JP2003164786A - Method for adhesive application - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for adhesive application in which adhesive- application mode can be optimized in accordance with the form of an object to be coated. <P>SOLUTION: In this method for adhesive application, a gas is ejected to the adhesive A which is being discharged threadlike from an outlet 20 on a discharge trajectory in a predetermined cycle so as to apply the threadlike adhesive A on the surface of the object O to be coated. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for applying an adhesive, and more particularly, it is suitable for applying an adhesive to the surfaces of various constituent members of an absorbent article. The present invention relates to a working method and a device.

[0002]

2. Description of the Related Art In an absorbent article, a hot melt adhesive is used for joining various constituent members such as a top sheet, an absorber and a back sheet.

A conventional hot melt adhesive coating method is as follows:
In a state in which a whirlwind is generated in a discharge direction below the discharge port so as to surround the discharge port, a filament adhesive is discharged from the discharge port toward various constituent members conveyed on a conveyance line below the discharge port,
The adhesive is continuously spirally applied to the surface of the member while swirling spirally.

By the way, in applying the hot-melt adhesive to various constituent members of the absorbent article, it is important to suppress the obstruction of the absorbent of the adhesive and the obstruction of the moisture permeability of the back sheet. Therefore, there has been a demand for a coating method capable of changing the coating form including the wire diameter of the hot melt adhesive according to the type and form of the member and the coating location.

However, in the conventional coating method, since the diameter of the adhesive ejection port is narrowed to narrow the wire diameter, there is a limit to thin the wire diameter while maintaining stable ejection from the nozzle. there were. Further, it has been difficult to change the coating form for the coating object that is continuously conveyed.

Therefore, an object of the present invention is to provide an adhesive coating method and apparatus capable of optimizing the wire diameter of the adhesive and the coating form depending on the form of the object to be coated.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a filamentous adhesive is applied by injecting a gas from an adhesive ejection port toward an adhesive which is ejected in a filamentous shape on an ejection track having a predetermined cycle. The above object is achieved by providing a method for applying an adhesive that is applied to the surface of an object to be processed.

According to the present invention, an adhesive ejection means for ejecting the adhesive in the form of threads from an ejection port in an ejection trajectory having a predetermined cycle, and a gas ejection for ejecting a gas to the adhesive ejected from the ejection means. The above-described object is achieved by providing an adhesive coating device including a means.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described based on its preferred embodiments with reference to the drawings.

1 and 2 show a first embodiment in which the adhesive coating device of the present invention is applied to the coating of an adhesive on a constituent member of an absorbent article. In FIG. 1, reference numeral 1 indicates an adhesive coating device (hereinafter, also simply referred to as a coating device).

As shown in FIG. 1, the coating apparatus 1 includes an adhesive hot melt gun 2 (discharging means) for discharging the adhesive A in a filament shape from a discharge port in a discharge orbit having a predetermined cycle, and a hot melt gun. An injection nozzle (gas injection means) 3 for injecting air (gas) onto the adhesive A discharged from the nozzle 2 is provided.

As shown in FIG. 2A, the hot melt gun 2 has four air injection ports 21 arranged so as to surround the ejection port 20. Then, by periodically injecting air of a predetermined pressure from these ejection ports 21 in a predetermined direction, the whirlwind is directed toward the ejection direction D (see FIG. 1) of the adhesive A ejected from the ejection ports 20. Then, the adhesive A is discharged from the hot melt gun 2 in a discharge orbit which spirally turns in a predetermined cycle.

The diameter (inner diameter) of the discharge port 20 is preferably 0.1 to 2 mm in order to prevent the hot melt from being completely coated (to prevent clogging).

The diameter (inner diameter) of the air ejection port 21 arranged around the ejection port 20 is 0.1 to 0.1 from the test result.
It is preferably 2 mm.

In the coating apparatus 1 of this embodiment, two hot melt guns 2 are fixed to the frame 4 in parallel at a predetermined interval. As the hot melt gun 2, for example, a product name “spiral gun” manufactured by Nordson can be used.

As shown in FIG. 2B, the injection nozzle 3
Is a direction (horizontal direction) substantially orthogonal to the discharge direction D of the adhesive A and the transport direction R of the coating object O (see FIG. 3).
Both of which have vertically two jetting ports 30 for jetting air in a direction substantially orthogonal to each other, and the application form of the adhesive A on the surface of the object O to be coated with the adhesive A discharged by the hot melt gun 2 is described. Can be spread in a direction orthogonal to the transport direction R of the object to be coated O after the wire diameter of the adhesive A is reduced.

