JPH03200533A - Sticking of label on glass bottle - Google Patents

Abstract

PURPOSE:To permit a label to be stuck properly to a glass bottle without suffering impairment to the appearance of the label by a method wherein a bonding strength between a hot melt agent and the surface of a glass at ordinary temperature is made smaller than that between the hot melt agent and the surface of the label and the strengths of the base materials for the label and the hot melt agent. CONSTITUTION:One end of a plastic label is stuck on a glass bottle with a hot melt agent, the label is wound around the glass bottle and the aforesaid end thereof is overlapped by the other end thereof and the overlapping ends are bonded together with a solvent. The hot melt agent consisting mainly of base material, tackifier, wax and plasticizer and having a bonding strength to the glass surface at ordinary temperature smaller than any of the bonding strength between the hot melt agent and the label and the strengths of the base materials for the label and the hot melt agent, is used. Since the solvent is used in only bonding the label ends together, the printed surface of the label is not contaminated with the solvent, the label can be peeled of easily from the bottle and the recycle cost of the bottle is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for applying labels to glass bottles.

[Conventional technology]

Conventionally, as a method of cutting a long plastic label in a predetermined manner and pasting it onto a glass bottle, there is a known method of pasting the label and the glass bottle using a plastic label solvent.

For example, in labels made of expanded polystyrene sheets, methylene chloride is used as a solvent for adhering to glass bottles, but in this case, if the amount of solvent applied is small, the solvent evaporates before the adhesion is completed. As a result, the adhesive strength between the glass bottle and the label is lost, and the label easily peels off.

However, if too much solvent is applied, the solvent may penetrate to the surface of the label, damaging its appearance, or depending on the atmosphere at the time of application, it may take time for the solvent to evaporate, resulting in insufficient adhesive strength. or misalignment of the label may occur.
There was a problem in that the allowable range of the amount of coating to obtain a predetermined adhesive strength was narrow.

On the other hand, hot-melt agents are also used to bond plastic labels and glass bottles together; In some cases, when the label is removed from the glass bottle, the hot melt agent remains in the glass bottle, which increases the cost of reuse.

[Problems to be solved by the present invention]

The present invention has been made to solve the above problems, and its purpose is to be able to reliably attach plastic labels to glass bottles without damaging the appearance of the label, but at the same time To provide a label pasting method that allows the label to be easily removed and reduces the cost of reusing glass bottles.

[Means to solve problems]

Under the above-mentioned circumstances, the inventors of the present invention have conducted intensive research on a method for attaching plastic labels to glass bottles, and as a result, have found that it is effective to combine specific hot melt agents, and have completed the present invention. It's arrived.

Therefore, the above-mentioned object of the present invention is to provide a hot-melt material whose adhesive strength with a glass surface at room temperature is lower than either of the adhesive strength between the hot-melt agent and the label and the strength of the base material of the label and the hot-melt agent. This is accomplished by applying the label to the glass bottle using an adhesive.

More specifically, one end of the label is affixed to a glass bottle using this hot melt agent, and
This is achieved by wrapping the label around the glass bottle once, and pasting the end of the label over one end of the label attached to the glass bottle using a solvent.

A plastic film is a thin, long, flexible membrane made of foamed or non-foamed plastic.
It is usually wound into a roll in the direction of wrapping it around a glass bottle, and a label is a film with desired printing applied to it, or a film cut into a predetermined length.

There are no particular restrictions on the material of the film, but foamed or non-foamed polystyrene resin, polyvinyl chloride, etc. are suitable.

As a label, a polystyrene foam sheet with a thickness of 0.1 to 0.3 mm and a density of about 0.7 to 0.01 g/crl has a non-foamed printing layer with a thickness of 0.01 to 0.05 mm on the surface. Recommended.

Polystyrene or polyvinyl chloride films with a thickness of about 0.02 to 0.2 mm are also recommended.

The hot melt agent is easily peeled off from the glass surface at room temperature, and its adhesive strength with the glass surface is 0.01 to 5 kg/25.4 per cm at an ambient temperature of 0 to 40°C.
mm can be used.

