EP-4434503-B1 - LAMINATE WEBS AND ABSORBENT ARTICLES HAVING THE SAME

EP4434503B1EP 4434503 B1EP4434503 B1EP 4434503B1EP-4434503-B1

Inventors

CECCHETTO, PIETRO
SAUER, LINDA ANN
LI, SHIHUANG

Dates

Publication Date: 20260513
Application Date: 20171220

Claims (6)

A process for producing a laminate web, wherein the laminate web comprises a polymer film layer comprising polymer film, a nonwoven layer comprising a nonwoven web, a first side comprising the polymer film, and a second side opposed to the first side comprising the nonwoven web, wherein the laminate web further comprises a) a plurality of first elements extending from the polymer film, b) a plurality of second elements selected from the group consisting of protrusions and recesses, each of the second elements comprising at least one first element, c) a land area comprising at least one first element, wherein the land area surrounds the second elements, and wherein at least two adjacent second elements, respectively, have one or more than one first element having an open distal end at least 1.5 times larger than the largest distal open end of a first element in a land between the two adjacent second elements; wherein the process comprises the steps of; a) providing a polymeric film layer comprising film, the film layer having a first surface and a second surface opposite to the first surface, b) supplying a nonwoven onto the second surface of the polymeric film to form a precursor laminate web, c) forming a plurality of first elements extending from the first surface of the film layer in the z direction by a vacuum formation process or mechanical deformation process, d) providing a forming apparatus for forming a plurality of the second elements in the precursor laminate web, the forming apparatus comprising a first member and a second member, wherein the first member comprises first male elements on its surface, the first male elements comprising first teeth having a shape to form a plurality of the second elements, wherein the second member comprises female elements on its surface that the male elements fit into, and wherein at least one of the first member and the second member is heated, e) moving the precursor laminate web through a nip that is formed between the first and second members so that the second elements are formed as the first male elements and the first female elements are engaged, and at least some of the open ends in the first elements are enlarged, f) heat-setting the second elements by maintaining the web on the first member after exiting the nip.
The process according to claim 1, wherein the heat-setting is conducted at or near the softening point of the film.
The process according to claim 1, wherein the step e) preforms at a process speed which does not cause ruptures in the second elements.
A process for producing a laminate web, wherein the laminate web comprises a polymer film layer comprising polymer film, a nonwoven layer comprising a nonwoven web, a first side comprising the polymer film, and a second side opposed to the first side comprising the nonwoven web, wherein the laminate web further comprises a) a plurality of first elements extending from the polymer film, b) a plurality of second elements selected from the group consisting of protrusions and recesses, each of the second elements comprising at least one first element, c) a land area comprising at least one first element, wherein the land area surrounds the second elements, and wherein at least two adjacent second elements, respectively, have one or more than one first element having an open distal end at least 1.5 times larger than the largest distal open end of a first element in a land between the two adjacent second elements; wherein the process comprises the steps of: a) providing a polymer film layer comprising polymer film, the film layer having a first surface and a second surface opposite to the first surface, comprising a plurality of first elements on the first surface, b) supplying a nonwoven onto the second surface of the polymeric film to form a precursor laminate web, c) providing a forming apparatus for forming a plurality of the second elements in the film layer, the forming apparatus comprising a first member and a second member, wherein the first member comprises first male elements on its surface, the first male elements comprising first teeth having a shape to form a plurality of the second elements, wherein the second member comprises discontinuous female elements on its surface that the male elements fit into, and wherein at least one of the first member and the second member is heated, d) moving the precursor laminate web through a nip that is formed between the first and second members so that the second elements are formed as the first male elements and the first female elements are engaged, and at least some of the open ends in the first elements are enlarged, e) heat-setting the second elements by maintaining the web on the first member after exiting the nip.
The process according to claim 4, wherein the heat-setting is conducted at or near the softening point of the polymer film.
The process according to claim 4, wherein the step e) preforms at a process speed which does not cause ruptures in the second elements.

