JP4689296B2 - Adhesive application method and adhesive application device - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive coating method and a pressure-sensitive adhesive coating device, and more particularly to a pressure-sensitive adhesive coating method and coating device for flat rubber used when forming gathered parts such as disposable diapers.

  When forming a gathered portion such as a disposable diaper, usually, a pressure sensitive adhesive such as hot melt is applied to a flat rubber, and a gathered portion is formed by adhering a base material such as paper, nonwoven fabric or film. In the application of the hot melt pressure-sensitive adhesive to such a flat rubber or the like, since efficient application of the hot-melt pressure-sensitive adhesive is required in a small amount, various application methods have been studied.

  For example, Patent Document 1 below discloses a method of applying a pressure-sensitive adhesive to the surface of a flat rubber or the like by spraying the pressure-sensitive adhesive while swirling and swinging with hot air in a non-contact manner.

In Patent Documents 2 and 3 below, a groove is formed in a contact-type pressure-sensitive adhesive applicator called a coater, the pressure-sensitive adhesive is applied from the groove, and a flat rubber is passed through the groove to adhere to the flat rubber outer surface. A method of applying the agent is disclosed.
JP 2003-328275 A JP 2001-347209 A JP 2004-249191 A

  However, in the method of Patent Document 1, the air blowing hole is positioned around the pressure-sensitive adhesive coating hole, and air pressure is blown to the pressure-sensitive adhesive to rotate and swing the pressure-sensitive adhesive on the flat (square) rubber. For this reason, the pressure-sensitive adhesive can be applied only to either the back side or the front side.

  In the method of Patent Document 2, a slit groove is provided in an applicator called a coater, the adhesive is applied from the side and upper portion, and the adhesive is applied by passing a flat (square) rubber through the adhesive. . Therefore, since the adhesive is applied only to the end portion of the flat (square) rubber that passes through the slit groove, the application area to the flat (square) rubber is extremely reduced.

  In the method of Patent Document 3, an enlarged portion (adhesive reservoir) filled with an adhesive is provided in the middle portion of the slit groove, and an elastic string state (flat rubber, thread rubber, etc.) is passed through the enlarged portion. It can be applied to the entire surface. However, in this method, since the coating is performed on the entire surface of the rubber, it is difficult to adjust the application position of the pressure-sensitive adhesive only to a specific position.

  The present invention has been made in view of the above problems, and its purpose is to apply a pressure-sensitive adhesive only to the surface where the flat rubber and the object to be bonded are in contact with each other, effectively sticking to the flat rubber. An object of the present invention is to provide an application method and apparatus for applying an agent.

  More specifically, the present invention provides the following.

  (1) A pressure-sensitive adhesive application method for applying pressure-sensitive adhesive to continuous flat rubber, wherein the pressure-sensitive adhesive is transferred into the slit while passing the flat rubber through a slit for guiding the flat rubber. A pressure-sensitive adhesive application method in which a pressure-sensitive adhesive is applied only to both side surfaces of the flat rubber that is being transported.

  According to the pressure-sensitive adhesive application method of the present invention, since the pressure-sensitive adhesive is applied only from both side wall surfaces in the slit, the pressure-sensitive adhesive can be applied only to both side surfaces of the flat rubber passing through the slit. Therefore, since the pressure-sensitive adhesive can be applied only to necessary portions, the amount of the pressure-sensitive adhesive applied can be reduced, and stable application can be achieved.

  (2) The discharge of the pressure-sensitive adhesive from the both side wall surfaces can be individually controlled on the left and right side wall surfaces, and the pressure-sensitive adhesive is applied to each side surface of the flat rubber in a different state (1) The adhesive application method.

  According to this aspect, the pressure-sensitive adhesive can be applied to each side surface of the flat rubber in a different state. Therefore, on each side, it is possible to control the amount of adhesive applied and to apply different adhesives.

  (3) The pressure-sensitive adhesive coating method according to (1) or (2), wherein the pressure-sensitive adhesive is discharged toward the vicinity of a half position in the width direction of the flat rubber.