Further, the jet nozzle 3 has a jet port 31 for jetting air in parallel with the discharge direction D of the adhesive A at the tip thereof, and jets air of a predetermined pressure from the jet port 31. Thus, it is possible to prevent the adhesive A from scattering outside the ejection port 31. The injection nozzle 3 communicates with a compressor (not shown) that individually supplies compressed air to the injection ports 30 and 31.

The injection nozzle 3 has a pressure control section (not shown) for changing the injection pressure of the air injected from the injection port 30.
Adhesive A on the surface of the coating object O
The coating mode can be changed in a direction orthogonal to the transport direction R (see FIG. 3) of the object to be coated O.

Further, the injection nozzle 3 is provided with a changing mechanism (not shown) for changing the ejection port 30 in the ejection direction D of the adhesive A, and the ejection ports 30 have different heights. By setting so that the coating form of the adhesive A on the surface of the coating object O can be changed in the transport direction R of the coating object O.

In the coating apparatus 1 of this embodiment, a spray nozzle 3 is attached to each hot melt gun 2. These two spray nozzles 3 are attached to the hot melt gun 2 so that the spray ports 30 face each other and the heights of the spray ports 30 are different. In this way, the coating apparatus 1 overlaps the adhesive A on the surface of the coating object O in the transport direction R of the coating object O by setting the height positions of the ejection ports 30 to be different from each other. The condition can be adjusted.

Next, the adhesive coating method of the present invention is applied as a preferred embodiment to an embodiment in which the adhesive is applied to the constituent members of the absorbent article using the coating apparatus 1. It will be explained based on.

First, in each of the two hot melt guns 2, the adhesive A is discharged in a filament form from the discharge port 20 in a state in which whirlpool is generated in the discharge direction so as to surround the discharge port 20, and the adhesive A is predetermined. It is spirally swirled in the discharge orbit of the cycle.

On the other hand, in a direction substantially horizontal from the ejection port 30 of the ejection nozzle 3 toward the adhesive A that is ejected from the ejection port 20 and swirls in a spiral shape, it is substantially in the conveyance direction R of the object to be coated O. The adhesive A is applied to the surface of the object to be coated O while jetting air in the orthogonal direction and jetting air for preventing the adhesive A from scattering from the jet port 31 downward.

In the present embodiment, the constituent members of the absorbent article which is the object to be coated include a top sheet, a back sheet and an absorber.

The cycle of the discharge trajectory of the adhesive discharged from the hot melt gun 2 can be appropriately set according to the coating form of the adhesive on the surface of the object to be coated.

As the adhesive A to be discharged by the hot melt gun 2 and the temperature at the time of discharging, the usual ones and temperatures used for bonding constituent members of an absorbent article can be applied without particular limitation.

The height from the surface of the object to be coated O to the discharge port 20 is appropriately set according to the coating form of the adhesive A on the surface of the object to be coated O.

The pressure of the air jetted from the jet ports 30 and 31 of the jet nozzle 3 can be appropriately set according to the coating form of the adhesive A on the surface of the object O to be coated. Considering the certainty, it is preferably 0.1 to 5 Pa. Moreover, when the adhesive A discharged in a filament shape by the air jetted from the jet port 30 is cut, the pressure of the jetted air is 1 to 5 P according to the test result.
It is preferably a.

The difference in fluctuation of the jet pressure of the air jetted from the jet port 30 of the jet nozzle 3 can be appropriately set according to the coating form of the adhesive A on the surface of the coating object O. This variation difference can be eliminated by the air tank. Further, the variation pattern of the ejection pressure of the air ejected from the ejection port 30 of the ejection nozzle 3 may be appropriately set according to the coating mode of the adhesive A on the surface of the coating object O such as periodic or intermittent. it can.

Further, the height of the injection port 30 of the injection nozzle 3 is set to the ejection direction D of the adhesive A by the changing mechanism.
Can be varied along. This variation difference can be appropriately set according to the coating form of the adhesive A on the surface of the coating object O.

In the adhesive coating method using the coating apparatus 1, since the wire diameter of the adhesive is thinned by the air jetted by the jet nozzle 3, the adhesive A on the surface of the coating object O is coated. Can have a wire diameter of 0.1 to 1 mm, that is, about 1/2 or less of the wire diameter when the injection nozzle 3 does not perform the injection. In addition, the spiral width W of the adhesive A on the surface of the coating object O (see FIGS. 3 to 5).
Can be about 1.5 to 2 times or more the width of the spiral when air is not jetted by the jet nozzle 3.

