JP6972944B2 - Thermoplastic sheet thermal processing equipment - Google Patents

Description

The present invention relates to a thermal processing apparatus for a thermoplastic sheet. Specifically, the thermal processing apparatus according to the present invention is for performing thermal processing such as embossing of a thermoplastic sheet, pore forming processing, and fusion processing using an embossing roller.

Conventionally, as a heat processing device for a thermoplastic sheet such as a non-woven fabric or a plastic film, for example, the thermoplastic sheet is provided on the outer peripheral surface of an embossing roller, and the thermoplastic sheet is sandwiched between a protrusion and a receiving roller to perform embossing while heating. The device is known (Patent Document 1). In such an embossing apparatus, the outer peripheral surface of the embossing roller or the receiving roller is heated, and by melting the portion of the thermoplastic sheet that is in contact with the protrusion, embossing (recess) is imparted to the surface of the sheet. Will be done. It is also possible to form openings in the thermoplastic sheet or fuse multiple thermoplastic sheets using the same device.

Japanese Unexamined Patent Publication No. 2016-203525

By the way, in a general embossing apparatus, the protrusion of the embossing roller has a substantially flat contact surface with the thermoplastic sheet, and the contact surface partially melts the thermoplastic sheet while pressing it. be. However, when the thermoplastic sheet in contact with the contact surface of the protrusion melts, the melted material flows toward the outer edge side of the contact surface, and then hardens around the outer edge of the contact surface, and the thermoplastic sheet remains as it is. It will remain on the surface. The hardened portion of the material thus formed is harder to the touch than the other portions of the thermoplastic sheet. For example, non-woven fabric is often used for disposable diapers, but if a hardened portion having a hard touch remains on the non-woven fabric constituting the disposable diaper, there is a problem that the wearer feels uncomfortable and the wearing feeling is impaired. In particular, when the contact area between the protrusion of the embossed roller and the thermoplastic sheet becomes large, a larger amount of material is hardened around the protrusion, so that the deterioration of the touch becomes more remarkable.

Therefore, an object of the present invention is to suppress the formation of a cured portion of a material on the surface of a thermoplastic sheet in a thermoplastic sheet thermal processing apparatus, and to maintain a good feel of the thermoplastic sheet. ..

As a result of diligent studies on means for solving the problems of the above-mentioned conventional invention, the inventor of the present invention forms a groove portion on the contact surface of the protrusion portion provided on the embossed roller along the outer edge thereof, thereby forming the protrusion portion. It has been found that the material of the thermoplastic sheet that has been melted by contacting with the material can be partially recovered or removed, and the amount of the molten material remaining on the surface of the thermoplastic sheet can be reduced. .. Then, the present inventor came up with the idea that the problems of the conventional invention could be solved based on the above findings, and completed the present invention. Specifically, the present invention has the following configurations.

The present invention relates to a thermal processing apparatus. The thermal processing apparatus according to the present invention includes an embossing roller 1. The emboss roller 1 has a plurality of protrusions 10 on its outer peripheral surface. The heat processing apparatus processes the thermoplastic sheet by heating the contact portion of the embossed roller 1 in a state where the protrusion 10 is in contact with the thermoplastic sheet. The "processing" referred to here includes various thermal processing such as embossing, pore forming processing, and fusion processing. Here, the protrusion 10 of the emboss roller 1 has a contact surface 11 that comes into contact with the thermoplastic sheet. Further, the protrusion 10 of the emboss roller 1 has a groove 12 formed along the outer edge of the contact surface 11 in the vicinity of the outer edge. The "near the outer edge" of the contact surface 11 means a position closer to the outer edge than the center of the contact surface.

By forming the groove portion 12 on the contact surface 11 of the protrusion 10 provided in the embossed roller 1 as described above, the thermoplasticity melted by touching the region (inner shell region 13) surrounded by the groove portion 12. Since the material of the sheet is trapped in the groove portion 12, it does not remain on the thermoplastic sheet. As a result, the material of the thermoplastic sheet melted by touching the contact surface 11 of the protrusion 10 can be partially recovered or removed, so that the amount of the material remaining on the sheet and hardening can be reduced. can.

