JPH0583068B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a thermoplastic synthetic resin tube reinforced by forming side seal portions along both sides of the tube structure, and a method for manufacturing the same.

[Conventional technology]

In general, synthetic resin cylindrical packaging materials are made by overlapping two sheet materials and sealing both sides to form a tube with side seals, or by pre-forming into a cylindrical shape to form a tube. I'm getting it either way. In consideration of appearance, appearance, and ease of molding, the latter tube shaped into a cylindrical shape without a seal portion is preferred.

[Problem to be solved by the invention]

By the way, unsealed tubes have no seams and have an excellent appearance, but because they are folded flat and have creases on both sides and are wound around a roll, local bending pressure is constantly applied to the creases. In addition to this, even when the package is stored and used, the folding action occurs along the creases each time it is handled, which often creates invisible pinholes and scratches, resulting in poor sealing performance. There was a problem that the stored items could not be preserved if they were lost.

This invention was made with a focus on these problems, and is a novel thermoplastic composite that eliminates sealing defects caused by pinholes and scratches along the folds and ensures complete sealing. An object of the present invention is to provide a resin tube and a method for manufacturing the same.

[Means to solve the problem]

This invention solves the above problems by providing side seal parts that are polymerized and heat-welded along the fold lines on both sides of the thermoplastic synthetic resin tube body, and the side seal parts are formed by inflation molding of the thermoplastic synthetic resin tube body. A pair of sealer belts are hung and pressed along both sides of the tube main body, which is formed so that it can be formed continuously during the process, and heat energy from a desired heat source is applied to the tube through the sealer belts. It can be manufactured by polymerizing and heat welding the press clamping parts of the main body.

The thermoplastic synthetic resin tube body provided with the side seal portion can be used as a storage bag by cutting it into a desired length and sealing the upper and lower opening sides by polymerization and heat welding.

In addition, in the method of manufacturing a thermoplastic synthetic resin tube for obtaining a side seal portion, each pair of sealer belts disposed along the folds on both sides of the tube body is designed to act strongly on the outside and weakly on the inside. It is preferable to arrange the

[Effect]

The thermoplastic synthetic resin tube body has side seals that are polymerized and heat-welded along the creases on both sides, so the creases have a thickness that is almost double wall thickness, increasing the strength and making it easy to roll. Even if the stored items are stored and shipped as a storage bag, pinholes will not occur easily.
Therefore, the sealing property is not destroyed. Furthermore, since the side seal portion can be heat-fused sealed while being held between a pair of sealer belts during the manufacturing process of the thermoplastic synthetic resin tube, it can be easily and efficiently processed.

Furthermore, the pair of sealer belts that can form the side seal portions are sandwiched between the sealer belts, which are strong on the outside and weakly on the inside, to increase the mechanical strength of the portions, so that the strength of the fold can be further increased.

〔Example〕

An embodiment of this invention will be shown below.

Reference numeral 1 indicates a thermoplastic synthetic resin tube body, which is a cylindrical body obtained by inflation molding, for example, polyethylene. 2, 2 shows side seal parts that are polymerized and thermally welded along the folds on both sides when the tube body 1 is folded flat, and the overlapped folds can be welded to form an integral structure. The strength of the crease area can be significantly increased.

The side seal portions 2, 2 can be easily formed by simple heat welding, or by any desired method such as heater or high frequency welding.

Moreover, the side seal parts 2, 2 can be formed independently each time, as well as when they can be continuously processed during the inflation molding process of the thermoplastic synthetic resin tube body 1 as described later. .

Moreover, by cutting the tube main body 1 to a desired length and sealing the upper and lower openings by polymerization heat welding, it is possible to store various items such as vegetables and grains.

Furthermore, it has been found that when forming the side seal portions 2, 2, an optimum bonding state can be obtained by applying a stronger thermal welding pressure on the outside and a weaker on the inside. Therefore, by forming the wall thickness d on the outside A of the side seal portions 2, 2 to be extremely slightly smaller than on the inside B, the stored items can be wrapped without difficulty when used.

