Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1995-08-04
2001-01-09
Crispino, Richard (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S265000, C156S267000, C156S270000, C156S271000, C156S301000
Reexamination Certificate
active
06171432
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to the art of manufacturing disposable absorbent products having a laminated construction, such as sanitary napkins, diapers, adult briefs, incontinence pads, wound dressings and the like. More specifically, the invention pertains to a method and apparatus for manufacturing with a comparatively small amount of waste matter a layer of such disposable absorbent products, such as a fluid-permeable cover layer, an absorbent core layer or the fluid-impervious backing layer, and the resulting product thereof. The invention extends to a method for manufacturing a complete disposable absorbent product and the resulting product thereof.
BACKGROUND OF THE INVENTION
A typical mass-production arrangement for manufacturing health-care, disposable, absorbent products includes an assembly line where the various components of the absorbent product are progressively combined and laminated into a continuous web which is cut transversely into discrete absorbent products.
This process is well-suited for disposable absorbent products with a periphery designed around a simple geometric figure, such as a rectangle with rounded ends. The plain side edge design of such products does not require trimming to finish the lateral edges of the absorbent products, whereby the process may be carried out without producing an inordinate amount of waste material.
To enhance the functionality of disposable absorbent products, manufacturers are now designing products with complex and sophisticated countour lines. For example, sanitary napkins have recently appeared on the market, provided with side flaps or winglets which create fastening points for the sanitary napkin on the garment facing side of the wearer's underpants. With traditional manufacturing techniques, extensive trimming is required to produce the highly irregular side edge contour of the sanitary napkin which necessarily generates a considerable amount of waste material. As a result, the manufacturing cost of the sanitary napkin increases because the starting material is used less efficiently and waste management facilities are required. Further, concurrent reduction in materials required for manufacture and reduction in waste materials requiring disposal present environmental advantages in terms of conservation of resources and reduction in waste disposal.
An object of the invention is to provide a method and an apparatus for producing a layer of a laminated, disposable absorbent product with a highly irregular contour, such as the fluid-permeable cover layer, the absorbent core layer or the fluid-impervious backing layer, with a comparatively small amount of useless by-products.
Another object of the invention is to provide a method and apparatus for manufacturing a laminated, disposable absorbent product having a highly irregular contour, with a comparatively small amount of useless by-products.
Another object of the invention is a compound layer for a laminated, disposable absorbent product, such as the fluid-permeable cover layer, the absorbent core layer or the fluid-impervious backing layer, having an arrangement of parts to permit manufacturing of the compound layer with a comparatively small amount of useless by-products.
Yet, another object of the invention is a laminated, disposable absorbent product with a structure which allows manufacture of absorbent product with a comparatively small amount of useless by-products.
SUMMARY OF THE INVENTION
The present inventors have made the unexpected discovery that a considerable reduction in useless by-products may be achieved when manufacturing laminated, disposable absorbent products with highly irregular shapes, by forming at least one layer of the disposable absorbent product from a continuous web with longitudinal edges patterned according to the absorbent product contour to substantially reduce the web trimming and cutting which would otherwise be required to give shape to the layer of the absorbent product. The patterned web is made by cutting a continuous web of starting material longitudinally into two strips, in a cyclic pattern which comprises line segments corresponding to selected sections of the edge contour of the absorbent product. The strips are then assembled in a parallel and a phase relationship to repeatedly produce the shape of the absorbent product layer.
More specifically, the invention provides a method for manufacturing a layer of a laminated, disposable absorbent product such as a fluid-permeable cover layer, an absorbent core layer or a fluid-impervious backing layer, having two opposite edges with inflected contours (for the purpose of the specification the term “inflected” should be construed to mean a deviation from a straight line forming an angularity or curvature), said method comprising the steps of:
longitudinally cutting a continuous web according to a cyclic pattern comprising a combination of line segments corresponding to a selected section of said opposite edges, thereby dividing said web in two strips, each strip having a patterned longitudinal edge whose outline corresponds to said cyclic pattern;
reassembling said strips in a parallel and selected phase relationship, with the longitudinal edges thereof which are opposite the adjacent patterned edges to produce a compound web having longitudinal edges formed by said patterned edges which are longitudinally matched to repeatedly produce the selected section; and
cutting said compound web transversely at selected longitudinal positions to produce discrete layers.
Integrating this method into an operation for manufacturing disposable absorbent products involves the following steps:
prior to cutting said compound web in individual layers, absorbent core layers in a spaced apart relationship are joined with said compound web at longitudinal positions thereof selected in accordance with the positional relationship absorbent core/opposite edges of the layer of the disposable absorbent product;
retaining said absorbent core layers to said compound web; and
cutting said compound web transversely between adjacent absorbent core layers to produce discrete disposable absorbent products.
In a preferred embodiment, the strips forming the compound web are united together in a partially overlapping relationship and are attached to one another adhesively or by thermal bonding. In a variant, the strips are combined in abutting relationship and individually attached to the absorbent core layer which forms a bridge holding the strips together in alignment.
Preferably, the strips forming the compound web are brought into the desired phase relationship by advancing the strips along respective paths having different lengths in order to achieve a condition of controlled longitudinal shift therebetween. In a most preferred embodiment, the strips, freshly cut, are supported on a conveyor moving in a predetermined direction. At a first position, stationary with respect to the conveyor, one of the strips is lifted off the conveyor while the other remains in supporting contact with the conveyor. At a second position, stationary with respect to the conveyor, the strip which has been previously lifted is brought back in contact with the conveyor. By this arrangement, runs of the strips between the first and second positions have different predetermined lengths to achieve the desired phase relationship between the strips.
To side match the strips, i.e. to bring the strips in a position where their longitudinal edges shaped as the cyclic pattern are brought in opposition to form the longitudinal edges of the compound web, the strips are preferably crossed one over the other. More preferably, the crossing operation is performed while the strips follow their respective paths to achieve the longitudinal shift therebetween.
The method according to the invention provides a fluid-permeable cover layer and a fluid-impervious backing layer in a laminated, disposable absorbent product, whereby a compound web of fluid-permeable material and a compound web of fluid-impervious material are assembled a
Brisebois Henri
Menard Michael J.
Crispino Richard
Johnson & Johnson Inc.
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