JP7232807B2 - Composite sheet manufacturing method and composite sheet manufacturing apparatus - Google Patents

Description

The present invention relates to a composite sheet manufacturing method and a composite sheet manufacturing apparatus.

In the above technical field, in Patent Document 1, a first sheet formed by a second roll is superimposed on the second sheet on the first roll, and the first roll and the anvil roll are welded at the meshing portion to form a composite. A sheet is obtained, and further, while the obtained composite sheet is conveyed on the first roll, the composite sheet is subjected to processing on the first roll by the perforation part of the perforated roll provided downstream of the anvil roll. Techniques for forming apertures in the convex portions have been disclosed (paragraphs [0024] to [0040] of the same document, FIG. 2, etc.).

JP 2007-130817 A

However, in the technique described in Patent Document 1, the welding step and the hole-opening step are performed while the composite sheet is kept along the first roll, so that through holes cannot be formed in the welded portion of the composite sheet.

Accordingly, an object of the present invention is to obtain a composite sheet in which a through hole is formed in a weld joint portion of the composite sheet obtained by overlapping and welding a plurality of sheets.

The present invention has a plurality of joints where a first sheet and a second sheet are joined together, and at least a portion of the first sheet other than the joints forms a protrusion protruding to the side opposite to the second sheet. and a through hole in the joint portion, wherein a first roll and a second roll having unevennesses on their peripheral surfaces that mesh with each other are placed in opposite directions while both rolls are meshed. While rotating, the first sheet is introduced into the meshing portion of both rolls to deform the first sheet into an uneven shape, and the first sheet deformed into an uneven shape is applied to the peripheral surface of the first roll. a stacking step of holding and conveying and stacking the second sheet on the first sheet being conveyed; A joint forming step of obtaining a joint sheet in which a plurality of joints are formed by sandwiching and fusing both sheets, and a position of the joint in the joint sheet is an anvil roll having a recess on the peripheral surface. a transfer step of transferring the joint sheet to the peripheral surface of the anvil roll so as to match the position of the recess; a step of introducing the joint sheet between them and inserting the hole pin into the recess to form the through hole in the joint portion of the joint sheet to obtain the composite sheet. It is intended to provide a manufacturing method of.

Further, according to the present invention, the first sheet and the second sheet have a plurality of joints joined together, and at least a portion of the first sheet other than the joints has a convex portion protruding to the side opposite to the second sheet. and a through hole in the joint portion, the apparatus for manufacturing a composite sheet, wherein the first roll and the first roll have concave and convex portions that mesh with each other on their peripheral surfaces and are arranged so that their rotation axes are parallel to each other. 2 rolls, a fusing machine arranged to face the peripheral surface of the first roll, a concave portion corresponding to the convex portion of the first roll on the peripheral surface, and a rotating shaft of the first roll. An anvil roll arranged to have parallel axes of rotation, and perforated pins on the peripheral surface corresponding to the recesses of the anvil roll, arranged to have axes of rotation parallel to the axis of rotation of the anvil roll. and a pin roll, wherein a phase shift prevention portion for preventing a phase shift of the sheet transferred from the first roll to the anvil roll is provided on the peripheral surface of the anvil roll. is to provide a manufacturing apparatus for

According to the present invention, a through hole can be formed in the joint portion of the composite sheet.

FIG. 1 is a perspective view of a main part showing an example of a composite sheet manufactured by the method and apparatus for manufacturing a composite sheet of the present invention. FIG. 2 is an enlarged plan view of the composite sheet shown in FIG. 1 as viewed from the first sheet side. FIG. 3 is a diagram for explaining a schematic configuration of a composite sheet manufacturing apparatus. FIG. 4 is a perspective view showing an enlarged main part of the first roll shown in FIG. 3. FIG. FIG. 5 is a diagram showing the waist of the ultrasonic fusion splicer shown in FIG. 3, and is a diagram showing a state seen from the left side in FIG. FIG. 6 is a top view for explaining the configuration of recesses on the peripheral surface of the anvil roll. FIG. 7 is a top view for explaining another structure of recesses on the peripheral surface of the anvil roll. FIG. 8 is a diagram for explaining the relationship between the joint portion of the composite sheet and the concave portion of the anvil roll. FIG. 9 is a diagram for explaining the size of the punch pin.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on its preferred embodiments with reference to the drawings. First, a composite sheet manufactured by the method or apparatus for manufacturing a composite sheet of the present invention will be described with reference to FIG.

A composite sheet 10 shown in FIG. 1 is an example of a composite sheet manufactured by the composite sheet manufacturing method or manufacturing apparatus of the present embodiment. As shown in FIG. 1, the first sheet 1 and the second sheet 2 have a plurality of joints 4, and at least a part of the first sheet 1 other than the joints 4 is on the second sheet 2 side. A convex portion 5 projecting to the opposite side is formed.

