MXPA00011436A - Compliant embosser assembly - Google Patents

Abstract

An apparatus for embossing a pattern into absorbent articles such as sanitary napkins, panty liners, diapers, and adult incontinence pads is disclosed. The apparatus for forming a pattern of embossments in an absorbent article comprises an embosser assembly (50) having a patterned die roll (52) and an anvil roll (54). In one embodiment, the anvil roll (54) comprises a multi-layered structure, that comprises a metal hub, encircled by a compressible layer and enclosed by a sleeve which reduces machine dynamics, such as vibration, associated with the embossing apparatus and significantly improves the embossing line process and quality. The embosser assembly (50) also has a mechanism for applying compressive pressure on the components of an absorbent article when the components are placed between the die roll (52) and the anvil roll (54).

Description

STAMP ASSEMBLY IN DOLLAR RELIEF FIELD OF THE INVENTION The invention relates to an apparatus for embossing a pattern in absorbent articles such as sanitary napkins, panty liners, and adult incontinence pads, more particularly the present invention relates to an anvil roller in a stamper assembly in relief that reduces machine dynamics such as the vibration associated with the embossing apparatus and significantly improve the process and quality of the embossing line BACKGROUND OF THE INVENTION All the manners and varieties of absorbent articles configured for the absorption of bodily fluids such as menstruation, urine, and faecal are of course well known. Some particularly preferred absorbent articles are described in U.S. Patent Nos. 5,308,346 and 5,234,422 issued to Sneller. , and others, U.S. Patent No. 5,460,623 entitled "Three-Section Sanitary Towel", issued to Emenaker, et al., and PCT Publication No. WO 94/10045, entitled "Sanitary Towel having a predisposed core in a convex configuration towards above ", published on March 23, 1995 in the name of Letha M Hiñes, and others The latter publication describes providing the sanitary napkin with one or more lines of weakness that allow the sanitary napkin to fold in a preferred manner. Weakness may be composed of discrete sites of enhancements In the manufacture of these absorbent articles, difficulties are often encountered with process accounting and enhancement quality, particularly when the sanitary napkin is manufactured in a high-speed manufacturing operation. The dynamics of the machine, such as vibration, cause high concentrations of stress, high wear, and fatigue that decreases the life of the embossing device in enhancement An apparatus that increases the durability of the machine, reduces vibrations of the machine, creates a wide distribution of stress concentrations and provides a degree High control over registration of embossing pattern is needed, particularly when the sanitary napkin or other absorbent articles are to be made in a high-speed manufacturing operation BRIEF DESCRIPTION OF THE INVENTION The present invention is directed to an apparatus for embossing a pattern in absorbent articles such as sanitary napkins, panty liners and adult incontinence pads, which significantly improves the process and quality of the embossing line The apparatus for forming a pattern of embossments in an absorbent article comprises an embossing embosser assembly having a patterned pattern roller and an anvil roller. The anvil roller comprises a multilayer structure preferably comprising a cube, surrounded by a compressible layer and enclosed by a sleeve The anvil roller in multiple layers reduces the dynamics of the machine, such as vibration, associated with embossing apparatus and significantly improves the process and the quality of the embossing line The embossing stamper assembly also includes a mechanism for apply compression pressure on the components of an absorbent article when the components are placed between the stamped roller and the anvil roller BRIEF DESCRIPTION OF THE DRAWINGS Although the description concludes with the claims pointing out in a particular way and claiming differently the exposed matter that is considered as formant of the present invention, it is believed that the invention will be better understood from the following description which is taken in combination with the accompanying drawings, in which Figure 1 is a top plan view of a sanitary napkin which was embossed with an apparatus of the present invention. Figure 2 is a cross-sectional view of the sanitary napkin shown in the FIG. Figure 1, taken along line 2-2 of Figure 1 Figure 3 is a perspective view of an anvil roller and an embossing roller in a preferred embodiment of an embossing embosser assembly of the present invention. Figure 4 is a perspective view of an anvil roller and an embossing roller in an alternative assembly of the embossing embosser of the present invention. Figure 4A