JPH03147837A - Method for automatically making bag out of continuous polyester film - Google Patents

Abstract

PURPOSE:To rapidly obtain bag, which is favorably heat-fused, out of polyester film having greatly a heat deterioration property by a method wherein folded polyester film is continuously fed so as to mechanically repeat intermitted short-period processes such as pinching, cutting, gap expanding and heating processes. CONSTITUTION:When the tip edge of the film 6 running on pinchingly supporting tables 4 and 4a or a position corresponding to the width of a bag, pinchingly supporting plates 3 and 3a are lowered and a cutting edge 5 is instantaneously traversed to the film 6, which is held by said supporting tables 4 and 4a and supporting plates 3 and 3a under tension, in order to cut the film 6. By slightly shifting the film 6 on downstream side under the state being pinched by the supporting table 4a and the supporting plate 3a downstream, the gap between pinching parts is enlarged. In succession, a heating body 2 is lowered in the enlarged gap. Towards both the end edges of the cut film 6, the heating body 2 is brought close to the positions, at which the fusion of the respective end edges starts and further flowingly brought close to parts to be joined at the speed same as the contraction speed of the parts to be joined by fusion and finally seceded from the parts rapidly when the fully fused parts are formed in the parts.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for automatically making bags from a polyester film that is continuously fed between rollers.

(Prior art) Polyester films have traditionally had a higher melting temperature than other thermoplastic synthetic resin films, and also have a strong thermal shrinkage force, and are thermally unstable near the melting temperature, so this thermal adhesion is extremely difficult. It was considered difficult.

However, this difficult thermal adhesion between polyester films has already been technically completed in Patent Application Publication No. 58-38297.

That is, as soon as shrinkage is induced at the stacked edge of the film, the heating element is brought close to follow it at a speed equivalent to the shrinkage speed, and as soon as a fused portion is formed, the heating element is quickly separated. This method involves cooling and completing the fusion.

However, this method of thermal bonding is based on principles and has not yet been applied to bag making, especially automatic bag making.

In addition, for films other than polyester film, a method was adopted in which a heating element at the required temperature is placed in close contact with the stacked films, and the double film is cut and fused at the same time. Bags are made using this method. It is.

However, if cutting and fusing are performed at the same time, the formed edge will not be straight, and especially considering the aforementioned shrinkage characteristics of polyester film, cutting and fusing will be difficult if the material is polyester film. If both are carried out at the same time, it becomes impossible to make bags and the bag becomes unusable.

Therefore, when completing bag making using polyester film, a unique bag making method is required.

(Problems to be Solved by the Invention) In the present invention, it is an object of the present invention to provide a method for automatically and continuously making bags for polyester films that are extremely likely to have inferior parts when heat-sealed. purpose.

Furthermore, the present invention is disclosed in the above-mentioned patent application publication number 58-382.
Applying and developing the principle of No. 97, mechanically, using a long polyester film from an unwinding roll,
The purpose is to "propose a method for automatically making bags."

Furthermore, it is an object of the present invention to provide an automatic bag-making process that produces straight edges from a continuous polyester film without inducing any shrinkage.

(Means for Solving the Problems) In order to achieve the above-mentioned purpose, in the method of automatically making bags from continuous polyester film according to the present invention, two polyester films that are vertically folded and overlapped are used. The blade is moved at a constant speed by the vertical drive rollers of the string, and is intermittently pinched between the two sets of drive rollers by two pinching parts with a certain distance between them, so that the blade crosses between the two pinching parts. Then, the downstream clamping section is moved downstream together with the film to create a gap between the cut surfaces, and a heating element approximately the width of the film maintained at about 400°C is applied in the direction perpendicular to the film with respect to the gap. The heating element is approached in stages according to the melting start speed and shrinkage speed, and after fusion, the heating body is quickly separated, both clamping parts are separated from the film surface, and the downstream clamping part is returned to its original position, and then the same process is repeated. The method is characterized by an automatic bag making method from continuous polyester film, in which the upstream clamping section is formed from a film support stand and a support plate that moves up and down, and the downstream clamping section is moved in the downstream direction. The method is characterized by a method for automatically making bags from a continuous polyester film, which is composed of a movable film support base that moves up and down and returns to its original position, and a movable support plate that moves up and down and moves downstream to return to its original position. It is characterized by a method of automatically making bags from a continuous polyester film whose heat dissipating portion has a square cross section.

(Example) i! according to the present invention! ! The device used in the method for automatically making bags from polyester film consists of two sets of drive rollers 1. la and
A nipping support plate 4.4a forming a nipping part of the film 6 between the two sets of drive rollers 1 and 12, a nipping support plate 3.3a on the upper surface thereof, a circular cutting blade 5, and a heating body 2. It is configured by interposing

The clamping support table 4.4a has the function of horizontally supporting the film 6.

The pinch support plate 3.3a is lowered onto the pinch support table 4.4a to enable the film 6 to be pinched.

The pinching support base 4a and the pinching support plate 3a have the function of moving the film 6 in the downstream direction in a sandwiched state and returning it in an open state.