The composite sheet 10 is preferably used as a surface sheet or the like of absorbent articles. When used as a topsheet of an absorbent article, the first sheet 1 forms a surface facing the wearer's skin, and the second sheet 2 forms a surface facing the absorber when worn.

The protrusions 5 and the joints 4 are alternately arranged in a row in the X direction, which is one direction parallel to the surface of the composite sheet 10 , and such rows are aligned with the surface of the composite sheet 10 . They are formed in multiple rows in the Y direction, which is parallel and perpendicular to the X direction. The protrusions 5 and the joints 4 in adjacent rows are arranged with a shift in the X direction, more specifically, with a half-pitch shift.

In the composite sheet 10, the Y direction matches the flow direction (MD direction, transport direction) during manufacture, and the X direction matches the direction (CD direction, width direction) perpendicular to the flow direction during manufacture. .

The first sheet 1 and the second sheet 2 are made of sheet material. As the sheet material, for example, a fiber sheet such as a nonwoven fabric, a woven fabric, a knitted fabric, or a film can be used. From the viewpoint of touch feeling, etc., it is preferable to use a fiber sheet, and it is particularly preferable to use a nonwoven fabric. The types of sheet materials forming the first sheet 1 and the second sheet 2 may be the same or different.

Examples of nonwoven fabrics in the case where nonwoven fabrics are used as sheet materials constituting the first sheet 1 and second sheet 2 include air-through nonwoven fabrics, spunbond nonwoven fabrics, spunlace nonwoven fabrics, melt-blown nonwoven fabrics, resin-bonded nonwoven fabrics, needle-punched nonwoven fabrics, and the like. mentioned. A laminate obtained by combining two or more of these nonwoven fabrics, or a laminate obtained by combining these nonwoven fabrics with a film or the like can also be used.

As fibers constituting the nonwoven fabric, fibers made of various thermoplastic resins can be used. Sheet materials other than non-woven fabrics are also preferably used in which constituent fibers and constituent resins are composed of various thermoplastic resins.

As shown in FIG. 1, the composite sheet 10 has a large number of recesses 3 sandwiched between protrusions 5 in both the X direction and the Y direction on the surface on the first sheet 1 side. A joint portion 4 having a through-hole 14 is formed at the bottom portion of 3 . When viewed as a whole, the composite sheet 10 has a surface on the side of the first sheet 1 that has large undulations formed by concave portions 3 and convex portions 5, and the surface on the side of the second sheet 2 is flat or It is a substantially flat surface with relatively small undulations with respect to the surface on the side of the first sheet 1 .

As shown in FIG. 2 , each joint 4 in the composite sheet 10 has a substantially rectangular plan view shape that is long in the Y direction. A hole 14 is formed. That is, each joint 4 is formed in an annular shape surrounding the through hole 14 . It is preferable that only one through-hole 14 is formed in one joint portion 4 , and it is preferable that the through-hole 14 is formed at a predetermined specific position in relation to the position of the joint portion 4 . Further, the shape of the through hole 14 in plan view may or may not be similar to the shape of the outer peripheral edge of the joint portion 4 in plan view, but is preferably similar.

At the joining portion 4 , the first sheet 1 and the second sheet 2 are joined by melting and solidifying the heat-fusible resin forming at least one of the first sheet 1 and the second sheet 2 . When the first sheet 1 and the second sheet 2 are made of fiber sheets such as non-woven fabric, at the joint 4, the constituent fibers of the first sheet 1 and the second sheet 2 are melted or dissolved in the melted resin. It is preferable that the fibrous form cannot be visually observed due to burial, that is, it is in a film-like state in appearance.

Next, a method for manufacturing the composite sheet of this embodiment will be described. In this embodiment, the composite sheet 10 is manufactured using the composite sheet manufacturing apparatus 20 shown in FIG.

The composite sheet manufacturing apparatus 20 includes a first roll 31 , a second roll 32 , an anvil roll 33 , a pin roll 36 and an ultrasonic processing section 40 .

The 1st roll 31 and the 2nd roll 32 have unevenness|corrugation in the surrounding surface, and the unevenness|corrugation of both rolls (31, 32) mutually meshes. While the first roll 31 and the second roll 32 are being rotated, the first sheet 1 is introduced into the meshing portion of both rolls (31, 32), so that the first sheet 1 is applied to the unevenness of the peripheral surface of the first roll. It is shaped by deforming into a shape along the shape of

FIG. 4 is a perspective view showing an enlarged main part of the first roll 31. As shown in FIG. A portion of the peripheral surface of the first roll 31 is shown in FIG. The first roll 31 is formed into a roll shape by combining a plurality of spur gears 31a, 31b, . . . each having a predetermined face width. The teeth of each gear form an uneven convex portion 35 on the peripheral surface of the first roll 31, and the tip surface 35c of the convex portion 35 is the tip surface 42t of the ultrasonic horn 42 of the ultrasonic fusion machine 41. It serves as a pressurizing surface for pressurizing the first sheet 1 and the second sheet 2 to be joined.

