JPH024505A - Machine for longitudinal orientation of film - Google Patents

Abstract

PURPOSE:To sharply improve the operability at the time of passing a film, by opening or closing a gap between orientation rolls automatically according to the presence or absence of an orientation force of the film. CONSTITUTION:When a film 2 is oriented, a rotating force (a rotating force in the direction of an arrow A around a pin 12) generated by an orientation force of the film 2 becomes larger than a rotating force (a rotating force in the direction of an arrow B opposite to the direction of the arrow A around the pin 12) generated under the own weight of an orientation roll 7 on the high speed side, and thereby a gap L is maintained. In the case when no orientation force of the film 2 exists between orientation rolls 6 and 7, a lever 11 rotates in the direction of the arrow B under the own weight of the orientation roll 7 on the high speed side until it strikes on a stopper 15, and thereby a gap Lo is maintained. Since the gap between the orientation rolls 6 and 7 is opened and closed automatically according to the presence or absence of the orientation force of the film 2, hindrance is little at the time of passing the film and thus the film can be passed rapidly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a longitudinal stretching machine that can be used for longitudinal stretching of plastic films, sheets, tapes, etc.

(Prior Art) Fig. 4 shows a conventional film longitudinal stretching machine, in which 5° is a low-speed side frame, 51 is a high-speed side frame, and the low-speed side frame 50 has take-up rolls 53 and 54 for a plastic film 52 for stretching. and preheating rolls 55 provided in a staggered manner.
A low-speed stretching roll 56 following this is provided. On the other hand, the high-speed side frame 51 is provided with a high-speed side stretching roll 57 at a distance from the low-speed side stretching roll 56, followed by a cooling roll 58 and a take-up roll 59,60. A film breakage detector 61 is provided between the cooling roll 58 and the film breakage detector 61 . Furthermore, wheels 62 are attached to the high-speed side frame 51.
The wheel 62 rolls on a rail 64 by the operation of an air cylinder 63 connected to the wheel 1, so that the wheel 62 can be moved away from the low speed side. Note that from the take-up roll 53 to the stretch roll 56 is driven by a low-speed side drive motor (not shown), and from the stretch roll 57 to the take-up roll 60 is driven by a high-speed side drive motor (not shown).
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Now, the plastic film 52 for stretching is taken up by a take-up roll 53.
．． 54, is heated by a preheating roll 55, reaches the stretching temperature on a stretching roll 56, is taken over by a high-speed side stretching roll 57, and is heated by a preheating roll 55.
It is stretched by the difference in peripheral speed of the rolls between the two. It is then cooled by a cooling roll 58 and taken off by take-up rolls 59,60.

If the film breaks during stretching, the film breakage detector 61 detects the breakage and immediately stops the low-speed drive motor in response to a command from the film breakage detector 61. At the same time, the air cylinder 63 is actuated by a solenoid valve or the like (not shown), and the high-speed side frame 51 is automatically moved on the rail 64 so as to be separated from the low-speed side. Note that, at the same time, the low-speed side take-up roll 54 may be automatically lowered to release the nip between the film and the take-up roll 53. Further, the moving portion on the high speed side may be only the high speed side stretching roll 57, or may be a portion including the high speed side stretching roll 57.

(Problem to be Solved by the Invention) It is widely known that in roll stretching of plastic films, it is advantageous to shorten the distance between the stretching rolls as much as possible in order to maintain uniformity of stretching, which is called short section stretching. .

However, in this case, in order to prevent the film from wrapping around the low-speed stretching roll when the film breaks and damaging the device,
In order to improve the ease of film threading before work, it is necessary to open and close the high-speed side stretching rolls as necessary.

Conventionally, as shown in FIG. 4, the presence or absence of a film between the stretch rolls was directly detected by a break detector 61 such as a phototube, and the high-speed stretch rolls were mechanically opened and closed using an air cylinder or the like. However, such a structure complicates the equipment, and the detection end etc. are provided in the film path, which becomes an obstacle and makes it difficult to speed up the film threading, which is required as the processing speed increases. 1
There was also a risk of malfunction due to the presence of shells and dirt on the detection end. Therefore, a more reliable and simple mechanism was required.

The present invention aims to provide a film longitudinal stretching machine that can solve the above-mentioned conventional problems by providing a simple, reliable, and easy-to-handle device.

(Means for Solving the Problems) Therefore, the present invention provides a film made of low/high speed stretching rolls, etc. for stretching a belt-like object such as a film or sheet heated to a stretching temperature using a difference in peripheral speed of the rolls.・A stretching machine for sheets, etc. is equipped with a lever that pivots on the high-speed side stretching roll, which oscillates due to the balance between the stretching force of the film/sheet and the self-weight of the movably mounted high-speed side stretching roll, and automatically adjusts the stretching force. The distance between the stretching rolls is narrowed during the intervention, and the distance between the stretching rolls is increased when no stretching force is present.This is a means for solving the problem.

(Function) The fed film or the like reaches the stretching temperature on the stretching rolls, is taken over by the high-speed stretching rolls, and is stretched between the stretching rolls. At this time, the lever is rotated in the direction of the arrow by the stretching force of the film, etc., and maintains the distance between the stretching rolls. If the film breaks during stretching, the stretching force of the film, etc. disappears, so the lever rotates in the direction of arrow B, the stretching roll interval increases to Lo, and the low-speed drive motor is stopped.

