1. Technical Field
The present invention relates to elasticized containment flaps and their construction. Specifically, the present invention relates to containment flaps used to improve the containment of body exudates in absorbent articles.
2. Description of the Related Art
Absorbent articles such as infant diapers, training pants, sanitary napkins, adult incontinence products and the like are well known. Such articles have achieved a wide acceptance due to their ability to absorb body exudates without leaking. In order to achieve a high degree of leakage protection, it has become increasingly common to rely on systems wherein numerous components cooperate. For example, in the case of infant diapers, urine is generally absorbed by an absorbent core comprising a matrix of wood pulp fluff and superabsorbent material. Such an absorbent core is known to be particularly well suited for absorbing and holding urine in a diaper structure. Unfortunately, it is not always possible for the absorbent core to absorb and hold urine at the rate at which it is delivered. Thus, it has become increasingly common to rely on various mechanical containment means to hold urine within the diaper until it can be absorbed and held by the absorbent core.
For example, it is well known to those skilled in the art to provide elasticized leg cuffs along the leg openings of a diaper. The leg cuffs are said to assist in the containment of body exudates. Similarly, it is well known to those skilled in the art to use waist elastics in a diaper to obtain a tighter seal about the waist of a wearer. The waist elastics also contribute to the mechanical containment of body exudates.
In an attempt to improve the mechanical containment of body exudates, it is also known to employ a pair of containment flaps along the longitudinal sides of absorbent articles such as infant diapers, training pants, sanitary napkins, adult incontinence products and the like. Such containment flaps are shown in U.S. Pat. No. 4,704,116 issued Nov. 3, 1987, to Enloe. The containment flaps are generally thought to be particularly well suited for the containment of fecal matter and the prevention of lateral flow of liquid waste until the liquid waste can be absorbed by the absorbent article. Elasticized leg cuffs are often used in conjunction with the containment flaps to help contain body exudates.
Containment flaps generally include a proximal edge which is attached to the absorbent article and an opposite distal edge which is generally not attached to the absorbent article along at least a portion of its length. Each of the containment flaps may also include elastic members which are generally located adjacent the distal edge to provide a sealing relationship by conforming the distal edge to the shape of the wearer during use. The elastic members also assist in maintaining the containment flaps in an upright position during use. Typically, the elastic members are attached to the containment flaps by folding the material of the containment flap in a longitudinal direction over the elastic members and back upon itself. The folded over portion of the containment flap is secured to another portion of the containment flap thereby forming a hem that contains the elastic members. For example, the folded over portion of the containment flaps may be secured by adhesive or ultrasonic bonding.
However, the methods of attaching the elastic members to the containment flaps as described above tend to undesirably affect the stiffness of the containment flaps. The double layer of material which provides the hem that contains the elastic members and the bonding of the hem to the containment flap undesirably reduces the flexibility and increases the stiffness of the containment flaps. Adhesive and ultrasonic bonding also reduce the flexibility and increase the stiffness of the containment flaps. Containment flaps that are too stiff do not conform to the shape of the wearer as snugly as desired and may irritate the skin of the wearer. The lack of a sealing relationship between the distal edge of the containment flap and the body of the wearer tends to decrease the effectiveness of the containment flaps in containing body exudates. Moreover, a certain amount of the elastic nature of the elastic member may be destroyed if the elastic member is bonded to the containment flap. Specifically, at the points where the elastic member is attached to the containment flap, the elastic member is no longer capable of being stretched. That is, it is no longer "elastic".
Accordingly, it is desired to provide containment flaps that are generally flexible and provide an improved fit and containment of body exudates in absorbent articles that employ such containment flaps.