The face width of each gear (the length in the axial direction of the gear) determines the dimension of the convex portion 5 of the composite sheet 10 in the X direction, and the thickness of the tooth of each gear (the length in the direction of rotation of the gear) determines the length of the composite sheet. The dimension in the Y direction of the projections 5 of the sheet 10 is determined. Adjacent gears are combined so that their tooth pitches are shifted by half a pitch. As a result, the first roll 31 has an uneven peripheral surface. A tip surface 35c of each projection 35 has a rectangular shape with a long side in the rotation direction of the first roll 31 and a short side in the axial direction. If the tip surface 35c has a shape that is longer in the rotational direction, the contact time of the tip surface 42t of the ultrasonic horn 42 with one of the projections 35 of the first roll 31 can be lengthened to facilitate raising the temperature. It is preferable because it can be done.

The tooth grooves of the gears of the first roll form uneven recesses on the peripheral surface of the first roll 31 . A suction hole 34 is formed at the bottom of the tooth space of each gear. The suction hole 34 communicates with a suction source (not shown) such as a blower or a vacuum pump, and extends from the engagement portion of the first roll 31 and the second roll 32 to the confluence portion of the first sheet 1 and the second sheet 2. It is controlled so that suction is performed between Therefore, the first sheet 1 deformed into an uneven shape by the engagement of the first roll 31 and the second roll 32 is deformed into a shape along the unevenness of the first roll 31 by the suction force of the suction holes 34 . In this state, the first sheet 1 and the second sheet 2 are conveyed to the joining portion and the pin roll 36 (applying portion) of the ultrasonic vibration by the ultrasonic fusing machine 41 .

In this case, if a predetermined gap G is provided between adjacent gears as shown in FIG. , the first sheet 1 can be suppressed from being cut, and the first sheet 1 can be deformed into a shape along the peripheral surface of the first roll 31, which is preferable.

The second roll 32 has, on its peripheral surface, an uneven shape that meshes with the unevenness of the peripheral surface of the first roll 31 . The second roll 32 has the same configuration as the first roll 31 except that it does not have the suction holes 34 . Then, while rotating the first roll 31 and the second roll 32 having irregularities that mesh with each other, the first sheet 1 is introduced into the meshing portions of the rolls (31, 32), thereby forming the first sheet 1 into the irregular shape. It can be transformed into a shape. At the meshing portion, a plurality of portions of the first sheet 1 are pushed into the concave portions of the peripheral surface of the first roll 31 by the convex portions of the second roll 32, and the pushed portions form the composite sheet 10 to be manufactured. A convex portion 5 is formed. A plurality of protrusions to be inserted into the recesses of the first roll 31 are formed on the peripheral surface of the second roll 32 . is not required to be formed. In addition, the second roll may have a non-uneven region in at least a part of the width direction.

As shown in FIG. 3, the ultrasonic processing unit 40 is equipped with an ultrasonic fusion machine 41 having an ultrasonic horn 42, and a second sheet 2 is placed on the first sheet 1 deformed into an uneven shape. After superimposing, both superimposed sheets (1, 2) are sandwiched between the convex portion of the first roll 31 and the ultrasonic horn 42, and ultrasonic vibration is partially applied to the joint portion 4. Form.

The ultrasonic fusion splicer 41 has an ultrasonic oscillator (not shown), a converter 43, a booster 44 and an ultrasonic horn 42, as shown in FIGS. The ultrasonic oscillator is electrically connected to the converter 43 , and a high-voltage electrical signal with a wavelength of about 15 kHz to 50 kHz generated by the ultrasonic oscillator is input to the converter 43 .

The converter 43 incorporates a piezoelectric element such as a piezoelectric element, and converts an electrical signal input from the ultrasonic oscillator into mechanical vibration by the piezoelectric element. Booster 44 adjusts, preferably amplifies, the amplitude of the mechanical vibration emitted from converter 43 and transmits it to ultrasonic horn 42 . The ultrasonic horn 42 is made of a lump of metal such as an aluminum alloy or a titanium alloy, and is designed to properly resonate at the frequency used. The ultrasonic vibration transmitted from the booster 44 to the ultrasonic horn 42 is also amplified or attenuated inside the ultrasonic horn 42 and applied to the first sheet 1 and the second sheet 2 to be joined. As such an ultrasonic fusion splicer 41, a commercially available ultrasonic horn, converter, booster, and ultrasonic oscillator can be used in combination.

The ultrasonic fusion splicer 41 is fixed to a movable table (not shown). By advancing and retreating the position of the movable table in a direction approaching the peripheral surface of the first roll 31, the clearance between the tip surface 42t of the ultrasonic horn 42 and the tip surface 35c of the convex portion 35 of the first roll 31 is increased. And the pressure applied to the stacked first sheet 1 and second sheet 2 can be adjusted.