(Embodiments) The present invention will be described below with reference to embodiments of the drawings. FIGS. 1 to 3 show embodiments of the present invention.

First of all, in Fig. 1, 1 is a frame, and in the same frame there is a stretched plastic film (hereinafter referred to as the film) 2.
take-up rolls 3 and 4, preheating rolls 5 arranged in a 1,000-n shape, and a low-speed stretching roll 6 following these, and a high-speed stretching roll 6 separated from the low-speed stretching roll 6. A roll 7 is provided, followed by a cooling roll 8 and a take-off roll 9.10.

Reference numeral 11 denotes a lever that pivotally supports the high-speed stretching roll 7, and is attached to the frame 1 so as to be swingable about a pin 12 attached to the frame 1. The related dimensions at this time are that, while the film 2 is being stretched, the rotational force in the direction of arrow A about the pin 12 generated by the stretching force of the film 2 is applied to the pin 12 generated by the self-weight of the high-speed side stretching roll 7.
is larger than the rotational force in the direction of the arrow B which is opposite to the arrow B centered on the lever 11.
rotates in the six directions of arrows until it hits the stopper bolt 13 to maintain the distance. Note that the spacing can also be adjusted by adjusting the stopper bolt 3 as shown in the figure. Further, 14 is a lock nut, and 17 is a bracket attached to the frame 1.

Here, if there is no stretching force of the film 2 between the stretching rolls 6 and 7, the lever 11 rotates in the direction of arrow B until it hits the stopper 15 due to the weight of the high-speed side paper (middle roll 7), and the distance is increased. Note that the take-up roll 3 to the draw roll 6 are driven by a low-speed drive motor (not shown), and the take-up roll 7 to take-up roll 10 are driven by a low-speed drive motor (not shown).
Up to this point, the motor is driven by a high-speed side drive motor (not shown). In addition, 16 has a stretching roll interval of Lo
This is a limit switch that detects when the water has spread.

Next, to explain the operation, the film 2 is
It is heated by the preheating roll 5, reaches the stretching temperature on the stretching roll 6, is taken up by the high-speed stretching roll 7, and is stretched between the intermediate rolls 6 and 7 due to the difference in circumferential speed of the rolls. Ru. At this time, the lever 11 is rotated in the six directions of arrows by the stretching force of the film 2, and the distance between the stretching rolls is maintained. Next, it is cooled by a cooling roll 8 and taken up by take-up rolls 9 and 10.

If the film breaks during stretching, the stretching force of the film 2 disappears, so the lever 11 rotates in the direction of arrow B.
Stretch roll spacing beam. At the same time, the limit switch 16 is activated to immediately stop the low-speed drive motor in response to the command. At the same time, the low-speed side take-up roll 4
may be automatically lowered to open the nip of the film 2. In addition, as in the case of film threading, etc., the distance between the stretching rolls should be adjusted. If the low speed side is to be driven while being enlarged, a device for canceling the signal of the limit switch 16 is provided as necessary.

In addition, in order to more securely open and close the high-speed side drawing roll 7,
As shown in FIGS. 2 and 3, a spring 21.
31 can be installed to make the above-described operation more reliable and to increase the degree of freedom in the position of the pin 12. It goes without saying that the force may be applied by other devices in place of the springs 21 and 31. As described above, this stretching machine eliminates the film breakage detector near the film path and maintains the short stretching interval while the film 2 is being stretched, and maintains the long interval L0 when the film 2 is broken or while the film is being passed. It is possible to ensure safety and usability with a simple mechanism.

(Effects of the Invention) The present invention is configured as explained in detail above, and it is possible to
The gap between the stretching rolls is automatically opened or closed depending on the presence or absence of the film stretching force, which is based on the balance between the film stretching force and the weight of the high-speed stretching rolls, thereby reducing obstacles during film threading and improving work efficiency. This allows for rapid film threading. Furthermore, the mechanism is simplified, the reliability of the device is increased, and more reliable operation is possible. Furthermore, maintenance and inspection of the device becomes easier, and the cost of the device can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a longitudinal film stretching machine showing an embodiment of the present invention, Figs. 2 and 3 are side views of main parts showing an embodiment different from Fig. 1, and Fig. 4 is a conventional It is a side sectional view of a film longitudinal stretching machine. Explanation of main parts of the figure 2--Film/sheet 6--Low speed stretching roll 7--High-speed stretching roll 11--Lever 12--Bin 13--Stopper bolt 15--Stopper 16- -Limit switch L and on. -・Stretching roll spacing Figure 2

Claims (1)

[Claims] A belt-shaped object such as a film or sheet heated to the stretching temperature,
In a film/sheet stretching machine consisting of low/high speed stretching rolls, etc. for stretching using a difference in roll circumferential speed, the balance between the stretching force of the film/sheet and the weight of the movably mounted high speed side stretching roll A vertical film comprising a lever that pivotally supports an oscillating high-speed stretch roll, and automatically narrows the stretch roll interval when a stretching force is applied, and widens the stretch roll interval when no stretching force is applied. Stretching machine.