JP2018094852A - Manufacturing method of composite contraction member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a composite contraction member having enhanced external appearance, hardly generating fall off of an elastic member and having suppressed abrasion of a nozzle.SOLUTION: There is provided a manufacturing method of a composite contraction member in which a plurality of elastic members 31 are sandwiched and fixed between a first unwoven fabric 11 and a second unwoven fabric 21, which are laminated, at an elongation state, and having a coating process for coating the elastic members 31 at the elongation state with a hot melt adhesive 34 by using a contact type coating device 51, a confluence process for letting the first unwoven fabric 11 get in contact with cooled chill roll 61 peripheral surface, joining the elastic member 31 coated with the hot melt adhesive in the coating process and adhering them, and a conjugation process for facing the second unwoven fabric 21 to the first unwoven fabric 11, sandwiching the elastic member 31 between both unwoven fabrics 11 and 21 and conjugation fixing the elastic member 31 and both unwoven fabrics 11 and 21 by nip rolls 62 and 63.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a composite elastic member.

Conventionally, as a nozzle for applying an adhesive such as a hot melt adhesive to a thread-like body such as a thin rubber thread that adheres to a sanitary article such as a disposable diaper, an adhesive application nozzle or an adhesive application described in Patent Documents 1 and 2 Apparatus.
The adhesive application nozzle described in Patent Document 1 is a nozzle that applies an adhesive to a traveling filamentous body, and includes an adhesive discharge port for supplying and applying the adhesive to the filamentous body, and the filamentous body. It has a slit-shaped guide groove for guiding it to the adhesive discharge port position. In the adhesive application nozzle, a flat surface with which the filamentous body comes into contact with the nozzle end is provided. Further, the adhesive discharge port is opened in the plane, and a slit-like guide groove of the filament is provided on the upstream side of the plane in the traveling direction of the filament.
Patent Document 2 describes an adhesive application device that applies an adhesive to a running elastic string. In this coating apparatus, an adhesive is supplied to the slit groove communicated with the adhesive supply hole, and a tensioned elastic string-like body is horizontally penetrated through the enlarged portion of the slit groove. Then, the elastic string-like body is supplied in the application line traveling direction, and the adhesive is applied to the entire circumferential surface of the elastic string-like body passing through the slit groove.

JP 2004-352494 A JP-A-2004-249191

In the invention described in Patent Document 1, it is said that there is no dropping of the adhesive, the intermittent application of the adhesive to the thread-like material such as thread rubber is good, and it can be applied to the application of the thread-like material of different thickness. Yes. It is also said that even a string-like body having a thick portion such as a seam can be prevented from being caught and cut. However, it has not been taken into account that the hot-melt adhesive can be easily wound around the surface of the elastic member, and that the nozzle wear caused by the elastic member rubbing the nozzle is not taken into consideration, and there is room for improvement.
Further, in the invention described in Patent Document 2, it is said that the adhesive surface to the base material can be increased by increasing the application surface of the adhesive to the elastic string. However, as described above, the suppression of nozzle wear caused by the elastic member rubbing the nozzle (slit plate) is not taken into consideration, and there is room for improvement.

  The present invention makes it easier for the hot melt adhesive to wrap around the surface of the elastic member, so that the elastic member is adhered and arranged at regular intervals, improving the appearance of the appearance and making it difficult for the elastic member to come off, The present invention relates to a method for manufacturing a composite elastic member in which wear of a nozzle is suppressed.

The present invention is a method for producing a composite elastic member in which a plurality of elastic members are stretched and fixed between a first nonwoven fabric and a second nonwoven fabric to be laminated,
A coating step of applying a hot melt adhesive to the elastic member in an elongated state using a contact coating device;
A merging step in which the elastic member coated with the hot melt adhesive is joined and bonded in the coating step with the first nonwoven fabric in contact with the cooled chill roll peripheral surface;
The second nonwoven fabric is opposed to the first nonwoven fabric, the elastic member is sandwiched between both nonwoven fabrics, and the elastic member and the nonwoven fabric are joined and fixed by a nip roll,
The sum of the entrance side angle θ1 at which the elastic member enters the gun nozzle coating position and the exit side angle θ2 at which the elastic member exits the coating position with respect to the gun nozzle of the contact coating apparatus is 180 °. And a method for producing a composite elastic member in which θ2> θ1.

