JP6782155B2 - Manufacturing method of composite telescopic member - Google Patents

Description

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

Conventionally, as a nozzle for applying an adhesive such as a hot melt adhesive to a thread-like body such as a thin thread rubber that adheres to a sanitary article such as a disposable diaper, the adhesive application nozzle or adhesive application described in Patent Documents 1 and 2 Equipment is mentioned.
The adhesive application nozzle described in Patent Document 1 is a nozzle for applying an adhesive to a traveling filament, and has an adhesive discharge port for supplying and applying the adhesive to the filament and the filament. It has a slit-shaped guide groove for guiding to the position of the adhesive discharge port. In the adhesive application nozzle, a flat surface is provided at the end of the nozzle so that the filaments come into contact with each other. Further, the adhesive discharge port is opened on the plane, and a slit-shaped guide groove of the filament is provided on the upstream side of the plane in the traveling direction of the filament.
Further, Patent Document 2 describes an adhesive application device for applying an adhesive to a running elastic cord-like body. In this coating device, the adhesive is supplied to the slit groove communicating with the adhesive supply hole, and the elastic cord-like body in a tense state is horizontally penetrated through the enlarged portion of the slit groove. Then, the elastic cord-like body is supplied in the traveling direction of the coating line, and the adhesive is applied to the entire peripheral surface of the elastic cord-like body passing through the slit groove.

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

In the invention described in Patent Document 1, it is said that the adhesive does not drop off, the adhesive is applied intermittently to a thread-like body such as rubber thread, and the adhesive can be applied to a thread-like body having a different thickness. There is. In addition, it is said that even a string-like body having thick parts such as seams can be prevented from being caught and cut. However, consideration has not been given to making it easier for the hot melt adhesive to wrap around the surface of the elastic member and suppressing nozzle wear caused by the elastic member rubbing the nozzle, and there is room for improvement.
Further, in the invention described in Patent Document 2, it is said that the surface on which the adhesive is applied to the elastic cord-like body can be increased to enhance the adhesive force to the base material. However, similarly to the above, the fact that the elastic member suppresses the nozzle wear generated by rubbing the nozzle (slit plate) is not considered, and there is room for improvement.

In the present invention, by making it easy for the hot melt adhesive to wrap around the surface of the elastic member, the elastic members are adhered and arranged at regular intervals to improve the appearance of the appearance and prevent the elastic members from coming off. The present invention relates to a method for manufacturing a composite elastic member that suppresses nozzle wear.

The present invention is a method for manufacturing a composite elastic member in which a plurality of elastic members are held and fixed in an elongated state between the first nonwoven fabric and the second nonwoven fabric to be laminated.
A coating process in which a hot melt adhesive is applied to the stretched elastic member using a contact coating device, and
A merging step in which the first non-woven fabric is brought into contact with the cooled chill roll peripheral surface and the elastic members coated with the hot melt adhesive are joined and bonded in the coating step.
It has a joining step in which the second non-woven fabric is opposed to the first non-woven fabric, the elastic member is sandwiched between the two non-woven fabrics, and the elastic member and both the non-woven fabrics are joined and fixed by a nip roll.
The sum of the entry side angle θ1 at which the elastic member enters the coating position of the gun nozzle and the exit side angle θ2 at which the elastic member exits the coating position is 180 ° with respect to the gun nozzle of the contact type coating device. Provided is a method for manufacturing a composite elastic member having less than or less than θ2> θ1.

According to the method for manufacturing a composite elastic member of the present invention, the elastic members are bonded and arranged at regular intervals by making it easy for the hot melt adhesive to wrap around the surface of the elastic member. As a result, it is possible to improve the appearance of the appearance and prevent the elastic member from coming off. Further, the elastic member makes it possible to apply the hot melt adhesive to the elastic member without wearing the nozzle.

It is a block diagram which showed a preferable embodiment of the manufacturing apparatus suitable for carrying out the manufacturing method which concerns on this invention. It is a perspective view which showed an example of another manufacturing apparatus suitable for carrying out the manufacturing method which concerns on this invention. It is sectional drawing which showed an example of the coating apparatus shown in FIGS. 1 and 2. It is a top view which showed a normal example after adhering an elastic member to a 1st nonwoven fabric. It is a top view which showed the example which the elastic member was disturbed after adhering the elastic member to the 1st nonwoven fabric.