Then, the first sheet 1 and the second sheet to be joined are sandwiched between the tip end surface 35c of the projection 35 of the first roll 31 and the tip end surface 42t of the ultrasonic horn 42 of the ultrasonic fusion splicer 41 and pressurized. By applying ultrasonic vibrations to the second sheet 2, the portions of the first sheet 1 located on the tip surfaces 35c of the projections 35 are fused to the second sheet 2, forming the joints 4. be.

In a preferred embodiment, the composite sheet manufacturing apparatus 20 comprises preheating means (not shown) having a heater (not shown) arranged within the first roll 31 . More specifically, a heating means such as a heater disposed in the first roll 31, a temperature measuring means (not shown) capable of measuring the temperature of the sheet before applying ultrasonic vibration, and the measured value of the temperature measuring means. A temperature control unit (not shown) is provided for controlling the temperature of the heater based on the above. By controlling the heating temperature of the peripheral surface of the first roll 31 by the heater based on the measured value by the temperature measuring means, the temperature of the first sheet 1 immediately before the ultrasonic vibration is applied can be set to a predetermined temperature with high accuracy. can be controlled to

In a preferred embodiment, a plurality of heaters are arranged at intervals in the circumferential direction in the vicinity of the outer peripheral portion around the rotating shaft of the first roll 31 . The heating temperature of the peripheral surface of the first roll 31 by the heater is controlled by the temperature control unit, and during operation of the composite sheet manufacturing apparatus 20, the temperature of the first sheet 1 introduced into the ultrasonically vibrating pin roll 36 is , can be maintained at a temperature within a predetermined range.

It is preferable that the preheating means includes a heating means for heating the object to be heated by applying heat energy from the outside. Examples of the heating means include, but are not limited to, a cartridge heater using an electric heating wire, and various known heating means can be used without particular limitation. The ultrasonic fusion splicer 41 applies ultrasonic vibrations to the objects to be joined, thereby heating and melting the objects to be joined, and is not included in the heating means here.

The anvil roll 33 has recesses 33 a corresponding to the protrusions 35 of the first roll 31 on its peripheral surface. The anvil roll 33 is arranged so as to have a rotation axis parallel to the rotation axis of the first roll 31 . Further, the anvil roll 33 has suction holes similarly to the first roll 31, sucks the joining sheet 10a transferred from the first roll, and holds it on its peripheral surface. Alternatively, instead of the suction holes, the anvil roll 33 may have a high-friction portion on the peripheral surface to prevent the joining sheet 10a from slipping on the peripheral surface, thereby holding the joining sheet 10a on the peripheral surface. Thus, the anvil roll 33 holds the joining sheet 10a by combining suction and friction. That is, it is possible to prevent the joining sheet 10a around the concave portion 33a from being pulled in when the punching pin 36a, which will be described later, is inserted into the joining sheet 10a due to the friction. In addition, the suction can prevent burrs from being generated on the uneven side of the joining sheet 10a. can prevent you from leaving. The first roll 31 and the anvil roll 33 may be rotated by the driving force of the same driving device, or may be rotated by the driving force of separate driving devices.

Here, the structure of the peripheral surface of the anvil roll 33 will be described with reference to FIGS. 6 to 8. FIG. As shown in FIG. 6A, the peripheral surface of the anvil roll 33 is provided with a recessed region 33b having a recessed portion 33a and a high-friction region 33c having no recessed portion 33a. In the example shown in the figure, a recessed region 33b having a plurality of recessed portions 33a is arranged in the center of the anvil roll 33, and high-friction regions 33c are arranged on both sides of the recessed region 33b and on both left and right sides of the peripheral surface of the anvil roll 33. It is The joining sheet 10a is delivered such that the joining portion 4 of the joining sheet 10a overlaps the recess 33a of the recess region 33b. As described above, in the anvil roll 33, there is at least a partial region without the concave portion 33a in the longitudinal direction and the width direction of the joined sheet 10a (composite sheet 10).

Next, the high friction area 33c will be described. Since the surface of the anvil roll 33 is normally a smooth surface with little friction, the joining sheet 10a transferred from the first roll 31 to the anvil roll 33 is smooth on the peripheral surface in the portion without the concave portion 33a. Slippery. Therefore, the position of the joint portion 4 of the joining sheet 10a does not overlap with the position of the recess 33a, and the phase of the joint portion 4 and the recess 33a is easily shifted. Therefore, a high-friction region 33c is provided as a phase shift preventing portion in order to prevent the phase shift of the joining sheet 10a in a region other than the recessed region 33b on the peripheral surface of the anvil roll 33. As shown in FIG. The high-friction region 33c as the phase shift prevention portion is, for example, a region in which the peripheral surface is surface-treated to provide high friction, or a region provided with a mechanism for sucking the joining sheet 10a held by the peripheral surface. is. In addition, the high-friction region 33c is surface-treated to make the peripheral surface rough, for example, by providing a plurality of protrusions or by winding a high-friction sheet or the like. The diameter of the anvil roll 33 in the friction area 33c is adjusted to be the same in both areas (33b, 33c).