Next, an example of a method for manufacturing a thermoplastic synthetic resin tube according to the present invention will be explained based on FIGS. 3 and 4.

3 is a die for inflation-molding the thermoplastic synthetic resin tube body 1, and the tube body 1 extruded into a cylindrical shape from the circular nozzle 4 is
It is obtained by biaxially stretching vertically and horizontally using known inflation forming means, passing through motor-driven tension nip rolls 5, 5, and folding it into a flat shape.

Reference numerals 6 and 6 denote a pair of sealer belts, which are disposed on the left and right sides of the tube body 1 which is folded into a flat state, and are mounted on a pair of pulleys 7, 7. By obtaining the rotational force of the shaft 9, the sealer belts 6, 6 can be transferred at the same speed and in the same direction as the movement of the tube body 1.

The sealer belts 6, 6 are made of a material that has good heat conductivity and high heat resistance for thermally welding the tube body 1, although no particular material is specified.
For example, it is preferable to knit glass fibers into an endless ring shape.

Reference numerals 10 and 10 indicate inlet press rolls disposed in parallel with the pulley 7, which keep the tube body 1 in an appropriate position so that the tube body 1 that is heat-treated with the sealer belts 6, 6 does not loosen or sag. It works by folding it into a flat state and feeding it.

Reference numerals 11 and 11 denote temperature-controlled heaters disposed inside the front half of the sealer belts 6, 6, which can generate thermal energy at a desired temperature, and transmit this to the sealer belts 6, 6 to heat the tube body. The side seal portion 2 can be integrally welded by locally melting the overlapped portions of the folds on both sides of the side seal portion 2.

12, 12 are cooling bars disposed along the rear half of the sealer belts 6, 6,
The side seal portion 2, which has been thermally welded, can be rapidly cooled and solidified by cooling blowers supplied from the cooling blowers 3 and 13.

Furthermore, the heaters 11, 11 are equipped with a heater edge that can freely adjust the seal width l of the side seal portion 2, and the side seal portion to be thermally welded is adjusted according to the size of the fold of the tube body 1. The seal width l of 2 can be freely changed.

Also, the width interval L between the left and right sealer belts 6, 6
In order to adjust the sealer belts 6, 6, left and right moving bases 14, 14 are provided for each sealer belt 6, 6, and can be moved in the direction of the arrow by means of handles 15, 15.

16, 16 indicates a pair of upper and lower intermediate rolls,
The tube main body 1 is maintained in a proper folded state and guided to the sealer belts 6, 6, and the side seal portions 2, 2 can be effectively thermally welded.

Reference numerals 17 and 17 denote a pair of tension rolls, which are provided to clamp the tube body 1 after treatment and transfer it to a winding roll (not shown), and are actuated by a torque motor 18.

During operation, tension of 0.5% or less is constantly applied to the tube body 1 by rotating the tension rolls 17, 17 slightly faster than the rotation speed of the tension rolls 5, 5. This prevents the tube body 1 from shrinking.

Furthermore, the pair of sealer belts 6, 6 are not parallel to the creases on both sides of the tube body 1, as shown in FIG.
It has been found that it is preferable in terms of durability to arrange the tube body 1 as a side seal portion 2 having the structure shown in FIG.

Since the configuration is as described above, the inflation-molded thermoplastic synthetic resin tube body 1 is flattened and transferred from the tension nip rolls 5, 5 to the sealer belts 6, 6 via one of the intermediate rolls 16. Ru.

Heaters 11, 1 are attached to the sealer belts 6, 6.
1 thermal energy is supplied to the pulleys 7, 7.
While being guided by the tube body 1, continuous heat welding can be performed with a desired sealing width l along the overlapping portions formed in the folds on both sides of the tube body 1, and the blower 13 and cooling bar 1
2 and 12, the side seal portion 2 can be formed to be extremely strong.