A preferred embodiment of the method for manufacturing a composite telescopic member according to the present invention will be described below with reference to the drawings. First, a preferred example of a manufacturing apparatus for carrying out a method for manufacturing a composite telescopic member will be described with reference to FIGS. 1 and 2. Although the arrangement of the coating device, the chill roll, and the nip roll is slightly different between FIGS. 1 and 2, the present invention can be applied to any of the configurations. In the following description, the description will be based on FIG. 1, but FIG. 2 will be referred to as appropriate. Further, in each figure, the arrows shown along the first nonwoven fabric 11, the second nonwoven fabric 21, and the elastic member 31 indicate the respective conveying directions. Further, the arrows shown on each roll indicate the direction of rotation of the rolls.

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

A chill roll 61 is arranged on the downstream side of the coating device 51. The chill roll 61 is provided with cooling means (not shown) inside the roll. The cooling means is composed of, for example, a flow path through which the refrigerant circulates inside the chill roll 61. 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. It is preferable that the chill roll 61 is connected to a refrigerant circulator (not shown) that circulates the refrigerant. The chill roll 61 is cooled to, for example, 10 ° C. or higher and 30 ° C. or lower. It is preferably cooled to 15 ° C. or higher and 25 ° C. or lower, and more preferably 18 ° C. or higher and 22 ° C. or lower. If the cooling temperature is too low, dew condensation is likely to occur, and if it is too high, a sufficient cooling effect cannot be obtained. The first non-woven fabric 11 is supplied to the chill roll 61. Further, 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 non-woven fabric 11 supplied from another direction and the elastic member 31 merge and are bonded. Further, although not shown, a nip roll for adjusting the tension of the first nonwoven fabric 11 in the chill roll 61 may be arranged on the upstream side of the chill roll 61. Further, the elastic member 31 is kept in the stretched state between the chill roll 61 and the elastic member guide roll 32 so that the elastic member 31 is stretched and the hot melt adhesive 34 is applied.

Nip rolls 62 and 63 are arranged on the downstream side of the chill roll 61. The second nonwoven fabric 21 is supplied between the nip rolls 62 and 63 so as to sandwich the elastic member 31 between the first nonwoven fabric 11 to which the elastic member 31 is adhered and the first nonwoven fabric 11. By pressurizing the nip rolls 62 and 63, the first non-woven fabric 11 and the second non-woven fabric 21 are joined and fixed with the elastic member 31 sandwiched between them. The nip roll 62 may be provided with a drive unit (not shown) for rotating the roll.

Next, the coating device 51 will be described below with reference to FIGS. 2 and 3. As shown in FIG. 2, a slit gun is used for the coating device 51. In the slit gun, a plurality of coating grooves 54 are arranged, an elastic member 31 is supplied to each coating groove 54, and a hot melt adhesive 34 is supplied to the surface of the elastic member 31 in the coating groove 54 to be elastic. The 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 device 51 includes a plurality of gun nozzles 53 so that the hot melt adhesive 34 can be applied to the plurality of elastic members 31 at the same time. By providing the plurality of gun nozzles 53, for example, the elastic member 31A for waist gather and the elastic member 31B for iliac gather can be coated with the hot melt adhesive at a time.
The gun nozzle 53 has a supply port 55 to which the hot melt adhesive 34 is supplied to the bottom (opposite side to the open side of the coating groove 54) 54B of the coating groove 54 having a V-shaped cross section. Has been done. The bottom 54B is flat. The flow path 56 of the hot melt adhesive 34 arranged in the gun nozzle 53 communicates with the supply port 55. A shim 58 having a recess 57 corresponding to the thickness of the elastic member 31 is arranged in the supply port 55. The shim 58 allows the hot melt adhesive 34 to be applied so as to wrap around the elastic member 33 according to the thickness of the elastic member 31. The arrows in the flow path 56 schematically indicate 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 to make it easier for the hot melt adhesive 34 to wrap around the elastic member 33. Can be handled.