If the adhesive strength at room temperature exceeds 5 kg/25.4 mm, the label may break the base material when the hot melt agent is removed from the glass bottle, and it will take time to remove the residue from the glass surface.

The adhesive strength referred to here is determined by linearly applying a hot melt agent melted at 180°C to a 3 mm thick glass plate at a coating amount of 2 g/m. A 180 degree wide label was crimped to make a sample, and this sample was peeled off at an angle of 180 degrees.
The value was obtained by measuring at 20°C at a peeling speed of 200 mm/min.

Hot melt adhesives mainly consist of a base polymer, tackifier, wax, and plasticizer.

Examples of this base polymer include ethylene/vinyl acetate copolymer, ethylene/ethyl acrylate copolymer, polyethylene, polypropylene, ethylene/(meth)acrylic acid copolymer and its metal salts, and ethylene/methyl methacrylate copolymer. Coalescence, styrene/butadiene/styrene block copolymer, styrene/isoprene/styrene block copolymer, styrene/styrene/butylene/styrene block copolymer, ethylene/butene copolymer, ethylene/styrene block copolymer,
Examples include propylene rubber, ethylene-propylene-butene copolymer, butyl rubber polyester, polyamide, polyisobutylene, saponified ethylene-vinyl acetate copolymer, etc., and these are usually used alone or in combination of two or more in the entire composition. Examples of the tackifier blended in the range of 00% to 100% by weight include aliphatic petroleum resins, aromatic petroleum resins, alicyclic petroleum resins, terpene resins, rosin and rosin derivatives, and water of each. Examples include additive resins, terpene phenol resins, coumaron-indene resins, xylene resins, etc., and these are used alone or in combination of two or more types, usually in the range of 0% to 90% in the entire composition.

Specific examples of wax include natural wax, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, polypropylene wax, or oxides or acid-modified products thereof, and these may be used alone or in combination of two or more. In combination, they are usually incorporated in the total composition in a range of 0% to 90%.

In addition, examples of the plasticizer include paraffin oil, aroma oil, naphthenic oil liquid paraffin, liquid polybutene, dioctyl phthalate, dibutyl phthalate, etc. These may be used alone or in combination of two or more,
It is usually used in the total composition in a range of 0% to 40%.

When carrying out the present invention, additives other than those mentioned above may be used within the range that does not impair the purpose of the present invention. Such additives include known antioxidants, colorants, fillers,
Examples include ultraviolet inhibitors.

In order to produce the hot melt adhesive used in the present invention, the above raw materials may be mixed in a molten state (usually at 150 to 200°C) by a conventional method.

After melting the hot melt agent at usually 150 to 200°C, apply 1 to 4 dots, preferably 1 dot, to the back of the label, then press the label against the glass bottle and fix the label tip so that it does not shift. , wrap the label around the glass bottle.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is an explanatory diagram showing the main parts of a typical device used in the present invention.

A long printed label l made of expanded polystyrene with a thickness of 0.17 mm is cut to a predetermined width, wound into a roll, placed on a stand provided in the apparatus, and sequentially fed out.

The fed out long label passes through a cutting positioning detector, is nipped by feed rolls, and is sent to a cutter.

A mark to determine the cutting position is stamped on the label in advance, and the cutter 2 cuts the label so that it reaches the predetermined cutting position and cutting size using the detector, resulting in a blank 3. The blank 3 is sucked by the vacuum drum 6. While moving.

During the movement, about 7 mm of the rear end of the non-printing surface comes into contact with the felt 4 soaked with tetrahydrofuran, and part of the surface of the portion 10 is dissolved. A fixed amount of tetrahydrofuran is dripped onto the felt using a metering pump, and the amount dissolved is controlled by the dropping speed.

The blank 3, which has been partially dissolved with the solvent, is sprayed and coated with a hot melt agent from the hot melt gun 5 in the next step.
Transfer with hot melt agent attached.

On the other hand, the glass bottles 7 sent by the conveyor are moved one by one at a predetermined interval by a star-shaped wheel 8 and brought into contact with the label 3.