  According to the method for manufacturing a composite stretchable member of the present invention, the hot melt adhesive is easily wrapped around the surface of the elastic member, so that the elastic member is arranged to be bonded at a constant interval. As a result, it is possible to improve the appearance of the appearance and to prevent the elastic member from coming off. Furthermore, the hot melt adhesive can be applied to the elastic member without causing the nozzle to be worn by the elastic member.

It is the block diagram which showed preferable one Embodiment of the manufacturing apparatus suitable for enforcing the manufacturing method which concerns on this invention. It is the perspective view which showed an example of another manufacturing apparatus suitable for enforcing the manufacturing method which concerns on this invention. It is sectional drawing which showed an example of the coating apparatus shown to FIG. It is the top view which showed a normal example after adhere | attaching an elastic member on the 1st nonwoven fabric. It is the top view which showed an example in which the elastic member was disturbed after bonding an elastic member to the 1st nonwoven fabric.

  A preferred embodiment of a method for producing a composite elastic member according to the present invention will be described below with reference to the drawings. First, a preferable example of a manufacturing apparatus that implements a method for manufacturing a composite elastic member will be described with reference to FIGS. 1 and 2. In FIG. 1 and FIG. 2, the arrangement of the coating device, the chill roll, and the nip roll is slightly different, but the present invention can be applied to any configuration. The following description will be made based on FIG. 1, but FIG. 2 will be referred to as appropriate. Moreover, in each figure, the arrow illustrated along the 1st nonwoven fabric 11, the 2nd nonwoven fabric 21, and the elastic member 31 shows each conveyance direction. Furthermore, the arrow shown in each roll shows the rotation direction of a roll.

  As shown in FIG. 1, the manufacturing apparatus 10 includes a contact-type coating apparatus 51 that applies a hot melt adhesive (not shown) to the elastic member 31. Hereinafter, the contact-type coating apparatus is also referred to as a coating apparatus. The coating device 51 will be described in detail later. On the upstream side of the coating apparatus 51, an elastic member roll (not shown) around which the elastic member 31 to which the hot melt adhesive is applied by the coating apparatus 51 is wound is disposed. Further, an elastic member guide roll 32 is disposed between the coating device 51 and the elastic member roll. The elastic member guide roll 32 determines the entry angle θ1 of the elastic member 31 supplied to the coating apparatus 51. That is, the difference in height between the coating position 52 of the coating apparatus 51 and the position 33 where the elastic member 31 is sent out from the elastic member guide roll 32 is defined as d, and the coating position 52 projected in the horizontal direction and the position 33 sent out. Let L be the distance to. The coating position 52 is a position where the hot melt adhesive 34 is attached to the elastic member 31, and the delivery position 33 is a position where the elastic member 31 is separated from the elastic member guide roll 32. θ1 is represented by an expression of 90− (arctan (d / L)). In the present specification, when viewed from a certain position, the side to which the member is supplied is also referred to as the upstream side, and the side from which the member is sent out is also referred to as the downstream side. The elastic member roll 32 is rotatably arranged so as to supply the elastic member 31 to the coating device 51. In addition, the drive part (not shown) which rotates the elastic member roll 32 may be arranged.

  A chill roll 61 is disposed on the downstream side of the coating apparatus 51. The chill roll 61 is provided with cooling means (not shown) inside the roll. The cooling means is constituted by a flow path in which a refrigerant circulates inside the chill roll 61, for example. As the refrigerant, water, a fluorocarbon refrigerant, a hydrofluorocarbon (HFC) refrigerant, or the like can be used, and water is preferable from the viewpoint of cost, safety, and the like. The chill roll 61 is preferably connected to a refrigerant circulator (not shown) that circulates the refrigerant. The chill roll 61 is cooled to 10 ° C. or higher and 30 ° C. or lower, for example. Preferably it is cooled to 15 ° C. or more and 25 ° C. or less, more preferably 18 ° C. or more and 22 ° C. or less. If the cooling temperature is too low, condensation tends to occur, and if it is too high, a sufficient cooling effect cannot be obtained. The first nonwoven fabric 11 is supplied to the chill roll 61. The elastic member 31 coated with the hot melt adhesive 34 by the coating device 51 is supplied to the chill roll 61 on the first nonwoven fabric 11 wound around a part of the chill roll 61. That is, in the chill roll 61, the first nonwoven fabric 11 and the elastic member 31 supplied from different directions are joined and bonded. Although not shown, a nip roll for adjusting the tension of the first nonwoven fabric 11 in the chill roll 61 may be disposed on the upstream side of the chill roll 61. Further, in order to apply the hot melt adhesive 34 between the chill roll 61 and the elastic member guide roll 32 so that the elastic member 31 is in the extended state, the elastic member 31 is set in the extended state.

