JPS6119421B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a synthetic resin made of multiple films,
In particular, it relates to a method of manufacturing large synthetic resin bags.

More specifically, the present invention relates to a method of manufacturing a multi-film synthetic resin bag having a clean seal without wrinkles by intermittently feeding a wide film at a constant speed.

Conventionally, when making bags, it has been common practice to feed the film sequentially using a roller drive, or to feed the film by sandwiching both ends of the film.

However, in these methods, the film expands and contracts rapidly, and in the former method, the film is fed by being sandwiched between two rollers, so the wrinkles in the film are pressed and remain in the bag.
In the latter method, the edges of the film may stretch because they are held in place with a claw, etc., and an extra portion is required at the end of the film for the area to be held in place. It wasn't pretty.

Furthermore, since multiple films are fed, misalignment occurs between the films during sealing, making it difficult to form bags neatly without wrinkles.

The present invention eliminates these conventional drawbacks and provides a method for manufacturing synthetic resin bags made of wrinkle-free multi-layered films by temporarily attaching the top and bottom seals of the film to a silicone belt that moves intermittently. It is to provide.

In the present invention, an upper film and a lower film each consisting of two or more multi-layered films such as a single layer or a laminated film are sent out from a winding roll,
The upper film and the lower film are overlapped and transferred onto the feed belt. First, top sealing and bottom sealing are performed in the same direction as the feed direction. At the same time, the lower film is temporarily attached to the feed belt, and then the next process is carried out in that state. This is a method of manufacturing a synthetic resin bag that is moved and side-sealed.

Here, the feed belt moves intermittently and performs top sealing, bottom sealing, and side sealing when stopped.

Next, one embodiment of the present invention will be described.

As shown in FIGS. 1 and 2, upper films 1 and 2 and lower films 3 and 4 are each sent out from a winding roll. At this time, the upper film 1 and the lower film 4, and the upper film 2 and the lower film 3 are made of the same type of synthetic resin film.

Next, the upper films 1 and 2 and the lower films 3 and 4 are sent out by feed rolls 5 and 6, respectively, while being separated from each other.

Furthermore, the upper films 1 and 2 and the lower films 3 and 4 are superimposed on each other by the roll 9, and the feeding belt 10
Send it up. The feed belt 10 moves intermittently, stopping when a seal bar (to be described later) is lowered and moving when the seal bar is raised.

First, the top seal bar 11 and the bottom seal bar 12 are lowered on the feed belt 10 when stopped, top sealing and bottom sealing are performed in the same direction as the feeding direction, and at the same time, the lower film 4 is temporarily attached on the feed belt 10. In this state, the next process is carried out, and the top seal bar 11 is side-sealed by the side seal bar 13 that descends in synchronization with the bottom seal bar 12 to form a bag. This is a method for manufacturing a synthetic resin bag made of multiple films that are peeled off from the film.

When the multilayer film constituting the bag is intended to preserve the contents, it is preferable that the upper film and the lower film include films with excellent gas barrier properties. For example, polyethylene/
polyethylene/polyvinylidene chloride, polyethylene/polyvinylidene chloride/polyvinylidene chloride,
Examples include films with multiple structures that cannot be bonded together, such as polyethylene/polyvinylidene chloride/polyethylene, saponified polyethylene/ethylene-vinyl acetate copolymer, polyethylene/polyamide, and polyethylene/polyester.

When the outer layers of the upper film and the lower film are made of polyethylene, if a silicone belt is used as the feed belt, a temporarily attached state can be obtained during sealing, and a good side seal portion can be formed.

For example, when manufacturing a bag from two films, an upper film and a lower film, it is necessary to heat seal four films at the same time in the heat sealing section. At this time, if the side seals in the direction perpendicular to the film flow direction are heat-sealed without temporarily attaching them on the belt, there is a risk of misalignment between the films at the heat-sealed portion.

However, as in the present invention, first heat-seal the part parallel to the film flow direction, and at the same time temporarily attach it to a feeding belt to prevent the film from shifting during side sealing. That is, by heat-sealing the side seal part, a clean seal part without wrinkles can be formed.

This is because the seal part of the film and the feed belt are temporarily bonded, so there is no expansion or contraction, and the film is fed accurately at the same speed as the drive belt, so even if you make a wide film bag, it will be clean and wrinkle-free. A synthetic resin bag can be obtained.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are explanatory diagrams showing one embodiment of the present invention. 1, 2... Upper film, 3, 4... Lower film, 5, 6... Feeding roll, 7... Picking tool opening device, 8... Picking tool mounting device, 9... Roll,
10...Feed belt, 11...Top seal bar, 12...Bottom seal bar, 13...Side seal bar.

Claims (1)

[Claims] 1. On a feeding belt made of silicone rubber that moves intermittently between an upper film and a lower film made of two or more multi-layered films whose outer layers are made of polyethylene, when the feeding belt stops, first the top seal bar and the bottom seal bar While top sealing and bottom sealing are performed in the same direction as the feeding direction, the lower film is temporarily attached to the feeding belt and moved to the next process, and when the feeding belt stops, it is lowered in synchronization with the top seal bar and bottom seal bar. A method for producing synthetic resin bags that are side-sealed using side seal bars.