The gap between the pinch pressure support plate 3 and the pinch pressure support base 4, and the gap between the pinch pressure support plate 3a and the pinch pressure support base 4a is set so that the cutting blade 5
The gap is relatively narrow enough to cross.

The heating element 2 is disposed at the top of the cross section of the cutting blade 5, and its tip is processed into a v-shape to form an outline having at least the width of the film 6.

Such a jJu heating body 2 is capable of imparting a temperature of about 400° C., and allows fine adjustment of the descending and rising speeds.

Although the speed and timing of each driving part require fine adjustment at the initial stage, once they are set, they can be automatically driven at a constant level.

Then, the desired polyester film is guided from the original roll to a two-folding device using a triangular plate, etc., and the continuously folded polyester film is further continuously introduced into a hot melt adhesive bag making device. Then, automatic bag making is carried out.

The folded polyester film 6 is guided at a constant speed by driving rollers 1 and 1a of 2 Mi above and below on the entrance side and the exit side.
It will be run.

The film 6 runs on the clamping supports 4.4a, and its leading edge (the leading edge is always formed by continuous operation) is a certain distance from the gap between the clamping supports 4.4a, that is, the width of the bag. When the position is reached, the clamping support plate 3.3aJfr is lowered and the cutting blade 5 is instantly moved across the film 6 which is held under tension by the support plate 4.4a and the support plate 3.3a. The film 6 is cut using the following steps.

After cutting, the upstream film 6 is maintained by the support stand 4 and the support plate 3.

On the other hand, the film 6 on the downstream side has a support base 4a and a support plate 3a.
By this, the gap between the pinched parts is widened by moving it slightly in the downstream direction under a pinched state.

Subsequently, the heating body 2 is lowered into this widened gap.

The heating element 2 is brought close to both edges of the cut film 6 to the point where each edge begins to melt, and is further brought closer to follow it at a speed equivalent to the shrinkage speed due to melting of the part to be adhered.
They separate quickly when a complete fusion is formed.

By this method, a complete fused portion is formed on each of both edge portions of the film 6, with no deteriorated portion due to shrinkage.

Since rapid cooling is preferable during fusion, it is preferable to select a material for the mechanical parts near the fusion part that has as low a thermal conductivity as possible.

After the edges of the polyester film 6 are fused in this manner, the support plate 3.3a is bounded above the support plate 3.3a, and the support base 4a and the support plate 3a are moved to a position adjacent to the original support base 4 and support plate 3. Restore until.

The fused edge of the film 6 on the upstream side is immediately moved onto the support stand 4a upon opening of the support plate 3, while the film 6 on the downstream side is carried to the next step by the drive roller 1a.

By repeating this method once, bags made of polyester film with both sides fused together can be continuously obtained.

Of course, it is also possible to reverse the vertical positional relationship between the heating body 2 and the cutting blade 5.

(Effects of the Invention) According to the method of the present invention, the folded polyester film is continuously fed, and the intermittent short-term intermittent steps of squeezing, cutting, gap expansion, and heating steps are mechanically repeated. By this method, a bag with good heat sealing can be quickly obtained from a polyester film that is highly heat degradable.

In particular, since the film is cut under tension when the polyester film is folded in half, there are no cutting errors, and after cutting, the process of widening the gap between the cut edges is extremely effective. It is possible to finely adjust the approach and separation operations of the heating element, and it is possible to perfectly fuse the polyester film, which is difficult to heat fuse, without causing any shrinkage or thermal deterioration. This is the result.

Furthermore, this fusion is extremely rational because both edge portions formed by cutting are fused at the same time.

4,

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention, and FIG. 1, FIG. 2, and FIG. 3 are schematic diagrams showing the sequential steps of the method of the present invention, and FIG. 4 is a side view of FIG. 1. The sketch, FIG. 5, is a side sketch of FIG. 3. 1, la-driving roller 2...heating body 3.3a...-pinching support plate 4.4a...pinching support base 5--cutting blade

Claims (1)

[Claims] 1. The vertically folded and stacked polyester film is moved at a constant speed by two sets of upper and lower drive rollers, and there are two pinching parts with a certain distance between the two sets of drive rollers. The film is intermittently clamped and cut by crossing the blade between both clamping parts, and then the downstream clamping part is moved downstream together with the film to provide a gap between the cut surfaces, and the film is cut in the gap. A heating element approximately the width of the film maintained at approximately 400°C is brought closer in stages in accordance with the melting start speed and shrinkage speed in a direction perpendicular to A method for automatically making bags from a continuous polyester film, in which the same process is repeated after separating from the film and restoring the downstream clamping section. 2. The upstream clamping part is formed of a film support base and a support plate that moves up and down, and the downstream clamping part is formed of a movable film support base that moves downstream and returns, and a movable film support base that moves up and down and moves downstream and returns. 2. A method for automatically making bags from a continuous polyester film according to claim 1, comprising a movable support plate. 3. Claim 1, wherein the heat radiation portion of the heating body has a V-shaped cross-sectional profile.
A method for automatically making bags from the described continuous polyester film.