Batt comprising crimped bi- or multi-component fibres

Abstract

A had comprising crimped bi- or multicomponent fibres consisting of at least two sections, which comprise a polymer or polymer blend as a predominant component and which are arranged across the cross-section of the fiber to promote crimping of the fibre during the setting process and which predominant components differ in. the crystallisation beat (dHc). The difference in the crystallisation heat (dHc) is in the range from 30 J/g to 5 J/g, and the predominant components differ in at least one of the other parameters selected from the group of melt flow index, degree of polydispersion and flexural modulus, while the relative difference of the predominant components is: for the flow index in the range from 100 g/10 min to 5 g/10 min and/or for the degree of polydispersion less than 1, but above 0.3, and/or for the flexural modulus in the range from 300 MPa to 50 MPa; where the relative difference in the melt flow index is not greater than 100 g/10 min, the degree of polydispersity is less than 1, the crystallisation heat is not greater than 300 Mpa. The fibres have the degree of crimping at least 5 crimps per 20 mm of fibre.

1 . A batt comprising crimped bi- or multicomponent fibres consisting of at least two sections, which comprise a polymer or polymer blend as a predominant component and which are arranged across the cross-section of the fiber in a way suitable to promote crimping of the fibre during the setting process and which predominant components differ in the crystallisation heat (dHc), wherein the difference in the crystallisation heat (dHc) is in the range from 30 J/g to 10 J/g, and that the predominant components differ in at least one of the other parameters selected from the group of melt flow index, degree of polydispersion and flexural modulus, while the relative difference of the predominant components is:
 for the flow index in the range from 100 g/10 min to 5 g/10 min and/or   for the degree of polydispersion less than 1, but above 0.3, and/or   for the flexural modulus in the range from 300 MPa to 50 MPa;   
       where the relative difference in the melt flow index is not greater than 100 g/10 min, in the degree of polydispersity is less than 1, in flexural modulus is not greater than 300 MPa; and 
       where said fibres have the degree of crimping at least 5 crimps per 20 mm of fibre. 
     
     
         2 . A batt comprising crimped fibres according to  claim 1 , wherein the relative differentiation of the predominant components in the melt flow index is in the range of 80 g/10 min. 
     
     
         3 . A batt comprising crimped fibres according to  claim 1 , wherein the relative differentiation of the predominant components in the degree of polydispersion is in the range of 1 to 0.5. 
     
     
         4 . (canceled) 
     
     
         5 . A batt comprising crimped fibres according to  claim 1 , wherein the relative differentiation of the predominant components in the flexural modulus is in the range of 250 MPa to 80 MPa. 
     
     
         6 . A batt comprising crimped fibres according to  claim 1 , wherein the fibres are bicomponent fibres of the side-by-side type. 
     
     
         7 . A batt comprising crimped fibres according to  claim 6 , wherein both predominant components of the bicomponent fibres are a propylene homopolymer. 
     
     
         8 . A batt comprising crimped fibres according to  claim 1 , wherein said predominant components are arranged across the cross-section of the fibres, centrally asymmetrically and/or axially asymmetrically relative to a number of axes passing through the centre of the fibre's cross-section, which evens the number of the polymer sections in the fibre. 
     
     
         9 . A batt according to  claim 1 , wherein the fibers comprise an additive, wherein the additive is present in the components such that it does not affect the crimping of the fiber to a significant degree. 
     
     
         10 . A nonwoven textile characterised in that it comprises the batt according to  claim 1 . 
     
     
         11 . The nonwoven textile according to  claim 10  wherein the nonwoven textile is of a spunmelt type. 
     
     
         12 . A method of producing a batt comprising multicomponent fibres, wherein the method comprises the following steps:
 i. preparing at least two materials comprising a polymer or polymer blend as a predominant component the materials being suitable for the formation of fibres;   ii. then forming multicomponent fibres from the prepared materials under a spinneret, namely multicomponent fibres comprising said materials arranged in sections, which are arranged across the cross-section of the fiber in a way suitable to promote crimping of the fibre during the setting process, and cooling and attenuating the fibres by cooling and attenuating air; and   iii. forming a batt from said multicomponent fibres;   
       wherein 
       said predominant components in sections are selected such that they differ in the heat of crystallisation (dHc) in the range from 30 J/g to 10 J/g, and that they differ in at least one other parameter selected from the group of melt flow index, degree of polydispersion and flexural modulus, where the relative differentiation of the polymer components is:
 for the flow index in the range from 100 g/10 min to 5 g/10 min and/or 
 for the degree of polydispersion in the range from 1 to 0.3, and/or 
 for the flexural modulus in the in the range from 300 MPa to 50 MPa; 
 wherein the relative difference in the melt flow index is no greater than 100 g/10 min, in the degree of polydispersity is no greater than 1, in the flexural modulus is no greater than 300 MPa; and 
 wherein said fibres have the degree of crimping at least 5 crimps per 20 mm of fibre. 
 
     
     
         13 . The method according to  claim 12 , wherein said sections with predominant components are arranged across the cross-section of the fibre centrally asymmetricaly and/or axially asymmetricaly relative to a number of axes passing through the centre of the cross-section of a fibre, which evens the number of present sections in the fibre. 
     
     
         14 . The method according to  claim 12 , wherein said multicomponent fibres are bicomponent fibres of the side-by-side type. 
     
     
         15 . The method according to  claim 12 , wherein said polymer sections contain as their predominant component a polypropylene homopolymer. 
     
     
         16 . A batt comprising crimped fibres according to  claim 1 , wherein the difference in the crystallisation heat (dHc) is in the range from 30 J/g to 20 J/g. 
     
     
         17 . A batt comprising crimped fibres according to  claim 2 , wherein the relative differentiation of the predominant components in the melt flow index is in the range of 60 g/10 min to 10 g/10 min. 
     
     
         18 . A batt comprising crimped fibres according to  claim 3 , wherein the relative differentiation of the predominant components in the degree of polydispersion is in the range of 1 to 0.7. 
     
     
         19 . A batt comprising crimped fibres according to  claim 5 , wherein the relative differentiation of the predominant components in the flexural modulus is in the range of 200 MPa to 80 MPa. 
     
     
         20 . The method according to  claim 12  wherein predominant components in sections are selected such that they differ in the heat of crystallisation (dHc) in the range from 30 J/g to 20 J/g.