  According to this aspect, since the pressure-sensitive adhesive can be applied to the central portion of the flat rubber, it is possible to prevent the pressure-sensitive adhesive from protruding from the nonwoven fabric or the film to be bonded.

  (4) The width of the slit is within the reference thickness + 0.4 mm, with the thickness in a state where a predetermined tension is applied to the flat rubber as a reference thickness, and the adhesive application according to any one of (1) to (3) Method.

  According to this aspect, by narrowing the slit width within the above range, almost all of the discharged adhesive is applied to the flat rubber while smoothly transporting the flat rubber. That is, since the adhesive that is not applied to the flat rubber can be prevented from falling into the slit, the adhesive can be efficiently applied.

  (5) The pressure-sensitive adhesive coating method according to any one of (1) to (4), which is used for gather formation of a paper diaper.

  Since the gathered portion of the disposable diaper is a portion that directly bites into the wearer's crotch portion, quality requirements are particularly severe from the viewpoint of wear and hygiene. For this reason, it is required to apply the pressure-sensitive adhesive only to the surface where the flat rubber and the object to be bonded such as the nonwoven fabric come into contact. In this regard, according to the method of the present invention, the pressure-sensitive adhesive can be applied only to both side surfaces of the flat rubber, so that the above requirements can be satisfied, and the wear feeling and hygiene of the gathered portion can be improved.

  (6) A pressure-sensitive adhesive application device for applying pressure-sensitive adhesive to continuous flat rubber, provided so as to sandwich the flat rubber conveyed in one direction, and a pair of guides for guiding the flat rubber being conveyed And a slit part having a side wall, and each side wall of the slit part is provided with an adhesive discharge part directed to both side surfaces of the flat rubber.

  According to the pressure-sensitive adhesive coating apparatus of the present invention, since the pair of side walls for guiding the flat rubber is provided, the flat rubber can be aligned until immediately before the pressure-sensitive adhesive is applied. Accordingly, it is possible to stably apply the adhesive. Moreover, since the adhesive discharge part which goes to the both sides | surfaces of a flat rubber is provided, an adhesive can be apply | coated only to the both sides | surfaces of a flat rubber. Therefore, the application amount of the pressure-sensitive adhesive can be reduced, and the application can be performed stably.

  (7) The pressure-sensitive adhesive coating apparatus according to (6), wherein a pressure-sensitive adhesive supply device that can be independently controlled is connected to the pressure-sensitive adhesive discharge section provided on each side wall.

  According to this aspect, since each adhesive discharge unit is connected with an independently controllable adhesive supply device, the adhesive is applied to each side surface of the flat rubber in a different state. Can do. Therefore, in each side, it is possible to control the application amount of an adhesive or to apply a different adhesive.

  (8) The pressure-sensitive adhesive coating apparatus according to (6) or (7), further comprising position adjusting means for adjusting a relative position between a position in the width direction of the flat rubber and a position of the pressure-sensitive adhesive discharge section.

  According to this aspect, even if the width of the flat rubber is different, the pressure-sensitive adhesive discharge position can be adjusted, so that the pressure-sensitive adhesive can be applied near the center in the width direction of the flat rubber.

  (9) The adhesive application device according to any one of (6) to (8), comprising: slit width adjusting means for adjusting the width of the slit portion; and tension adjusting means for adjusting the tension of the flat rubber.

  According to this aspect, the slit width can be adjusted by the slit width adjusting means so that almost all of the discharged adhesive is applied to the flat rubber while smoothly transporting the flat rubber. The thickness of the flat rubber varies depending on the tension. For this reason, the gap between the left and right side wall surfaces of the slit and both side surfaces of the flat rubber can be adjusted to the optimum position by using the tension adjusting means together.

  According to the pressure-sensitive adhesive coating method and pressure-sensitive adhesive coating apparatus of the present invention, only the required amount of pressure-sensitive adhesive can be efficiently applied to the flat rubber, the amount of pressure-sensitive adhesive applied can be reduced, and stable. Can be applied.

