KR200348800Y1 - Method to manufacture flexible tube sheet for ultrasonic welding - Google Patents

Abstract

The present invention is in the manufacture of a flexible tube consisting of a metal sheet and plastic used for packaging containers such as toothpaste, cosmetics, food, pharmaceuticals, etc., the laminated structure of the present invention is an internal heating method using an ultrasonic welder (ultrasonic welder). It is designed to be suitable for the longitudial seam of the tube body. In the laminated structure of the present invention, the inner barrier layer is laminated to prevent the erosion of the thin metal plate of the seam and the retention of the contents, the restoring force of the pressed parts, and the like. The present invention relates to a sheet structure and a method of manufacturing the same, which are capable of diversifying the external functions of the tube body.

Description

Method for manufacturing flexible tube sheet for ultrasonic welding

The present invention relates to a flexible sheet structure and manufacturing method in the form of a flexible tube commonly used for filling paste products, and to a circular joint of a tube body. The sieve is composed of inner and outer heat adhesive layers, adhesive resin layers and inner barrier layers, and the base of the inner barrier layer is laminated with a metal foil (aluminum thin plate) or a high barrier plastic film to prevent ultraviolet rays, gas permeation, and moisture permeation. It is used for the purpose of

In the sheet structure of the flexible tube as shown in Fig. 1, the first heat-adhesive layer 10 (polyethylene film) / first adhesive water has a structure in which an inner barrier layer is laminated on an aluminum thin plate alone and a plurality of polymers are laminated. Laminate layer 20 (ethylene acrylic acid copolymer) / internal barrier layer 30 (aluminum thin plate) / second adhesive resin layer 40 (ethylene acrylic acid copolymer) / second thermal adhesive layer 50 (polyethylene film) One flexible sheet is common.

The circular joint (b) method of the tube body (a) includes an external heating method using a heating heater bar and an internal heating method using a high frequency or ultrasonic wave, but is generally bonded by an internal heating method.

High-frequency bonding is a heat-induced aluminum thin plate by induction heating to melt the adhesive resin layer and the polyethylene film as the heat-adhesive layer, and pressurize to bond the tube to the laminated body in consideration of heating temperature, time, pressure, and adhesive strength. It is common for the thickness of to be determined.

Ultrasonic bonding, on the other hand, generates ultrasonic friction on the bonding surface of the polyethylene film of the thermal bonding layer to generate frictional heat and simultaneously pressurizes it to obtain a bonding strength by applying pressure and prevents cracking of the aluminum sheet due to pressure. The thickness of the aluminum sheet should be taken into account.

In the circular joint (b) of the tube body, the overlapped portion (c) (over-lap) has a width of 1.5 to 2 mm, and the bonding strength is 0.3 kg or more, and the bursting strength due to the air pressure of the tube is 3.5 bar or more, Resin film for prevention of oxidation should be formed on the cut surface of aluminum sheet. As a test to confirm this, check whether it is corroded by precipitation test of sodium hydroxide (NaOH) (0.5% dilution of distilled water. 24h).

When the multilayer laminate sheet used for a conventional flexible tube is circularly bonded (b) to the tube body by high frequency and ultrasonic welding, the results as shown in <Table 1> can be confirmed.

<Table 1>

The result of <Table 1> is the welding condition of ultrasonic welding 2.8KW, pneumatic pressure of 2.9Kgf / ㎠. In order to maintain the joint strength, in the circular joint of the tube body, the volume of the joint portion (c) is 70 to 80. Should keep%.

The result of <Table 1> shows that there is no quality defect in high frequency bonding, but in the case of ultrasonic bonding, cracking occurs due to the difference in thickness of aluminum (BCD type). As a result of the precipitation test in an aqueous solution of sodium hydroxide, it can be confirmed that the aluminum sheet is partially exposed and eroded.

In the case of high frequency bonding, the aluminum sheet is heated to melt and pressurize the EAA and PE films, and the molten resin is pushed out to cover the cut portions of the aluminum sheet with resin to prevent erosion, and the ultrasonic bonding is a PE film interface of the thermal bonding layer. Friction heat is generated to soften, melt and press to form a resin film on the inner and outer cut portions, and a resin film is formed unstable, so that the aluminum thin plate is exposed.

