JP2003020014A - Shrink tube having anti-slip property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a surface property of a shrink tube to be installed on a bottle and the like, in particular to apply a slip preventing effect to a tube surface for increasing a handling and operating properties of the bottle having the shrink tube installed on it. SOLUTION: This shrink tube is constituted by a uniaxially drawn film in which some fine corrugations (2) constituted by small holes (21) and rimmed thick segments (22) around the small holes are dispersed and formed at a surface of desired area of the film. The thick segments (22) around the small holes (21) are made such that, for example, a protrusion height (h) is 30 μm or more, a span diameter (w) is 0.3 to 1.5 mm, and a dispersion density of some fine corrugations (2) is about 1 to 25 pcs./cm<2> . Some fine corrugations (2) can be formed more efficiently by scanning the surface of the uniaxially drawn film while a laser beam is being intermittently radiated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a shrink tube attached to a container such as a bottle, and more particularly, it is necessary to improve the handling operability of the bottle attached to the market and supplied to the market. The tube surface has anti-slip properties.

[0002]

2. Description of the Related Art Various containers such as bottles (plastic bottles, glass bottles) used as beverage filling containers are fitted with shrink tubes (printed with product information such as product name, usage, vendor name, etc.) for distribution. It is generally supplied to the market. On the surface of the shrink tube,
In order to improve the handling in the distribution process of the product equipped with this, the handling of the product purchaser when using it,
A surface treatment may be applied to prevent slippage. As its surface treatment, it has been proposed to coat the surface of the film with an anti-slip agent such as matte medium so that it has graininess to prevent slipping.

[0003]

The method of coating the surface of the film with the anti-slip agent not only accompanies an increase in material cost due to the use of the anti-slip agent, but also cannot easily obtain a sufficient anti-slip effect. It is possible to increase the coating thickness to enhance the anti-slip effect, but it is difficult to perform thick wall construction. Even if a thick coating can be formed, in the process of attaching the tube to a container such as a bottle (heat shrinkage treatment of the tube), since it is thick, crack peeling easily occurs and the coating layer is stably maintained. Is difficult. Also, if the coating is applied over the printed area of the film (printed area such as product name, usage, vendor name, etc.), the appearance will be inconvenient, and the surface area where the coating can be applied is also limited. .

The present invention has been made in view of the above circumstances, and provides a shrink tube having a surface property excellent in anti-slip effect, by solving the above-mentioned problems associated with coating with an anti-slip agent. .

[0005]

The anti-slip shrink tube of the present invention has fine irregularities (2) consisting of small holes (21) and thick portions (22) around the small holes (21) in a required surface area of the film surface. Is composed of a uniaxially stretched film in which is dispersed and formed. The fine irregularities (2) can be efficiently formed by intermittently irradiating the surface of the shrink film with a laser beam as described later.

Since the anti-slip effect according to the present invention is based on the roughening of the film itself (distribution of fine irregularities), it is more stable than a tube coated with an anti-slip agent (matte medium, etc.). . Moreover, as a unique shape effect of the fine concavities and convexities (2) composed of the small holes roughening the film and the thick rim-shaped portion, the anti-slip effect is provided as compared with a simple mountain-shaped (hemispherical or conical) protrusion. Is excellent. Also, unlike coating with anti-slip agent, fine unevenness can be dispersed and formed even in the area where printed indication (product name, design, etc.) is applied without impairing the visual effect of printed indication. Selection of construction area for
The degree of freedom in design is high, and the anti-slip action can be more effectively exhibited by appropriate dispersion formation according to the shape of the target container.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The form of fine irregularities formed on the surface of a shrink tube of the present invention will be specifically described with reference to the drawings showing an embodiment. FIG. 1 schematically shows a dotted pattern of fine irregularities formed on the film surface of the shrink tube, and FIG. 2 shows an enlarged part (A portion) of the dotted pattern. The fine unevenness (2) is composed of a small hole (21) and a rim-shaped thick portion (22) surrounding it. Small hole (2
1) is formed as a hole (through hole) penetrating the film or as a recess (the film thickness remains) as described later. In FIG. 1, the arrow X (circumferential direction of the tube) is the stretching direction of the film. In the following description, this is called the horizontal direction, and the arrow Y direction orthogonal to this is called the vertical direction.