Further, the arrangement pattern of the recesses 33a provided on the peripheral surface of the anvil roll 33 is, for example, as shown in FIG. 33a may be arranged in a plurality of rows, and a pattern in which the concave portions 33a appear alternately in the rotation direction of the anvil roll 33 (MD direction, transport direction) may be employed. Further, as shown in FIG. 6C, a plurality of rows of recesses 33a are arranged in the rotation direction (MD direction, transport direction) of the anvil roll 33, and the recesses are arranged in the axial direction (CD direction, width direction) of the anvil roll 33. A pattern in which 33a appears alternately may be used. The arrangement pattern of the concave portions 33a is not limited to the pattern illustrated here, and can be freely set according to the arrangement of the joint portions 4 and the convex portions 5 provided on the joint sheet 10a. Moreover, the size of each of the recesses 33a may not be constant, and may be different.

Further, as shown in FIG. 7A, all the diameters (sizes) of the recesses 33a provided in the recessed region 33b may be the same size (uniform size). Alternatively, as shown in FIG. 7B, recesses 33a having two different diameters (sizes) may appear alternately. That is, the concave portions 33a having the same size may be arranged in the MD direction, and the concave portions 33a having different sizes may be arranged alternately in the CD direction. Furthermore, as shown in FIG. 7(c), the recesses 33a may be intermittently provided in the CD direction, and the recesses 33a may be provided in the CD direction with one line skipped compared to the arrangement of FIG. 7(a). Similarly, as shown in FIG. 7(d), the recesses 33a may be intermittently provided in the MD direction, and the recesses 33a may be provided in the MD direction by skipping one line as compared with the arrangement of FIG. 7(a). The diameter and arrangement of the recesses 33a are not limited to those shown in FIGS. 7(a) to 7(d). For example, in FIG. 7(b), the concave portions 33a with two diameters, large and small, are illustrated, but the concave portions 33a with three diameters, large, medium, and small, or the concave portions 33a with four or more diameters may appear. good. Furthermore, in FIGS. 7C and 7D, an example in which the concave portions 33a appear with one row skipped in the CD and MD directions is shown, but two rows or three or more rows may be skipped.

8A to 8D show the relationship between the joint portion 4 of the joint sheet 10a (composite sheet 10) and the concave portion 33a of the anvil roll 33. FIG. As shown in FIG. 8( a ), when the joining sheet 10 a is transferred from the first roll 31 , all the joining portions 4 of the joining sheet 10 a and the concave portions 33 a of the anvil roll 33 are formed on the peripheral surface of the anvil roll 33 . The positions of and overlap with each other.

Next, as shown in FIG. 8B, the number of recesses 33a may be greater than the number of joints 4 of the joining sheet 10a. That is, as in FIG. 8A, all the joints 4 overlap the recesses 33a of the anvil roll 33, but the joints 4 do not overlap some of the recesses 33a. . On the contrary, as shown in FIG. 8(c), the number of recesses 33a may be smaller than the number of joints 4. FIG. That is, the number of rows of recesses 33a is smaller than the number of rows of joints 4 in the CD direction, and some joints 4 do not overlap recesses 33a. Furthermore, as shown in FIG. 8(d), recesses 33a into which punching pins 36a of pin rolls 36, which will be described later, are not inserted may be provided. That is, the number of recesses 33a provided on the peripheral surface of the anvil roll 33 may be greater than the number of perforation pins 36a.

The pin roll 36 has perforation pins 36 a on its peripheral surface corresponding to the recesses 33 a of the anvil roll 33 . The perforating pin 36a is inserted into the recess 33a of the anvil roll 33 to form the through hole 14 in the joint 4 overlying the recess 33a. Moreover, the pin roll 36 is arranged so as to have a rotation axis parallel to the rotation axis of the anvil roll 33 . The diameters of the first roll 31, the second roll 32, the anvil roll 33 and the pin roll 36 may be the same or different. The through holes 14 may be formed by inserting the perforating pins 36a into the joining sheet 10a while the pin roll 36 is being heated.

