Method of making laminate structures for mechanical activation

Abstract

A method for producing a stretch laminate includes forming an intermediate stretch laminate. Forming the intermediate stretch laminate includes providing a first substrate and attaching an elastic film to a surface of the first substrate via an adhesive. The first substrate and the elastic film are in a face to face orientation. The intermediate stretch laminate has a residual energy of greater than or equal to 50% at a predetermined applied strain. The method of forming the stretch laminate further includes mechanically activating the intermediate stretch laminate at a strain rate of at least 100 s−1.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a stretch laminate and a method of producing the stretch laminate such that the stretch laminate exhibits reduced defects from mechanical activation. The stretch laminate may be used in a variety of articles and is particularly useful in disposable absorbent articles such as baby diapers, adult incontinence articles, feminine hygiene articles, baby swim diapers, bibs, wound dressings, and any other articles where an elastically extensible stretch laminate may be desirable. BACKGROUND OF THE INVENTION [0002] Stretch laminates can be used in a wide variety of disposable absorbent articles. For example, in order to provide a disposable absorbent diaper which can fit a range of wearers and minimize leaks, disposable absorbent diapers often include stretch laminates. Because the wearers of disposable absorbent diapers vary in size, stretch laminates are often used in the waist region and leg regions of the disposable absorben...

AI Technical Summary

Benefits of technology

[0009] An intermediate stretch laminate of the present invention can incur reduced defects from a mechanical activation process. In some embodiments, the intermediate stretch laminate may comprise a first nonwoven, an elastic film, and a second nonwoven. The elastic film can be attached to the first nonwoven via an adhesive such that the elastic film and the first nonwoven are in a face to face orientation. The second nonwoven can be attached to the elastic film via an adhesive. The second nonwoven can be attached to the elastic film opposite the first nonwoven such that the second nonwoven and the elastic film are in a face to face orientation. The intermediate stretch laminate has a residual energy which is greater than about 50%.

Problems solved by technology

Because the activation region of the stretch laminate is intermeshed between the teeth of the activation rolls, the nonwoven materials are permanently elongated at least to a certain degree, so that upon release of the applied tensile forces, the stretch laminate generally will not fully return to its original undistorted configuration.

Consequently, the stretch laminate experiencing the mechanical activation process can be exposed to very high strain rates.

Unfortunately, many stretch laminates may incur defects, in part, as a result of the high strain rates and high percentages of strain experienced during the mechanical activation process.

Many of the defects are structural in nature.

For example, an elastic film which undergoes the mechanical activation process may experience defects such as holes which reduce the structural integrity of the elastic film.

The reduction of the structural integrity of the elastic film can lead to premature failure of the stretch laminate.

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