FIG. 3 and FIG. 4 show a sectional form of fine irregularities (2) formed by laser beam irradiation. In each drawing, a drawing is a cross section taken along the line XX in FIG. 2 (parallel to the stretching direction of the film = horizontal direction of the tube = plane),
FIG. b is a cross-sectional view taken along the line YY (direction perpendicular to the stretching direction = vertical direction = plane). The fine irregularities (2) in FIG.
1) is formed as a through hole (21a), and in FIG. 4 it is formed as a recess (21b), but the small hole (21) and the rim-shaped thick portion (2) surrounding it are formed.
Both are common in that they consist of 2).

It is to be noted that FIG. 3 and FIG.
As contrasted to the cross section taken along) and b view and (Y-Y sectional view taken along the line), the thick portion in the transverse cross section (X-X sectional view taken on line) protruding height (22 ₁₎ is longitudinal cross section (Y-Y cross-sectional view taken along line) of the thick portion (22 ₂₎ greater than that of. This shape anisotropy is due to the anisotropy of the stretching process of the film (difference in stretching ratio between the horizontal direction and the vertical direction), and the fine unevenness (2) formed by laser beam irradiation has such anisotropy. Tend to accompany.

The profile of the fine irregularities (2) is shown in FIG.
When a specific example is given with reference to FIG.
The protruding height of the thick portion (22) surrounding the hole (21) (front surface
Side) (h₂₂) Is about 30 μm or more (usually about 30-300 μ
m), delivery diameter (opposing width of thick portion on front side) (w
₂₂) Is about 0.3-1.5 mm. Small holes are through holes
(21a) hole diameter (d₂₁) Is about 0.2-0.
8 mm, if the small hole (21) is a recess (21b), the recess depth
c₂₁(Depth from the film surface) is the film thickness (t
₁) About 1/3 or more. The numerical values of the above specifications are
Change in heat shrinkage when mounting the tube on a bottle (heat treatment)
The shape changes slightly depending on the shape, so make sure it is attached to the container.
The profile and distribution density of fine unevenness are
Or different.

The fine concavities and convexities (2) are formed on the entire surface or a partial area (one place or a plurality of places) of the tube. FIG. 1 shows an example formed on the entire surface of the tube, and tube (3) in FIG. 7 shows an example formed partially. In this way, the construction area of the fine irregularities (2) is the target container (bottle etc.)
It is appropriately selected according to the shape, size, etc. The distribution pattern (dispersion pattern) of the fine irregularities (2) is arbitrary. 6A shows an example of a lattice pattern, and FIG. 6B shows an example of a concentric circle or spiral spiral regular distribution pattern, but a random dispersion pattern may also be used. Fine unevenness (2)
The dispersion density (number of distributions per unit area) of is, for example, 1
It is up to 25 pieces / cm ² , and is appropriately increased or decreased depending on the material type of the film, the shape of the target container, and the like.

The dispersed formation of the fine irregularities (2) can be efficiently performed by laser beam irradiation. When the surface of the uniaxially stretched heat-shrinkable film is irradiated with a laser beam, the irradiated minute region is instantly dissolved or evaporated to form a small hole (21) (through hole 21a or recess 21b). A rim-shaped thick portion (22) is formed around the small hole. Along with the formation of the small holes (21), the rim-shaped thick wall portion (2
It is considered that 2) is formed by the action of local heat shrinkage stress and surface tension in the vicinity of the small holes (21) caused by the thermal effect of laser beam irradiation.

Therefore, fine irregularities (2) can be efficiently dispersed and formed by scanning the surface of the uniaxially stretched film with a laser beam while intermittently irradiating the film (intermittent irradiation). The distribution pattern such as the dispersion pattern or dispersion density of the fine irregularities (2) to be formed is the scanning pattern of the beam, the scanning speed (relative movement speed with respect to the film surface),
It is arbitrarily adjusted by the intermittent period of irradiation. Rimmed thick portion protruding height (22) _{(h 22),} the across the diameter _{(w 22),} and a pore size (21) the through hole (21
For the profile of fine irregularities such as a) / recession (21b), the laser output, the depth of the beam focus, and its
It can be adjusted by the ON / OFF cycle.

The laser beam irradiation for forming fine irregularities is carried out, for example, by a film slit line (cutting process of a predetermined width) or a center seal line (tube forming process).
In the above, it can be carried out under continuous transfer of the film unwound from the roll. The laser may be an argon laser, a YAG laser, or the like, but a carbon dioxide gas laser is preferably used because it is easy to obtain high energy and is easily absorbed by a polyester film which is a typical film material of a shrink tube. .