is a top plan view of a sanitary napkin with embossing made using the apparatus of the invention. the present invention shown in Figure 4 Figure 5 is a plan view of an anvil roll in the embossing stamper assembly of the present invention and a cut-away view of an anvil roll in the embossing stamper assembly with the outer sleeve removed Figure 5A is a cross-sectional view of an anvil roller shown in Figure 5 taken along line 5-5 of Figure 5 DETAILED DESCRIPTION OF THE INVENTION This invention relates to an apparatus for embossing a pattern in absorbent articles, such as sanitary napkins, panty liners, diapers, and adult incontinence pads, which reduces the dynamics of the machine associated with the stamping apparatus. in relief and significantly improves the process and quality of the embossing line Figure 1 shows an embodiment of a disposable absorbent article, sanitary pad 20 embossed using the process and apparatus of the present invention The sanitary napkin 20 has two surfaces, a surface that is in contact with the body permeable to the liquid or "body surface" 20A and a liquid impervious surface 20B The sanitary napkin 20 is shown in Figure 1 as seen from its body surface 20A As shown in Figure 2, the sanitary napkin 20 basically comprises an upper sheet 22 permeable to liquid, a liquid-impermeable backsheet 24, and an absorbent core 26 positioned on the topsheet 22 and the backsheet 24 The sanitary napkins 20 have two centerlines, a main longitudinal centerline L and a main transverse centerline T The term "longitudinal ", as used herein, refers to a line, axis or direction within the plane of the sanitary napkin 20 that is generally aligned with (eg, approximately parallel to) a vertical plane that divides a user standing in halves of left and right body when the sanitary napkin is worn 20 The terms "transverse" or "lateral" used herein, are interchangeable, and refer to a line, axis or direction that is located within the plane of the sanitary napkin 20 which is generally perpendicular to the longitudinal direction The sanitary napkin 20 has two separate longitudinal apart edges 28, two separate transverse edges or separate ends (or "ends") 30, which together form the periphery 32 of the sanitary napkin 20 The sanitary napkin embodiment 20 shown in Figure 1 is intended to be an example of a sanitary napkin having embossed channels similar to those described in U.S. Patent Nos. 5,308,346 and 5,234,422 issued to Sneller, et al. It should be understood that the sanitary napkin shown is merely a preferred embodiment, and that the present invention is limited to the manufacture of absorbent articles of the type or having the specific configuration shown in the drawings. The sanitary napkin can be provided with 34 channel enhancements either in addition to, or as an alternative to, another L enhancement pattern Suitable materials for the various components of the sanitary napkin 20 shown in Figure 1 are described in greater detail in U.S. Patent Nos. 5,308,346 and 5,234,422 issued to Sneller, et al. and in the patent publications incorporated by reference. Here Preferably, the materials comprising at least the top sheet and the backsheet are thermoplastics in order to join these components at their edges. In a particularly preferred embodiment, the top sheet 22 comprises the thermoplastic film with openings sold in the sanitary napkins by The Procter & Gamble Company of Cincinnati, Ohio, under the trademark DRI-WEAVE, which is manufactured under United States Patent No. 4,342,315 issued to Radel et al. On August 3, 1982, and in United States Patent No. 4,463,045 issued to Ahr, et al. on July 31, 1984 The absorbent core 26 can be manufactured in a wide variety of sizes and shapes as described in U.S. Patent Nos. 5,308,346 and ,234,422 issued to Sneller et al. The backsheet 24 preferably comprises a polyethylene film. In an alternative embodiment in which the absorbent article comprises an ultrathin sanitary napkin (shown in Figure 4A), the absorbent core 26 comprises the absorbent core described in FIG. U.S. Patent No. 5,460,623 issued to Emenaker, and others In this case, the absorbent core 26 preferably comprises a tissue laminate with absorbent particles of gelling material therebetween. The sanitary napkin 20 shown in Figure 2 is assembled in a sandwich configuration in which the topsheet 22 and the backsheet 24 have length dimensions. and width generally greater than those of the absorbent core 26 and enclose the absorbent core 26 The enhanced channels 34 are shown in Figure 2 as being a region of the sanitary napkin 20 wherein preferably the channels 34 are printed on both of the upper sheet 22 and the absorbent core 26 Figure 3 shows an embossing stamper assembly 50 of the present invention used to make the patterns of enhancements such as the embossments 34 in the sanitary napkin 20 shown in Figure 1 Embossing Emboss Assembly 50 