Almost simultaneously with the contact, the tip of the label 3 is attached to the glass bottle 7 by the hot sewage agent 9 which is in a molten state.

The hot melt agent 9 is sandwiched between the label 3 of the vacuum drum 6 and the glass bottle 7 and stretched to accurately fix the label 3 to the glass bottle 7. When the hot melt agent 9 is continuously moved on the glass bottle 7 or the conveyor, the label 3 or the periphery of the glass bottle 7 is stretched. The melted portion 10 of the rear end of the non-printing surface is overlapped with the leading end of the printing surface and crimped.

Depending on the shape of the glass bottle, a heat-shrinkable label may be used; in this case, the bonded label is heated to adhere to the glass bottle 7.

FIG. 2 shows the moment when the label 3 on the vacuum drum 6 comes into contact with the glass bottle 7.

The label 3 is adhered to the glass bottle 7 with the hot melt agent 9, and then, as the glass bottle 7 rotates and moves, the label 3 is wrapped around the glass bottle. The portion 10 whose surface is partially dissolved by the solvent is superimposed on the leading end portion of the printed surface of the label 3.

The label 3 is a label that is strongly heat-shrinkable in a certain direction depending on the shape of the glass bottle around which the label is wrapped. FIG. 3 shows an example in which the label 3 shown in FIG. 2 is made into a cylindrical shape and then passed through a shrink tunnel.

Next, a label was attached to a glass bottle using the above apparatus and the hot melt agent shown in the columns of Examples 1 to 4 in Table 1.

Table 1 shows each composition, physical properties, and peeling state from glass.
It was shown to.

No matter which hot melt adhesive is used to adhere the label to the glass bottle, there will be no problem with positional deviation, and the 30°
When removing the label from a labeled glass bottle that had been left in the atmosphere of C, the label could be removed extremely easily without any hot melt agent remaining on the glass bottle.

In addition, the adhesion to glass was examined using hot melt agents having the compositions shown in Comparative Examples 1 and 2. In both cases, hot melt agent remained on the glass when the label was removed.

〔Effect of the invention〕

According to the present invention, adhesive using solvent is only used for adhering the edges of labels that are easy to adhere, and since the glass bottle and label are adhered using hot melt agent, the printed surface of the label may be contaminated with solvent. Since the label can be reliably fixed without being damaged, labeled glass bottles with high commercial value can be obtained at a high yield.

Additionally, if the label needs to be removed later, it can be easily peeled off from the glass bottle.
The cost of reusing glass bottles is significantly reduced.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the main parts of a typical device used in the present invention, FIG. 2 is an explanatory diagram showing the state in which the label 3 on the vacuum drum 6 is in contact with the glass bottle 7, and FIG. , is an explanatory diagram showing a state in which the label 3 shown in FIG. 2 is made into a cylindrical shape and then passed through a shrink tunnel. l -... Long label 2 - Cutter 3 - Label blank 4 - Felt 5 - Hot melt gun 6 - Vacuum drum 7 - Glass bottle 8 ...-Wheel 9~ Hot melt agent

Claims (2)

[Claims] (1) A long printed plastic film is cut to a predetermined size to form a label, and the surface of the label is placed in close contact with a continuously rotating vacuum drum to arrange the label.
After applying a solvent to the trailing edge of the back side of the label and a hot melt agent to the leading edge of the back side of the label, the label coated with the hot melt agent is brought into contact with a glass bottle that is being fed while rotating at predetermined intervals. By pressing the rear end of the wrapped and solvent-coated label over the top of the label that has already been wrapped around the glass bottle,
In the method of attaching labels to glass bottles, the adhesive strength at the interface between the hot melt agent and the glass at room temperature is
The method for pasting a label as described above, characterized in that the adhesive strength between the hot melt agent and the label interface, the strength of the base material of the label, and the use of a hot melt agent that is lower than the strength of the base material of the hot melt agent. (2) The adhesive strength between the hot melt agent and the glass interface is 0~
0.01~5kg/25.4mm at 40℃ ambient temperature
The method for applying a label according to claim 1, which uses a hot melt agent.