Method for producing high tensile strength nanofiber yarn

Patent metadata

Field	Value
Publication number	US-2017356102-A1
Application number	US-201515538931-A
Country	US
Kind code	A1
Filing date	Dec 23, 2015
Priority date	Dec 23, 2014
Publication date	Dec 14, 2017
Grant date	—

Abstract

The present invention relates to a process for producing high tensile strength nanofiber yarn by wet-extrusion on a slippery surface. In particular, the present invention discloses a method wherein individual nanocellulose fibers are aligned by high speed in-nozzle-alignment and on-surface-alignment, which comprise controlling the fiber width on a moving slippery surface.

First claim

1 . A method for producing a high tensile strength nanofiber yarn by wet-extrusion, wherein individual nanocellulose fibers are aligned together and form a nanofiber network first by in-nozzle-alignment, wherein a nanocellulose hydrogel is prepared from natural and non-modified nanofibrillated cellulose and extruded through a nozzle at high jet speed, after which the nanofiber network is stretched by on-surface-alignment, wherein a hydrogel jet from the nozzle is applied on a moving slippery surface.

2 . The method according to claim 1 , wherein the nanofiber network is stretched along a jet flow direction through an interaction of a continuous water phase with the nanofiber network.

3 . The method according to claim 1 , wherein the moving surface is a drum or a belt covered with a plastic film that has been pre-coated with an oil, such as a vegetable oil, or with a non-immiscible fluid.

4 . The method according to claim 1 , wherein the nanofiber network is stretched at a stretching ratio of at least 0.1.

5 . The method according to claim 1 , wherein the jet speed is between 3 and 30 m/s.

6 . The method according to claim 1 , wherein the nozzle has an inner diameter between 10 and 150 μm.

7 . The method according to claim 1 , wherein the hydrogel comprises non-modified nanocellulose fibers.

8 . The method according to claim 1 wherein the hydrogel comprises TEMPO-oxidized nanocellulose fibers.

9 . The method according to claim 1 , wherein the produced nanofiber yarns are air dried simultaneously on the moving surface.

10 . The method according to claim 1 , wherein the hydrogel jet from the nozzle impinges on the moving surface at an impingement angle between 90 and 20 degrees, wherein the jet is perpendicular to the surface at 90 degrees and tangential to the surface at 0 degree.

11 . The method according to claim 10 , wherein the impingement angle is between 90 and 40 degrees.

12 . The method according to claim 1 , wherein a distance between the nozzle and the moving surface is such that it enables a continuous water phase and a uniform wet filament.

13 . The method according to claim 1 , wherein the nanofiber yarn is produced at a speed of at least 500 m/min.

14 . The method according to claim 1 , wherein a high molecular weight polymer additive is added to the nanocellulose hydrogel to reduce extrusion pressure and prevent nozzle clogging.

15 . A nanofiber yarn, produced according to a method of claim 1 .

16 . Use of the nanofiber yarn of claim 15 as a composite reinforcement fiber and/or as a precursor for carbon fiber.

17 . The method according to claim 1 , wherein the nanofiber network is stretched at a stretching ratio of more than 1.

18 . The method according to claim 1 , wherein the jet speed is between 10 and 25 m/s.

19 . The method according to claim 10 , wherein the impingement angle is between 75 and 55 degrees.

Assignees

• Teknologian Tutkimuskeskus Vtt Oy
• Spinnova Oy

Inventors

• Shen Yingfeng
• Harlin Ali
• Salmela Juha

Classifications

• D01F2/00 Primary

  Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C08J3/05

  from solid polymers · CPC title

• D01F9/16

  from products of vegetable origin or derivatives thereof, e.g. from cellulose acetate (D01F9/18 takes precedence) · CPC title

• D01D5/04 Primary

  Dry spinning methods {(D01D5/0038 takes precedence)} · CPC title