preferably it comprises a stamping roll 52 and an anvil roll 54 Stamping roll 52 uses a stamper 52 Embossing pattern 60 to form a pattern of embossments Embossments are formed by raised portions 62 comprising part of embossing member 60. The pattern of embossments may also be in the form of embossments 34A embossed in sanitary napkin 20 as shown in FIG. shown in Figure 4A, however the design and scope of the embossing pattern is not limited to the specific configurations shown in the figures. Any suitable pattern of enhancements can be used. The modality of the sanitary napkin 20 shown in Figure 4A is intended to be an example of a sanitary towel similar to that described in U.S. Patent No. 5,460,623 entitled "Sanitary Towel of Three Sections" issued to Emenaker, et al., which is provided with an embossing pattern 34A. The embossing roll 52 and anvil roller 54 are both preferably made of a hard metal, such as steel In other embodiments, the anvil roller 54 may be provided with an anvil surface comprising an insert or enhancement portions The anvil roller 54 preferably has a substantially smooth surface In operation, the forces created during the stamping process they occur in a stage function. The forces are greater when the anvil is in contact with the sanitary napkin imparting embossing patterns and lowered or abated during the rotation of the anvil before the towel is embossed Next sanitary Providing the docile anvil roller with a substantially smooth surface minimizes distributions no force uniforms that would be caused by the substantial portions of enhancement on the surface of the embossing member 60 The embossing member 60 may be provided in any suitable manner The embossing member 60 may be in the form of a pattern directly on the roll of embossing 52 as shown in Figure 3, or of a removable insert In the embodiment shown in Figure 4, the embossing member is in the form of a removable insert, embossing member 60 In Figure 4 the embossing roll 52 has a recessed region 58 having a stamping insert or stamping member 60 therein. The stamping member 60 is preferably provided with a pair of bolt holes 65 and is bolted to the stamping roll 52 in such a manner that it is capable of This allows the stamping member 60 to be easily replaced when worn. Also provided the bending ability to change the pattern of enhancement by replacing the removable insert with a different insert. The embossments 34 or 34A can also be removed from the absorbent article entirely by simply removing the stamping member 60 The recessed region 50 allows the stamped embossing assembly accommodate the additional thickness of the absorbent core in the central area of the sanitary napkin He stamping member 60 comprises a stamping surface 60A with at least one highlighting portion 62 extending therefrom. The surface 60A of stamping member 60 can have a plurality of enhancement portions 62 as seen in Figure 4. of enhancement 62 will be used to form the embossments 34 and 34A on the body surface 20A of the sanitary napkin 20 When the components of the absorbent article are fed into the gripping space 80 between the embossing roll 52 and the anvil roller 54, the embossing portions 62 on the embossing surface 60A form an embossing pattern 34 and 34A on at least some of the components In operation, the components of the absorbent article (i.e., the top sheet, the back sheet, and absorbent core) are placed on top of each other in the proper sequence, and if desired, at least some of these components are secured together on their faces. The components for the absorbent article are preferably provided in the form of a weft or weft. continuous lamination (except for the absorbent core and the secondary topsheet which are preferably patches or discontinuous pieces) When the components are supplied to the embossing stamper assembly shown in Figures 3 and 4, the components will be arranged in a laminate with the weft of the upper sheet material facing down The stamping roll 52 and the anvil roller 54 are maintained in a relationship separately desired by a mechanism, such as a frame, to applying the compression pressure on the components of the sanitary napkin 20 The chassis can be connected directly or indirectly to the stamping and anvil rolls and aligns vertically to the stamping roll 52 and the anvil roll 54 The stamping roll 52 and the Anvil roller 54 are preferably held at a certain distance apart to define a gripping space 80 between the rollers, through which the components of the sanitary napkin are fed to form the particular ultrathin sanitary napkin (shown in Figure 4A) , the distance between the stamping and anvil rollers is preferably less than or equal to about 0 064 cm, and most preferably is about 0 038 cm. The components are fed between the gripping space 80 which applies compression pressure on the components of the absorbent article which is sufficient to form the