JPH0624780B2 - How to automatically make bags from continuous polyester film - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically making a bag from a polyester film continuously fed between rollers.

(Prior Art) Conventionally, polyester films have a high melting temperature in films of various thermoplastic synthetic resins, and also have a strong heat shrinkage force, and are thermally unstable near the melting temperature. It was said to be difficult.

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

That is, when contraction is induced at the stacking edge of the film, the heating body immediately follows and approaches at a speed equivalent to the contraction speed, and when a fused portion is formed, the heating body is immediately separated from each other. This is a method of cooling and completing fusion bonding.

However, the heat-bonding method by this method is a principle and is not applied to bag making, especially automatic bag making.

For films other than polyester film,
A method has been adopted in which a heating body having a required temperature is brought into close contact with the stacked films to fuse the double films together with the cutting, and bags are manufactured by this method.

However, when the cutting and the fusion are performed at the same time, the formed edge does not become a straight line. Especially, in consideration of the shrinkage property of the polyester film described above, when the material is the polyester film, the cutting and the fusion are performed. If both and are performed at the same time, bag making becomes impossible and unusable.

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

(Problems to be Solved by the Invention) In the present invention, there is provided a method for automatically and continuously forming a bag for a polyester film in which an extremely inferior portion is likely to occur during heat fusion. To aim.

Furthermore, the present invention also discloses the above-mentioned patent application publication No. 58-382.
The principle of No. 97 is applied and developed, using a long polyester film from an unwinding roll, mechanically,
And it aims at providing the method of making a bag automatically.

A further object of the present invention is to provide an automatic bag-making method for straight edges of continuous polyester film without inducing any shrinkage.

(Means for Solving the Problems) In order to achieve the above-mentioned object, in the method for automatically making a bag from a continuous polyester film according to the present invention, a polyester film which is vertically folded and overlapped is used. A pair of upper and lower driving rollers are used to move at a constant speed, and the two driving rollers of the pair are intermittently clamped by two clamping portions that are spaced apart from each other so that the blade traverses between the clamping rollers. And then move the downstream pinching part in the downstream direction together with the film to provide a space between the cut surfaces, and a heating member having a film width of approximately 400 ° C. is maintained in the direction orthogonal to the film with respect to the gap. The film is moved to the point just before the start of melting the film at an optimum speed, then the heating element is moved closer to the film in accordance with the shrinking speed due to the melting of the film, the heating element is quickly separated after fusing, and both the pinching parts are pressed. surface It is characterized by a method of automatically making a bag from a continuous polyester film, which is made to repeat the same process after separating from the downstream clamping unit, and then the upstream clamping unit and the film support base A continuous polyester film composed of a movable support plate formed of a moving support plate and moving and returning the downstream pinching portion in the downstream direction, and a movable support plate moving up and down and moving in the downstream direction to return. The method is characterized by an automatic bag-making method, and a method of automatically making a bag from a continuous polyester film having a V-shaped cross-section for the heat radiating portion of the heating element.

(Embodiment) The apparatus used in the method for automatically producing a bag from a continuous polyester film according to the present invention comprises two sets of drive rollers 1 and 1a for running a folded polyester film 6, and
Clamping support bases 4 and 4a that form a clamping portion of the film 6 between the driving rollers 1 and 1a of the set, clamping support plates 3 and 3a on the upper surface thereof, a circular cutting blade 5, and a heating element 2. It is made to intervene.

The pinching support bases 4 and 4a have a function of horizontally supporting the film 6.

The pinching support plates 3 and 3a are lowered onto the pinching support bases 4 and 4a to enable pinching of the film 6.

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

The gap between the pinching support plate 3 and the pinching support base 4 and the pinching support plate 3a and the pinching support base 4a has a cutting blade 5 at an initial stage.
The gap is relatively narrow enough to cross over.

The heating element 2 is arranged at the top of the cross section of the cutting blade 5, and the tip portion is processed into a V shape to have a contour having at least the width of the film 6.

The heating element 2 is capable of applying a temperature of about 400 ° C., and the descending and ascending speeds can be finely adjusted.

The speed and timing of each drive portion require fine adjustment in the initial stage, but after setting, constant drive can be automatically performed.

