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EP-4740919-A1 - A METHOD AND A MACHINE FOR MANUFACTURING ABSORBENT SANITARY ARTICLES

EP4740919A1EP 4740919 A1EP4740919 A1EP 4740919A1EP-4740919-A1

Abstract

Method for manufacturing absorbent sanitary articles, wherein a first (12) and a second continuous band (14) advance parallel to each other in a machine direction (X), and a plurality of first chassis (20) and second chassis (22) oriented transversely to the continuous bands (12, 14), spaced apart in the machine direction (X) and alternately inverted are fixed to the first (12) and second continuous band (14), wherein the method comprises cutting and removing front portions (30, 34) of the chassis (20, 22) and corresponding portions (104, 106) of the continuous bands (12, 14) to form a first and a second array of product blanks (34, 36) each having a respective continuous band (12, 14) and rear portions (28, 32) of respective chassis (20, 22) fixed thereto.

Inventors

  • SABLONE, GABRIELE
  • GIANSANTE, ANTONIO
  • CUCCHIELLA, Devin

Assignees

  • Fameccanica.Data S.p.A.

Dates

Publication Date
20260513
Application Date
20251103

Claims (7)

  1. A method for manufacturing absorbent sanitary articles (10), comprising: - providing a plurality of first elastic threads (62) and a plurality of second elastic threads (64) parallel to each other and tensioned in the longitudinal direction, - enclosing the first elastic threads (62) and the second elastic threads (64) between two layers of non-woven fabric (66, 68), - fixing the first and second elastic threads (62, 64) to the first and second layers of non-woven fabric (66, 68) by a pattern of fixing points, so as to form a single continuous elastic band (80), - cutting the first and second elastic threads (62, 64) of the single continuous elastic band (80) in selected areas to form transverse non-elasticized areas (82) and central non-elasticized areas (84), - longitudinally cutting in the longitudinal direction said single continuous elastic band (80) to form a first and a second continuous band (12, 14) and spacing apart the first and second continuous bands (12, 14) in a transverse direction, - providing a plurality of first chassis (20) having respective chassis axes (24) and respective rear portions (28) and front portions (30), and a plurality of second chassis (22) having respective chassis axes (26) and respective rear portions (32) and front portions (34), - orienting said chassis (20, 22) with their respective chassis axes (24, 26) transverse to the machine direction (X), alternated and spaced apart from each other in the machine direction (X) and alternately inverted, so that the first chassis (20) have their respective rear portions (28) overlapping the first continuous band (12) and their respective front portions (30) overlapping the second continuous band (14), and the second chassis (22) have their respective rear portions (32) overlapping the second continuous band (14) and their respective front portions (34) overlapping the first continuous band (12), - arranging the first chassis (20) and the second chassis (22) in positions offset from each other in a direction transverse to the machine direction (X) so that the areas of the first rear portions (28) overlapping the first continuous band (12) are larger than the areas of the first front portions (30) overlapping the second continuous band (14), and the areas of the second rear portions (32) overlapping the second continuous band (14) are larger than the areas of the second front portions (34) overlapping the first continuous band (12), - applying and fixing rear portions (28) and front portions (30) of said first chassis (20) respectively to the first and second continuous bands (12, 14), and rear portions (32) and front portions (34) of said second chassis (22) respectively to the second and first continuous bands (14, 12), and - cutting portions (106) of the second continuous band (14) and portions (104) of the first continuous band (12) to form a first array of product blanks (36) including the first continuous band (12) and a plurality of first chassis (20) having their respective rear portions (28) fixed to the first continuous band (12), and a second array of product blanks (38) separated from the first array of product blanks (36) and including the second continuous band (14) and a plurality of second chassis (22) having their respective rear portions (32) fixed to the second continuous band (12).
  2. A method according to claim 1, comprising cutting and removing front portions (30) of said first chassis (20) and corresponding portions (106) of the second continuous band (14), and front portions (34) of said second chassis (22) and corresponding portions (104) of the first continuous band (12).
