JPS5822335B2 - Soukou file - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for making a welded part stronger in a method of melt joining (hereinafter referred to as welding) a band-shaped vinylidene chloride thermoplastic synthetic resin film (hereinafter simply referred to as a film) using high frequency. It is related to the device.

It is well known that a vinylidene chloride strip film, which easily generates heat when high frequency is applied, is overlapped with its longitudinal ends and run between high frequency application electrodes, and the combined films are welded to form a cylindrical casing film. That's true.

For example, a long strip-shaped film is formed into a cylindrical body surrounding an internal electrode, which is a negative electrode, and is run, and the external electrode (positive electrode) and the internal A method of forming a cylindrical casing film by placing it between electrodes (negative electrodes) and applying a high frequency voltage to the film at the overlapping portions of both ends and welding intermittently or continuously, or by using an automatic filling machine etc. A stuffer that combines a long strip-shaped film with an internal electrode (negative electrode).
While continuously supplying the film while surrounding the nozzle to form a cylindrical body, the overlapped portions on both sides of the film formed in the cylindrical shape are contacted or pressed with an external electrode (positive electrode) and an internal electrode is applied. A high-frequency current is applied between the and external electrodes to weld the overlapping portions of both ends of the film running between the electrodes to continuously form a cylindrical casing film, and then the contents are supplied from the tip of the stuffer nozzle. , a method of filling and manufacturing a package is known.

Conventionally, the strength of the welded part of vinylidene chloride film by high frequency is generally determined by adjusting the high frequency power used to melt the resin and the pressure applied to the film welded part by the high frequency application electrode (!:, t or electrode). It has been adjusted by adjusting the way the film is applied and the width and smoothness between the electrodes.

However, there is a limit to the strength improvement of the welded part due to the high frequency power, the contact pressure of the electrode, the angle of the electrode, etc., and it has been difficult to improve the strength by such conventional means.

For example, when a sausage package is produced by welding a strip film under the best conventional conditions, filling it with sausage raw meat, ligating and sealing both ends with aluminum wire, etc., and sterilizing it by boiling or retort, the welded part is Approximately 5 to 6% of bags break due to insufficient strength.

This resulted in a large amount of product loss, which was a major problem in the production of hams and sausages.

One of the reasons for the lack of strength of the welded part is that during welding by applying high frequency, the resin film, which tends to flow easily when melted, is melted and softened because it is welded while being pinched or pressed between the external electrode (positive electrode) and internal electrode (negative electrode). It was thought that this was because the resin escaped to both sides of the external electrode and the area pressurized by the electrode became thinner, making it easier to break.

A solution to this problem was proposed in Japanese Patent Laid-Open No. 118774/1983.

In other words, regarding the insufficient thickness of the welded part that occurs when welding by pinching or pressing between the external electrode (positive) and the internal electrode (negative), a high frequency voltage is applied to A pedestal and a pressure roller are installed in the passage between the electrode and the cylindrical film welding area behind the electrode, and the welded area that has not yet solidified after welding is crushed to eliminate unevenness and the formation of thin spots in the welded area. A method has been proposed to improve the strength of welded parts.

On the other hand, the present inventors have proposed a method and apparatus for improving the strength of welded parts by using an angular method, which is a full force method, in Japanese Patent Application Laid-Open No. 49-118774.

In other words, the inventors believe that the lack of strength in the welded part is not only caused by the thinner film thickness of the welded part due to pressure welding, but also by the fact that the strength of the welded part is essentially caused by If left after extrusion, the molecules will be in an unoriented state and the mechanical properties such as impact strength will be weak and brittle. It is possible to make a strong and strong film, but by melting it again by applying special high frequency welding, the resin returns to the non-oriented and non-stretched state before stretching and orientation,
Focusing on the fact that this may occur due to brittle properties, we conducted repeated research on improving the strength of the welded part in this direction.After the film was high-frequency welded using a conventional method, the welded part was cooled. They have discovered a method to further strengthen the strength of the welded part by imparting mechanical properties such as impact resistance by stretching the material in the circumferential direction.

