Patent Application
20090088719
The present invention relates to absorbent articles such as diapers, training pants, and the like. More specifically, the invention relates to absorbent articles having integral side panels that are stretchable in at least one direction.
Absorbent articles such as disposable diapers, training pants, and the like are known for their major function of absorbing and containing body exudates. Such articles are thus intended to prevent the soiling, wetting, or other contamination of clothing or other articles, such as bedding, that come in contact with the wearer. In the case of disposable training pants, they typically include a chassis with a liquid permeable topsheet, a liquid impermeable backsheet, and an absorbent core positioned between the topsheet and the backsheet. Side panels are sometimes attached to the chassis for fitting the training pant about the wearer's waist so the training pant may be pulled up or down like traditional underwear.
While many developments have been made in the art of absorbent articles, there remains a need for further improvements in terms of at least one of improved fit, comfort, manufacturability, and visual appearance.
In one aspect, the invention provides an absorbent article having a chassis with a contiguous front section, a contiguous rear section, and a crotch section extending between the front section and the rear section. Edges of the front section are connected to edges of the rear section to define a waist opening. The chassis includes a substrate layer having pairs of film sections attached to the front section and the rear section. Each film section is spaced apart from one another and is stretchable in at least a direction along the waist opening.
In another aspect of the invention, a method of applying a stretchable layer of an absorbent article is provided. The method includes the step of advancing a substrate of the absorbent article in a machine direction. A layer of adhesive is applied to the substrate in a slot coating corresponding to a shape of the stretchable layer. The stretchable layer is then oriented such that it is stretchable in the machine direction. The stretchable layer is attached by means of the adhesive.
The invention is best understood from the following detailed description when read in connection with the accompanying drawings, with like elements having the same reference numerals. This emphasizes that according to common practice, the various features of the drawings are not drawn to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. Included in the drawings are the following figures:
Referring generally to the drawings (
In another exemplary embodiment, a method for method of applying a stretchable layer 40 of an absorbent article 100, 200 is provided. The method includes the step of advancing a substrate 109 of the absorbent article 100, 200 in a machine direction MD. A layer of adhesive 1 is applied to the substrate 109 in a slot coating corresponding to a shape of the stretchable layer 40. The stretchable layer 40 is oriented such that it is stretchable in the machine direction MD and the stretchable layer 40 is attached to the substrate 109 by means of the adhesive 1.
Referring now to the drawing in detail,
The front section 110 is configured to be positioned against the anterior or front end of a wearer and the rear section 120 is configured to be positioned on the posterior or back end of a wearer. When worn by an individual standing upright, the crotch portion 130 of chassis forms the lowest point on absorbent article 100.
As shown in
Referring now to
In order to enable liquid to quickly and efficiently pass through the topsheet 101 and into the absorbent core 50 for trapping therein, the topsheet 101 is preferably liquid permeable. In particular, the topsheet 101 may be selected from a variety of textile-like films and fabrics. Suitable fabrics include non-woven materials that are pervious to liquid, soft and pliable. Preferred non-woven materials include spun-bonded polypropylene, spunbonded polyethylene, and thermally bonded webs of staple fibers, preferably polypropylene shape or sheath/core bi-component fibers having a core of polyester or polypropylene and a sheath of polyethylene.
As seen with respect to the embodiment of the absorbent article 100 shown in
According to an exemplary embodiment, the chassis includes an acquisition layer 103 interposed between the topsheet 101 and absorbent core 150 to rapidly take up fluid through the topsheet 101 and then release it into the absorbent core 150. Acquisition layer 103 remains substantially dry even after liquid has penetrated the acquisition layer 103. Thus, acquisition layer 103 provides an insulating layer between the absorbent core 150 and topsheet 101 to prevent contact between a wet absorbent core 150 and the wearer's skin.
The acquisition layer 103 is generally composed of resilient fibrous webs that provide a small absorbent volume to rapidly take up liquids and then direct it to the absorbent core 106. This allows adequate time for super absorbent materials in the core 150 to absorb the liquid. The thickness of the acquisition layer 103 is preferrably thin to provide the small absorbent volume.