As described above, the flexible tube is composed of a thin aluminum sheet as an inner barrier layer and laminated with a plurality of polymers, and is an example of a tube for improving chemical resistance, bending stability, gas barrier, moisture barrier, etc., Korean Patent Publication No. 1991 08844 (Application No. 1984-0001766) discloses multilayer flexible substrates in the form of flexible tubes commonly used for filling paste-like products and the use of these substrates.

In the circular joining of the tube body, which is essential for the manufacture of the tube, it can be seen that the structure that surrounds both sides of the thin aluminum plate with the adhesive resin layer is a laminated structure that is easy for high frequency bonding. As shown in <Table 1>, the conventional flexible tube sheet produces a flexible tube in a stack structure of sheets suitable for ultrasonic welding because a change in quality of the tube occurs depending on the tube body joining method.

The present invention relates to the manufacture of a flexible tube sheet laminated with a metal thin plate and a plastic substrate, by forming a resin film on the tube body bonding side (cutting portion) by ultrasonic welding method, to prevent erosion of the aluminum thin plate, It is to prevent the deterioration of the contents preservation caused by the pinhole generation of aluminum sheet due to the improvement of the stacking structure of the sheet and the resilience of the tube to prevent the cracking and bending, and to provide the variety of tubes.

Different colorants (master batch: salt and pigment) in the resin laminated on the adhesive plastic film layer 305 and the second thermal adhesive layer 50 laminated on the internal barrier layer of the present invention in a high concentration in the resin and processed Ash) is added to produce a tube that traps features that can vary the color of the tube.

As described above, in the manufacture of a flexible tube using a metal thin plate, it can be seen that when the circular welding by ultrasonic welding is closely related to the thickness of the metal thin plate, the aluminum plate of the minimum thickness (6 ~ 9㎛) in the tube body In order to maintain the effect of the thin metal plate and to produce a sheet trapping the external function of the tube, that is, stiffness, appearance diversification, restoring force, so as to enable a circular joint of the tube body by ultrasonic welding.

Figure 1. Circular junction cross section of the flexible tube

Figure 2 is a cross-sectional view showing the laminated structure of the sheet and the tube structure for ultrasonic welding of the sheet according to the present invention.

(Ultrasonic welding: The device structure consists of an oscillator that generates electrical energy, a vibrator that generates ultrasonic vibrations by converting electrical energy into mechanical energy, and a horn that raises the amplitude. Structural device which produces strong heat and molecular bond by melting friction surface by generating frictional heat on adhesion surface.

Figure 3 is a cross-sectional view showing an embodiment constituting the inner blocking layer of the sheet according to the present invention.

Figure 4 is a cross-sectional view showing an embodiment in which the polyethylene resin extrusion coating the tube body bonded to the sheet according to the present invention by ultrasonic welding.

<Description of the code | symbol about the principal part of drawing>

a: tube body b: circular joint of tube body

c: over-lap d: extrusion coating of polyethylene resin

10: first heat adhesive layer 20: first adhesive resin layer

30: internal barrier layer 40: second adhesive resin layer

50: second heat adhesive layer

301: aluminum thin layer of the internal barrier layer

302: adhesive layer of the internal barrier layer

303: plastic film layer of the internal barrier layer

304: adhesive layer of the internal barrier layer

305: adhesive plastic film layer of the internal barrier layer

In order to achieve the above object, the flexible tube sheet of the present invention is designed to have a thickness of 310 μm as shown in <Fig. 2>, so that the first thermal adhesive layer 10 (90 μm) / first adhesive resin layer (20) (35 mu m) / internal barrier layer 30 (65 mu m) / second adhesive resin layer 40 (30 mu m) / second heat adhesive layer 50 (90 mu m) = 29.0%: 11.3%: It is preferable to form a substrate at a ratio of 21.0%: 9.7%: 29.0%. A conventional flexible tube sheet is laminated with an aluminum sheet of 12 to 40 µm and a polyethylene film and an adhesive resin to a thickness of 275 to 310 µm. It is common to use it as a sheet of a flexible tube. The thickness of the aluminum sheet is suitable for high frequency bonding, but due to the crack generation, exposure to the cut portion due to the thickness difference of the aluminum sheet in the ultrasonic bonding is limited to use as a paste product container.