The gist of the present invention is to attach a band-shaped film made of vinylidene chloride-based synthetic resin film to the stuffer nozzle and internal electrode (
The inner electrode (negative) attached to the stuffer nozzle and the corresponding external electrode (Positive) In a method of welding by applying high frequency while applying pressure between the electrodes and continuously forming a cylindrical film, the welded part is cooled by applying high frequency between the external electrode (positive) and the internal electrode (negative). However, this method uses high-frequency waves, which is characterized by stretching the weld in the circumferential direction using a stretching device installed on the extension of the internal electrode through which the weld passes, thereby imparting mechanical strength such as impact resistance to the weld. The present invention relates to a welding method and a welding device for a belt-shaped running film made of vinylidene chloride-based synthetic resin.

The most important point in the present invention is the stretching of the welded part.
After the welded part welded by high frequency according to the above-mentioned conventional method is left to cool or forcibly cooled, a cylindrical film is formed by a stretching ring or a deforming ring provided on the extension of the internal electrode (negative) through which the cooling part passes. Stretching is performed by applying an action that pushes the welded portion outward toward the outside of the circumference.

In addition, in the method of the present invention, the external electrode (positive) and the internal electrode (
The process of melting and stretching the welded part of the welded film by applying high frequency between the negative and negative) is to melt the crystalline vinylidene chloride synthetic resin and stretch it in an unoriented state.
This is done to take advantage of the characteristic that mechanical strength, which represents impact resistance, can be imparted most effectively by rapidly cooling to around 15° C. and then stretching.

This cooling power method cools the welded area by blowing cold air or cold water onto the welded area from above, or indirectly cooling the welded area by passing cooling water through the internal electrode that contacts the cylindrical casing film after welding. can do.

When filling sausage material using an automatic filling and ligating machine, etc., the temperature of the sausage material itself is 2 to 10°C.
Since the cooling effect is naturally achieved by maintaining the temperature, no particular cooling device is required.

In addition, the method of the present invention is also effective in improving the strength of the welded part by performing full force welding (using the force method of JP-A No. 49-118774) to suppress the unsolidified welded part to eliminate unevenness and then stretching it. Demonstrate.

The vinylidene chloride-based synthetic resin film applied to the present invention refers to a copolymer of vinyl chloride, acrylonitrile, vinyl acetate, acrylic acid ester, etc. that can be copolymerized with vinylidene chloride, or a multi-component resin of these 100 parts by weight. The composition comprises 1 to 10 parts by weight of a plasticizer, a stabilizer, and a total of 0.01 to 2.0 parts of other inorganic and organic fillers, and 0.01 to 3.0 parts of other color pigments.

In addition, this vinylidene chloride-based synthetic resin composition contains 0.5 to 5
．． It is also effective for vinylidene chloride synthetic resin films made of polymer blends of low melting point polyamide resins, polyurethane resins, polyethylene-vinyl acetate copolymers, etc. in the range of 0 parts by weight. A method using a filling and ligating machine will be explained with reference to the drawings as an example.

In FIG. 1, the supplied strip-shaped film 1 passes through a forming plate 4 provided surrounding a stuffer nozzle 3 that forms a supply passage for the filling contents, so that both ends of the film are overlapped. It becomes cylindrical and moves downward while surrounding the stuffer nozzle 3.

The cylindrical unwelded film is adjusted to a predetermined inner diameter with the first size ring 5, and in this state, the overlapped portions of both ends of the film correspond to the inner electrode 6 added on the stuffer nozzle. A high frequency voltage is applied when passing between the external electrodes 7, and the cylindrical film 11 becomes continuous on the circumference.

The welded tubular film is then generally simply passed through a second size ring 9 or a third size ring 10 to 12
It is taken up by a taking-off roller.

In this case, in the method of the present invention, the welded part that has been high-frequency welded by the conventional method as described above is normally welded by 6 welded parts within the section up to the time when the welded part passes through the 10th third size ring attached to the tip of the stuffer nozzle. A method of lengthening the contact time by lengthening the metal lower electrode, or a method of contacting a pipe that has been cooled by passing cold water through a metal or plastic pipe as in 13, or a method of blowing cold air with a blower as in 14. After cooling the non-crystallized and solidified weld zone by a method such as the above, and then performing an operation to make the stretching effect more effective, the weld zone is stretched by the following two methods. It improves the mechanical properties of the weld.

