JPS63246222A - T-die - Google Patents

Abstract

PURPOSE:To enable the title T-die to perform control in thickness in a short period of time, with high accuracy and automatically, by a method wherein a corrective signal is sent out by calculating a difference between a thickness of a molded resin film and, established thickness and thickness control or local fine adjustment of a non-uniform thickness is performed by driving an adjusting bolt of a lip width. CONSTITUTION:A thickness of every part in a widthwise direction of a resin film 3 is detected by a thickness detecting device 4 provided with thickness detecting instruments 4a mounted on the resin film 3 at equal intervals in the widthwise direction of the same. The detected thickness is sent to a data, treatment device 5 as a detected signal. A difference between the detected signal of the thickness which has been sent to the data treatment device 5 and the established thickness data which has been applied beforehand is calculated, and a corrective signal is sent out based on calculated data, in the data treatment device 5. Then a width of a, lip 2 is controlled by driving a lip width control bolt 7 based on the corrective signal which has been sent to a lip width control device 6 through a data treatment device 5 and a width of the resin film is controlled so as to fall within a range of predetermined accuracy. As the resin which becomes wasteful at the time of control of the lip width is little and there is no necessity to discontinue molding of the resin film, operation efficiency can be improved, and laborsaving can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a T-die, and more particularly, to a T-die that enables automatic adjustment of the depth of a resin film in a short period of time and with high precision.

[Prior art and its problems] Methods for forming polyethylene and polypropylene films include the T-die method and the inflation method. Among these, the T-die method is a method in which a film of polyethylene, polypropylene, ethylene-vinyl acetate, etc. is extruded, and the resulting resin film is laminated while hot on metal foil, cellophane paper, kraft paper, etc. by pressing it with a roll. The material is rolled up and used for applications such as fertilizer bags, packaging bags, and moisture-proof bags.

Therefore, the resin film obtained by T-die is required to have a uniform thickness.

Conventionally, the adjustment of the thickness of the resin film in T-die J3 was as follows:
The width of the lip which is T die resin outflow [1] during use is T
After manually adjusting the thickness of the resin film using multiple bolts installed in the width direction of the die, the resin film is molded at a constant temperature and wound around a mortar.
- Measure the thickness of each part of the T-die, use this thickness to remove unevenness of the resin film, that is, uneven thickness, and adjust the resin temperature of each part within the T-die using multiple heaters installed in the width direction of the T-die. By doing so, this uneven thickness was corrected.

However, since it takes time to adjust the resin temperature, it has not been possible to adjust the uneven thickness by adjusting the resin temperature quickly and with high precision.

In addition, the winding speed of the resin film is 100 m/1n.
Because of this high speed, the resin film of uneven thickness wound up during that time was wasted, which was uneconomical.

Furthermore, in addition to adjusting the thickness at the start of resin film molding using a T-die, it is also necessary to correct the thickness of the resin film during operation. In other words, it is common for one heater to have 4 to 5 lip width adjustment bolts in the range controlled by 'fiArfi, so if there is uneven thickness of the film within the range of one heater, the lip width adjustment It is necessary to finely adjust (correct) the lip width using the width adjustment bolt.

Conventionally, this fine adjustment of the lip width had to be made after stopping the molding of the resin film. For this reason, the molding of the resin film had to be interrupted for more than 30 minutes.
In terms of time [1st time was big].

Further, since there are as many as 30 to 60 bolts in adjusting the lip width adjustment bolts, manual adjustment would be inefficient and complicated work. Moreover, since the T-die becomes hot during operation, adjusting the bolts is dangerous and the workability is extremely poor.

As mentioned above, adjusting the thickness of the resin film using the conventional T-die not only takes time, but also makes it impossible to control the thickness of the resin film as a product, and the resin has an uneven thickness that cannot be used as a product. When film came into existence, it was uneconomical.

[Object of the invention] The present invention has been made in view of the above problems, and
An object of the present invention is to provide a T-die that allows automatic adjustment of the thickness of a resin film in a short time and with high precision.

Means for Solving Problem L] That is, the present invention includes a device that detects the thickness of a resin film and issues a detection signal, a device that issues a correction signal based on the difference between the detection signal and set thickness data, The T-die is characterized by comprising a device for driving a lip width adjusting bolt based on the correction signal to adjust the lip width to a set thickness.

[Operation] In the present invention, the thickness of the molded resin film is quickly detected, and the CPU or the like that receives the detection signal immediately calculates the difference from the set thickness and issues a correction signal. Upon receiving this correction signal, the lip width adjustment device drives the lip width adjustment bolt to adjust the thickness of the resin film and finely adjust the partial thickness deviation.

Therefore, the thickness of the resin film can be adjusted automatically, without requiring manual labor, and without interrupting the molding of the resin film. Furthermore, the generation of resin films that cannot be used as a product can be suppressed to a minimum, thereby eliminating waste of resin.

[Example] Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a schematic diagram of the T-die of the present invention, and FIG. 2 is a front view thereof. In Figures 1 and 2, 1 is the T-die body;
2 is a lip portion of the T-die, 3 is a resin film, 4 is a thickness detection device, 5 is a data processing device, 6 is a lip width adjustment device,
7 is a lip width adjustment bolt.

The resin introduced into the T-die main body 1 is led out from the lip portion 2, and a resin film 3 is formed.

This resin film 3 has a thickness detection device 4 having thickness detectors 4a installed at equal intervals in the width direction of the resin film 3.
The thickness of each portion of the resin film 3 in the width direction is detected, and the detected thickness is sent to the data processing device 5 as a detection signal. As such a thickness detecting device 4, any optical, electrical, mechanical, or other device that can accurately detect the thickness of the resin film can be used, but in order to accurately and quickly detect the thickness of the resin film, Optical type is most preferable.

