CN111041590A

CN111041590A - Aramid short fiber

Info

Publication number: CN111041590A
Application number: CN201911362507.0A
Authority: CN
Inventors: 于发家
Original assignee: Qingdao Tipont Cord Co ltd
Current assignee: Qingdao Tipont Cord Co ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-04-21

Abstract

The invention discloses aramid short fiber, which comprises the following steps: preparing an aramid polymer; preparing a solidification solution; mixing the aramid polymer with the fashion solidification liquid, stirring at a high speed, and uniformly mixing to obtain aramid short fibers; and washing the aramid short fiber. According to the preparation method of the aramid ultrashort fiber, the aramid polymer and the prepared solidification solution in a certain proportion are simultaneously conveyed into the high-speed mixing equipment to be efficiently mixed to form a short fiber mixture, and the preparation method is simple, environment-friendly and low in cost.

Description

Aramid short fiber

Technical Field

The invention belongs to the technical field of short fibers, and particularly relates to aramid short fibers.

Background

The aramid fiber is a novel high-tech synthetic fiber, has the characteristics of soft texture, small density, high strength, high modulus and high temperature resistance, can be used for more than 10 years at the temperature of 220 ℃, and does not decompose or melt at the temperature of 560 ℃. However, the length and shape of the short fibers produced by the methods described in the prior documents are suitable for papermaking grade, and the short fibers are all in a super-young fiber shape, so that the tear strength of the short fibers in the finished paper is far from the international advanced level.

Disclosure of Invention

Aiming at various defects in the prior art, the aramid short fiber is provided.

In order to achieve the purpose, the invention provides the following technical scheme:

an aramid staple fiber is prepared by preparing an aramid polymer; preparing a solidification solution; mixing the aramid polymer with the solidification solution, stirring at a high speed, and uniformly mixing to obtain aramid short fibers; and washing the aramid short fiber.

Further, the short fibers directly fall into the receiving container, the short fibers in the receiving container are kept within a certain concentration range, stirring is carried out, the short fibers are gradually dispersed in water, and heavy or light impurities in the short fibers are gradually separated from the surfaces of the short fibers.

And further, carrying out squeezing dehydration on the clean short fiber slurry, and refluxing the dehydrated liquid into a receiving container for recycling.

Further, the dehydrated short fiber is dried at the drying temperature of 110-130 ℃ to obtain the well-dispersed and clean short fiber.

Further, the concentration of the aramid polymer is 12-15%, the relative viscosity is 1.4-1.6, and the temperature is 40-43 ℃.

Further, the solidification solution is a mixture of inorganic salts, an amide solvent and water, wherein the content of the inorganic salts in the solidification solution is 30-50%, and the content of the amide solvent is 5-35%.

Further, the rotation speed of the high-speed stirring is 4000-7000 rpm.

Further, the aramid short fiber is produced by the production method of the aramid short fiber according to any one of claims 1 to 7.

Furthermore, the tear strength of the aramid short fiber is 3000-4000N.

Furthermore, the concentration of the short fiber in the receiving container in the second step is 0.7-9%.

The invention has the beneficial effects that:

according to the preparation method of the aramid ultrashort fiber provided by the embodiment of the invention, the aramid polymer and the prepared solidification solution in a certain proportion are simultaneously conveyed into a high-speed mixing device to be efficiently mixed to form an ultrashort fiber mixture, and the ultrashort fiber mixture is cleaned after being discharged to form the aramid ultrashort fiber with rich hairiness, short fiber length of 0.1-1mm and tear strength of 2000-3000N. The embodiment of the invention forms the aramid fiber ultrashort fiber by selecting proper solidification liquid for solidification, and has simple process and stable fiber performance.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The first embodiment is as follows:

The short fibers directly fall into a receiving container, the short fibers in the receiving container are kept within a certain concentration range, stirring is carried out, the short fibers are gradually dispersed in water, heavy or light impurities in the short fibers are gradually separated from the surfaces of the short fibers, clean short fiber slurry is squeezed and dehydrated, the dehydrated liquid flows back into the receiving container for recycling, the dehydrated short fibers are dried at the drying temperature of 110-, the ultra-short aramid fiber is prepared by the method for preparing the ultra-short aramid fiber of any one of claims 1 to 7. The tearing strength of the aramid fiber ultra-short fiber is 3000-4000N, and the concentration of the short fiber in the receiving container in the second step is 0.7-9%.

Example two:

preparing an aramid polymer, wherein the solid content of the aramid polymer is 8.5%, and the relative viscosity of the aramid polymer is 1.4. The components for preparing the solidification liquid are as follows: 20% of lithium chloride, 18% of dimethylacetamide and the balance of water. The aramid fiber polymer and the solidification liquid are mixed according to the mass ratio of 1: 25, the coagulation liquid, which is fed by means of a metering pump and likewise by means of a metering pump, is simultaneously fed into the high-speed mixing apparatus at a speed of 6000 rpm. The ultrashort fiber formed by the method is washed and cleaned in common pulping to form a product, the mechanical beating degree of the product is 35SR, the fiber shape is very long under observation of a fiberscope, the length reaches 0.3-0.4mm, and the forming is good. The test shows that the tear strength of the prepared aramid ultrashort fiber is 3000N. The wet product can be used for manufacturing paper sheets, and the dry product can be used in the fields of friction materials, plastic reinforcement and the like.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The aramid short fiber is characterized by comprising the following steps of preparing an aramid polymer; preparing a solidification solution; mixing the aramid polymer with the solidification solution, stirring at a high speed, and uniformly mixing to obtain aramid short fibers; and washing the aramid short fiber.

2. The aramid staple fiber as claimed in claim 1, wherein the staple fiber is dropped into a holding vessel, the staple fiber is kept in the holding vessel within a certain concentration range, stirring is carried out to gradually disperse the staple fiber in water, and heavy or light impurities in the staple fiber are gradually separated from the surface of the staple fiber.

3. The aramid staple fiber as claimed in claim 1, wherein the clean staple fiber slurry is subjected to press dewatering, and the dewatered liquid is returned to a receiving container for recycling.

4. The aramid staple fiber as claimed in claim 1, wherein the dehydrated staple fiber is dried at a temperature of 110 ℃ to 130 ℃ to obtain a well-dispersed, clean staple fiber.

5. The aramid staple fiber as claimed in claim 1, wherein the concentration of the aramid polymer is 12-15%, the relative viscosity is 1.4-1.6, and the temperature is 40-43 degrees.

6. The aramid staple fiber as claimed in claim 1, wherein the coagulating liquid is a mixture of inorganic salts, amide solvents and water, the content of the inorganic salts in the coagulating liquid is 30-50%, and the content of the amide solvents is 5-35%.

7. The aramid staple fiber as claimed in claim 1, wherein the high-speed stirring is carried out at 4000-7000 rpm.

8. The aramid staple fiber according to claim 1, which is produced by the process for producing the aramid staple fiber according to any one of claims 1 to 7.

9. The aramid staple fiber as claimed in claim 1, wherein the tear strength of the aramid staple fiber is 3000-4000N.

10. The aramid staple fiber as claimed in claim 1, wherein the concentration of the staple fiber in the receiving container in the second step is 0.7-9%.