  Nip rolls 62 and 63 are disposed on the downstream side of the chill roll 61. Between the nip rolls 62 and 63, the 2nd nonwoven fabric 21 is supplied so that the elastic member 31 may be pinched | interposed between the 1st nonwoven fabric 11 to which the elastic member 31 was adhere | attached, and the 1st nonwoven fabric 11. FIG. The first nonwoven fabric 11 and the second nonwoven fabric 21 are bonded and fixed by pressing the nip rolls 62 and 63 with the elastic member 31 sandwiched therebetween. The nip roll 62 may be provided with a drive unit (not shown) that rotates the roll.

  Next, the coating apparatus 51 is demonstrated below with reference to FIG. 2 and FIG. As shown in FIG. 2, the coating device 51 uses a slit gun. The slit gun is provided with a plurality of coating grooves 54, the elastic members 31 are supplied to the respective coating grooves 54, and the hot melt adhesive 34 is supplied to the surface of the elastic members 31 in the coating grooves 54 to be elastic. A hot melt adhesive 34 is applied so as to cover the surface of the member 31.

This will be described in detail below. As shown in FIGS. 2 and 3, the coating apparatus 51 includes a plurality of gun nozzles 53 so that the hot melt adhesive 34 can be applied simultaneously to the plurality of elastic members 31. By providing the plurality of gun nozzles 53, for example, the hot melt adhesive can be applied to the elastic member 31A for waist gathers and the elastic member 31B for iliac gathers at a time.
The gun nozzle 53 is provided with a supply port 55 through which a hot melt adhesive 34 is supplied to the bottom (the opposite side to the side where the coating groove 54 is opened) 54B of the coating groove 54 having a V-shaped cross section. Has been. The bottom 54B is flat. A flow path 56 of hot melt adhesive 34 disposed in the gun nozzle 53 is communicated with the supply port 55. The supply port 55 is provided with a shim 58 having a recess 57 that matches the thickness of the elastic member 31. The shim 58 can be applied so that the hot melt adhesive 34 wraps around the elastic member 33 in accordance with the thickness of the elastic member 31. The arrow in the flow path 56 schematically shows the flow direction of the hot melt adhesive 34. Even when the shim 58 is not used, the temperature of the hot melt adhesive 34 and the amount of the hot melt adhesive 34 are adjusted so that the hot melt adhesive 34 can be easily wrapped around the elastic member 33. Can respond.

Next, the manufacturing method of the composite elastic member of this invention is demonstrated below with reference to the said FIG. 1 and FIG. This manufacturing method includes a step of sandwiching and fixing the elastic member 31 between the first nonwoven fabric 11 and the second nonwoven fabric 21 to be laminated.
Specifically, a process of applying the hot melt adhesive 34 to the stretched elastic member 31 using the contact type coating apparatus 51 is performed (hot melt adhesive coating process).
Next, the process of making the elastic member 31 coated in the state which made the 1st nonwoven fabric 11 contact the cooled chill roll 61 surrounding surface and making it adhere is performed (merging process of the 1st nonwoven fabric 11 and an elastic member).
The second nonwoven fabric 21 is opposed to the first nonwoven fabric 11, the elastic member 31 is sandwiched between both nonwoven fabrics, and the elastic member 31 and both nonwoven fabrics are joined and fixed by nip rolls 62 and 63 (first and second nonwoven fabrics and elastic member). Joining process). In this way, a composite elastic member is formed.

  In the above manufacturing method, with respect to the gun nozzle 53 of the coating apparatus 51, the sum of the entrance angle θ1 at which the elastic member 31 enters the gun nozzle coating position 53 and the exit angle θ2 at which the elastic member 31 exits from the coating position 53. Is less than 180 °. Further, θ2> θ1. Details will be described below.

  The entry side angle θ1 is an angle at which the elastic member 31 enters the coating position 53 of the gun nozzle 53 with respect to the gun nozzle 53 of the coating apparatus 51, preferably 75 ° or more, more preferably 80 ° or more, More preferably, it is 85 ° or more. Further, the entry side angle θ1 is preferably less than 90 °, more preferably 88 ° or less, and still more preferably 86 ° or less. And it is preferably 75 ° or more and less than 90 °, more preferably 80 ° or more and 88 ° or less, and even more preferably 85 ° or more and 86 ° or less. Since the entry side angle θ1 is not less than 75 ° and less than 90 °, the elastic member 31 bites into the concave portion 57 and easily moves around along the wall surface of the concave portion 57, so that the hot melt adhesive sufficiently wraps around the elastic member. Become.