One method is that when manufacturing a cylindrical film using a normal automatic filling and ligating machine, the circumference ratio of each of the first, second, and three size rings 5, 9, and 10 is always constant. On the other hand, in the case of the method of the present invention, the circumference ratio of the third size ring 10 to the first or second size ring 5 or 9 is 1.00:1.01 to 1.05, preferably 1.00:
1.03 (Fig. 2 IQ-a), or another method is to set the third size ring 10 to Fig. 2 (10
-b ~ 1O-f) Instead of a deformable ring for welding part stretching having a convex structure, the effect of the convex part of this deformable ring and (
The deformation ring is set so that the welded part contacts the convex part of the deformed ring) 12, and the welded part is stretched in the circumferential direction by the pulling action of the cylindrical film by the take-up roller (Fig. 3). It imparts impact strength, etc.

In the method of the present invention, the stretching process involves stretching the unoriented resin part after melting and before cooling and crystallization to solidify the crystals and increase the strength of the welded part.

The cooling operation is carried out while the film is being transferred between the outer electrode 7, the inner electrode 6, and the third size ring 10 (which serves as a stretching ring in the method of the present invention).

In addition, in the method of the present invention, the distance between the external (positive) and internal (negative) electrodes when welding the film by applying high frequency to the film, the pressure during clamping, etc. are determined depending on the resin composition and the surface of the film. Optimal conditions should be found depending on the state, film slipperiness, electrode material, shape, current, film running speed, etc.

The method of the present invention increases the strength of the welded part by stretching the welded part under such conditions.

In this method, stretching the welded part makes the welded part even thinner, and there is a question that the strength of the welded part may decrease. This problem can be solved by not stretching the weld unnecessarily and by improving the strength of the welded part even if it becomes a little thinner.

That is, the very slight stretching effect of this method has a surprising effect on improving the strength of the weld.

Example 1 2.5 parts of dibutyl sebacate, 4 parts of dioctyl adipate, as a heat stabilizer to 100 parts of a copolymer resin consisting of 78 parts of vinylidene chloride (the same below weight parts) and 22 parts of vinyl chloride in the polymerization charge composition ratio. Epoxidized linseed oil 1.5
A mixture of 0.08 parts of sorbitan monostearate as a lubricant and 0.1 part of silica as a matte finish agent was melt-extruded and formed into a film with a thickness of 20μ using a conventional inflation method, which was crushed using a pinch roller. The film was flattened and wound onto a bobbin, and then slit and wound as a 95 mm wide double wand film (total thickness 40 μm).

This film was transferred to the KAP automatic filling and ligation machine (Gugen Kagaku Kogyo K).
2. Suspend it on the film feed section (K product name).
Apply a 0 kg brake and pass the strip film through the forming plate to reduce the overlap width on both sides of the film by 6.
Form a cylindrical casing film with a fold width of 42 mm,
The film was allowed to travel at a running speed of 25 rn/ynin, and a high frequency application type i-pole (carbon electrode width Q in the external electrode,
Contact pressure 30o against a film with a length of 7 mm and a length of 40 mm
z, high voltage transformer voltage 800V, frequency 40.46 megacycles, room temperature 23℃, relative humidity 75%, setting of size ring for stretching, conventional method, circumference ratio of 1st and 2.3 size rings, respectively. constant, the method of the present invention:
The first and second size rings are kept constant, and the third size ring is a deformed ring as shown in Fig. 2, 10-f, and is deformed so that the circumference ratio of the first and second size rings is 1.00:1.03. The electrode plate current was set to 40, 45, 50 while passing cold water at 5°C through the stuffer nozzle using a ring.
, 55, 60771 kA.

At this time, the bag breakage strength of the welded portion was investigated using the conventional method and the method of the present invention.