Next, the method for manufacturing the composite telescopic member of the present invention will be described below with reference to FIGS. 1 and 2. The present manufacturing method includes a step of holding and fixing the elastic member 31 in an elongated state between the first nonwoven fabric 11 and the second nonwoven fabric 21 to be laminated.
Specifically, a step of applying the hot melt adhesive 34 to the elastic member 31 in the stretched state is performed using the contact type coating device 51 (hot melt adhesive coating step).
Next, a step of merging and adhering the coated elastic member 31 with the first nonwoven fabric 11 in contact with the peripheral surface of the cooled chill roll 61 is performed (merging step of the first nonwoven fabric 11 and the elastic member).
The second non-woven fabric 21 is opposed to the first non-woven fabric 11, the elastic member 31 is sandwiched between the two non-woven fabrics, and the elastic member 31 and both the non-woven fabrics are joined and fixed by the nip rolls 62 and 63 (the first and second non-woven fabrics and the elastic member). Joining process with). In this way, the composite telescopic member is formed.

In the above manufacturing method, the sum of the entrance angle θ1 at which the elastic member 31 enters the coating position 53 of the gun nozzle and the exit angle θ2 at which the elastic member 31 exits the coating position 53 with respect to the gun nozzle 53 of the coating device 51. Is less than 180 °. Further, θ2> θ1. The 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 device 51, preferably 75 ° or more, more preferably 80 ° or more, and further. More preferably, it is 85 ° or more. The entry side angle θ1 is preferably less than 90 °, more preferably 88 ° or less, and even more preferably 86 ° or less. Then, 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 75 ° or more and less than 90 °, the elastic member 31 bites into the recess 57 and easily wraps around the wall surface of the recess 57, so that the hot melt adhesive wraps around the elastic member sufficiently. Become.

The exit side angle θ2 is an angle at which the elastic member 31 exits from the coating position 53, 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. Then, 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 portion 54B becomes obtuse. Therefore, the friction angle becomes small, the frictional force becomes small, and the wear of the shim 58 of the coating device 51 due to the rubbing of the elastic member 31 is reduced, and the production efficiency is improved. It also prevents the coated hot melt adhesive 34 from dripping. On the other hand, if the exit angle θ2 is too small, the shim 58 is likely to be worn, and if the exit angle θ2 exceeds 90 °, the hot melt adhesive drips.

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, there is a mounting surface of the gun nozzle 53 in the direction perpendicular to the axis Z of the gun nozzle 53. Therefore, the direction perpendicular to the mounting surface through the coating position 53 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 in which the hot melt adhesive 34 is ejected vertically downward toward the elastic member 31.

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

The merging angle θ3 formed on the chill roll 61 side of the elastic member 31 at the position where the chill roll 61 merges with the first non-woven fabric 11 is 85 ° or more, preferably 86 ° or more, and more preferably 87 ° or more. The merging angle θ3 is 90 ° or less, preferably 89 ° or less, and more preferably 88 ° or less. Then, it is 85 ° or more and 90 ° or less, preferably 86 ° or more and 89 ° or less, and more preferably 87 ° or more and 88 ° or less. Further, since the merging angle θ3 is 85 ° or more and 90 ° or less, by being wound on the chill roll 61, a sufficient time for adhesion can be obtained and cooling and fixing can be performed. When θ3 is set in the above angle range, at the confluence of the first non-woven fabric 11 and the elastic member 31 in the chill roll 61, the elastic member 31 in the stretched state is the component force of the stretching force in the rotation axis direction of the chill roll 61. Is pressed against the first non-woven fabric 11 side by the force of. Therefore, the elastic member 31 coated with the hot melt adhesive 34 is pressed against the first non-woven fabric 11 in an elongated state and adhered to the first non-woven fabric 11. Therefore, as shown in FIG. 4, the elastic member 31 is adhered to the first non-woven fabric 11 without disturbing the pitch of the elastic member 31. On the other hand, if θ3 is too small, it leads to strike-through and wear of the hot melt adhesive 34. Further, when θ3 is too large, the pitch of the elastic member 31 is disturbed as shown in FIG. This is because the pressing force of the elastic member 31 on the first non-woven fabric 11 becomes insufficient.
It is important that the first non-woven fabric 11 is transported so as not to generate wrinkles. When the first non-woven fabric 11 is wrinkled, the elastic member 31 may not be fixed at a predetermined position of the first non-woven fabric 11.