Side seal part 2 heat-welded in this way
The tube body 1 which has been formed passes through the other intermediate roll 16 and then passes through the tension roll 1 rotated by a torque motor.
7 and 17, and then wound up by the next take-up roll.

According to this manufacturing method, the heat welding means for the side seal portion is provided continuously in the molding process of the thermoplastic synthetic resin tube, so that the heat sealing mechanism including the sealer belts 6, 6 can be simply inserted into the existing equipment. It has the advantage of being more efficient and cheaper than manufacturing separately.

First, the thermoplastic synthetic resin tube body 1 with heat-welded side seals is cut into a desired length, and one opening is polymerized and heat-welded using a similar sealer belt configuration to seal vegetables, grains, fertilizers,
It can be shipped as a storage bag for feed, etc.

After storing the stored items, the opening can be sealed by heat welding.

In this embodiment, a series of heat sealing equipment including sealer belts 6, 6 is configured. Although we have described the case in which the thermoplastic synthetic resin tube is installed in-line for molding, the thermoplastic synthetic resin tube itself with side seals is not necessarily limited to the manufacturing method described above, and can be manufactured using any heat sealing method of your choice. Of course, this also includes the case where it can be molded independently from a tube-shaped film material. Furthermore, for the configuration of the heaters 11, 11, a desired heating welding means such as high frequency welding means may be used.

〔Effect of the invention〕

According to this invention, as described above, the side seal portions are thermally welded in a polymerized state along both sides of the thermoplastic synthetic resin tube body, so the creases are significantly reinforced compared to the conventional method. It is strong and strong, and there are no scratches, pinholes, or other inconveniences that impair airtightness, and the sealing function can be greatly improved.Moreover, even if the tube body is made thin, the side seal part of the crease will not be damaged. In addition to providing sufficient reinforcement, the side seal portion can be processed and molded continuously during the molding process of the thermoplastic synthetic resin tube, making it possible to process efficiently and inexpensively.
Moreover, the sandwiching state of the pair of sealer belts is strong on the outside and weak on the inside to disperse the clamping force as much as possible, so the structure of the folds of the heat-welded side seal part is extremely strong and tough. Therefore, durability can be improved.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of a thermoplastic synthetic resin tube according to the present invention, FIG. 2 is an enlarged cross-sectional perspective view of the same essential parts, and FIG. 3 is a schematic front view of an apparatus showing a manufacturing method according to the present invention. FIG. 4 is an explanatory side view of the same as above, and FIG. 5 is an enlarged explanatory view showing the gap configuration of a pair of sealer belts. 1...Thermoplastic synthetic resin tube body, 2, 2
...Side seal part, 6,6...Sealer belt, 11,11...Heater, 12,12...Cooling bar, 13,13...Blower, A...Outside of side seal part 2, B...Side Inside the seal part 2,
d...Thickness of the side seal part 2, l...Seal width of the side seal part 2, a...Gap between the outer sides of the pair of sealer belts 6, 6, b...Inner side of the pair of sealer belts 6, 6 gap.

Claims (1)

[Scope of Claims] 1. A thermoplastic synthetic resin tube comprising a thermoplastic synthetic resin tube body with side seals welded by polymerization along the folds on both sides. 2. A thermoplastic synthetic resin tube made by polymerizing and thermally welding both sides of the thermoplastic synthetic resin tube body to form side seals, and polymerizing and sealing the upper and lower sides so that it can be used as a storage bag. 3. In the process of folding the thermoplastic synthetic resin tube body to be stretch-molded into a flat shape and transporting it, a pair of sealer belts are suspended and pressed along both sides of the tube body, and the tube body is stretched along the sealer belts. A thermoplastic synthetic resin tube characterized in that thermal energy from a disposed heat source is supplied to the sealer belt to polymerize and thermally weld the pressure clamping portion of the tube body to form a side seal portion. Production method. 4. The thermoplastic synthetic resin according to claim 3, wherein the pair of sealer belts that press and hold both sides of the thermoplastic synthetic resin tube main body are tightly held on the outside and weakly held on the inside. How to make tubes.