As a result, the apparent welding range of both the conventional method and the method of the present invention showed a weldable range of 15WLk, but when the bag breakage strength was measured, it was clear that the bag breakage strength of the welded film of the present invention was greater than that of the conventional method. It was confirmed that it became stronger.

Example 2 Using the same film composition as in Example 1, using the same automatic filling and ligating machine, and using the same welding conditions and stretching device as in Example 1, sausage material meat at 4°C was passed through a stuffer nozzle. Electrode plate current 50m, A, 2 of 5577LA
A cylindrical casing film is continuously produced by high-frequency welding at a standard level and by the conventional method of not stretching the welded part and the method of stretching the welded part, one end of this cylindrical film is ligated with an aluminum wire, and then the sausage raw material meat is Filling rate 9
5% and a filling amount of 100 g, one end of the tube was sealed with aluminum wire, and 500 sausage raw meat filling bodies were continuously manufactured.

This package was sterilized by boiling at 95°C for 90 minutes, then cooled in tap water for 30 minutes, and immersed in hot water at 99°C for 20 seconds to smooth out wrinkles that had occurred on the surface of the package due to cooling. The number of broken bags from the welded parts of the body was investigated.

As a result, it was confirmed that the welded film obtained by the method of the present invention had extremely low bag breakage loss.

Example 3 Polymerization charge composition ratio: 80 parts vinylidene chloride (same parts below by weight), 20 parts vinyl chloride, 4 parts dibuterol sebacate as a plasticizer, 2.5 parts dioctyl sebacate, 1.0 parts epoxidized soybean oil as a stabilizer. A mixture of 0.08 parts of stearamide as a solvent and 0.1 parts of calcium carbonate as a matte finishing agent was melt-extruded using an extruder to make a film with a thickness of 25μ by the inflation method, and this was crushed. Flatten it and make it into a 50μ film with double wand film,
It was slit to a size of 305 m'llL and wound around a bobbin.

This film was placed on a KAP rigid chevron-shaped automatic filling and ligating machine, and welded into bags with a fold width of 140 m1 rL using high-frequency welding under the following conditions, filled with curry raw material (viscous material) at 70°C, and wrapped with aluminum wire at both ends. Seal the ligature by
The number of broken bags of bags made by welding by the conventional welding method and the method of the present invention when heat sterilized at 0° C. for 60 minutes was investigated.

As a result, it was confirmed that bags made by welding according to the method of the present invention had a significantly lower number of broken bags than those made using the conventional method.

[Brief explanation of drawings]

Fig. 1 is a schematic illustration of welding, cooling, and stretching parts in a vertical automatic filling and ligating machine according to the method of the present invention, Fig. 2 is a welded part stretching ring or deformation ring, and Fig. 3 is a welded part stretched on the stretching ring. It is a schematic diagram of the mechanism. 1: strip film, 2 guide rollers, 3: stuffer nozzle, 4: forming plate, 5: first size ring, 6: internal electrode (negative), 7: external electrode (positive),
8: External electrode load weight, 9: Second size ring, 10
: Third size ring, 11: Welded casing film, 12: Take-up roller, 13: Pipe for cooling the welded area, 14: Cold air blower for cooling the welded area, 15: Filled contents.

Claims (1)

[Scope of Claims] 1. A band-shaped film made of vinylidene chloride-based synthetic resin is guided into a cylindrical shape surrounding a stuffer nozzle. In the method of continuously welding to form a cylindrical casing film, the welded part that is welded by applying high frequency and passed between the electrodes is cooled between the high frequency electrode part and the tip of the stuffer nozzle, and the welded part is welded by applying high frequency. A method of welding a running film, which is characterized by stretching it. 2. A strip-shaped film made of vinylidene chloride is guided into a cylindrical shape surrounding the stuffer nozzle, and its synergistic longitudinal ends are run between high-frequency electrodes, which are continuously welded to form a cylindrical casing film. In the forming device,
A running device characterized in that a third size ring having a circumferential length longer than that of the second size ring is provided between the second size ring after the high-frequency electrode and the tip of the stuffer nozzle. Film welding equipment.