The inner blocking layer 30 of the flexible tube of the present invention is made of aluminum thin plate 301 / adhesive 302 / plastic film 303 / adhesive 304 / adhesive plastic film 305 as shown in <Fig. 3>. ) Is made of a multilayer composite substrate sequentially laminated using a dry lamination method. At this time, the thickness of the entire internal barrier layer 30 is appropriately 65㎛ (± 5%), when the composition ratio of the substrate is 100%, aluminum thin plate (7㎛): adhesive layer (1.5㎛): plastic It is preferable that a composition is formed in the ratio of peel (20 mu m): adhesive layer (1.5 mu m): adhesive plastic film (35 mu m) = 11.7%: 2.5%: 33.3%: 2.5%: 50%. The material of the present invention is to stack the quality code '0' based on the classification of the whole body aluminum sheet (KSD6705) and the quality code of the aluminum sheet (KSD0004), and to stack the thickness of 6 to 9 μm.

The action of the plastic film 303 laminated on the inner blocking layer 10 is in the circular joint (b) of the tube body (a), the crack of the aluminum sheet due to the ultrasonic welding pressure (2.5 ~ 3.5Kgf / ㎠) In order to prevent gas permeability and to compensate for gas permeability and moisture permeability due to pin-hole of thin aluminum sheet (6 ~ 9㎛), tensile strength to support pressurization of ultrasonic welding It is preferable to selectively use a film that satisfies the usual conditions as shown in <Table 2> based on the elongation and gas permeability.

<Table 2>

The purpose of the aluminum sheet as a substrate of the flexible tube is to block moisture permeation and gas permeation at the level of '0' (zero). The plastic film and the aluminum sheet of <Table 2> are used as the polyurethane adhesive 302. By laminating, the gas barrier effect is expressed.

The purpose of laminating the adhesive plastic film 305 on the internal barrier layer 30 is to separate the adhesives due to thermal deformation stress differences between the substrates due to the adhesion between the substrates, creation of various colors, and frictional heat generated during ultrasonic welding. It is preferable to laminate the polyethylene film in order to prevent the permeability of the polyethylene film. The oxygen permeability of the internal barrier layer laminated as described above is 1.0 cm 3 / m 2, 24hrs, atm (Test method: ASTM D 3985) or less and the moisture permeability is 1.0g. / M 2, 24hrs (Test method: KS M 3088-99) The following results are preferred.

In other words. In order to bond the heterogeneous materials of the plastic film 303 and the adhesive plastic film 305 shown in Table 2, the polyurethane-based adhesive 304 by the dry lamination method is used to bond the second thermal contact film 50. In order to bond the same material of the adhesive plastic film 305 with each other, the adhesive resin 40 of <Table 3> by the extrusion lamination method is used for adhesion.

The adhesive plastic film 305 has a softening point / melting point than that of the adhesive resin 40 in order to prevent the adhesive force from being lowered due to the thermal strain stress difference between the substrates during the circular welding of the tube by ultrasonic welding. It is preferable to use a high polyethylene film. In this invention, a linear low density polyethylene (LLDPE) film or a low density polyethylene (LDPE) film is surface treated (double-sided corona treatment) and laminated.

In addition, in order to diversify the color of the tube body, an opaque film mixed with a white colorant at a level of 10% is bonded to the polyethylene film used as the adhesive plastic film 305 to block gray of the aluminum sheet, and the second row When laminating a polyethylene film mixed with a translucent colorant in the adhesive layer 50 can be made of a tube body in a variety of colors can provide a variety of tubes.