The data processing device @5 calculates the difference between the sent thickness detection signal and the set thickness data inputted in advance, and outputs a correction signal based on the calculated data.

The data processing device 5 is composed of a keyboard 51, a CRT display 52, a CPLJ 53, and a link unit 54, as shown in FIG. Here, the keyboard 51 is mainly used for inputting set thickness data. The CRT display 52 is used for displaying input data and monitoring the thickness adjustment control status. C.P.
The U 53 detects the difference between the thickness detection signal and the set thickness data, and generates a correction signal based on the calculated data. The link unit 54 connects the data processing device 5 and the lip width adjustment bolt drive device 6. The data processing device 5 used in the present invention has at least a function to memorize and hold data on the set thickness, a numbing function to output the difference between the thickness detection signal and the set warp, and an arithmetic processing result. It suffices if the device has a function to issue a correction signal based on.

Next, the lip width adjusting bolt 7 is adjusted based on the correction signal sent from the data processing device 51 to the lip width adjusting device 6.
is driven to adjust the width of the lip 2, and the width of the resin film is adjusted within a predetermined accuracy.

The lip width adjusting device 6 is operated by a motor 61 as shown in FIG.
, a drive shaft 62, a drive screw 63, a worm (gear) 64, a worm wheel (gear) 65, a lip width adjusting bolt drive shaft 66, a clutch 67, a clutch head 68, and a clutch plate 69.

The lip width adjustment device 6 is a data processing l! I! Each bolt is driven based on the signal sent from the device 5, that is, the position of the lip width adjustment bolt 7 to be driven and the signal for driving it. The motors 61 placed on both sides drive the drive shaft 62 that drives the drive screw 63 provided in the same direction to the right, and the clutch 61 connects the drive screw 63 and the worm 64.
is driven to transmit the driving force of the motor 61 to the lip width adjustment bolt drive shaft 66. In this way, the motor 61 is
By installing it away from the die, the motor can be protected from the high heat generated by the T-die.

The operation of connecting and disengaging the clutch is performed by a latch plate (cam) 69 as shown in FIG.
When driving the lip width adjustment bolt 9, for example, in FIG. 5, move the clutch plate 69a to the right by 1 point, and the clutch plate 69b to the right by 1 point, so that the grooves of each clutch plate are aligned, as shown in FIG. The clutch head 68 falls into the groove, and the drive screw 63 and the A-muro 4 are connected. Furthermore, when stopping the drive, the connection can be released by returning the clutch plate to its original position and removing the groove. As mentioned above, the drive shaft provided in the longitudinal direction of the T-die is used as the driving force, and the position of the driving bolt is selected by the clutch, so there is no need to install a motor for each bolt, simplifying the device. It is possible to realize automation at low cost. Therefore, the bolt drive device according to the present invention can drive several tens of bolts using several motors. For example, it is possible to drive 64 bolts with four motors. The number of motors corresponds to the number of bolts that can be driven simultaneously. The number of bolts varies depending on the size of the T-die, and the number of motors is selected accordingly.

In addition, the spacing between the lip width adjustment bolts 7 is normally as narrow as 45 mm, and the low-speed high torque gear (worm, four-wheel) is larger than 45%, so the torque gear should be placed on a straight line passing through the lip width adjustment bolts 7. They cannot be placed in a line. Therefore, they are placed alternately on the left and right with height differences in relation to a straight line. Here, the worm wheels having the same positional relationship are driven by the same driving axis. For example, 6th to 9th
As shown in the figure, the drive shaft 62a drives the lip width adjusting bolt drive shift 66a (FIGS. 6 and 7) having worm coils 65a installed every other bolt, while the drive shaft 62b drives the lip width adjustment bolt drive shaft 66b (FIGS. 8 and 9), which has spur gears 602 installed at every other shaft, via @601 having a worm wheel 65b and spur gears 600. good. Roughly speaking, in order to enable fine adjustment of the lip width, it is preferable to set the gear ratio to such a degree that the gear 17 rotates once in about one minute, and the shift lever l~ rotates 1/4 accordingly.

Such a lip width adjusting device 6 is not particularly limited as long as it has a mechanism that can drive the lip width adjusting bolt 7 at an arbitrary position by an arbitrary constant.

[Effects of the Invention] As explained above, by using the T-die of the present invention, the lip thickness can be automatically adjusted in a short time and at a high degree of 1 fi. In addition, less resin is wasted when adjusting the lip width, making it highly economical.Furthermore, since there is no need to interrupt resin film molding, work efficiency and labor savings can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a T-die according to the present invention, FIG. 2 is a front view of FIG. 1, FIG. 3 is a layout diagram of a data processing device according to the present invention, and FIG. FIG. 5 is a conceptual diagram showing the action of the clutch plate (cam) used in the present invention; FIG. 6 is a vertical cross-section showing an example of the lip width adjusting device according to the present invention. 7 is a cross-sectional view of FIG. 6, FIG. 8 is a partial longitudinal sectional view showing an example of the lip width adjusting device according to the present invention, and FIG. 9 is a cross-sectional view of FIG. 8. It is a diagram. 1: T-die main body, 2: T-die lip, 3: resin film, 4: thickness detection device, 5: data processing]! l device, 6: lip width adjustment device, 7: lip width adjustment bolt.

Claims (1)

[Claims] 1. A device that detects the thickness of the resin film and issues a detection signal, a device that issues a correction signal based on the difference between the detection signal and the set thickness data, and a device that adjusts the film lip width adjustment bolt based on the correction signal. A T-die characterized by comprising a device for driving the lip width and adjusting the lip width to a set thickness.