embossments 34 therein, and in the embodiment shown FIG. 4 also provides the perimeter seal 40 on the sanitary napkin 20 shown in FIG. 4A. The anvil roller 54 used in the present invention to reduce the vibrations of the machine and to achieve a high degree of control over the registration of the embossing pattern 34, is shown in greater detail in Figures 5 and 5A. The anvil roll 54, shown in Figures 5 and 5A preferably comprises an anvil arrow 55 and a multi-layered structure comprising a cube 90 that is connected to the anvil shaft 55, which is surrounded by an elastic and compliant intermediate layer or element 92 which is preferably made of an elastomeric material, and a rigid, compliant, stiffer sleeve or cover 94 that covers the element or layer intermediate 92 to reduce wear and provide durability In the present embodiment, the surface of the anvil roll 54A preferably has a substantial surface area. and smooth The relationship of the components of the multilayer structure is shown in Figure 5A The preferred material for the hub 90 and the anvil shaft 55 is steel, and more preferably stainless steel. Using a hard metal provides a bucket 90 and a firm and rigid anvil shaft 55 This allows the hub 90 and the arrow 55 to support the high loads with little deflection The next layer is the intermediate layer or element 92 The intermediate layer or element 92 is preferably made of an elastomeric material that is molded on the outer diameter 91 of the anvil hub 90 The intermediate layer 92 absorbs the stresses and the compression forces that occur when the embossing embosser assembly is in operation, reducing the vibration in the stamping assembly in full relief. The elastomeric material of the intermediate layer 92 and the hardness of the hub 90 and the anvil shaft 55 can vary depending on the mode Specifically to form the embossed channels, the material of the intermediate layer is preferably a polyurethane. retaining with hardness levels from 30 Shore A to 50 Shore A The thickness of the intermediate layer 92 is preferably 0 20 to 7 6 cm, more preferably 0 38 to 3 80 cm, and most preferably 0 65 to 1 27 cm As seen in Figure 5A, a thermal fixative or adhesive 97 is applied to the outer surface 93 of the molded intermediate layer 92 and to the inner surface 95 of the sleeve 94. The sleeve 94, made of a material similar to steel, is the final layer of material on the anvil roll 54 The thickness of the sleeve 94 is preferably 0 25 to 10 2 cm, more preferably 063 to 3 2 cm, and most preferably 1 27 to 2 1 cm The sleeve 94 it is preferably press fit on the coated elastomeric hub 90 In some embodiments, the elastomeric matepal is compressed when the sleeve 94 is press fit onto the coated hub 90 The interference of the snap fit is mode dependent Preferably, the interference for stamping r in relief is approximately 015 cm The fully assembled roller is then subjected to a final polish, adjusting the concentpadad of roll within about 0 0025 cm The sleeve 94 distributes the force of the embossing embossing assembly 50 uniformly through the intermediate elastomer layer 92. The intermediate layer 92 (e.g., the elastomeric material) can be molded into different shapes creating raised spaces or areas 96 to provide different levels of submission or stress absorption One embodiment of the shape of intermediate layer 92 is shown in detail in Figure 6 Embossed areas 96 provide discontinuities in intermediate layer 92 that are perpendicular to the axis of anvil 55 In other embodiments, the discontinuities may be parallel to the anvil shaft 55 Many other orientations are possible (eg, diagonal) The discontinuities in the intermediate layer 92 provide the anvil roller with the increased ability to absorb stress giving the elastomeric material an area to flow when the forces of compression during the embossing process This provides better submission (ability to perform under compression) without exceeding the ability of the elastomeric material to absorb stress and does not generate excess heat The unique appearance of the anvil roll 54 is that it produces a distribution of equal force throughout the roller rotation, which provides several advantages including uniform submission, low wear, and wide distribution of stress concentrations. This also increases the life of the embossing roller and the precision of embossing embossing assembly. In the preferred embodiment of the anvil roller 54, the layers of the anvil roller 54 are concentrically applied and are open at their ends 57 to allow the materials to remain under compression pressures during the embossing process. In alternative embodiments, the ends 57 of the multiple layered structure can be sealed or the extensions of the sleeve 94 joining the hub 90 or the anvil shaft 55 Other embodiments of embossing the stamper are also possible and not limited to rollers. For example, an anvil surface and a stamping