  The exit angle θ2 is an angle at which the elastic member 31 exits from the coating position 53, and is preferably 85 ° or more, more preferably 86 ° or more, and even more preferably 87 ° or more. The exit angle θ2 is preferably 90 ° or less, more preferably 89 ° or less, and even more preferably 88 ° or less. And it is preferably 85 ° or more and 90 ° or less, more preferably 86 ° or more and 89 ° or less, and even more preferably 87 ° or more and 88 ° or less. As a result, the angle at which the elastic member 31 rubs against the bottom 54B becomes an obtuse angle. For this reason, the friction angle becomes smaller, the frictional force becomes smaller, and the wear of the shim 58 of the coating device 51 due to rubbing of the elastic member 31 is reduced to increase the production efficiency. Further, dripping of the applied hot melt adhesive 34 is prevented. On the other hand, when the exit side angle θ2 is too small, the shim 58 is likely to be worn, and when the exit side angle θ2 exceeds 90 °, the hot melt adhesive droops.

  The entry side angle θ1 and the exit side angle θ2 are angles with respect to the gun nozzle 53 and are based on the axis Z of the gun nozzle 53. Usually, the mounting surface of the gun nozzle 53 is perpendicular to the axis Z of the gun nozzle 53. Therefore, the vertical direction passing through the coating position 53 with respect to the mounting surface may be used as a reference. In other words, the vertical direction of the coating position 53 to which the hot melt adhesive 34 is supplied may be used as a reference. The reference coating position 53 is specifically the center of the supply port 55 of the gun nozzle 53 through which the hot melt adhesive 34 is injected vertically downward toward the elastic member 31.

  Furthermore, θ2> θ1. By satisfying θ2> θ1, there is an effect that the hot melt adhesive 34 can be easily wound around the elastic member 31 and the elastic member 31 is less likely to come off.

The joining angle θ3 formed on the chill roll 61 side of the elastic member 31 at the position where it joins the first nonwoven fabric 11 in the chill roll 61 is 85 ° or more, preferably 86 ° or more, and more preferably 87 ° or more. Further, the joining angle θ3 is 90 ° or less, preferably 89 ° or less, and more preferably 88 ° or less. And it is 85 degree or more and 90 degrees or less, Preferably it is 86 degrees or more and 89 degrees or less, More preferably, it is 87 degrees or more and 88 degrees or less. Further, since the merging angle θ3 is not less than 85 ° and not more than 90 °, by being wound on the chill roll 61, a sufficient time for adhesion can be obtained and cooling and fixing can be performed. If θ3 is set in the above angle range, the elastic member 31 in the stretched state is the component of the stretching force at the joining point of the first nonwoven fabric 11 and the elastic member 31 in the chill roll 61. Is pressed against the first nonwoven fabric 11 side. Therefore, the elastic member 31 coated with the hot melt adhesive 34 is stretched and pressed against the first nonwoven fabric 11 to be bonded to the first nonwoven fabric 11. For this reason, as shown in FIG. 4, the elastic member 31 is bonded to the first nonwoven fabric 11 without disturbing the pitch of the elastic member 31. On the other hand, if θ3 is too small, the hot-melt adhesive 34 will be pulled through and worn. Further, when θ3 is too large, the pitch of the elastic members 31 is disturbed as shown in FIG. This is because the pressing force of the elastic member 31 to the first nonwoven fabric 11 becomes insufficient.
In addition, it is important that the 1st nonwoven fabric 11 is conveyed so that a wrinkle may not generate | occur | produce. If wrinkles occur in the first nonwoven fabric 11, the elastic member 31 may not be fixed at a predetermined position of the first nonwoven fabric 11.

  In the said manufacturing method, it is preferable that the coverage area rate of the hot-melt-adhesive 34 in the elastic member 31 is 50% or more and 100% or less. The coverage area ratio is calculated from the cross-sectional area of the hot melt adhesive 34 covering the elastic member 31 using a microscope. The evaluation standard is evaluated from the circumference and angle of the hot melt adhesive 34 covering the elastic member 31. As a result of obtaining the covering area ratio by the above evaluation method, the relationship between the entrance angle θ1 and the covering area ratio was as follows. If the entry side angle θ1 is too small, the amount of the hot melt adhesive 34 is small on the side where the hot melt adhesive 34 is applied to the elastic member 31 and the damage to the elastic member 31 is large, so the elastic member 31 is cut. . When the entry side angle θ1 is too large, the hot melt adhesive 34 is applied more on the side where the hot melt adhesive 34 is applied, and the wraparound is reduced.

