JPS5812920B2 - How to remove static electricity from adhesive sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for eliminating static electricity generated between adhesive sheets during the step of peeling them off.

The adhesive sheet is constructed by sandwiching an adhesive between an upper sheet and a release sheet.

Regarding such a structure, for example, Monthly, Machining Technology 1973
Various forms are described on pages 1 to 13 of the November issue.

For example, when an adhesive sheet is processed into an adhesive label, automatically peeled off using an air jet auto-labeler, and attached to a bottle body such as a liquor bottle, soy sauce bottle, or other item, the adhesive label peels off from the release sheet. At the time of peeling, the peelability becomes heavy at the end of the peeling process, and the adhesive label cannot be fed out smoothly, resulting in the adhesive label attached to the item being misaligned.
Problems such as tilting occur frequently.

As a result of various investigations and studies to find out the reason why the peelability becomes slow at the end of peeling when the adhesive label is peeled off from the release sheet, we found that when the surface of the adhesive sheet is measured with a surface electrometer during the peeling process, as shown in Figure 1. It was discovered that positive and negative charges are generated, and as the peeling progresses, the generated charges migrate toward the unpeeled region and accumulate at the ends.

It was also found that the weight of peeling at the ends is caused by the bonding force of accumulated charges.

Regarding charge transfer, the potential in the first half of the peeling process from the beginning of peeling to the middle of the peeling does not change much, but as the peeling moves from the middle to the end, the potential gradually increases, and at the end. It has been confirmed that the potential shows a maximum at the end of the adhesive label, and this maximum potential is related to the length of the adhesive label, such that as the adhesive label becomes longer, the amount of accumulated charge in the end region increases proportionally.

The inventors of the present invention have discovered the phenomenon of generation of such electric charge and that removing it enables smooth peeling of the adhesive label, and has completed the present invention.

The structure of the present invention is characterized in that static electricity generated between the sheets is removed by exposing the pressure-sensitive adhesive sheet in the peeling stage to ionized air.

For example, Japanese Patent Publication No. Sho 52-13919 discloses a method for eliminating electric charges generated on a sheet, but in the case of a sheet in which either a positive or negative electric charge is generated, it is possible to eliminate the electric charge generated on the sheet by grounding it through conductive fibers. This is a method to remove it.

On the other hand, when both positive and negative charges are generated between adhesive sheets during the peeling process, this
Even if the method of No. 2-13919 is used, the static electricity cannot be removed.

This is because the electrostatic attraction between positive charges and negative charges is large.

According to the static elimination method of the present invention, even when such electrostatic attraction is large, the charges can be easily neutralized and erased.

Hereinafter, the configuration of the present invention will be explained with reference to the drawings.

FIG. 2 is a schematic diagram of an air jet type autolabeler, and FIG. 4 is an enlarged view of the area around the dispenser plate of the autolabeler. ) is the adhesive label 4 when bending the tip 3 of the dispenser plate 2.
is peeled off from the release sheet 5, and after being peeled off, it moves to the suction cup part 7 of the air box 6, and once it is sucked by the suction cup,
It is sprayed and pasted onto an article 8 such as a liquor bottle.

In the present invention, when the adhesive label 4 is peeled from the release sheet 5 at the tip 3 of the dispenser plate 2, the adhesive sheet in the peeling stage is exposed to ionized air, thereby neutralizing the static electricity generated between the sheets during the peeling process. and erased.

Note that ionized air means positively and/or negatively charged air, and the phenomenon in which the charges generated between the sheets during the peeling stage are erased by exposure to ionized air is as follows:
This is probably because the charges between the sheets are attracted to each other without causing a short circuit due to electrostatic attraction, but as soon as they come into contact with ionized air, the charges between the sheets are immediately neutralized with the ionized air.

Note that air contains a small amount of dust, and when this dust is ionized, the adhesion of this dust also has a static elimination effect, and the ionized air in the present invention also includes this ionized dust. It is a concept.

Note that ionized air can be generated by corona discharge, spark discharge, etc., but the present invention does not particularly limit the generation means, and any means may be used.

When generating ionized air by corona discharge, it is preferable to use a corona discharge bar 9 as shown in FIG. 3, for example.

As shown in FIG. 2, the corona discharge bar 9 is installed close to (to the extent that it does not come in contact with) the surface of the adhesive label and/or the back surface of the release sheet that is in the process of being peeled, or it is used together with an air compressor to supply ionized air to the surface of the adhesive label and/or the back surface of the release sheet. A method can be adopted in which the label and/or sheet is sprayed.

In the method of blowing ionized air, the corona discharge bar 9 can be placed at a somewhat greater distance from the label and/or sheet than in the case of not blowing.

If the ionized air generator is installed at any position from when the adhesive label begins to peel off from the release sheet until the peeling is completed, the continuously supplied adhesive sheet will be constantly exposed to ionized air. It will be peeled off while being removed.

The static electricity generated between the sheets during the peeling process is neutralized and eliminated by ionized air at the same time as it is generated.

Therefore, when static electricity is not removed, the present invention solves the problem of heavy peeling due to the charge accumulated at the peeling end, and the peeled adhesive label is normally supplied to the suction cup 7 of the air box 6 and placed on the article. Can be pasted precisely in position.

[Brief explanation of drawings]

Figure 1 is an enlarged side cross-sectional view showing the state in which charges are accumulated at the end of peeling while the adhesive sheet is being peeled off from the release sheet, and Figure 2 is a schematic diagram of an air jet auto-labeler. 3 is a schematic view of the corona discharge bar, and FIG. 4 is an enlarged view of the vicinity of the dispenser plate of the autolabeler shown in FIG. 2.

Claims (1)

[Claims] 1. A method for removing static electricity from a pressure-sensitive adhesive sheet, which comprises exposing the pressure-sensitive adhesive sheet in the peeling stage to ionized air to remove static electricity generated between the sheets.