  3. A method according to claim 1 or claim 2, comprising providing a plurality of first fastening elements (40) and a plurality of second fastening elements (42), fixing the first fastening elements (40) to the first continuous band (12) in positions spaced apart from each other along the longitudinal axis (16) of the first continuous band (12), and fixing the second fastening elements (42) to the second continuous band (14) in positions spaced apart from each other along the longitudinal axis (18) of the second continuous band (14).
  4. A method according to claim 3, comprising fixing the first fastening elements (40) to the first continuous band (12) aligned with respective second chassis (22) and fixing the second fastening elements (42) to the second continuous band (14) aligned with respective first chassis (20).
  5. A method according to claim 3 or claim 4, comprising cutting the first continuous band (12) along first cutting lines (52) extending along planes of symmetry of respective first fastening elements (40) and cutting the second continuous band (14) along second cutting lines (54) extending along planes of symmetry of respective second fastening elements (42) so that each of said first and second individual products (44, 46) has at each end of the respective waistband (48, 50) two side closures (108, 110) each of which is formed by half of a fastening element (40, 42).
  6. A method according to any of the preceding claims, comprising cutting the first continuous band (12) of the first array of product blanks (36) and the second continuous band (14) of the second array of product blanks (38) to form a plurality of first individual products (44) and a plurality of second individual products (46), each of which comprises a waistband (48, 50) and a respective chassis (20, 22).
  7. A machine (10) for manufacturing absorbent sanitary articles, comprising: • a band forming unit (72) configured to: ∘ feed a plurality of first elastic threads (62) and a plurality of second elastic threads (64) parallel to each other and tensioned in the longitudinal direction, ∘ enclose said first and second elastic threads (62, 64) between a first layer of non-woven fabric (66) and a second layer of non-woven fabric (68), ∘ fix said first and second elastic threads (62, 64) to the respective layers (66, 68) by a pattern of fixing points, so as to form a single continuous elastic band (80), ∘ cut said elastic threads (62, 64) in selected areas of the continuous elastic band (80) to form transverse non-elasticized areas (82) and central non-elasticized areas (84), ∘ longitudinally cut said single continuous elastic band (80) to obtain a first continuous band (12) and a second continuous band (14) separated from each other in the transverse direction; • a chassis forming unit (74) configured to form: o a plurality of first chassis (20) and a plurality of second chassis (22) having respectively chassis axes (24, 26), rear portions (28, 32) and front portions (30, 34); • a turn-and-repitch unit (76) configured to: ∘ orient said first and second chassis (20, 22) with their respective chassis axes (24, 26) transverse to the machine direction (X), ∘ arrange said chassis (20, 22) alternately and spaced apart from each other in the machine direction (X) and alternately inverted, ∘ overlapping: ▪ the rear portions (28) of the first chassis (20) to the first continuous band (12) and the front portions (30) to the second continuous band (14), ▪ the rear portions (32) of the second chassis (22) to the second continuous band (14) and the front portions (34) to the first continuous band (12), ∘ arrange the first and second chassis (20, 22) in transversely offset positions such that: ▪ the areas of the rear portions (28) overlapping the first continuous band (12) are larger than the corresponding front portions (30), ▪ the areas of the rear portions (32) overlapping the second continuous band (14) are larger than the corresponding front portions (34), ∘ apply and fix: ▪ the rear portions (28) and front portions (30) of the first chassis (20) respectively to the first and second continuous bands (12, 14), ▪ the rear portions (32) and front portions (34) of the second chassis (22) respectively to the second and first continuous bands (14, 12); • a shaped cutting unit (78) configured to: o cut portions (106) of the second continuous band (14) and portions (104) of the first continuous band (12) to form: ▪ a first array of product blanks (36) including the first continuous band (12) and a plurality of first chassis (20) fixed thereto, ▪ a second array of product blanks (38) separated from the first and including the second continuous band (14) and a plurality of second chassis (22) fixed thereto.