In the heat processing apparatus according to the present invention, the contact surface 11 of the protrusion 10 is divided into an inner region 13 surrounded by the groove 12 and an outer region 14 located between the groove 12 and the outer edge of the contact surface 11. Will be done. In this case, it is preferable that the area of the inner shell region 13 is larger than the area of the outer shell region 14. By increasing the area of the inner shell region 13 in this way, the amount of materials that can be collected and removed increases. The material melted by touching the outer region 14 may remain on the thermoplastic sheet and harden, but the residual amount can be reduced by reducing the area of the outer region 14. ..

In the thermal processing apparatus according to the present invention, the outer shell region 14 may be formed at a position protruding toward the radial outer side of the embossed roller 1 from the inner shell region 13. By providing the height difference between the inner shell region 13 and the outer shell region 14 in this way, the molten material can easily enter the inside of the groove portion 12, so that this material can be recovered or removed more effectively.

In the present invention, the outer region 14 may be inclined so as to be lower toward the groove portion 12. By making the outer region 14 an inclined surface in this way, the material of the thermoplastic sheet melted by touching the outer region 14 can easily partially enter the groove 12. This further reduces the amount of material remaining on the thermoplastic sheet.

In the heat processing apparatus according to the present invention, the inner region 13 may have a plurality of groove paths 15 connected to the groove portion 12. By forming the groove 15 in the inner region 13 in this way, the material in contact with the inner region 13 flows into the groove 12 through the groove 15, so that the material can be removed more efficiently.

According to the present invention, after the thermoplastic sheet is subjected to thermal processing such as embossing, it is possible to prevent the molten portion of the material from remaining on the surface of the sheet, and as a result, the texture of the thermoplastic sheet is maintained well. be able to.

FIG. 1 shows an embodiment of a heat processing apparatus according to the present invention. FIG. 2 shows an enlarged view of a protrusion provided on the outer peripheral surface of the emboss roller. FIG. 3 is a cross-sectional view schematically showing the flow path of the material melted by touching the protrusion of the emboss roller. FIG. 4 is a cross-sectional view of a protrusion of an embossed roller, showing a plurality of embodiments. FIG. 5 is a perspective view of the protrusion of the embossed roller, and shows an embodiment in which a grid-like groove is formed in the inner region.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention is not limited to the form described below, and includes a form appropriately modified by a person skilled in the art from the following form to the extent obvious to those skilled in the art.
In the specification of the present application, "A to B" means "A or more and B or less".

FIG. 1 shows an embodiment of a heat processing apparatus according to the present invention. In the embodiment shown in FIG. 1, the heat processing apparatus includes an embossing roller 1 and a receiving roller 2 arranged so as to face the embossing roller 1, and two rollers are provided between the pair of rollers 1 and 2. It is used in applications where a thermoplastic sheet is sandwiched and both are heat-sealed. Further, in the present embodiment, the heat processing device further includes a heating device 3 for heating the outer peripheral surface of the receiving roller 2. The heating device 3 may heat the outer peripheral surface of the embossing roller 1 instead of heating the outer peripheral surface of the receiving roller 2.

The emboss roller 1 has a plurality of protrusions 10 on its outer peripheral surface. The pattern for arranging the protrusions 10 can be appropriately designed according to the pattern for fusing the thermoplastic sheet. Further, the shape and size of the protrusion 10 may be appropriately designed according to the use of the thermoplastic sheet. Further, the outer peripheral surface of the receiving roller 2 is formed to be substantially flat, and a plurality of thermoplastic sheets are sandwiched between the receiving roller 2 and the protrusion 10 of the embossing roller 1. Since the outer peripheral surface of the receiving roller 2 is heated by the heating device 3, the thermoplastic sheet sandwiched between the outer peripheral surface of the receiving roller 2 and the protrusion 10 of the embossing roller 1 is heated at the portion in contact with the protrusion 10. Being partially melted. As a result, the thermoplastic sheets laminated in the two layers are fused to each other.