  Hereinafter, an example of an embodiment of the present invention will be described based on the drawings. In the following description of the embodiments, the same reference numerals are assigned to common components, and the description thereof is omitted or simplified.

<Adhesive application device>
〔overall structure〕
1 to 3 are diagrams showing an outline of the pressure-sensitive adhesive coating apparatus 100 of the present invention, FIG. 1 is a plan view showing the whole pressure-sensitive adhesive coating apparatus of the present invention, and FIG. 2 is the vicinity of the coating portion of FIG. FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG.

  As shown in FIG. 1, in this adhesive application device 100, a continuous flat rubber 90 is vertically arranged so that the width direction of both side surfaces is vertical, and the left side is directed toward the arrow direction in FIG. Can be transported from right to left. And in the middle of conveyance, the applicator 150 having the adhesive applicators 30 and 31 is disposed so as to surround the flat rubber 90. After the adhesive is applied by the adhesive applicators 30 and 31, the adhesive is applied. The target film 80 is drawn out from both sides and joined to both sides of the flat rubber 90.

  Referring also to FIGS. 2 and 3, the application unit 150 includes a pair of guide side walls 20, 21 disposed on the upstream side in the conveying direction of the flat rubber 90 on the heater base 10, and guide side walls 20, 21. A pair of adhesive applicators 30 and 31 are provided on the downstream side. Further, a gear pump 40 for supplying an adhesive is provided below the heater base 10, and the gear pump 40 and nozzles 50 and 51 provided in the adhesive applicators 30 and 31, respectively. Adhesive paths 60 and 61 for connecting the two are provided. That is, in this embodiment, the adhesive paths 60 and 61 extending from the gear pump 40 branch into two at the switching valve 70, and after extending in the horizontal direction from there, rise upward and are connected to the nozzles 50 and 51, The nozzles 50 and 51 extend upward as they are and then extend horizontally again to reach both wall surfaces of the adhesive applicators 30 and 31. The switching valve 70 can adjust the coating length of the adhesive application, continuous application, intermittent application, and adhesive application position.

  Hereinafter, the main components of the pressure-sensitive adhesive coating apparatus of the present invention will be described in more detail.

[Guide side wall]
The pair of guide side walls 20, 21 having a guide function is installed on the upper side of the heater base 10 and upstream of the flat rubber 90 in the conveying direction. As shown in FIG. 3, the guide side walls 20, 21 form a slit W, and the flat rubber 90 passes through the slit W and is sent to the downstream adhesive applicators 30, 31.

[Adhesive applicator]
The pair of adhesive applicators 30 and 31 is installed on the upper side of the heater base 10 and on the downstream side of the guide side walls 20 and 21. As shown in FIG. 3, the adhesive applicators 30 and 31 also form a slit W by a pair of side walls 30a and 31a, and a nozzle 50 from which the adhesive is discharged to each of the adhesive applicators 30 and 31. 51 is provided. The nozzles 50 and 51 are provided in the horizontal direction toward the slits W of the adhesive applicators 30 and 31, and have discharge portions 50 a and 51 a at the side walls 30 a and 31 a. With this configuration, the adhesive can be applied to the left and right surfaces of the flat rubber 90 that passes through the slit W using the independent adhesive applicators 30 and 31. Therefore, the pressure-sensitive adhesive can be stably applied to both surfaces of the flat rubber 90.

[Composition of discharge part]
FIG. 4 is an enlarged view of the vicinity of the discharge unit 50a (51a). The flat rubber 90 may have fine particles 91 attached to the surface from the viewpoint of the stability of the material, but the hardness of the fine particles 91 is the tip 50b (51b) of the discharge portion 50a (51a) contacting the flat rubber 90. If the hardness exceeds the hardness of), the discharge portion 50a (51a) is deteriorated by exhibiting the same effect as the abrasive. In order to prevent this, as shown in FIG. 4, it is preferable that the material of the tip 50b (51b) of the discharge part 50a (51a) is a high-hardness substance. Thereby, the abrasion resistance of the front-end | tip part 50b (51b) can be improved, and coating can be stabilized.

