Method and apparatus for making absorbent structures with absorbent material

• US 9,668,926 B2
• Filed: 06/08/2012
• Issued: 06/06/2017
• Est. Priority Date: 06/10/2011
• Status: Active Grant

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Kreuzer, Carsten Heinrich, Jackels, Hans Adolf
• Primary Examiner(s): Daniels, Matthew
• Assistant Examiner(s): DULKO, MARTA S
• Application Number:
  US13/491,902
• Publication Number:
  US 20120316046A1
• Time in Patent Office: 1,824 Days
• Field of Search: 156199, 156201, 156276, 604382, 493331, 493374
• CPC Class Codes: A61F 13/15642 by depositing continuous layers or pads of fibrous material on single sheets or webs
• CPC Class Codes: A61F 13/15764 Transferring, feeding or handling devices; Drives
• CPC Class Codes: A61F 13/514 Backsheet, i.e. the impermeable cover or layer furthest from the skin A61F13/15211, A61F13/15252 take precedence
• CPC Class Codes: A61F 13/53 characterised by the absorbing medium A61F13/20 takes precedence
• CPC Class Codes: A61F 13/5323 having absorbent material located in discrete regions, e.g. pockets
• CPC Class Codes: A61F 2013/1591 via adhesive
• CPC Class Codes: A61F 2013/15926 for vacuum forming
• CPC Class Codes: A61F 2013/53908 with adhesive
• CPC Class Codes: B29C 59/022 characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29K 2995/0068 Permeability to liquids; Adsorption
• CPC Class Codes: B29L 2031/4878 Diapers, napkins

Abstract

A method and apparatus for making specific absorbent structures with an absorbent layer with absorbent material with therein substantially longitudinally extending strips that are free of absorbent material, using or having thereto a moving endless surface with receptacle(s) with specific longitudinally extending rods; and specific absorbent structures obtained therewith, suitable for absorbent articles, such as diapers and sanitary napkins.

Claims

1. A method of making an absorbent structure having an absorbent layer and therein longitudinally extending strips that are free of absorbent material, the absorbent layer being supported on a supporting sheet, the method comprising the steps of:

providing a moving endless surface moving in a machine direction (MD) having an outer shell with a forming receptacle, having an average width and transverse direction and dimension, and having an average length and longitudinal dimension, the average length being more than the average width;

the receptacle comprising a multitude of substantially longitudinally extending rods, spaced apart from one another in a transverse direction, each rod having a maximum transverse width dimension of at least 0.3 mm and each of the rods having a top portion and an opposing bottom portion, the bottom portion being adjacent an inner grid, and the minimum distance transversely between neighboring rods being at least 1 mm, and the rods each having an average height dimension perpendicular to the transverse and longitudinal dimensions of at least 1 mm;

the moving endless surface being connected to one or more vacuum systems applying a vacuum suction to the receptacle;

receiving absorbent material on a second moving endless surface comprising longitudinally extending rows of cavities, wherein the rows of cavities are separated from each other by raised strips;

retaining the absorbent material in the cavities;

applying adhesive to the supporting sheet in substantially longitudinal stripes;

transporting the supporting sheet to the outer shell, onto the top portions of the rods;

pulling the supporting sheet having the longitudinal stripes of adhesive partially in between neighboring rods by the vacuum suction, to form undulations in the supporting sheet between the rods and to form crests on the upper portion of the rods;

depositing absorbent material onto the supporting sheet present on the forming receptacle;

mating the raised strips and the rods during transfer of the absorbent material to the supporting sheet;

pulling the absorbent material with the vacuum suction into the undulations of the supporting sheet and onto the longitudinal stripes of adhesive between neighboring rods to form absorbent strips;

removing absorbent material remaining on the crests of the supporting sheet;

applying adhesive to the absorbent strips and the supporting sheet between the absorbent strips to form a first absorbent structure; and

removing the first absorbent structure from the moving endless surface;

repeating the previous steps to form a second absorbent structure; and

combining the first absorbent structure and the second absorbent structure with a pressure roll having a raised pressure pattern by applying pressure with the raised pressure pattern to the first absorbent structure and the second absorbent structure where no absorbent material is present, such that the absorbent layers of both structures are sandwiched between the supporting sheet of the first structure and the supporting sheet of the second structure.

2. The method of claim 1, wherein the receptacle has a front edge zone and a back edge zone, each zone extending the respective transverse dimension of the receptacle, and wherein the front edge zone and back edge zone do not comprise the rods.

3. The method of claim 1, wherein the receptacle has a first average width dimension and the supporting sheet, or portion thereof that is on the receptacle, has a second average width dimension, and the ratio of the first to the second average width dimension is at least 1:

1.2.

4. The method of claim 1, wherein the supporting sheet is a nonwoven sheet and the absorbent material is a particulate superabsorbent polymer material.

5. The method of claim 1, wherein the rods have a maximum width dimension which is at least 2 mm and the minimum distance transversely between neighboring rods being at least 3 mm.