JPS6237679Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for punching holes in thermoplastic film.

As shown in FIG. 1, a thermoplastic film 1 made of polyethylene or the like with holes 11 of a predetermined diameter and pitch is commonly used as an aid for planting agricultural crops. Conventionally, the following methods have been known as means or methods for obtaining such perforated films, but each has its own advantages and disadvantages and is not necessarily practical.

Punching method using a die and punch Rotary cutting method using a flexible bed or die and a vertically moving rotary blade Heat melting method using a soft roll and a solid heated roll with protrusions Punching method using a guide roll and a roll with needles Among these, the film The process of cutting the film to a regular length and stacking them is inefficient, which is inefficient as a whole.Also, since the holes are made by shearing, the film material may be soft, or it may not have the same elongation and elasticity as linear polyethylene. In the case of high-strength materials, the sharp wear of the cutting edge makes it difficult to reliably drill holes, resulting in large variations in hole diameter, and debris remaining locally connected to the edge of the hole. remain. Therefore, there are disadvantages in that the yield of non-defective products is low and it is very troublesome to remove punched and cut-out scraps. Furthermore, because it uses a rotating blade, it is not possible to drill holes with a small diameter, whereas it cannot be applied to holes with a large diameter, and it also has the drawback of low commercial value because scratches occur on the film surface.

On the other hand, although the method allows continuous drilling,
This method involves inserting protrusions into a soft roll and melting local parts of the film through heat conduction from the protrusions, so it takes a long time to drill holes, which is inefficient, and it is difficult to apply to large diameter holes. be. In addition, with this method, hot melted resin builds up in a ring shape on the edge of the hole and solidifies, or conversely sticks in a ring shape to the outer periphery of the protrusion, reducing product value and requiring troublesome scrap removal work. There is a problem that requires it.

This invention was devised after repeated research in order to solve the above-mentioned problems in the process of punching holes in thermoplastic films. To provide a drilling device that can reliably drill holes and automatically and cleanly remove drilling debris.

In order to achieve this purpose, the present invention has a roll body having a through hole in the center opposite to the rubber roll that guides the thermoplastic film, and a roll body having a solid body and a tip end formed on the roll body so that the rear end communicates with the through hole. A perforated roll is provided with a large number of nozzle-shaped blades having annular blades and a heater that heats the nozzle-shaped blades and the roll body, and a heating screw is loosely inserted into the through-hole to form a thermoplastic film. The tip of each nozzle-shaped blade is intermittently brought into contact with the rubber roll while being transported by a rubber roll, and at this time, the nozzle-shaped blade provides a closed-contour cut and heating to the film to efficiently form holes, and The scum from the drilling is forced into the nozzle-shaped blade and melted, and the molten scum is automatically discharged by a heated screw that rotates relative to the roll body.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Figures 2 to 4 show the thermoplastic film perforation device according to the present invention, in which 1 is a thermoplastic film such as high pressure, medium pressure, medium and low pressure polyethylene or linear polyethylene, and 2 is a guide for the thermoplastic film. The rubber roll is preferably made of hard rubber or the like. 3 is a perforated roll which is a feature of the present invention, and includes a roll main body 4 having a through hole 41 in the center, and a perforated roll arranged at a predetermined pitch around the periphery of the roll main body 4, and embedded and fixed with the rear half. It is equipped with a large number of nozzle-shaped blades 5 and a heater 6 that heats the nozzle-shaped blades 5 and the roll body 4 to a temperature higher than the melting point of the thermoplastic film.

In this embodiment, the roll main body 4 is made of a metal pipe with a predetermined wall thickness, and has bearings 10 and 1 at both ends.
It is rotatably supported by 0. Nozzle-shaped blade body 5
are in the shape of a thin tube, and protrude in the radial direction through the thickness of the roll body 4, and a tapered and thinned annular blade part 51 is formed at the tip end, and the annular blade part 5
A guide hole 52 communicating with the through hole 41 of the roll body 4 is formed inside the roll body 1 . The outer diameter virtually formed by the tip of each nozzle-shaped blade 5 is designed to approximately match the outer diameter of the rubber roll 2.

The nozzle-shaped blade 5 may be embedded in the roll body 4 by any method such as welding, caulking, screwing, press-fitting, etc. In this embodiment, the heater 6 is also provided so as to cover the entire circumference of the roll body 4. However, instead of this, a linear tape heater along the longitudinal direction of the roll body 4 may be used.

Reference numeral 7 denotes a rod-shaped heating screw loosely inserted so as to form a gap 8 between it and the inner wall of the through hole of the roll body 4, and is constructed by, for example, inserting a rod-shaped heater into the center of the screw body.

In other figures, 9 is a receiving container.