FIGS. 3 to 5 show the coating mode of the adhesive A on the surface O of the coating object coated by the coating method of the adhesive using the coating apparatus 1 (FIGS. It shows only the coating form by the melt gun).

FIG. 3 shows a coating form in the coating apparatus 1 in which the height position of the discharge port 20 of the hot melt gun 2 is the same and the height of the spray port 30 of the spray nozzle 3 is different. It is shown. By thus setting the ejection openings 30 of the ejection nozzles 3 to have different heights, it is possible to apply the spiral of the two adhesives A in the transport direction R of the coating object O with a predetermined length. .

FIG. 4 shows a coating form of the adhesive in the coating apparatus 1 when the jet pressure of the air jetted from the jet port 30 of the jet nozzle 3 is periodically changed. By periodically varying the ejection pressure of the ejection port 30 of the ejection nozzle 3 in this manner, the spiral of the adhesive A formed on the surface of the object to be coated O is applied in a wavy form having a predetermined wavelength L. Can be engineered.

FIG. 5 shows a coating form of the adhesive A in the coating apparatus 1 when the jet pressure of the air jetted from the jet port 30 of the jet nozzle 3 is intermittently changed. . By intermittently varying the ejection pressure of the ejection port 30 of the ejection nozzle 3 in this way, the spiral width W of the spiral of the adhesive A formed on the surface of the object to be coated O varies at predetermined intervals. It can be applied in the form.

As described above, according to the coating apparatus 1 of this embodiment and the adhesive coating method using the same, the wire diameter of the adhesive A is reduced and then the coating object O The width of the spiral of the adhesive A formed on the surface, the overlap of the spirals, and the like can be changed, and the coating form of the adhesive A can be optimized according to the form of the coating object O. Therefore, it is possible to prevent unnecessary overlap of the adhesive A on the surface of the object to be coated O and form a more precise coating form,
It is possible to more reliably suppress the obstruction of absorbency and the impermeability of moisture in the resulting absorbent article.

In addition to the hot melt gun 2, the air can be jetted by the jet nozzle 3 to reduce the wire diameter of the adhesive A, so that a desired coating form can be stably formed.

By adjusting the heights of the injection ports 30 of the injection nozzles 3 to be different, the degree of overlap of the adhesive A on the surface of the coating object O in the transport direction R of the coating object O is adjusted. Therefore, it is not necessary to arrange the hot melt gun 2 itself at a predetermined interval in the transport direction R of the object to be coated O, and the installation space of the apparatus can be suppressed.

Further, since the spray nozzle 3 is provided with the spray port 31 for preventing the scattering of the adhesive A, it is possible to prevent the scattering of the adhesive A from the surface of the object to be coated O, and to improve the coating environment. Staining can be suppressed and the coating environment of the adhesive A can be kept good.

FIG. 6 shows a second embodiment of the adhesive coating apparatus of the present invention.
1 shows an embodiment. The coating apparatus of the second embodiment is the one in which the arrangement of the ejection means in the first embodiment is changed, and in the following description, only the different parts will be described.

As shown in FIG. 6, in the coating apparatus 1 of the second embodiment, the injection nozzles 3 are arranged between two hot melt guns 2 arranged in parallel. The injection nozzles 3 are arranged so that the injection ports 30 thereof face each other, and air can be injected from the injection ports 30 substantially horizontally.

FIG. 7 shows a coating form of the adhesive A coated on the surface of the coating object O by the coating apparatus 1'of the second embodiment. As shown in FIG. 7, according to the coating apparatus 1 ′ of the second embodiment, the adhesive A is applied in a coating form in which the spiral width W spreads on both sides of the surface of the object to be coated O at predetermined intervals. Can be applied continuously

The present invention is not limited to the above-described embodiment, but can be modified as appropriate without departing from the spirit of the present invention.

In the present invention, as in the coating apparatus 1 of the above-described embodiment, it is preferable that the air is jetted from the four air jetting ports 21 so as to surround the jetting port 20 to generate whirlwind. It is also possible to inject air from one or more injection ports to generate a whirlwind, and to eject the adhesive A in a spiral orbit of a predetermined orbital discharge orbit.