FIGS. 9(a) to 9(d) show the relationship between the joint 4 and the through hole 14 and the like. 9(a) shows the joining sheet 10a on the anvil roll 33, and FIGS. 9(b) to 9(d) are partial enlarged views of the portion surrounded by the dotted line in FIG. 9(a). there is FIG. 9B shows the recess 33 a of the anvil roll 33 and the joint 4 , and the diameter of the recess 33 a is larger than the diameter of the joint 4 . FIG. 9(c) shows the recess 33a of the anvil roll 33, the joint 4 and the perforating pin 36a of the pin roll 36, the diameter of the recess 33a being larger than the diameter of the perforating pin 36a. That is, the size of the through hole 14 formed by the punch pin 36 a is such that it can be accommodated in the joint portion 4 . FIG. 9(d) shows the joint 4 and the perforation pin 36a, and as shown on the left side of the figure, the perforation pin 36a may be larger than the joint 4. . That is, the size of the punch pin 36a may be larger or smaller than the size (area) of the joint portion 4 . That is, the size of the through hole 14 formed by the punch pin 36 a may be a size that fits in the joint portion 4 or a size that protrudes from the joint portion 4 . The diameters (thicknesses) of the plurality of perforating pins 36a provided on the pin roll 36 may not be the same, and the perforating pins 36a having a large diameter and the perforating pins 36a having a small diameter may be mixed. The perforation pins 36a may be arranged such that at least a part of the joined sheet 10a (composite sheet 10) has no perforation pins 36a in the longitudinal direction and the width direction.

In the manufacturing method of the present embodiment, as shown in FIG. 3, while rotating the first roll 31 and the second roll 32, the first sheet 1 fed out from the original roll (not shown) is spread between both rolls (31 , 32) and deformed into an uneven shape (shaping step). Next, the first sheet 1 deformed into an uneven shape is conveyed while being held on the peripheral surface of the first roll 31, and the second sheet 2 is superimposed on the first sheet 1 being conveyed (superposition step). Then, the superposed first sheet 1 and second sheet 2 are sandwiched between the convex portion 35 of the first roll 31 and the ultrasonic horn 42 of the ultrasonic fusion splicer 41, and ultrasonic vibration is applied to both of them. A bonded sheet 10a having a plurality of bonded portions 4 formed by fusing the sheets (1, 2) is obtained (bonded portion forming step). After that, the joining sheet 10a is delivered to the peripheral surface of the anvil roll 33 so that the position of the joining portion 4 in the joining sheet 10a matches the position of the recessed portion 33a in the anvil roll 33 having the recessed portion 33a on the peripheral surface (delivery step ). Then, the joined sheet 10a delivered to the anvil roll 33 is introduced between the anvil roll 33 and the pin roll 36 having perforation pins 36a corresponding to the recesses 33a of the anvil roll 33 on the peripheral surface thereof. By inserting 36a, a through hole 14 is formed in the joint portion 4 of the joint sheet 10a to obtain the composite sheet 10 (piercing step).

In the manufacturing method of the present embodiment, prior to the application of ultrasonic vibration, at least one of the first sheet 1 and the second sheet 2 is heated to a temperature lower than the melting point of these sheets (1, 2) and 50°C lower than the melting point. It is preferable to heat to above. That is, it is preferable to perform one or both of the following (1) and (2) prior to applying ultrasonic vibration. (1) The first sheet 1 is heated to a temperature lower than the melting point of the first sheet 1 and 50° C. lower than the melting point. (2) The second sheet 2 is heated to a temperature lower than the melting point of the second sheet 2 and 50° C. lower than the melting point. Preferably, the first sheet 1 is heated to a temperature lower than the melting point of the first sheet 1 and 50°C lower than the melting point, and the second sheet 2 is heated to a temperature lower than the melting point of the second sheet 2 and 50°C lower than the melting point. Heat to a temperature lower than °C.

As a method of setting the first sheet 1 to a temperature lower than the melting point of the first sheet 1 and 50° C. lower than the melting point, for example, the temperature of the first sheet 1 on the first roll 31 is set to Measurement is performed between the meshing portion of the two rolls 32 and the pin roll 36 subjected to ultrasonic vibration by the ultrasonic fusion machine 41, and the first roll is adjusted so that the measured value is within the above-mentioned specific range. The temperature of the peripheral surface of 31 is controlled. As a method for preheating the first sheet 1 to a temperature within a specific range, the temperature of the peripheral surface of the first roll 31 is set within the first roll 31 so that the first sheet 1 reaches a temperature within a specific range. Various methods can be used in place of the method of controlling by the heater provided. For example, a heater, a hot air outlet, and a far-infrared irradiation device are provided in the vicinity of the peripheral surface of the first roll 31, so that the temperature of the peripheral surface of the first roll 31 before or after the first sheet 1 is brought along. can be controlled. Further, the second roll 32 in contact with the first sheet 1 is heated at the meshing portion between the first roll 31 and the second roll 32, and the temperature of the first sheet 1 is controlled by controlling the temperature of the peripheral surface of the second roll 32. can be controlled. Furthermore, the first sheet before being run along the first roll 31 may be brought into contact with a heated roller, passed through a space maintained at a high temperature, or blown with hot air.