surface may be in the form of plates. The anvil roller 54 in FIG. 4 may also have a region. recess 68 having an anvil insert 70 therein Anvil insert 70 is preferably provided with a pair of bolt holes 72 and is bolted to anvil roll 54 such that it is also preferably capable of being removed The anvil insert 70 has a substantially smooth surface and is accommodated within the recessed region 68 of the anvil roller 54. The anvil insert 70 is preferably softer than the remaining portions of the surface of the anvil roller in such a manner that the portions of enhancement 62 envelope in stamping member 60 do not break the side that gives the sanitary napkin garment 20 Various alternative uses for the anvil of submission are possible Another use for the anvil of submission include cutting operations anywhere in a process for make an absorbent article The multiple layered system of an anvil of submission reduces stress and wear to increase the cutting life of the final or initial blade The anvil can also be used when joining discrete parts of a frame in the manufacture of diapers and catamenial product For example, the anvil can be used in a method for dynamically joining a laminate between a pair of rollers having a surface velocity differential therebetween, described in U.S. Patent No. 4,854,984 issued to Ball and others on August 8, 1989 In addition, in other modalities the components of the sanitary napkin can be assembled in a variety of ways. Different configurations known in the art and enhanced using the method and apparatus of the present invention Generally preferred vain configurations of the sanitary napkin are described in the US patent.

United States No. 4,321, 924"Seal Disposable Absorbent Article" issued to Ahr on March 30, 1982, United States Patent No. 4,425,130, "Composite Sanitary Towel" issued to DesMarais on January 10, 1984, United States Patents Nos. 4,950,264 and 5,009,653, both entitled "Thin, Flexible Sanitary Towel" issued to Osborn on August 21, 1990 and April 23, 1991, respectively, US Patents Nos B1 4,589,876, 4,687,478 and 5,267,992 issued to Van Tilburg, which disclose sanitary towels having fins, and the aforementioned patent applications issued to Sneller and others The disclosure of all patents, patent applications (and any of the patents issued thereon), as well as any of the foreign applications published patent applications), and the publications mentioned throughout this description are hereby incorporated by reference herein Without emb It is not expressly admitted that some of the documents incorporated by reference herein disclose the present invention Although the particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without depart from the spirit and scope of the invention

Claims (1)

1. CLAIMS A raised embossing assembly for forming an embossing pattern on an absorbent article, said embossing embossing assembly comprising a embossing roll, and being characterized in that it further comprises an anvil roll comprising an anvil surface against which they are placed the components of an absorbent article, the anvil roller having a multiple layered configuration comprising an anvil shaft substantially surrounded by a hub, said hub substantially surrounded by at least one layer capable of compressing, the layer being able to compress substantially enclosed by a sleeve, wherein said anvil roll is vertically aligned with said stamping roll, and a mechanism for applying compression pressure on the components of an absorbent article when the components are passed through said stamper embossing assembly between said stamping roller and said anvil roller, wherein said mechanism aligns vertically to said anvil roller and said stamping roll 2 The apparatus according to claim 1, wherein said compressible layer comprises a layer of discontinuous compressible material 3 The apparatus according to claim 2, wherein said discontinuous layer is oriented perpendicular to said anvil shaft 4 The apparatus according to claim 2, wherein said discontinuous layer is oriented parallel to the anvil shaft The apparatus according to claim 2, wherein said discontinuous layer is diagonally oriented to the arrow of the anvil 6. The apparatus according to any of the preceding claims, wherein the compressible layer comprises a polymer layer. with claim 6, wherein the polymer layer comprises an elastomeric material. The apparatus according to any of the preceding claims, wherein said sleeve comprises a hardened metal material. The apparatus according to any of the preceding claims, wherein said embossing roller is patterned 10 An anvil roller for use in a embossing assembly to form a pattern of embossments in an absorbent article, said anvil roller characterized in that it comprises a multiple layered structure comprising a cube surrounded by a compressible layer, the compressible layer being substantial Being enclosed by a sleeve