[Other examples of adhesive applicator]
FIG. 5 shows another example of the application unit in the adhesive application device. The applicator 250 is different from FIG. 3 in that the number of side walls having a guide function and an adhesive applicator are increased, and the other configuration is basically the same as that of the above embodiment.

  In FIG. 5, two pairs of adhesive applicators 230 and 231 and a pair of adhesive applicators 232 and 233 are arranged instead of the adhesive applicators 30 and 31 of FIG. It is possible to apply the adhesive simultaneously on both surfaces of the two flat rubbers 90. Although not shown, two sets corresponding to the guide side walls 20 and 21 are also arranged. Thus, an adhesive can be apply | coated to both surfaces of several flat rubber by increasing a side wall and an adhesive applicator. The number of sets of the side walls and the adhesive applicator is not particularly limited, and can be increased as necessary.

  FIG. 6 shows still another example of the application unit in the adhesive application device. This application unit 350 is different from FIG. 3 in that two sets of switching valves 70 are arranged and the adhesive sent to the adhesive paths 360 and 361 can be independently controlled. Is the same as the above embodiment.

  In this way, the adhesive supply system is made independent, and a separate supply system is provided on each side of the flat rubber 90, thereby controlling the coating amount of the adhesive for each side or a different adhesive. It becomes possible to apply.

<Manufacturing method>
Next, the pressure-sensitive adhesive coating method of the present invention using the pressure-sensitive adhesive coating apparatus will be described. The pressure-sensitive adhesive coating method of the present invention includes a flat rubber transporting process in which a flat rubber is passed through a slit that guides the flat rubber, and the pressure-sensitive adhesive is discharged only from both side walls in the slit, and is being transported. It comprises an adhesive application step of applying an adhesive only to both side surfaces of the flat rubber. Hereinafter, it demonstrates along the manufacturing method.

[Flat rubber transport process]
First, as shown in FIG. 1, the continuous flat rubber 90 is vertically arranged so that the width directions of both side surfaces are vertical. Thereafter, the flat rubber 90 is brought into a tension state with a predetermined tension.

  Next, with this tension applied, the flat rubber 90 is conveyed in the direction of the arrow in FIG. 1 and passes through the flat rubber 90 in the order of the pair of guide side walls 20, 21 and the pair of adhesive applicators 30, 31. Let By the guide side walls 20 and 21, the flat rubber 90 can be aligned until just before the adhesive is applied.

  At this time, the pair of side walls 20, 21 and the pair of adhesive applicators 30, 31 form a slit W as shown in FIG. The width of the slit W is preferably within +0.4 mm, with the thickness after applying a predetermined tension to the flat rubber as the reference thickness. By setting to this range, it is possible to prevent the adhesive that cannot be adhered to the rubber from the adhesive applicator from dropping.

  Further, as shown in FIG. 3, the position H of the discharge portions 50a and 51a is from +0.1 mm to −0, with 1/2 of the width of the flat rubber 90 after applying a predetermined tension to the flat rubber 90 as a reference width. It is preferable to be within a range of 1 mm. In this embodiment, since the flat rubber 90 is substantially in contact with the upper part of the heater base 10, the position H is a position that is ½ of the width of the flat rubber 90 from the upper part of the heater base 10. In this way, by providing the discharge portion near the center of the flat rubber 90 in the width direction, the adhesive can be applied to the central portion of the flat rubber, so that the necessary amount can be efficiently applied to the flat rubber 90. .