On the other hand, as a method of setting the second sheet 2 to a temperature lower than the melting point of the second sheet 2 and 50° C. lower than the melting point, the temperature of the second sheet 2 before being superimposed on the first sheet 1 is The temperature of the second sheet 2 arranged in the conveying path of the second sheet 2 is measured so that the measured value is within the above-mentioned specific range. Preferably, the temperature of the heating means (not shown) is controlled. The heating means for the second sheet 2 may be a contact method such as contact with a heated roller or the like, a method of passing through a space maintained at a high temperature, or a method of blowing or penetrating hot air. Alternatively, a method of irradiating infrared rays (non-contact type) may be used.

The melting points of the first sheet 1 and the second sheet 2 are measured by the following method. For example, it is measured using a differential scanning calorimeter (DSC) PYRIS Diamond DSC manufactured by Perkin-Elmer. The melting point is determined from the peak value of the measurement data. When the first sheet 1 or the second sheet 2 is a fiber sheet such as a non-woven fabric, and the constituent fibers are composite fibers consisting of multiple components such as core-sheath type and side-by-side type, these sheets Regarding the melting point, the melting point of the lowest temperature among multiple melting points measured by DSC is taken as the melting point of the composite fiber sheet.

In the manufacturing method of the composite sheet of the present embodiment, the first sheet 1 and the second sheet 2 thus overlapped are combined with the convex portion 35 of the first roll 31 and the ultrasonic horn 42 of the ultrasonic fusion splicer 41 . The bonding portion 4 is formed by sandwiching between and applying ultrasonic vibration. In this embodiment, at least one of the first sheet 1 and the second sheet 2 is preheated to a temperature within the above-mentioned specific range at which both sheets (1, 2) do not melt, and then one or It is preferable to apply ultrasonic vibrations to both sheets (1, 2) in a preheated state. At this time, by adjusting the conditions for applying ultrasonic vibration, for example, the wavelength and intensity of the ultrasonic vibration to be applied, the pressure to press both sheets (1, 2), etc., both sheets (1, 2) are 1 and 2) are melted to form a joint 4. Moreover, since the through hole 14 is formed in the joint 4 by the punching pin 36 a , the through hole 14 can be formed while being surrounded by the melted portion of the joint 4 .

According to the manufacturing method of the composite sheet of the present embodiment, at least one of the first sheet 1 and the second sheet 2, preferably both, is heated by a heating means such as a heater to a high temperature such that both sheets (1, 2) do not melt. After that, the bonding portion 4 is formed by applying ultrasonic vibration while applying pressure between the convex portion 35 of the first roll 31 and the ultrasonic horn 42 of the ultrasonic fusion splicer 41. As compared with the case where both sheets (1, 2) are not preheated, it is possible to form the joint 4 more reliably, and the problem occurs when both sheets (1, 2) are preheated to a temperature exceeding the melting point. Since problems such as adhesion of the molten resin to the conveying means and winding of the sheet around the conveying roll are less likely to occur, the maintenance burden of the apparatus is also small.

Also, after the first sheet 1 and the second sheet 2 are bonded and shaped on the first roll 31, the bonded sheet 10a is transferred to the anvil roll 33, and then the through holes 14 are formed on the anvil roll 33. Therefore, no positional deviation occurs between the position of the joint portion 4 and the position of the through hole 14 .

The composite sheet 10 obtained by the manufacturing method of the composite sheet of the present embodiment has unevenness and has the joint portion 4 having the through holes 14 at the bottom of the concave portion. It is also excellent in air permeability and liquid drawing ability. The composite sheet 10 is preferably used as a surface sheet of absorbent articles by taking advantage of such properties, but the application of the composite sheet 10 is not limited to these.

From the viewpoint of ensuring that one or more of the above-described effects are exhibited, the manufacturing method and manufacturing apparatus of the present embodiment preferably have the following configuration. (1) The first sheet 1 is preferably preheated to a temperature lower than or equal to 50°C lower than the melting point of the first sheet 1, and higher than or equal to 20°C lower than the melting point of the first sheet 1 and 5°C lower than the melting point. Preheating below a low temperature is even more preferred. (2) The second sheet 2 is preferably preheated to a temperature lower than or equal to 50°C lower than the melting point of the second sheet 2, and higher than or equal to 20°C lower than the melting point of the second sheet 2 and 5°C lower than the melting point. Preheating to a temperature below the low temperature is even more preferred.

The preheating temperature of each of the first sheet 1 and the second sheet 2 is preferably 100° C. or higher, more preferably 130° C. or higher, from the viewpoint of facilitating the formation of the joint 4. From the viewpoint of preventing the adhesion of , and the prevention of winding around the transport roll, the temperature is preferably 150°C or less, more preferably 145°C or less.

In addition, from the viewpoint of ease of forming the joint portion 4, the first sheet 1 and the second sheet are sandwiched between the tip surface 35c of the convex portion 35 of the first roll 31 and the tip surface 42t of the ultrasonic horn 42. The pressure applied to the sheet 2 is preferably 10 N/mm or more, more preferably 15 N/mm or more, and preferably 150 N/mm or less, more preferably 120 N/mm or less. , 10 N/mm or more and 150 N/mm or less, more preferably 15 N/mm or more and 120 N/mm or less.

