METHOD AND APPARATUS FOR PRODUCING COMPOSITE STRUCTURE
The present invention relates to a method and apparatus for forming a composite structure, preferably for use in an absorbent structure used within the personal hygiene industry, such as for instance feminine hygiene garments, baby diapers and pants and adult incontinence garments. The present invention preferably provides a method and apparatus for depositing and positioning particulate materials in a desired pattern onto a moving carrier layer. The method allows accurate forming of a pattern of particulate material clusters at high production speed having improved attachment properties, with reduced raw material usage and relative low cost. The present invention foresees in the need for improved thin, flexible, lightweight absorbent structure having optimal absorption, distribution and retention.
1 . A process for producing an absorbent structure comprising the following steps:
providing a carrier layer;
depositing and positioning absorbent material onto the carrier layer according to a pocketing pattern of absorbent material clusters with substantially no absorbent material in between the absorbent material clusters;
providing an auxiliary layer covering the absorbent material so as to form a sandwich structure of the carrier layer, the auxiliary layer and the absorbent material;
attaching an adhesive to the carrier layer and/or to the auxiliary layer prior to the bringing together of the sandwich structure;
after the bringing together of the sandwich structure, attaching the carrier layer to the auxiliary layer to provide substantially permanent primary bonding regions and substantially detachable or temporary secondary bonding regions which are substantially free of absorbent material; said secondary bonding regions being configured to release under the swelling force of the absorbent materials and/or under the influence of water.
2 . The process according to claim 1 , wherein the attaching of an adhesive comprises attaching of an adhesive to the carrier layer prior to the disposing of absorbent material on the carrier layer.
3 . The process according to claim 1 , wherein the attaching of an adhesive comprises attaching of an adhesive to the auxiliary layer prior to the covering of the absorbent material with the auxiliary layer.
4 . The process according to claim 1 , wherein the providing of the auxiliary layer is done by spraying an adhesive layer on the absorbent material.
5 . The process according to claim 1 , wherein the attaching of an adhesive comprises spraying an adhesive on the absorbent material clusters.
6 . The process according to claim 1 , wherein the attaching comprises providing any one or more of the following: adhesive bonds, thermal bonds, sonic bonds, stapling, stitching.
7 . The process according to claim 1 , wherein the attaching comprises applying thermo-sealing.
8 . The process according to claim 1 , wherein the absorbent material is substantially cellulose-free.
9 . The process according to claim 1 , wherein the attaching of the adhesive comprises applying any one of the following adhesive patterns: swirl patterns, stripes.
10 . The process according to claim 1 , wherein the absorbent structure is disposed between a liquid pervious top sheet and a liquid impervious back sheet to obtain an absorbent article, wherein said absorbent article is any one of the following: a feminine hygiene garment, baby diaper, baby pants and adult incontinence garment.
11 . A process for producing an absorbent structure comprising the following steps:
providing a carrier layer;
depositing and positioning absorbent material onto the carrier layer according to a pocketing pattern of absorbent material clusters with substantially no absorbent material in between the absorbent material clusters;
providing an auxiliary layer covering the absorbent material so as to form a sandwich structure of the carrier layer, the auxiliary layer and the absorbent material;
attaching an adhesive to the carrier layer and to the auxiliary layer prior to the bringing together of the sandwich structure;
after the bringing together of the sandwich structure, attaching the carrier layer to the auxiliary layer to provide substantially permanent primary bonding regions and substantially detachable or temporary secondary bonding regions which are substantially free of absorbent material; said secondary bonding regions being configured to release under the swelling force of the absorbent materials and/or under the influence of water.
12 . The process according to claim 11 , wherein the attaching of an adhesive comprises attaching of an adhesive to the carrier layer prior to the disposing of absorbent material on the carrier layer.
13 . The process according to claim 12 , wherein the attaching of an adhesive comprises attaching of an adhesive to the auxiliary layer prior to the covering of the absorbent material with the auxiliary layer.
14 . The process according to claim 13 , wherein the attaching of an adhesive comprises spraying an adhesive on the absorbent material clusters.
15 . The process according to claim 13 , wherein the attaching comprises providing any one or more of the following: adhesive bonds, thermal bonds, sonic bonds, stapling, stitching.
16 . The process according to claim 14 , wherein the attaching comprises providing any one or more of the following: adhesive bonds, thermal bonds, sonic bonds, stapling, stitching.
17 . The process according to claim 13 , wherein the absorbent material is substantially cellulose-free.
18 . The process according to claim 13 , wherein the absorbent structure is disposed between a liquid pervious top sheet and a liquid impervious back sheet to form an absorbent article, wherein said absorbent article is any one of the following: a feminine hygiene garment, baby diaper, baby pants and adult incontinence garment.
19 . A process for producing an absorbent article comprising the following steps:
providing a carrier layer;
depositing and positioning absorbent material onto the carrier layer according to a pocketing pattern of absorbent material clusters with substantially no absorbent material in between the absorbent material clusters; wherein the absorbent material is substantially cellulose-free;
providing an auxiliary layer covering the absorbent material so as to form a sandwich structure of the carrier layer, the auxiliary layer and the absorbent material;
attaching an adhesive to the carrier layer and to the auxiliary layer prior to the bringing together of the sandwich structure;
after the bringing together of the sandwich structure, attaching the carrier layer to the auxiliary layer to provide substantially permanent primary bonding regions and substantially detachable or temporary secondary bonding regions which are substantially free of absorbent material, in order to obtain an absorbent structure; said secondary bonding regions being configured to release under the swelling force of the absorbent materials and/or under the influence of water;
disposing the absorbent structure between a liquid pervious top sheet and a liquid impervious back sheet to form an absorbent article, wherein said absorbent article is any one of the following: a feminine hygiene garment, baby diaper, baby pants and adult incontinence garment.
20 . The process according to claim 19 , wherein the attaching comprises providing any one or more of the following: adhesive bonds, thermal bonds, sonic bonds, stapling, stitching.