Description

FIELD OF THE INVENTION The present invention is directed to processes for producing laminate webs comprising a polymer film having microtextures. BACKGROUND OF THE INVENTION Laminates of webs such as films and fibrous webs are known in the art. For example, nonwoven webs are often laminated with polymer films such that they are useful as materials in disposable products such as topsheets on disposable absorbent articles. The laminate can be structured such that a skin-facing side of the laminate, when used in absorbent articles, is the polymer film. The laminate also can be structured in absorbent articles such that the polymer film is oriented as a garment-facing side. Polymer film is desirable to have a microtextured, preferably apertured three-dimensional surface which can provide the surface of the laminate web with a desirable feel (e.g., soft, silky), visual impression, and/or audible impression, as well as one or more desirable properties such as improved fluid handling. Webs exhibiting a desirable feel can be made by forming microtextures such as protrusions and recesses in the webs via technologies such as a vacuum forming process and embossing process. Laminate webs having a microtextured film are utilized in a wide variety of industrial and consumer products. Such laminate webs are known for use in disposable absorbent articles such as disposable diapers and feminine hygiene articles such as sanitary napkins, and the like. Such articles typically have a fluid pervious topsheet, a fluid impervious breathable backsheet, and optionally an absorbent core disposed between the topsheet and the backsheet. Laminate webs having a microtextured film layer and a nonwoven layer can be made to form a fluid pervious topsheet that transports fluid from the body facing surface of the sanitary napkin more deeply into the sanitary napkin or diaper towards the absorbent core. Laminate webs comprising a microtextured polymer film layer can be further deformed to have two-dimensional or three-dimensional macro structures improving fluid transport such as apertures for improving fluid drainage. One approach as an effort to improve the ability of fluid drainage in a laminate having a film layer and nonwoven web is to expose fibers extended from the nonwoven web. US patent 8,273,943 discloses an absorbent article provided with a composite sheet which comprises a film sheet having multiple pores formed therein a fiber mass laminated on one side of the film sheet, wherein the fiber mass has a projected section in which a part of the fiber mass projects through the multiple pores toward the other side of the film sheet. WO2010/117636 discloses a laminate web having a nonwoven web and a microtexxtured polymer film, wherein the laminate web has a first side comprising the polymer film having caps and tufts including fibers extending from the nonwoven web. Each of the caps is an integral extension of the polymer film and having at least one opening including a location of rupture in the polymer film above which the tuft extends. The exposed fibers extended from nonwoven web acquire and retain some fluid in small capillaries that might exist between the fibers which may be visually perceptible to the user of the product as an undesirable stain. However, even with formation of macro apertures for improving fluid transport in a microtextured web, there still is a challenge in fluid drainage especially when the polymer film layer has microprotrusions, as fluid tends to be trapped in valleys between the microprotrusions. Especially when microtextures are in the form of discrete extended elements like protrusions, in case the microtextured web is used as a topsheet of absorbent articles, fluid tends to be trapped in valleys among the discrete extended elements. Trapped fluid may be visually perceptible to the user of the product and the user may misinterpret the staining as an indication that the utility of the product is exhausted even when such a determination is in reality premature. Meanwhile, post-formation of macrostructures on a microtextured laminate may do damage on microtextures such as microprotrusions on the surface of the laminate which may deteriorate surface smoothness or negatively affect fluid transport as embossing sites is embossed at the zero plane of the laminate and is flatted. Meanwhile, US patent 5,643,240 discloses a body side liner for absorbent articles comprising an aperture film layer and a separation layer comprising lofty fibrous nonwoven suited for use as a cover material which provides an improved fluid penetration rate, and mitigated rewet by reducing flow-back to the surface of the absorbent article. US 7,695,799 discloses a perforated laminate useful as a topsheet for absorbent articles that comprises first and second layers and perforated apertures that extend through at least the first layer wherein the first layer is a nonwoven that has filaments from about 0.2 to about 15 dpf, or a formed fil