Here, the pressure is a so-called linear pressure, and the pressure (N) of the ultrasonic horn 42 is the total face width (X direction) of the convex portion 35 in contact with the ultrasonic horn 42 (the concave portion of the first roll 31 is (excluding pressure) divided by the length (pressure per unit length).

Further, from the viewpoint of ease of forming the joint 4, the frequency of the ultrasonic vibration to be applied is preferably 15 kHz or more, more preferably 20 kHz or more, and preferably 50 kHz or less, more preferably It is 40 kHz or less, preferably 15 kHz or more and 50 kHz or less, more preferably 20 kHz or more and 40 kHz or less.

[Frequency measurement method]
Measure the displacement of the tip of the horn with a laser displacement meter or the like. The frequency is measured with a sampling rate of 200 kHz or higher and an accuracy of 1 μm or higher.

Further, from the viewpoint of ease of forming the joint 4, the amplitude of the ultrasonic vibration to be applied is preferably 20 μm or more, more preferably 25 μm or more, and preferably 50 μm or less, more preferably It is 40 μm or less, preferably 20 μm or more and 50 μm or less, more preferably 25 μm or more and 40 μm or less.

[Method of measuring amplitude]
Measure the displacement of the tip of the horn with a laser displacement meter or the like. Amplitude is measured with a sampling rate of 200 kHz or higher and an accuracy of 1 μm or higher.

1 first sheet 2 second sheet 3 concave portion 4 joint portion 5 convex portion 10 composite sheet 10a joint sheet 14 through hole 20 composite sheet manufacturing apparatus 31 first roll 32 second roll 33 anvil roll 33a concave portion 33b concave region 33c high friction Area 34 Suction hole 35 Projection 36 Pin roll 36a Perforating pin 40 Ultrasonic processor 41 Ultrasonic fusion machine 42 Ultrasonic horn

Claims (5)

having a plurality of joints where the first sheet and the second sheet are joined, and at least a portion of the first sheet other than the joints forms a protrusion projecting to the side opposite to the second sheet; And a method for manufacturing a composite sheet having a through hole in the joint,
A first roll and a second roll having unevennesses on their peripheral surfaces that mesh with each other are rotated in opposite directions to each other while the first sheet is introduced into the meshing portion of both rolls to remove the first sheet. A shaping step of deforming into an uneven shape;
A superposition step of conveying the first sheet deformed into an uneven shape while holding it on the peripheral surface of the first roll, and superimposing the second sheet on the first sheet being conveyed;
A joined sheet is obtained in which a plurality of joined portions are formed by sandwiching the superimposed first sheet and the second sheet between the convex portion of the first roll and the fuser and fusing the two sheets. a joint forming step;
a transfer step of transferring the joint sheet to the peripheral surface of the anvil roll such that the position of the joint portion in the joint sheet matches the position of the recess in the anvil roll having the recess in the peripheral surface;
The bonding sheet is joined by introducing the joining sheet between a pin roll having perforation pins on the peripheral surface thereof corresponding to the recesses in the anvil roll and the anvil roll, and inserting the perforation pins into the recesses. a piercing step of forming the through-hole in the portion to obtain the composite sheet;
A method of manufacturing a composite sheet comprising: 2. The method for producing a composite sheet according to claim 1, wherein in the inserting step, the punch pin is inserted from the first sheet side of the joined sheet. a first sheet and a second sheet having a plurality of joints joined together, at least a portion of the first sheet other than the joints forming a projection projecting to the side opposite to the second sheet; An apparatus for manufacturing a composite sheet having a through hole in the joint,
a first roll and a second roll having recesses and protrusions that mesh with each other on their peripheral surfaces and arranged so that their rotation axes are parallel to each other;
a fusion machine arranged to face the peripheral surface of the first roll;
an anvil roll having recesses corresponding to the protrusions of the first roll on its peripheral surface and arranged to have a rotation axis parallel to the rotation axis of the first roll;
a pin roll having perforated pins on its peripheral surface corresponding to the recesses of the anvil roll and arranged to have a rotation axis parallel to the rotation axis of the anvil roll;
with
A manufacturing apparatus for a composite sheet, wherein a phase shift preventing portion for preventing a phase shift of a sheet transferred from a first roll to the anvil roll is provided on the peripheral surface of the anvil roll. 4. The manufacturing apparatus according to claim 3, wherein the phase shift prevention unit has a structure for holding the sheet by suction on the peripheral surface of the anvil roll, or has a structure for holding the sheet on the peripheral surface of the anvil roll by frictional force. . The concave portion of the anvil roll has a suction hole, and the sheet is sucked and held on the peripheral surface of the anvil roll by sucking air from the outside to the inside of the anvil roll through the suction hole. 5. The manufacturing apparatus according to claim 3 or 4.

Images