The film (1) is a film material type (polyester, polypropylene, polystyrene, etc.) usually used as a shrink tube material, and besides a film uniaxially stretched in the horizontal direction (circumferential direction of the formed tube). A biaxially stretched film that can be regarded as a substantially uniaxially stretched film is also used. In the case of a biaxially stretched film, the stretching ratio in the horizontal direction is 2 times or more in the vertical direction (for example, 2 to 7).
And the draw ratio in the vertical direction is preferably about 1.5 or less. The heat shrinkage ratio (horizontal direction) of the film is preferably about 30% or more (90 ° C. hot water × 10 seconds) in order to effectively form the thick portion (22) upon laser beam irradiation. As a specific example of a film having such physical properties,
Examples include “Space Clean S7553” and “S7570” (both polyester films) (manufactured by Toyobo Co., Ltd.).

[0016]

[Example] Fine irregularities are dispersedly formed on the surface of a shrink film by scanning with a laser beam, and then formed into a tube and mounted on a bottle.

Film Space Clean S7553 (Polyester) (Toyobo Co., Ltd.) Heat shrinkage: 68% in horizontal direction, 4% in vertical direction (90 ° C hot water × 10
Second) Thickness (t ₁ ): 50 μm Formation of fine irregularities Using a carbon dioxide laser beam device. Intermittent irradiation of the beam on the film surface (side that will be the front surface of the tube). Output: 5W, irradiation time: about 0.01 seconds

Fine asperity profile and distribution form Projection height of thick part (h ₂₂ ): Approximately 65 μm Transfer diameter (w ₂₂ ): Approximately 0.4 mm Small hole (through hole) (21a) Pore diameter: Approximately 0.25 mm Fine uneven distribution pattern: lattice pattern shape (FIG. 6 (a)) the dispersion density: about 4 / cm ² distribution plane zone: 2 places region facing the tube (Figure 7)

The above film was formed into a tube (folding diameter: 110 mm,
It was molded into a length of 120 mm) and mounted on the body of a bottle (filled with juice) as shown in FIG. The bottle with the tube attached in this way has a good anti-slip property, and after being taken out from a cold place, it can be gripped stably even when the surface is covered with water due to dew condensation and when the label surface is dry. I was able to.

[0020]

The anti-slip function of the shrink tube of the present invention is based on the roughening effect of the film itself due to the fine irregularities formed dispersed on the film surface.
It has superior stability compared to the conventional shrink tube coated with anti-slip agent. Further, an anti-slip agent (matte medium, etc.) is not required, and a material cost reduction effect can be obtained. Moreover, the fine irregularities can be efficiently formed by laser beam irradiation, and unlike the anti-slip agent coating, it can be applied to the print display area without impairing the visual effect of the print display (product name, design, etc.) of the film. It can be dispersed. Therefore, there is a high degree of freedom in selecting and designing the construction surface area of the fine irregularities, and the slip prevention effect can be more effectively exhibited by the appropriate dispersion formation according to the shape of the target container.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an example of a shrink tube in which fine irregularities of the present invention are dispersedly formed.

FIG. 2 is an enlarged view of a portion A of the shrink tube shown in FIG.

3A and 3B are diagrams showing a cross-sectional profile of fine concavities and convexities (a diagram: cross section taken along arrow XX in FIG. 2, b diagram: cross section taken along arrow YY in FIG. 2).

FIG. 4 is a diagram showing a cross-sectional profile of fine irregularities (a diagram: a cross section taken along the line XX in FIG. 2, b diagram: a cross section taken along the YY line in FIG. 2).

FIG. 5 is an explanatory diagram of a cross-sectional profile of fine irregularities.

FIG. 6 is a plan view schematically showing an example of a distribution pattern (dispersion point pattern) of fine irregularities.

FIG. 7 is an external perspective view showing a shrink tube in which fine irregularities are dispersedly formed and a bottle mounting example thereof.

[Explanation of symbols]

1: Shrink film 2: Fine irregularities 21: Small hole 21a: Through hole 21b: Depression 22: Rim-shaped thick part 3: Shrink tube 4: Container (bottle)

Claims (3)

[Claims] 1. A small hole (2) is formed on the surface of a required area of a film.
A shrink tube having anti-slip properties, which is formed by molding a uniaxially stretched film in which fine irregularities (2) composed of (1) and a thick portion (22) around the same are dispersed and formed into a tube. 2. The thick portion (22) around the small hole has a protrusion height (h) of 30 μm or more and a delivery diameter (w) of 0.3 to 1.5.
The shrink tube having the anti-slip property according to claim 1, which has a size of mm. 3. The shrink tube having anti-slip properties according to claim 1, wherein the fine irregularities (2) are formed by scanning the surface of the film with intermittent irradiation of a laser beam.