Elastic Laminates and Methods of Manufacturing Same

Abstract

A method for forming an elastic laminate comprising: bonding a first nonwoven to an elastic film to form a laminate; activating the laminate to form an activated laminate; and bonding a consolidated nonwoven to the elastic film of the activated laminate to form the elastic laminate.

Description

REFERENCE TO RELATED APPLICATION [0001] This application claims priority to U.S. Provisional Application No. 60 / 740,036, filed Nov. 28, 2005, which is hereby incorporated by reference.FIELD OF INVENTION [0002] The present invention relates generally to elastic laminates and their methods of manufacture, and, more particularly, to breathable elastic laminates having nonwoven surfaces on both sides. BACKGROUND OF INVENTION [0003] Breathable elastic laminates are used in the manufacture of many goods, including, for example, disposable articles such as diapers, feminine sanitary articles, and bandages. These applications require that the laminate be strong, stretchable, and soft to the touch. Improving one of these features, however, tends to diminish the others. Consequently, previously-introduced laminates tend to represent a compromise among softness, elasticity, and strength. [0004] For example, one prior art laminate comprises an apertured elastic laminate produced by vacuum lamin...

AI Technical Summary

Benefits of technology

[0008] Applicants have discovered unexpectedly that the laminate of the present invention has an exceptional degree of cross direction stretch, offers a pleasant, soft feel, and can be bonded ultrasonically at full line speed to obtain an exceptionally strong interlayer bond. Without being bound to any particular theory, applicants hypothesize that the high level of stretch results from “elasticizing” the two nonwoven layers using two different techniques—i.e., activation and consolidation. This approach synergistically combines the strengths of the two technologies, resulting in a laminate having the high tensile strength and a strong bond characteristic of a consolidated / ultrasonically bonded nonwoven, and the softness and tear resistance characteristic of an activated nonwoven. Furthermore, this approach appears to minimize the observed tendency of one nonwoven layer to constrain the extensibility of the other nonwoven layer in the same laminate.

Problems solved by technology

Improving one of these features, however, tends to diminish the others.

This construction has the advantage of a soft feel, but is limited to two layers (nonwoven and film) and lacks high peel strength.

Although this laminate tends to be strong, it has a harsher feel than desired, requires substantial ultrasonic energy to bond the layers, and, because it has three layers, it tends to lack the level of stretch obtainable from a laminate with just a single layer of nonwoven.

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