Further, by arranging air injection ports at equal intervals on both sides of the ejection port in a direction orthogonal to the direction of transport of the object to be coated, the air is alternately ejected from these ejection ports. It is also possible to discharge the adhesive from the discharge port in a discharge trajectory that reciprocates in a direction (one direction) orthogonal to the transport direction at a predetermined cycle. Then, by using such a coating device, for example, by injecting air to the adhesive discharged on the discharge track while changing the injection pressure at a predetermined cycle, it is possible to remove the hot melt in FIG. As shown in the discharge form by the gun only), it has a wavy form (continuous omega form), and periodically fluctuates in a direction orthogonal to the transport direction R at a wavelength L corresponding to the fluctuation period of the injection pressure. The adhesive A can be applied in a form.

The present invention is as in the above embodiment,
Two hot melt guns are arranged in parallel and the injection nozzle 3
It is preferable to adjust the degree of overlap of the adhesive A on the surface of the object to be coated O in the transport direction of the object to be coated O by making the injection ports of the nozzles have different heights. Are arranged at the same height, and two or more hot melt guns are arranged in the conveyance direction R of the object to be coated O at predetermined intervals to form a houndstooth check pattern.
It is also possible to adjust the degree of overlap of the adhesive A on the surface of the object in the transport direction R of the coating object O.

Further, in the present invention, three or more hot melt guns may be arranged in a line, and the hot melt guns on both sides thereof may be arranged like the hot melt gun and the injection nozzle of the first embodiment. .

The present invention is as in the above embodiment,
It is particularly suitable for applying an adhesive to various constituent members of the absorbent article, but can also be applied to applying an adhesive to other members.

[0049]

According to the present invention, the coating form of the adhesive can be optimized according to the form of the object to be coated.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a first embodiment of an adhesive coating device of the present invention.

FIG. 2 is a diagram schematically showing a main part of the adhesive coating device of the same embodiment, where (a) is a plan view showing the vicinity of the ejection port of the ejection means, (b) and (c). [Fig. 3] is a view schematically showing a tip end portion of an injection unit.

FIG. 3 is a diagram schematically showing the form of an adhesive applied to the surface of an object to be applied by the adhesive applying apparatus of the same embodiment.

FIG. 4 is a diagram schematically showing a form of an adhesive applied to the surface of an object to be applied by the adhesive applying apparatus of the same embodiment.

FIG. 5 is a diagram schematically showing the form of an adhesive applied to the surface of an object to be applied by the adhesive applying apparatus of the same embodiment.

FIG. 6 is a diagram schematically showing a second embodiment of the adhesive coating device of the present invention.

FIG. 7 is a diagram schematically showing the form of an adhesive applied to the surface of an object to be applied by the adhesive applying apparatus of the embodiment.

FIG. 8 is a diagram schematically showing the form of an adhesive applied to the surface of an object to be coated by another embodiment of the adhesive coating device of the present invention.

[Explanation of symbols]

1 Adhesive coating equipment 2 Hot melt gun (Means for discharging adhesive) 20 outlets 21 jet 3 injection nozzle (gas injection means) 30, 31 injection port A adhesive O coating target

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4D075 AC08 AC11 AC88 AC93 AC95                       BB14Y BB22X BB32X DA03                       EA35                 4F041 AA12 AB02 BA07 BA48 BA54                 4F042 AA22 AB01 BA06 BA08 EB18

Claims (6)

[Claims] 1. A filamentous adhesive agent is applied to the surface of an object to be coated by injecting a gas from the adhesive agent ejection port toward the adhesive agent which is ejected in a filamentous shape on an ejection track having a predetermined cycle. Adhesive coating method. 2. The adhesive according to claim 1, wherein the adhesive is spirally swirled by a whirlwind generated in the discharge direction so as to surround the discharge port, or is discharged in a discharge trajectory reciprocating in one direction. Agent coating method. 3. The adhesive coating method according to claim 1, wherein the coating pressure of the gas is changed to control the coating form of the adhesive. 4. An adhesive ejection means for ejecting the adhesive in the form of threads from an ejection port on an ejection track having a predetermined cycle, and a gas ejection means for ejecting a gas onto the adhesive ejected from the ejection means. Adhesive coating equipment equipped with. 5. An ejection port is provided so as to generate a whirlwind in the ejection direction so as to surround the ejection port, and the adhesive is spirally swirled or ejected in a reciprocating ejection trajectory in one direction. The adhesive coating device according to claim 4, wherein 6. The adhesive coating apparatus according to claim 5, wherein the injection unit includes a pressure control unit that changes the injection pressure of the gas.