Method for the production of an elastic laminate and laminated elastic product

Abstract

A method for the production of an elastic laminate, with the following steps in a production line: coextrudeing a first web of elastic film with at least three layers, with at least two different polymer materials, to feed contemporaneously said coextruded first elastic film web and two second nonwoven webs to a thermal, binding calender, wherein the first elastic film web is arranged between said two second nonwoven webs when entering the calender; wherein said first elastic film web, during the movement from the coextrusion step to the thermal binding step, passes from a melted state, to a solidified and cold state when entering the calender, to join, through spot welding in said calender, said second nonwoven webs with respective opposite outer layers of said first elastic film web, thus producing an intermediate web, to stretch mechanically said intermediate web according to a direction transverse to the same web.

What is claimed is: 
     
         1 . An elastic laminate comprising:
 a polymer intermediate elastic film formed by three coextruded layers, wherein outer layers of said three coextruded layers are made of the same polymer material, and an inner layer of said three coextruded layers is made of a different polymer material from polymer material of said outer layers;   two nonwoven fabrics joined, through spot or areas welding, to two opposite faces of said polymer intermediate elastic film, wherein at least one of:   a ratio between MD elongation at break at 10 N, and laminate thickness after stretching of said polymer intermediate elastic film is lower than one of 8 and 7.5;   a ratio in (N/50 mm)/(mm), between CD tensile strength and laminate thickness after stretching is lower than one of 79 and 78;   a ratio in g/m 2 /mm between laminate weight and thickness after stretching is lower than one of 105 and 100.   
     
     
         2 . An elastic laminate according to  claim 1 , wherein one or more layers of said polymer intermediate elastic film are made of one or more of:
 elastomers comprising at least one of poly (ethylene-butene), poly (ethylene-hexene), poly (ethylene-octene), poly (ethylene-propylene), poly (styrene-butadiene-styrene), poly (styrene-isoprene-styrene), poly (styrene-ethylene-butylene-styrene), poly (ester-ether), poly (ether-amide), poly (ethylene-vinyl acetate), poly (ethylene-methyl acrylate), poly (ethylene-acrylic acid), poly (ethylene butyl acrylate), polyurethane, poly (ethylene-propylene-diene) and ethylene-propylene rubber;   polymers made using polyolefins from single-site catalysts;   polyolefin elastomers; and   a combination of elastomers, polymers made using polyolefins from single-site catalysts and/or polyolefin elastomers.   
     
     
         3 . An elastic laminate according to  claim 1 , wherein at least part of said materials forming said outer layers of said coextruded elastic film are thermally compatible with at least part of materials of said nonwoven webs with which said outer layers are in contact. 
     
     
         4 . An elastic laminate according to  claim 1 , wherein at least one of said second nonwoven webs is extendible.