KR20070109342A - Method of manufacturing armid pulp - Google Patents

Abstract

A method for manufacturing aramid pulp is provided to simplify the manufacturing process of the aramid pulp, by pulverizing chopped aramid fibers within a dry type milling machine and omitting pressing/squeezing process and drying process according to wet type pulverization. A main body(1) of a milling machine has a material inlet(4) and an aramid pulp outlet(5). A rotator(2) is installed within the main body. Blades(3) are installed on a wall surface of the main body and the rotator. Chopped fibers obtained by chopping aramid filaments are inputted into the main body of the milling machine through the material inlet, and then dry-milled by blades. Air is inputted into the main body of the milling machine through the material inlet.

Description

Method for manufacturing aramid pulp {Method of manufacturing armid pulp}

1 is a cross-sectional view of an example of a dry mill (Impeller Mill) used in the present invention.

Figure 2 is a process schematic diagram of producing an aramid filament by wet-wet spinning method.

* Explanation of symbols on the main parts of the drawings

1: Dry Grinder Body 2: Rotor

3: grinding blade 4: aramid short fiber inlet.

5: aramid pulp outlet 6: motor

30: spinning solution storage tank 40: spinneret

50: coagulation liquid bath 60: washing device

70: drying apparatus 80: heat treatment apparatus

90: winding machine

The present invention relates to a method for producing aramid pulp, and more specifically, a wet refining process / squeezing process / by refining a chopped fiber prepared by cutting aramid filament in a dry mill A method for producing aramid pulp without a drying step.

Aramid pulp is an aromatic polyamide pulp. To date, aramid filaments that have been spun are cut and wet pulverized and then squeezed, dried, crushed, and opened to improve dispersibility in use. It is manufactured through a weighting process and a packaging process.

The aramid filament is a wholly aromatic poly by polymerizing an aromatic diamine and an aromatic dieside chloride in a polymerization solvent containing N-methyl-2-pyrrolidone, as disclosed in US Pat. Nos. 3,869,492 and 3,869,430. Preparing a amide polymer, dissolving the polymer in a concentrated sulfuric acid solvent to prepare a spinning stock solution, spinning the spinning stock solution from a spinneret, and passing the spinning material through a non-coagulant fluid layer into a coagulating bath; It is produced through the process of forming the filament, and the steps of washing, drying and heat treating the filament.

FIG. 2 is a process schematic diagram of preparing aramid filaments in a conventional wet and dry spinning manner. FIG.

The conventional method of preparing aramid pulp by cutting, wet grinding, compressing / squeezing, drying, crushing, opening, and packaging the aramid filaments prepared as described above has a complicated process. In other words, since the conventional method adopts a wet refining method, the process is complicated because the wet grinding is followed by a compression / squeezing process and a drying process.

It is an object of the present invention to provide a method for producing aramid pulp in a simpler process by dry grinding the short aramid fibers in order to improve these conventional problems.

The present invention aims to simplify the process of preparing aramid pulp by refining the cut aramid chopped fibers in a dry tpye refiner.

In order to achieve such a problem, in the method for producing aramid pulp according to the present invention, a rotor (Rotor) 2 is positioned in the main body 1 having an aramid short fiber inlet 4 and an aramid pulp outlet 5 on one side. Dry pulverization treatment is performed after inputting chopped fibers obtained by cutting aramid filaments in a mill in which grinding blades 3 are fixed to the wall surface and the rotor of the main body 1. It characterized by including a process.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross sectional view of an example of an mill mill used in the present invention for dry milling short aramid fibers.

Looking at the process of dry grinding the aramid short fibers (chopped fiber) prepared by cutting the aramid filaments produced by the dry wet spinning method shown in Figure 2, the aramid short fibers aramid short fibers of the dry mill shown in Figure 1 After the inlet (4) is put into a dry mill to dry them (Refining) and the aramid pulp outlet (5) to discharge the aramid pulp.

At this time, in order to control the time that the short aramid fibers stay in the dry mill, the air can be injected through the inlet 4, the air can be discharged (intake) through the outlet 5, or they can be carried out simultaneously. .

The dry mill of FIG. 1 is composed of a main body 1 and a rotor 2 located within the main body.

Grinding blades 3 are mounted on the wall surface of the main body 1 and the rotor 2, respectively. The rotor 2 is rotated by the motor 6. The aramid short fiber inlet 4 and the aramid pulp outlet 5 are formed at one side of the main body.

The grinding blade 3 is mounted in multiple stages on the wall surface of the main body 1 and the rotor 2 as a rectangular blade.

The dry pulverized aramid pulp as described above is in a finished product state through a crushing process, an opening process, and a packaging process without undergoing a compression / squeezing process and a drying process.

However, depending on the condition of the pulverized aramid pulp, it may go to the packaging process after additional crushing and opening process if necessary.

Hereinafter, the present invention will be described in detail through examples.

However, the present invention is not limited to the scope of protection by the following examples.

Example  One

An aromatic diamine solution (B) was prepared by dissolving 1,000 kg of N-methyl-2-pyrrolidone at 80 ° C. and dissolving 80 kg of calcium chloride and 48.67 kg of para-phenylenediamine.

The aromatic diamine solution (B) was introduced into the polymerization reactor 20, and at the same time, molten terephthaloyl chloride (A) in an equimolar amount of para-phenylenediamine was simultaneously introduced into the polymerization reactor 20, followed by stirring thereof. To prepare a poly (para-phenylene terephthalamide) polymer having an intrinsic viscosity of 6.8.

Next, the prepared polymer was dissolved in 99% concentrated sulfuric acid to prepare an optically anisotropic radiation stock solution having a polymer content of 18% by weight.

Next, after spinning the spinning solution prepared as described above through the spinneret 40 as shown in Figure 2, the coagulated liquid bath containing the water, which is the coagulating solution through the spinning layer 7mm air layer ( 50) to form aramid filaments.

Next, the aramid filament formed as described above was washed with water and dried to prepare a poly (para-phenylene terephthalamide) aramid filament.

Next, by cutting the aramid filament prepared as described above to produce aramid short fibers (Chopped fiber), and then put it into the dry mill of Figure 1 and dry grinding, after crushing (Crushing) after the surface treatment, Aramid pulp was prepared by weighing and packaging.

At this time, air was injected into the aramid short fiber inlet 4 of the dry mill and air was discharged to the aramid pulp outlet 5.

In the present invention, the pressing / squeezing process and the drying process according to wet grinding can be omitted, thereby simplifying the manufacturing process of aramid pulp.

Claims (5)

A rotor 2 is located in the main body 1 having an aramid short fiber inlet 4 and an aramid pulp outlet 5 on one side, and a grinding blade on the wall and the rotor of the main body 1. 3) a method of producing aramid pulp, characterized in that it comprises a step of dry grinding after inputting a chopped fiber obtained by cutting the aramid filament in a mill (Mill) is fixed. The method for producing aramid pulp according to claim 1, wherein air is injected into the raw material inlet (4). The method for producing aramid pulp according to claim 1, wherein the air is discharged through the outlet (5). The method for producing aramid pulp according to claim 1, wherein the grinding blade (3) is a square blade. The method for producing aramid pulp according to claim 1, characterized in that the grinding blades (3) are mounted in multiple stages on the wall of the main body (1) and the rotor (2).

Images