The thermoplastic sheet is not particularly limited, and for example, a non-woven fabric made of thermoplastic resin fibers such as polypropylene, polyethylene, polyester, and nylon, or a plastic film made of these resins may be used. Further, the type of the non-woven fabric is not particularly limited, and examples thereof include air-through non-woven fabric, point-bonded non-woven fabric, spun-bonded non-woven fabric, air-laid non-woven fabric, melt-blow non-woven fabric, SMS non-woven fabric, and SMMS non-woven fabric.

In the embodiment shown in FIG. 1, the heated receiving roller 2 is used, but instead of this, an ultrasonic horn (not shown) for ultrasonic sealing may be used. In the ultrasonic seal, a thermoplastic sheet is sandwiched between an ultrasonic horn that vibrates ultrasonically and an embossed roll, and frictional heat is generated by applying vibration to this sheet, and the sheet is made using this frictional heat. This is a method of crimping while melting. When the ultrasonic horn is pressed against the thermoplastic sheet and the vibration is sufficiently transmitted, the material melts and the sheets are fused by the pressing pressure.

Further, FIG. 1 shows an example of a thermal processing apparatus according to the present invention in which a plurality of thermoplastic sheets are fused, but the thermal processing apparatus according to the present invention is not limited to this. For example, the heat processing apparatus of the present invention is known for heat using an emboss roller 1, such as embossing that presses a thermoplastic sheet while heating it, and opening forming processing that forms an opening while heating a thermoplastic sheet. It can be used for processing.

FIG. 2 shows an example of a protrusion 10 provided on the outer peripheral surface of the emboss roller 1. In the example shown in FIG. 2, the protrusion 10 is formed in a columnar shape, but the shape of the protrusion 10 is not limited to this, and a quadrangular columnar shape or a frustum may be used depending on the application for thermal processing. It may be shaped like a quadrangular pyramid, or other polygonal columnar or polygonal frustum. As shown in FIG. 2, the protrusion 10 has a groove 12 formed on the contact surface 11 with the thermoplastic sheet. The groove portion 12 is provided in the vicinity of the outer edge of the contact surface 11, and is formed along the outer edge of the contact surface 11. That is, it is preferable that the groove portion 12 is formed in a shape similar to the outer edge of the contact surface 11 in a plan view, and the distance between the groove portion 12 and the outer edge is uniform.

Further, as shown in FIG. 2, the contact surface 11 of the protrusion 10 is divided into an inner region 13 and an outer region 14 with the groove 12 as a boundary. The inner region 13 is a region surrounded by the groove 12 and is located inside the groove 12. The outer region 14 is a region located between the groove 12 and the outer edge, and is located outside the groove 12. In the present invention, it is preferable that the area of the inner shell region 13 is larger than the area of the outer shell region 14. Specifically, the area of the inner shell region 13 is 60% or more, 70% or more, or 80% or more with respect to the total area of the contact surface 11 (that is, the total area of the inner shell region 13 and the outer shell region 14). It is preferable to occupy. The upper limit of the occupied area ratio of the inner region 13 is not particularly limited, but considering that the outer region 14 is inevitably formed, the upper limit may be about 95% or 90%.

FIG. 3 is a cross-sectional view schematically showing the protrusion 10 and the thermoplastic sheet, and the flow path of the material of the molten thermoplastic sheet in contact with the protrusion 10 is indicated by a broken line arrow. In particular, FIG. 3 (a) shows the protrusion 10 in the present invention, and FIG. 3 (b) shows the conventional protrusion 10 ′ to be compared with the present invention. As shown in FIG. 3A, in the present invention, since the groove 12 is formed in the protrusion 10, the material of the thermoplastic sheet melted in contact with the inner region 13 and the outer region 14 is this. It is designed to flow into the groove portion 12. In particular, since the inner shell region 13 is a region isolated by the groove portion 12, does the material melted by touching the inner shell region 13 not reach the outer edge of the protrusion 10 and flow into the groove portion 12? Or, it will be attached to and held in the inner region 13 as it is. On the other hand, a part of the material melted by touching the outer region 14 flows into the groove 12, but the residue reaches the outer edge of the protrusion 10. The molten material that has reached the outer edge of the protrusion 10 is then cured on the surface of the thermoplastic sheet and remains on the sheet as it is. The cured portion remaining on the thermoplastic sheet is hard to the touch, but according to the protrusion 10 of the present invention, such a cured portion is almost nonexistent, or even if it is present, it is extremely small. As described above, according to the present invention, it is possible to prevent the texture of the thermoplastic sheet from being impaired by the cured portion of the material.