  It is preferable that the tension during conveyance of the first nonwoven fabric 11 at a position in contact with the chill roll 61 is 30 N / m or more and 60 N / m or less. Specifically, the tension is preferably 30 N / m or more, more preferably 35 N / m or more, and further preferably 40 N / m or more. The tension is preferably 60 N / m or less, more preferably 55 N / m or less, and even more preferably 50 N / m or less. And 30 N / m or more and 60 N / m or less are preferable, 35 N / m or more and 55 N / m or less are more preferable, and 40 N / m or more and 55 N / m or less are further more preferable. The tension was measured by winding the first nonwoven fabric 11 around a tension pickup. The evaluation criteria were evaluated because the presence or absence of wrinkles in the first nonwoven fabric 11 and the amount of meandering were 5 mm or less. It is. As a result of obtaining the tension by the above evaluation method, it was as follows. When it was less than 30 N / m, wrinkles occurred and the amount of meandering exceeded 5 mm. When it was higher than 60 N / m, wrinkles occurred vertically.

As described above, according to the method for manufacturing a composite stretchable member of the present embodiment, the hot melt adhesive 34 can easily go around the surface of the elastic member 31. As a result, the elastic member 31 is disposed by being bonded at a constant interval, so that the appearance can be improved and the elastic member 31 can be prevented from coming off. Moreover, wear of the nozzle can be suppressed.
The composite stretchable member thus obtained is used for various absorbent articles that require stretchability. For example, the composite stretchable member can be applied to a site where stretchability is required in a pants-type or tape-deployed disposable diaper. Such a disposable diaper has an absorptive main body and the exterior body arrange | positioned at the non-skin opposing surface side, for example. And a composite elastic member can be arrange | positioned to a part of exterior body.

DESCRIPTION OF SYMBOLS 10 Manufacturing apparatus 11 1st nonwoven fabric 21 2nd nonwoven fabric 31 Elastic member 31A Elastic member for waist gathers 31B Elastic member for iliac gathers 32 Elastic member guide roll 33 Feeding position 34 Hot melt adhesive 41 Outer packaging material 51 Coating apparatus (Contact type coating equipment)
52 coating position 53 gun nozzle 54 coating groove 54B bottom 55 supply port 56 flow path 57 recess 58 shim 61 chill roll 62, 63 nip roll θ1 entry side angle θ2 exit side angle θ3 merge angle Z axis

Claims (6)

A method for producing a composite elastic member in which a plurality of elastic members are stretched and fixed between a first nonwoven fabric and a second nonwoven fabric,
A coating step of applying a hot melt adhesive to the elastic member in an elongated state using a contact coating device;
A merging step in which the elastic member coated with the hot melt adhesive is joined and bonded in the coating step with the first nonwoven fabric in contact with the cooled chill roll peripheral surface;
The second nonwoven fabric is opposed to the first nonwoven fabric, the elastic member is sandwiched between both nonwoven fabrics, and the elastic member and the nonwoven fabric are joined and fixed by a nip roll,
The sum of the entrance side angle θ1 at which the elastic member enters the gun nozzle coating position and the exit side angle θ2 at which the elastic member exits the coating position with respect to the gun nozzle of the contact coating apparatus is 180 °. And a method for producing a composite elastic member in which θ2> θ1.   The entry angle θ1 at which the elastic member enters the coating position of the gun nozzle is 75 ° or more and less than 90 °, and the exit angle θ2 at which the elastic member exits the coating position is 85 ° or more and 90 ° or less. Item 2. A method for producing a composite elastic member according to Item 1.   3. The method for producing a composite stretchable member according to claim 1, wherein an angle θ <b> 3 formed on the chill roll side of the elastic member at a position where the first nonwoven fabric joins the chill roll is 85 ° or more and 90 ° or less.   The manufacturing method of the composite elastic | stretch member of any one of Claims 1-3 which uses a slit gun as the said contact-type coating apparatus.   The method for producing a composite stretchable member according to any one of claims 1 to 4, wherein a covering area ratio of the hot melt adhesive in the elastic member is 50% or more and 100% or less. The manufacturing method of the composite elastic member according to any one of claims 1 to 5, wherein a tension during conveyance of the first nonwoven fabric at a position in contact with the chill roll is 10N or more and 50N or less.

Images