It is preferable to use a linear low density polyethylene (LLDPE-C6) film among polyethylene resins having excellent heat-sealing strength and excellent oil resistance, chemical resistance, and the like. Also, in order to diversify the printing method, the polyethylene film laminated on the outer surface heat-adhesive layer is preferably applied with an LLDPE: LDPE or a coextrusion inflation film having an LLDPE: HDPE: LLDPE structure in order to maintain dimensional stability.

The adhesive resins 20 and 40 of this paper are softened at a temperature lower than the heat sealing temperature of the thermal bonding layer film interface 10 and 50 during ultrasonic welding and are pushed out by pressure to form the molten resin and the resin film of the thermal bonding layer film. It is. The resin film surrounds the cutout portion and prevents erosion of the aluminum sheet. The melting point of the adhesive resin should be relatively softened at a temperature lower than that of the films 10 and 50 of the thermal adhesive layer, as shown in <Table 3>. It is preferable to use in consideration of the binding force of.

<Table 3>

In order to bond with the polyethylene film of the aluminum thin plate layer 301 and the first thermal adhesive layer 10, an ethylene acrylic acid copolymer adhesive resin 20 is used by an extruded lamination method, so that ionic bonding at high temperatures can be exerted. In addition, the low-density polyethylene or ethylene acrylic acid copolymer adhesive resin 40 is used for the bonding of the polyethylene film of the adhesive plastic film 305 layer and the polyethylene film of the second heat-adhesive layer 50 by using an extrusion lamination method. To make it work.

In the manufacture of a tube body for producing a flexible tube by laminating a metal thin plate and plastic as described above, the present invention relates to a laminated structure of a sheet and a method for producing the tube body by ultrasonic welding.

Fig. 4 is an extrusion coating (d) of polyethylene resin on a tube body (a) bonded by ultrasonic welding based on the tube body of the present invention to improve the restoring force and stiffness of the tube. In order to improve the restoring force and the stiffness of the tube body, the polyethylene resin is 40 to 100 μm thick by extrusion coating (d). It is applied to the tube body to reinforce the laminated thickness of the tube body (a) so as to improve the function.

In the laminated structure according to the above embodiment, the tube may be manufactured by the manufacture of the sheet by dry lamination, extrusion lamination method, and the manufacture of the tube body by the ultrasonic welding method, and the strength of the tube body by the extrusion coating method. It can be improved and processed into tubes of high capacity packaging.

Hereinafter, the configuration and effects of the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following examples.

Example

An internal barrier layer 30 was prepared by a dry laminate method.

Referring to FIG. 3, a polyurethane-based adhesive is used as the adhesive to form the adhesive layers 302 and 304, a biaxially stretched polyester film is used as the plastic film 303, and the adhesive plastic film 305 is used as the adhesive. Linear low density polyethylene films were used.

Apply 25% ~ 35% of solid content of polyurethane adhesive to # 100 ~ 130 cylinder with biaxially stretched polyester film (20㎛) and dry it in 70 ℃ atmosphere, and aluminum thin plate (7㎛) on dried adhesive coating surface After stacking again, the laminated base material is hardened | cured for 72 hours or more in 45 degreeC atmosphere under temperature conditions. Subsequently, an adhesive is also applied to the opposite side of the surface of the polyester film in the same manner as above, and the polyethylene film (35 μm) is laminated and cured under the same conditions.

When the laminated substrate was completely cured, the sheet was prepared by the extrusion lamination method.

Referring to Figure 2, the adhesive resin for forming the adhesive resin layer (20, 40) is used as the ethylene acrylic acid copolymer adhesive resin, the thermal adhesive layer (10, 50) using a polyethylene film, internal blocking The layer 30 was a multilayer laminate substrate prepared by the dry laminate method described above.

Laminate flexible in order of polyethylene film (90㎛) / ethylene acrylic acid copolymer (35㎛) / internal barrier layer (65㎛) / ethylene acrylic acid copolymer (30㎛) / polyethylene film (90㎛) The sheet of tubes was prepared.

