idea]

In the present invention constructed and operated as described above, the amount of cooling air flowing from the blower 13 to the external cooling ring 12 can be finely adjusted by finely adjusting the auxiliary damper 18, and the expansion rate of the bubble B can be adjusted based on the flow rate of this cooling air. It can be increased or decreased appropriately by increasing or decreasing, and there is no unevenness in thickness or variation in strength, and the folding diameter or folding width of the bubble B can be adjusted and changed over a wide range, and the folding width dimension can be finely adjusted.

In the embodiment in which the drive source 19 is an air cylinder device, the drive source 19 can be made inexpensive and can be a servo motor,
When an impulse motor is used, the amount of intake air of the blower 13 can be finely adjusted more accurately.

When the blower 13 is a variable-rotation-speed blower, the bubble folding width can be changed and adjusted over a wider range by opening and closing the auxiliary damper 18.

In the embodiment in which the auxiliary air intake port 17 has an elongated shape in the operating direction of the auxiliary damper 18, even if the operating dimension of the auxiliary damper is increased, the opening area changes less and fine adjustments can be made easily and accurately using the auxiliary damper.

[Brief explanation of the drawing]

The drawings show a typical embodiment of this invention. Fig. 1 is a schematic mechanical diagram of the folding width adjustment device for blown film, and Fig. 2 is a side view thereof. Explanation of main symbols in the drawings: 13...Blower, 16
...Main damper, 18...Auxiliary damper.

Claims (1)

[Claims for Utility Model Registration] 1) In an inflation film forming machine having an external cooling ring that surrounds a bubble discharged from an annular outlet of a forming die of the inflation film forming machine and cools the outer peripheral surface of the bubble. , A part of the air system of the cooling air supply blower of the external cooling ring includes a main damper for opening and closing the main suction port having substantially the entire cross-sectional area of the passage, and a main damper having an area much narrower than the cross-sectional area of this passage. An inflation film folding width adjusting device characterized in that an auxiliary damper for opening and closing an auxiliary suction port is provided, and a reversible fine movement drive source for opening and closing the auxiliary damper is connected to the auxiliary damper. 2) The blown film folding width adjusting device according to claim 1, wherein the drive source is an air cylinder device. 3) The blown film folding width adjusting device according to claim 1, wherein the drive source is one of a servo motor and an impulse motor. 4) The blown film folding width adjusting device according to claim 1, wherein the blower is a variable speed blower.