Description

Field of the invention The present invention relates to a method and a machine for manufacturing absorbent sanitary articles. The invention was developed particularly for manufacturing reclosable absorbent sanitary articles, such as diapers, training pants, absorbent articles for incontinent adults, etc. The invention was specifically developed for application to manufacturing processes called "Cross Direction". Prior art A well-established technique for manufacturing reclosable absorbent sanitary articles consists of forming a continuous moving composite web in a machine direction comprising two continuous bands parallel to the machine direction and a plurality of chassis with opposite ends fixed to the continuous bands and extending orthogonally to the machine direction. Sometimes the manufacturing process involves using a single continuous band parallel to the machine direction, to which end portions of chassis extending orthogonally to the machine direction are fixed. This manufacturing technique called Cross Direction differs from the manufacturing technique called Machine Direction, which involves manufacturing absorbent sanitary articles while they advance with their longitudinal axes parallel to the machine direction. Examples of methods for manufacturing absorbent sanitary articles according to the Cross Direction technique are described in documents EP-A-1013251, IT1379452, IT1410464 and IT1410465 by the same applicant. For manufacturing reclosable absorbent sanitary articles, openable and reclosable fastening elements spaced apart in the machine direction are applied to one of the continuous waistbands. EP-A-1523968 by the same applicant describes a fastening element for manufacturing absorbent sanitary articles wearable like underpants, comprising a non-woven web folded in a general omega-shaped configuration and including surface fastening elements. Modern machines for manufacturing absorbent sanitary articles have extremely high production capacities, on the order of 800-1000 pieces/minute. To make such high production rates possible, materials must be advanced along the production line at very high speeds, on the order of 350-550 meters/min. When the advancement speeds of materials along the production line are too high, numerous problems must be addressed and solved. For example, if materials do not have sufficient time to adhere properly, defects may form at the joining points between various components, which can lead to loss of absorbency and compromise the structural integrity of the products. At high speeds, materials are subject to greater stress and may involve higher risks of machine jams or stoppages. Moreover, as speed increases, lightweight and delicate materials are subject to higher risks of damage. With excessively high speeds, materials may not be positioned correctly during the assembly process, leading to misalignment with consequent increase in product defects and waste. Furthermore, increasing machine speeds can lead to premature wear and reduced service life of certain mechanical components, as well as increased maintenance costs. Object and summary of the invention The object of the present invention is to provide a method for manufacturing absorbent sanitary articles that solves the problems of the prior art. In particular, the present invention aims to reduce the advancement speed of materials along the production line without compromising the production capacity (throughput) of the machine. According to the present invention, this object is achieved by a method having the features forming the subject of claim 1. According to another aspect, the invention relates to a machine for manufacturing absorbent sanitary articles according to claim 7. Preferred embodiments form the subject of the dependent claims. The claims form an integral part of the teaching provided in relation to the invention. Brief description of the drawings The present invention will now be described in detail with reference to the accompanying drawings, given by way of non-limiting example, in which: Figures 1-14 are schematic views illustrating different phases of a method for manufacturing absorbent sanitary articles according to the present invention, andFigure 15 is a schematic side view of a machine for manufacturing absorbent sanitary articles configured to implement the method illustrated in Figures 1-14. Detailed description Figures 1-14 are schematic views illustrating a sequence of phases of a method for manufacturing absorbent sanitary articles according to the manufacturing technique called Cross Direction. With reference to Figure 3, in a first phase the method involves forming a first and a second continuous band 12, 14 having respective longitudinal axes 16, 18 parallel to each other and advancing in a machine direction X parallel to the longitudinal axes 16, 18. The "machine direction" in the context of manufacturing absorbent sanitary articles indicates the path along which raw mater