At this time, the gas barrier effect of the sheet of the final laminate tube body is the oxygen permeability 0.000 cm 3 / m 2, 24hrs, atm, the moisture permeability was measured to 0.00g / m 2, 24hrs, it was confirmed that the contents storage excellent.

The sheet thus prepared is cut in a roll state based on the filling amount of the tube body, and is circularly bonded by ultrasonic welding. As a condition for ultrasonic welding, the output is 2.8KW. Pneumatic 2.9Kgf / ㎠. Welding time 0.5 seconds. Feeding time 0.5 seconds. Thus, the ultrasonically welded tube body had a sealing strength of 0.3kg or more, and was precipitated in an aqueous solution of sodium hydroxide (NaOH) (0.5% dilution of distilled water. As a result, it can be confirmed that there is no erosion reaction. The tube body manufactured as described above is completed by the process of forming the opening, bonding the lead seal, and sealing the cap.

As shown in Fig. 4, the tubular body joined by ultrasonic welding was made of polyethylene resin, and the resin was applied to the surface of the second heat-adhesive layer 50 by an extrusion coating machine (d) to a thickness of 100 µm. According to the drawing direction, it is cut to a practical standard. The extruded coated tube body is completed by forming the opening, bonding the lead seal, and closing the cap.

The flexible tube sheet constructed and operated as described above is bonded to the circular joint of the tube body by ultrasonic welding, thereby preventing erosion by completely covering the aluminum thin layer layer on the sheet side (cutting portion) with a synthetic resin material and preventing cracking of aluminum. The inner barrier layer structure of the sheet to prevent the resilience of the excellent excellent resilience when forming the inner barrier layer of the aluminum sheet alone, and the inner barrier layer of this paper is to prevent the occurrence of pinholes in the aluminum by bending the tube body. It is possible to prevent the deterioration of the contents retention.

In addition, different coloring materials (master batch: coloring materials processed by dispersing salts and pigments in resin at high concentration) are added to the adhesive plastic film laminated on the inner barrier layer and the film laminated on the second heat adhesive layer, and the color of the tube is added. Provides the effect of manufacturing a tube trapping features that can be diversified.

Existing flexible tube sheet (aluminum thin plate: 40㎛) capable of ultrasonic welding and the sheet according to the present invention can guarantee the same performance in terms of functionality, but can significantly reduce the use of expensive aluminum sheet in terms of manufacturing cost, thereby reducing production costs. Provides an economic advantage.

Claims (6)

A first thermal adhesive layer 10 of the inner surface layer of the tube forming the inner surface of the flexible tube and a second thermal adhesive layer 50 of the outer surface layer of the tube forming the outer surface, and an internal barrier layer 30 that prevents gas permeation into the tube; In the flexible tube sheet composed of adhesive resin layers 20 and 40 for adhering the surface layer and the internal barrier layer, the substrate of the first thermal adhesive layer and the second thermal adhesive layer is laminated with a polyethylene film, and the first adhesive layer 20 ) Resin of the ethylene acrylic acid copolymer is laminated, the resin of the second adhesive layer 40 is laminated ethylene acrylic acid copolymer or polyethylene resin, the inner barrier layer 30 is an aluminum thin plate 301 and the adhesive layer ( 302), a plastic film (303), an adhesive layer (304) and an adhesive plastic film (305) sequentially laminated. The flexible tube which cut | disconnects the sheet | seat of Claim 1 with a roll or a sheet, and is manufactured by circular joining of the tube body by ultrasonic welding. The flexible aluminum sheet of claim 1, wherein the thin aluminum sheet of the inner barrier layer is laminated to a thickness of 9 µm or less. The flexible plastic sheet according to claim 1, wherein the adhesive plastic film of the inner barrier layer is laminated with an inflation film of linear low density polyethylene or low density polyethylene. A flexible tube sheet, comprising: a colorant is mixed with the adhesive plastic film of the internal barrier layer of claim 1 and laminated with a film capable of blocking the color of aluminum; The flexible film sheet according to claim 1, wherein the plastic film of the inner barrier layer is any one of a biaxially stretched polyester film, a biaxially stretched nylon film, and a biaxially stretched polypropylene film.