A liquid impermeable barrier layer 105 is interposed between the absorbent core 150 and substrate layer 109. Barrier layer 105 is arranged facing away from the wearer (i.e. away from the skin of the wearer) and is preferably formed from a hydrophobic polymeric film to prevent liquid from seeping through absorbent core 150 and wetting a wearer's clothing. Materials for forming the barrier layer 105 may include polyethylene films, polypropylene films, co-extruded films (polyethylene and ethylene vinyl acetate), co-polymer films (polyethylene/polypropylene), and polylaminates (polypropylene nonwoven and polyethylene film). In an exemplary embodiment, barrier layer 105 may be joined to tissue 104b of absorbent core 150 in any suitable manner such as hot melt adhesive 1.
According to the present invention as shown in
In an exemplary embodiment, film section 40a, 40c are stretched prior to adhering the film section 40a, 40c on substrate layer 109. Thus, after film sections 40a, 40c have been attached, stretch panels “retract” due to tension from the film sections 40a, 40c. Each film section 40a, 40c is spaced apart from one another such that when edges 15a-b, 16a-b (
According to an exemplary embodiment, film sections 40a, 40c may be made of any thermoplastic elastomer (TPE). Such resins/copolymers may include, for example, styrene-ethylene/butylene-styrene (SEBS) or styrene-ethylene/propylene-styrene (SEPS) that may be used to create films that are extrudable at higher temperatures then become elastic at an ambient temperature. The stretchable film sections may be breathable or non-breathable depending on the desired properties of the absorbent article 100. For example, a stretchable film made of a “breathable” microporous polyethylene to provided added comfort and passage of air through the stretch panel laminate.
Referring now to
In an exemplary embodiment, film sections 40a-d may be stretched in a direction perpendicular to the machine direction MD such that film sections 40a-d are stretchable in at least two directions. In this embodiment, film sections 40a-d may be stretched in both the cross-direction CD and machine direction MD, to provide and absorbent article 100 with integral panels that are stretchable in at least two directions. According to another embodiment, film sections 40a-d may be oriented with respect to substrate layer 109 such that the film sections 40a-d are stretchable in the machine direction MD. For example, rolls of substrate layer 109 and/or stretchable film layer 40a-d may be oriented parallel to each other using a machine direction orienter such that as substrate layer 109 is running in the machine direction MD, the stretchable layer may be stretched and attached to the substrate layer 109 in the same direction.
In an exemplary embodiment, the substrate layer 109 may be a non-elastic material may be formed from a single layer of non-woven material, and may exhibit substantially no elastic/stretch properties (i.e. inelastic). The substrate layer 109 is optionally formed from a laminated sheet of a non-woven material and film (with the non-woven side positioned as the outermost layer). One particularly suitable material is a spunbond-meltblow-spunbond (SMS) web. The spunbond layer is optionally made of polypropylene fibers. Such composites provide the dual advantages of liquid barrier properties of film along with a soft, outer fabric texture.
The substrate layer 109 can also be made of other suitable cloth-like materials, e.g., spun-bond or thermal-bond non-woven web made of either polypropylene, polyethylene, polyester, bi-component fibers (polyethylene/polypropylene or polyethylene/polyester), or any combinations of these fibers. Various multiple layer configurations or fiber denier variations may be used. Another example includes hydro-entangled non-woven webs, which may contain some cotton and/or rayon fibers blended in with thermal-plastic fibers. Cellulose fibers can also be blended in at small percentages to reduce cost. Still, other materials for forming the substrate layer 109 may include polypropylene films, co-extruded films (polyethylene and ethylene vinyl acetate), co-polymer films (polyethylene/polypropylene), and polylaminates (polypropylene nonwoven and polyethylene film). In yet another embodiment, the substrate layer 109 is optionally selected from a variety of textile-like films and fabrics.
Referring now to
Although the present invention has been particularly described in conjunction with specific embodiments, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications, and variations as falling within the true scope and spirit of the present invention.