Next, to explain the operating condition and operation of the device of the present invention, when making holes, the rubber roll 2 and the hole-making roll 3 are periodically rotated in opposite directions at a predetermined speed, and the heater 6 and the heating screw 7 are operated. The thermoplastic film 1 is in contact with the rubber roll 2 and is sequentially wound up at the same circumferential speed as the rubber roll 2.
, the nozzle-shaped blade 5 protruding from the perforating roll 3 which rotates synchronously with the perforating roll 3 approaches.
The annular blade portion 51 at the tip contacts the surface of the rubber roll 2 with the thermoplastic film 1 interposed therebetween. As a result, a ring-shaped incision is made in the thermoplastic film 1 by the sharp annular blade part 51, and since the annular blade part 51 is heated by the heater 6 to a temperature higher than the melting point of the film, this incision is made at the same time as the aforementioned incision. The cut contour portion is heated by heat radiation from the tip of the annular blade portion 51, and thereby a hole having a size corresponding to the outer contour of the annular blade portion 51 is formed in the thermoplastic film 1.

In the case of simple punching, the edge of the hole becomes a fractured surface, and the punched debris tends to connect, and in the case of simple hot melting, excess resin rises on the surface of the hole, but in the case of the present invention, the cut is made by pressure welding. Holes are formed by both heating and heating, and the cracks formed by the cuts are melted by heat, making it possible to form holes with very neat contours even when the thermoplastic film is made of a material similar to rubber, such as linear polyethylene. . Moreover, since the hole is drilled by the synergistic effect of the ring-shaped cut made by the annular blade part 51 and heat, the hole-cutting speed is fast.
Large diameter holes can also be formed with high efficiency.

When a hole is made by the nozzle-shaped blade 5 and the rubber roll 2 as described above, a scrap 1a corresponding to the inner contour of the annular blade portion 51 is generated.
The outer edge of the annular blade 51 comes into contact with the heated inner wall of the annular blade 51 and is immediately welded to the inner wall of the annular blade 51, so even if drilling is performed at high speed, the outer edge will not be scattered outward due to centrifugal force. Moreover, the nozzle-shaped blade 5 has a high temperature on the side where it is embedded in the roll body 4, and the temperature in the through hole 41 of the roll body 4 is even higher due to radiant heat and the loosely inserted heating screw 7, as shown in FIG. As shown, the debris 1a captured by the nozzle-shaped blade 5 is successively embedded in the guide hole of the nozzle-shaped blade 5 by the debris generated in the next hole drilling, and the pushed debris 1a is trapped by the previous temperature conditions. It is gradually heated, and while passing through the guide hole 52, it melts from a semi-molten state A to a liquid B and becomes fluid. As the hole-drilling operation continues, the solid waste 1a is pushed one after another from the tip of the nozzle-shaped blade 5, so that the melted waste flows into the through hole of the roll body 4 due to a kind of piston phenomenon, and the through hole 41 and are sequentially accommodated in the receiving container 9 from the longitudinal end of the roll body 4.

At this time, the heating screw 7 is loosely inserted into the through hole 41, and although the perforating roll 3 rotates, the heating screw 7 is stationary, so an extrusion action occurs due to the screw movement, and the melt flowing down from the guide hole 52 The scum is sequentially conveyed in a molten state in the axial direction of the perforated roll 3 through the gap 8, and efficiently discharged into the receiving container 9. Therefore, scrap removal is performed automatically and smoothly, and workability is also very good.

The present invention as described above is comprised of a rubber roll 2 for guiding a thermoplastic film and a perforated roll 3 paired with the rubber roll 2, and the perforated roll 3 has a roll body 4 having a through hole 41 in the center, A large number of nozzle-shaped blades 5 are fixed to the roll body 4 so that their ends communicate with the through holes 41 and have an annular blade portion 51 at their tips, and a heater 6 for heating the nozzle-shaped blades 5 and the roll body 4. Since the heating screw 7 is loosely inserted into the through hole 41, the synergistic effect of cutting and heating by the nozzle-shaped blade 5 makes it possible to form holes from small diameters to large diameters very efficiently and with certainty. This makes it possible to greatly improve the yield of good products, and also allows for effective drilling of thin and strong materials such as linear polyethylene, which have had processing problems. becomes possible. Furthermore, the hollow blade and hollow roll body function as a melting and discharging mechanism for the scum generated during drilling, and the heating screw 7 loosely inserted into the through hole sequentially extrudes the scum while it is melted, leaving no residue at all. Since it is smoothly and automatically removed, it is extremely easy to work with, and provides excellent labor savings.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing an embodiment of the thermoplastic film perforation device according to the present invention, Fig. 2 is a longitudinal sectional front view thereof, and Fig. 3 is a portion showing the scrap removal mechanism in the present invention. FIG. 4 is an enlarged vertical sectional side view showing the device of the present invention in use. 1...Thermoplastic film, 2...Rubber roll,
3...Perforated roll, 4...Roll body, 5...
Nozzle-shaped blade body, 6... heater, 7... heating screw, 41... through hole, 51... annular blade portion.

Claims (1)

[Scope of utility model registration request] Consisting of a rubber roll 2 that guides the thermoplastic film and a perforated roll 3 paired with the rubber roll 2,
The perforated roll 3 includes a roll body 4 having a through hole 41 at the center, and an annular blade portion 5 at the tip, which is fixed to the roll body 4 so that the rear end communicates with the through hole 41.
1, a heater 6 for heating the nozzle-shaped blades 5 and the roll body 4, and a heating screw 7 loosely inserted into the through hole 41. Plastic film perforation device.