On the other hand, as shown in FIG. 3B, the contact surface 11'of the protrusion 10'provided on the conventional emboss roller is formed to be substantially flat. Therefore, almost all of the material of the thermoplastic sheet melted by touching the flat contact surface 11'of the protrusion 10'is extruded to the outer edge by the contact surface 11', hardened around the outer edge, and heats as it is. It will remain on the surface of the plastic sheet. Therefore, in the conventional embossed roller, a relatively large hardened portion is formed on the sheet. As described above, as is clear when comparing FIGS. 3 (a) and 3 (b), it is better to use the protrusion 10 of the present invention to keep the cured portion of the material remaining on the thermoplastic sheet smaller. Can be done.

Subsequently, a specific dimensional example of the groove portion 12 of the protrusion portion 10 will be described with reference to FIG. 4 (a). In the example shown in FIG. 4A, there is no difference in height between the inner region 13 and the outer region 14, and the height levels are the same. Reference numeral W indicates a distance between the outer edge of the contact surface 11 of the protrusion 10 and the groove 12, that is, the width of the outer region 14. Further, the reference numeral R indicates the maximum distance from the center (center of gravity) of the contact surface 11 of the protrusion 10 to the outer edge. When the contact surface 11 is circular, the maximum distance R is the radius of the circle. Further, when the contact surface 11 is a quadrangle, the maximum distance is half of the diagonal line. In this case, the width W of the outer region 14 may be less than 50% with respect to the distance R, and may be, for example, 5 to 40% or 10 to 25%. The width W of the outer region 14 may be, for example, about 1 to 5 mm.

Further, the reference numeral G indicates the width of the groove portion 12. The width G of the groove portion 12 is preferably formed to such an extent that the base material of the molten thermoplastic sheet easily flows in, and is preferably 0.5 to 10 mm or 1 to 5 mm, for example. Further, reference numeral D indicates the depth of the groove portion 12. The depth D of the groove portion 12 is preferably formed to such an extent that the base material of the molten thermoplastic sheet can be sufficiently accommodated, and is preferably, for example, 1 to 20 mm or 2 mm to 10 mm. The dimensional example shown here is just an example, and may be appropriately set appropriately according to the area of the contact surface 11 and the like.

FIG. 4B shows a modified example of the protrusion 10. In the example shown in FIG. 4B, the outer shell region 14 is formed at a position protruding from the inner shell region 13 toward the radially outer side (that is, above the drawing) of the emboss roller 1. Therefore, there is a height difference between the inner region 13 and the outer region 14, and the height level of the outer region 14 is higher than that of the inner region 13. In FIG. 4B, the height difference between the inner region 13 and the outer region 14 is indicated by reference numeral H. The height difference H is preferably formed so that the outer region 14 is in contact with the thermoplastic sheet and the inner region 13 is sufficiently in contact with the thermoplastic sheet, for example, 0.5 to 5 mm or 1 to 1. It is preferably 3 mm. By forming the inner shell region 13 at a position lower than the outer shell region 14 in this way, it is more reliable that the base material of the thermoplastic sheet melted by touching the inner shell region 13 reaches the outer edge of the protrusion 10. Can be prevented.

FIG. 4C shows another modification of the protrusion 10. In the example shown in FIG. 4 (c), the outer region 14 is inclined so as to be lower toward the groove portion 12. That is, the inner edge is lower than the outer edge of the outer region 14. The inclination angle θ of the outer region 14 may be, for example, 5 to 60 degrees, 10 to 45 degrees, or 15 to 30 degrees. By making the outer region 14 an inclined surface in this way, the base material of the thermoplastic sheet melted by touching the outer region 14 easily flows into the groove portion 12. That is, if the inflow amount of the base material from the outer region 14 to the groove portion 12 increases, the amount of the base material that reaches the outer edge of the contact surface 11 and is hardened can be reduced.

