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KR-102760586-B9 - Nonwoven fabric containing crimped multi-component fibers

KR102760586B9KR 102760586 B9KR102760586 B9KR 102760586B9KR-102760586-B9

Abstract

The present invention relates to a nonwoven sheet comprising crimped multi-component fibers.

Inventors

  • 왕 징보
  • 브로흐 토마스
  • 피비그 요아힘 에드문드
  • 반 파리돈 헹크
  • 토비에손 구스타프
  • 졸머 세바스티안
  • 볼 패트릭
  • 게우스 한스-게오르그
  • 한센 모르텐 리세
  • 아거스납 셰러 마티아스

Assignees

  • 파이버텍스 퍼스널 케어 에이/에스
  • 라이펜호이저 게엠베하 운트 코. 카게 마쉬넨파브릭

Dates

Publication Date
20260513
Application Date
20230103
Priority Date
20220105

Claims (15)

  1. A nonwoven fabric sheet comprising crimped multicomponent fibers, wherein the crimped multicomponent fibers comprise two different polymer components (A) and (B) distributed across the cross-section of the fibers in a side-by-side arrangement, and Characterized by the following: The interface line between two polymer components (A) and (B) included in the radial plane of the crimped multi-component fiber is curved and its curvature (c) is c = h/b = 0.08 to 0.20, where the baseline length (b) is the length of an imaginary straight baseline connecting two endpoints of the curved interface line, and the bow height (h) is the distance from the apex of the curved interface line to the baseline, and the curved interface line has the shape of a single arc without an inflection point where the sign of the curvature changes. non-woven fabric sheet
  2. delete
  3. In claim 1, the sheet is a spunbonded nonwoven sheet and the crimped multi-component fiber is a spunbond fiber, Non-woven fabric sheet.
  4. In claim 1, one of the polymer components (A) is a propylene homopolymer and the other of the polymer components (B) is a propylene-α-olefin copolymer, wherein the propylene-α-olefin copolymer has a co-monomer content of 1.0 to 5.5 weight percent. Non-woven fabric sheet.
  5. In claim 1, when measured by DSC according to ISO 11357-1 & -2, the absolute value of the difference between the crystallization temperature [T c (A)] of polymer component (A) and the crystallization temperature [T c (B)] of polymer component (B) is greater than 0°C and less than 30°C, and the curved radial interface line is arched toward the polymer component having the lower crystallization temperature. Non-woven fabric sheet.
  6. In claim 1, the absolute value of the crystallization temperature [T c (A)] of the polymer component (A) having a higher crystallization temperature, when measured by DSC according to ISO 11357-1 & -2, is in the range of 90°C to 135°C, and the absolute value of the crystallization temperature [T c (B)] of the polymer component (B) having a lower crystallization temperature, when measured by DSC according to ISO 11357-1 & -2, is in the range of 80°C to 125°C. Non-woven fabric sheet.
  7. In claim 1, one or both of the polymer components (A) and (B) comprise a nucleating agent, said nucleating agent is present in an amount of 0.15 ppm to 3000 ppm. Non-woven fabric sheet.
  8. In claim 1, the absolute value of the melting temperature [T m (A)] of the polymer component (A) having a higher melting temperature, when measured by DSC according to ISO 11357-1 & -2, is in the range of 155°C to 164°C, and the absolute value of the melting temperature [T m (B)] of the polymer component (B) having a lower melting temperature, when measured by DSC according to ISO 11357-1 & -2, is in the range of 142°C to 155°C. Non-woven fabric sheet.
  9. In claim 1, one or both of polymer components (A) and (B) have a melt flow rate of 15 to 120 g/10 min (when determined at 230°C and 2.16 kg according to ISO 1133) and/or one or both of polymer components (A) and (B) have a polydispersity (M w / M n ) of 2.5 to 10.0 (when measured by size exclusion chromatography according to ISO 16014), and the absolute difference between the polydispersity of the two polymer components is 0.3 or greater. Non-woven fabric sheet.
  10. In claim 1, one or both of the polymer components (A) and (B) comprise a visbreaking additive, said visbreaking additive is present in an amount of 100 ppm to 500 ppm, Non-woven fabric sheet.
  11. In claim 1, the weight ratio between the two polymer components (A) and (B) is 80:20 to 20:80, Non-woven fabric sheet.
  12. A nonwoven sheet according to any one of claims 5 to 11, wherein a polymer component (B) having a lower crystallization temperature is present in excess in the crimped multi-component fiber.
  13. A multilayer sheet comprising a nonwoven sheet according to any one of claims 1, 3 to 11, and additionally at least one spunbond nonwoven sheet and/or at least one meltblown nonwoven sheet.
  14. A method for manufacturing a nonwoven sheet according to any one of claims 1, 3 to 11, wherein the nonwoven sheet is manufactured in an apparatus comprising at least two extruders having a spinnerette, a drawing channel, and a moving belt, and the crimped multi-component fiber is spun in the spinnerette, drawn in the drawing channel, and laid down on the moving belt, and the apparatus comprises a pressurized process air cabin in which process air is guided through the drawing channel to draw the fiber.
  15. A hygiene product comprising a non-woven sheet according to any one of paragraphs 1, 3 through 11.