Then, the desired polyester film is guided from the original roll to a two-folding device using a triangular plate or the like, and the continuously laminated polyester films are further continuously introduced into a hot-melt adhesive bag-making device. Automatic bag making.

The folded polyester film 6 is guided and run at a constant speed by two sets of upper and lower drive rollers 1 and 1a on the inlet side and the outlet side.

The film 6 runs on the pinching support bases 4 and 4a, and its leading edge (the leading edge is always formed by continuous operation) has a fixed distance from the gap between the pinching support bases 4 and 4a, that is, the bag width. When the position is reached, the clamping support plates 3 and 3a are lowered, and the supporting blades 4 and 4a and the film 6 held in a tension state by the support plates 3 and 3a cross the cutting blade 5 instantaneously. Then, the film 6 is cut.

After cutting, the upstream film 6 is maintained by the support base 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.
With this, it is moved slightly downstream in the pinched state to widen the gap between the pinched portions.

Then, the heating body 2 is lowered into the expanded gap.

The heating element 2 is made to approach the respective edges of the cut film 6 to the respective edges to a position where melting starts, and further follow them at a speed equivalent to the contraction speed due to melting of the adhered portion,
When the complete fused portion is formed, it separates quickly.

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

Since rapid cooling is preferable at the time of fusion, it is preferable to select a material for the mechanical portion in the vicinity of the fusion portion as low as possible in thermal conductivity.

After the edges of the polyester film 6 have been fused in this way, the support plates 3 and 3a are raised, and the support base 4a and the support plate 3a are moved to a position near the original support base 4 and the support plate 3. Restore.

The fusing edge on the upstream side of the film 6 immediately moves onto the support base 4a by opening the supporting 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, a bag made of polyester film having both edges fused is continuously obtained.

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

(Effects of the Invention) According to the method of the present invention, a method in which a folded polyester film is continuously supplied and mechanically repeats an intermittent interrupting process of a short time period such as clamping, cutting, gap expansion, and heating processes. As a result, a bag having good heat fusion can be quickly obtained from a polyester film having a strong heat deterioration property.

In particular, since the film is cut in a tension state where the folded polyester film is sandwiched and pressed, there are no cutting mistakes, and after cutting, a process of expanding the gap between the cut edges is extremely provided. A finely adjusted heating element approaching and separating operations can be given, and even polyester film, which has a high degree of difficulty in heat fusion, can be perfectly fused without causing shrinkage and without thermal deterioration. It will be.

Further, in this fusion, both edge portions formed by cutting are fused at the same time, which is extremely rational.

[Brief description of drawings]

The drawings show an example of implementation of the present invention.
FIG. 2, FIG. 2 and FIG. 3 are schematic views showing sequential steps of the method of the present invention, FIG. 4 is a side view sketch in FIG. 1, and FIG. 5 is a side view view in FIG. 1, 1a ... Driving roller 2 ... Heating body 3, 3a ... Clamping support plate 4, 4a ... Clamping support 5 ... Cutting blade 6 ... Folded polyester film

Claims (3)

[Claims] 1. A vertically folded and laminated polyester film is moved at a constant speed by two sets of upper and lower drive rollers, and is intermittently provided by two pinching portions having a certain distance between both sets of drive rollers. It is cut by sandwiching it between the clamping parts by crossing the blade between them, and then moving the downstream clamping part in the downstream direction together with the film to give a gap between the cutting planes, and a direction orthogonal to the film with respect to the gap. In addition, the heating element of almost the width of the film maintained at about 400 ° C is moved to the point just before the start of melting the film at an optimum speed, and then the heating element is brought close to the film in accordance with the shrinking speed due to the melting of the film to melt the film. A method for automatically producing a bag from a continuous polyester film, in which the heating body is rapidly separated after the attachment, the both pressure portions are separated from the film surface to restore the downstream pressure portion, and the same process is repeated. 2. A movable film support base for forming an upstream clamping unit from a film support base and a support plate which moves up and down, and a downstream film compression unit for moving and returning in the downstream direction, and a vertical movement and a movement in the downstream direction. A method for automatically producing a bag from the continuous polyester film according to claim 1, which is constituted by a movable support plate that returns after being restored. 3. A heat radiating portion of the heating element has a V-shaped cross section,
A method for automatically producing a bag from the continuous polyester film according to claim 1.