[Adhesive application process]
The adhesive is pushed out by the gear pump 40, passes through the L-shaped adhesive paths 60 and 61, and is supplied to the adhesive applicators 30 and 31. The pressure-sensitive adhesive supplied to the pressure-sensitive adhesive applicators 30 and 31 is discharged from both nozzles 50 and 51 provided in the pressure-sensitive adhesive applicators 30 and 31 onto both sides of the flat rubber 90 passing through the slit W. Moreover, since the switching path 70 is provided in the adhesive paths 60 and 61, by adjusting the switching valve 70, adjustment of the coating length of the adhesive application of the adhesive, continuous application, intermittent application, The adhesive application position can be adjusted. The pressure-sensitive adhesive used in the present invention is not particularly limited, but hot melt is preferably used. As shown in FIG. 7, the flat rubber 90 obtained in this way is coated with the adhesive 95 only on both side surfaces of the flat rubber 90. The application width P ₁ of the adhesive 95 to the flat rubber 90 is preferably 20 to 90% with respect to the total width P ₂ of the flat rubber 90. Also, the amount applied to the flat rubber 90 is preferably 100 to 1250 g / m ² on each side.

  The nozzles 50 and 51 are provided so as to discharge horizontally into the slits W of the adhesive applicators 30 and 31, and have discharge portions 50a and 51a at the side walls 30a and 31a. By setting it as such a structure, an adhesive can be apply | coated to both surfaces of the flat rubber 90 which passes the slit W using an independent adhesive applicator. Therefore, the adhesive can be stably applied to both surfaces of the flat rubber 90.

  As described above in detail, according to the present invention, the pressure-sensitive adhesive can be applied only to the surface where the flat rubber and the object to be bonded contact, and the application that effectively applies the pressure-sensitive adhesive to the flat rubber. A method and apparatus is obtained.

It is a top view which shows the whole adhesive coating device of this invention. It is a front view of the application part vicinity in FIG. It is A-A 'sectional drawing of FIG. FIG. 2 is an enlarged view of the vicinity of a discharge unit in FIG. 1. It is a figure which shows the other example of the application part in an adhesive coating device. It is a figure which shows the further another example of the application part in an adhesive coating device. It is a figure which shows the flat rubber after an adhesive application.

Explanation of symbols

10 Heater base 20, 21 Guide side wall 30a, 31a Side wall 30, 31, 230, 231, 232, 233 Adhesive applicator 40 Gear pump 50, 51 Nozzle 50a, 51a Discharge part 50b, 51b Tip part 60, 61, 360, 361 Adhesive path 70 Switching valve 80 Film 90 Flat rubber 91 Fine particle 95 Adhesive 100 Adhesive application device 150, 250, 350 Application part W Slit width H Adhesive discharge position P ₁ Adhesive application width P ₂ Full width of flat rubber

Claims (7)

An adhesive application method for applying an adhesive to continuous flat rubber,
While passing the flat rubber through the slit that guides the flat rubber,
The pressure-sensitive adhesive is discharged only from both side walls in the slit, and the pressure-sensitive adhesive is applied only to both side surfaces of the flat rubber being conveyed ,
The discharge of the adhesive from the both side wall surfaces can be individually controlled on the left and right side wall surfaces, and the adhesive is applied to the side surfaces of the flat rubber in different states . The discharge of the adhesive, the adhesive coating method of claim 1 Symbol placement performed toward the vicinity of half the position in the width direction of the flat rubber. The pressure-sensitive adhesive coating method according to claim 1 or 2 , wherein the width of the slit is within the reference thickness + 0.4 mm, with a thickness obtained by applying a predetermined tension to the flat rubber as a reference thickness. The pressure-sensitive adhesive coating method according to any one of claims 1 to 3, which is used for gathering of disposable diapers. An adhesive application device for applying an adhesive to continuous flat rubber,
A slit portion provided to sandwich the flat rubber conveyed in one direction and having a pair of side walls for guiding the flat rubber being conveyed;
Each side wall of the slit part is provided with an adhesive discharge part directed to both side surfaces of the flat rubber ,
An adhesive application device in which an adhesive supply device that can be independently controlled is connected to the adhesive discharge section provided on each of the side walls . The pressure-sensitive adhesive coating apparatus according to claim 5 , further comprising a position adjusting unit that adjusts a relative position between a position of the flat rubber in a width direction and a position of the pressure-sensitive adhesive discharge unit. The pressure-sensitive adhesive coating apparatus according to claim 5 or 6 , comprising slit width adjusting means for adjusting the width of the slit portion and tension adjusting means for adjusting the tension of the flat rubber.

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