In the above manufacturing method, the coverage area ratio of the hot melt adhesive 34 in the elastic member 31 is preferably 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 entry side angle θ1 and the covering area ratio is 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 that the elastic member 31 is cut. .. If the entry side angle θ1 is too large, a large amount of the hot melt adhesive 34 is applied to the side to which the hot melt adhesive 34 is applied, and the wraparound is reduced.

It is preferable that the tension during transportation of the first nonwoven fabric 11 at the position where it is 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 even more 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. Then, 30 N / m or more and 60 N / m or less is preferable, 35 N / m or more and 55 N / m or less is more preferable, and 40 N / m or more and 55 N / m or less is further preferable. The tension was measured by winding the first non-woven fabric 11 around the tension pickup. The evaluation criteria were evaluated based on the presence or absence of wrinkles on the first non-woven fabric 11 and the amount of meandering of 5 mm or less. Is. As a result of obtaining the tension by the above evaluation method, the result was as follows. When it was less than 30 N / m, wrinkles occurred and the meandering amount exceeded 5 mm. When it was larger than 60 N / m, vertical wrinkles occurred.

As described above, according to the method for manufacturing the composite elastic member of the present embodiment, the hot melt adhesive 34 can easily wrap around the surface of the elastic member 31. As a result, the elastic members 31 are adhered and arranged at regular intervals to improve the appearance of the appearance and prevent the elastic members 31 from coming off. Moreover, the wear of the nozzle can be suppressed.
The composite stretchable member thus obtained is used for various absorbent articles that require stretchability. For example, a composite elastic member can be applied to a portion of a pants-type or tape-fastened deployable disposable diaper that requires elasticity. Such a disposable diaper has, for example, an absorbent body and an exterior body arranged on the non-skin facing surface side thereof. Then, the composite elastic member can be arranged on a part of the exterior body.

10 Manufacturing equipment 11 1st non-woven fabric 21 2nd non-woven fabric 31 Elastic member 31A Elastic member for waist gather 31B Elastic member for iliac gather 32 Elastic member Guide roll 33 Delivery position 34 Hot melt adhesive 41 Outer packaging material 51 Coating device (Contact type coating device)
52 Coating position 53 Gun nozzle 54 Coating groove 54B Bottom 55 Supply port 56 Flow path 57 Recess 58 Sim 61 Chill roll 62, 63 Nip roll θ1 Enter side angle θ2 Exit side angle θ3 Confluence angle Z axis

Claims (6)

A method for manufacturing a composite elastic member in which a plurality of elastic members are held and fixed in an elongated state between the first nonwoven fabric and the second nonwoven fabric to be laminated.
A coating process in which a hot melt adhesive is applied to the stretched elastic member using a contact coating device, and
A merging step in which the first non-woven fabric is brought into contact with the cooled chill roll peripheral surface and the elastic members coated with the hot melt adhesive are joined and bonded in the coating step.
It has a joining step in which the second non-woven fabric is opposed to the first non-woven fabric, the elastic member is sandwiched between the two non-woven fabrics, and the elastic member and both the non-woven fabrics are joined and fixed by a nip roll.
The sum of the entry side angle θ1 at which the elastic member enters the coating position of the gun nozzle and the exit side angle θ2 at which the elastic member exits the coating position is 180 ° with respect to the gun nozzle of the contact type coating device. A method for manufacturing a composite elastic member that is less than or equal to θ2> θ1. Claim that the entrance 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. The method for manufacturing a composite elastic member according to Item 1. The method for manufacturing a composite elastic member according to claim 1 or 2, wherein the angle θ3 formed on the chill roll side of the elastic member at a position where the elastic member merges with the first non-woven fabric in the chill roll is 85 ° or more and 90 ° or less. The method for manufacturing a composite telescopic member according to any one of claims 1 to 3, wherein a slit gun is used as the contact coating device. The method for producing a composite elastic member according to any one of claims 1 to 4, wherein the coverage area ratio of the hot melt adhesive in the elastic member is 50% or more and 100% or less. The method for manufacturing a composite elastic member according to any one of claims 1 to 5, wherein the tension during transportation of the first nonwoven fabric at a position in contact with the chill roll is 30 N / m or more and 60 N / m or less. ..

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