It should be noted that a height difference should be provided between the inner region 13 and the outer region 14 as shown in FIG. 4 (b), and the outer region 14 should be an inclined surface as shown in FIG. 4 (c). Can also be adopted at the same time.

FIG. 5 is a perspective view showing another modified example of the protrusion 10. In the modified example shown in FIG. 5, a plurality of groove paths 15 connected to the groove portion 12 are formed in the inner shell region 13. The groove 15 is a groove formed in the inner region 13, and the depth thereof is smaller than that of the groove 12. FIG. 5 shows an example in which the groove 15 is formed in a square grid pattern. However, the pattern of the groove 15 is not limited to this, and may be formed in a pattern that reaches the groove 12 radially from the center of the inner region 13, for example. By forming the groove 15 in the inner region 13 in this way, the melted base material easily flows into the groove 12 along the groove 15. A similar groove 15 may be formed not only in the inner region 13 but also in the outer region 14.

As described above, in the present specification, in order to express the content of the present invention, the embodiments of the present invention have been described with reference to the drawings. However, the present invention is not limited to the above embodiment, and includes modifications and improvements which are obvious to those skilled in the art based on the matters described in the present specification.

The present invention relates to a thermal processing apparatus for a thermoplastic sheet. Therefore, the present invention can be suitably used in a method for manufacturing a product that requires thermal processing of a thermoplastic sheet, for example, in a manufacturing industry such as a disposable diaper using a non-woven fabric.

1 ... Embossed roller 2 ... Receiving roller 3 ... Heating device 10 ... Projection part 11 ... Contact surface 12 ... Groove part 13 ... Inner shell area 14 ... Outer shell area 15 ... Groove path

Claims (3)

An embossing roller (1) having a plurality of protrusions (10) on the outer peripheral surface is provided.
It is a thermal processing apparatus for processing the thermoplastic sheet by heating the contact portion in a state where the protrusion (10) is in contact with the thermoplastic sheet.
The protrusion (10) is
The contact surface (11) in contact with the thermoplastic sheet and
A groove portion (12) formed along the outer edge thereof is provided in the vicinity of the outer edge of the contact surface (11).
The contact surface (11) includes an inner shell area (13) surrounded by the groove portion (12) and an outer shell area (14) located between the groove portion (12) and the outer edge of the contact surface (11). The area of the inner shell region (13) is larger than the area of the outer shell region (14).
The outer region (14) is a thermal processing apparatus formed at a position protruding outward in the radial direction of the emboss roller (1) from the inner region (13). An embossing roller (1) having a plurality of protrusions (10) on the outer peripheral surface is provided.
It is a thermal processing apparatus for processing the thermoplastic sheet by heating the contact portion in a state where the protrusion (10) is in contact with the thermoplastic sheet.
The protrusion (10) is
The contact surface (11) in contact with the thermoplastic sheet and
A groove portion (12) formed along the outer edge thereof is provided in the vicinity of the outer edge of the contact surface (11).
The contact surface (11) includes an inner shell area (13) surrounded by the groove portion (12) and an outer shell area (14) located between the groove portion (12) and the outer edge of the contact surface (11). The area of the inner shell region (13) is larger than the area of the outer shell region (14).
The outer region (14) is a thermal processing apparatus that is inclined so as to be lower toward the groove portion (12). An embossing roller (1) having a plurality of protrusions (10) on the outer peripheral surface is provided.
A heat processing device for forming an opening in the thermoplastic sheet by heating the contact portion in a state where the protrusion (10) is in contact with the thermoplastic sheet.
The protrusion (10) is
The contact surface (11) in contact with the thermoplastic sheet and
A groove portion (12) formed along the outer edge thereof is provided in the vicinity of the outer edge of the contact surface (11).
The contact surface (11) includes an inner shell region (13) surrounded by the groove portion (12) and an outer shell region (14) located between the groove portion (12) and the outer edge of the contact surface (11). It is divided into
The area of the inner shell region (13) is larger than the area of the outer shell region (14).
The inner region (13) is a heat processing apparatus having a plurality of groove paths (15) connected to the groove portion (12).

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