Description

Nonwoven fabric containing crimped multi-component fibers The present invention relates to a nonwoven sheet comprising crimped multi-component fibers. Flat sheets of nonwoven materials are used in the hygiene industry on a large scale to manufacture diapers and similar products. To enhance the comfort and functionality of these products, the industry is striving to increase the softness and flexibility of the materials. Introducing crimped multi-component fibers into such materials, instead of or in addition to linear single-component fibers, is an approach to meet these demands that has been extensively described in the literature and implemented in the market. The use of crimped fibers makes the nonwoven fabric softer and less dense, while making the fabric more flexible and soft. This is analogous to straight hair versus curly hair. Generally, crimped multicomponent fibers contain two or more polymers with different physical properties that are asymmetrically distributed across the cross-section. The most common is side-by-side. This configuration causes the fiber to crimp when subjected to physical stress, such as drawing and quenching, as in the case of spunbond fibers. One of the first patents for this technology is US 6,454,989 B1, originally filed by the U.S. company Kimberly-Clark. This document describes the basic principles in the context of spunbonding, which has become the industry standard for nonwoven materials for sanitary applications, and includes a list of options in which the polymer distributed across the cross-section of the fiber may differ. The options mentioned include melting point differences, differences in crystallization behavior, differences in melt elasticity, and differences in molecular weight averages or distributions, and many other options are included in addition to the general range of degrees of difference. However, only some of the options have been actually tested, and since then, much research work has been done to identify actual operable conditions and to identify compositions that provide materials with particularly desirable properties in various aspects. Patents resulting from these developments include EP 3 165 656 B1, EP 3 121 314 B1, EP 3 246 443 B1 and EP 3 246 444 B1, all of which are based on research made by the co-applicants of the present application. However, despite these various improvements, there is still a need for the optimization and diversification of polymers that can be used to manufacture such materials. Against this backdrop, the present invention proposes a nonwoven sheet comprising crimped multi-component fibers, wherein the fibers comprise two different polymer components (A) and (B) distributed across the cross-section of the fibers in a side-by-side arrangement, and the interface line between the two polymer components (A) and (B), which is contained in the radial plane of the fibers, is curved and its curvature (c) is defined as (h)/(b) and is 0.05 to 0.25, where (b), the "baseline length," is the length of an imaginary straight baseline connecting two endpoints of the curved interface line, and (h), the "bow height," is the distance from the vertex of the curved interface line to the baseline. The interface line has the shape of a single arc, that is, it is not wavy, or, in more mathematical terms, there is no inflection point where the sign of the curvature changes. It refers again to the shape of the interface line contained in the spinning plane of the fiber, and thus is the shape seen when the fiber is cut in the radial direction. The radial plane is perpendicular to the longitudinal direction of the fiber and thus forms a 90° angle with respect to the longitudinal axis of the fiber at a given location. The shape of the radial interface line defining the present invention is the shape of the interface line contained within this plane. This is intended to distinguish it from the contour of the interface along the longitudinal or oblique line, which is naturally curved to some extent by geometric relationships in a crimped fiber. The curved characteristic of the radial interface line defining the present invention is not geometrically related to the crimp of the fiber. Further research was conducted to aim for a more fundamental understanding of crimped bicomponent fibers, revealing that beneficial crimping behavior can be observed when the radial interface lines between the components of a multicomponent fiber having side-by-side arranged polymer components have a defined curvature. In a preferred embodiment, the curvature (c) of the radial interface line is 0.08 to 0.22, preferably 0.10 to 0.20, and more preferably 0.12 to 0.18. When the curvature is within this range, very favorable crimping behavior has been observed in many cases. For the purposes of this application, the side-by-side arrangement of polymer components (A) and (B) is provided in standard side-by-side fibers, but may also exist in eccentric sheath-core fibers