阅读说明：本技术 一种大直径pfa单丝及其生产方法 (Large-diameter PFA monofilament and production method thereof ) 是由 马海燕 徐燕 于 2019-11-11 设计创作，主要内容包括：本发明公开了一种大直径PFA单丝及其生产方法,单丝强度为：≥1.5cN/dtex,直径为：0.08-3.0mm,流动性指标：MFR=2-40g/10min(372℃/2.16kg负荷,ASTM)。本发明方法简便,可有效提高大直径PFA单丝的强度。(The invention discloses a large-diameter PFA monofilament and a production method thereof, wherein the strength of the monofilament is as follows: not less than 1.5cN/dtex, diameter: 0.08-3.0mm, fluidity index: MFR =2-40g/10min (372 ℃/2.16kg load, ASTM). The method is simple and convenient, and can effectively improve the strength of the PFA monofilament with large diameter.)

1. A large-diameter PFA monofilament characterized by: the strength is as follows: not less than 1.5cN/dtex, diameter: 0.08-3.0mm, fluidity index: 372 ℃/2.16kg load, ASTM, MFR =2-40g/10 min.

2. A preparation method of a large-diameter PFA monofilament is characterized by comprising the following steps:

(1) preparing materials: taking the following raw materials in percentage by mass:

PFA 100%；

(2) feeding the raw materials into a single-screw extruder for melt extrusion, and adding an auxiliary agent for reaction in the melt extrusion process, wherein the reaction time is 30 seconds-5 minutes; the screw diameter of the single screw extruder is 36-53 mm, the screw temperature is 330-;

the auxiliary agent is prepared by compounding a lubricant and a strength-improving additive according to the mass ratio of 1:

the lubricant comprises: two or more of polyethylene wax, stearic acids, fatty acids and silicone oil, and the dosage of various lubricants is the same;

the strength-enhancing additives include: a nano-additive;

the total dosage of the auxiliary agent is 5-15% of the dosage of the raw material in the step (1);

(3) and filtering, water cooling, hot water tank stretching, hot air stretching, shaping, winding and packaging after single screw extrusion to obtain the large-diameter PFA monofilament.

3. The method of preparing a large diameter PFA monofilament according to claim 2, wherein: the spinning temperature is 330-.

4. The method of preparing a large diameter PFA monofilament according to claim 2, wherein: the spinning temperature is 380 ℃, the liquid cooling temperature is 60 ℃, the hot water drawing temperature is 90 ℃, the hot air drawing temperature is 170 ℃, the drawing ratio is 5 times, and the setting temperature is 190 ℃.

Technical Field

The invention relates to a large-diameter PFA monofilament and a production method thereof.

Background

The conventional PFA monofilament has the problems of low strength, poor flowability and the like, and the use of the PFA monofilament is influenced.

Disclosure of Invention

The invention aims to provide a PFA monofilament with large strength and large diameter and a production method thereof.

The technical solution of the invention is as follows:

a large-diameter PFA monofilament characterized by: the preparation method comprises the following steps:

(1) preparing materials: taking the following raw materials in percentage by mass:

PFA 100%；

(2) feeding the raw materials into a single-screw extruder for melt extrusion, and adding an auxiliary agent for reaction in the melt extrusion process, wherein the reaction time is 30 seconds-5 minutes; the screw diameter of the single screw extruder is 36-53 mm, the screw temperature is 330-.

The auxiliary agent is prepared by compounding a lubricant and a strength-improving additive according to the mass ratio of 1:

the lubricant comprises: two or more of polyethylene wax, stearic acids (calcium stearate, zinc stearate, barium stearate, etc.), fatty acids (n-butyl stearate, stearamide, oleamide), silicone oils, etc., and the amount (mass) of each lubricant is the same; some additives can be used as internal lubricants, and the internal lubricants can be uniformly dispersed among molecular chains, so that the internal friction of the molecular chains is reduced, and the fluidity of the polymer is improved; some additives may act as external lubricants which act to reduce friction between the polymer melt and the barrel wall of the screw machine, so that when two or more internal and external lubricants are used in combination, the effect is better, the PFA melt in the screw is more fluid, and the resulting filaments are smoother.

The strength-enhancing additives include: nano additives (nano silicon dioxide, nano titanium dioxide or nano calcium carbonate, etc.);

the total dosage of the auxiliary agent is 5-15% of the dosage of the raw material in the step (1).

(3) And filtering, water cooling, hot water tank stretching, hot air stretching, shaping, winding and packaging after single screw extrusion to obtain the large-diameter PFA monofilament. Wherein the spinning temperature is 330-. The optimal process parameters are as follows: the spinning temperature is 380 ℃, the liquid cooling temperature is 60 ℃, the hot water drawing temperature is 90 ℃, the hot air drawing temperature is 170 ℃, the drawing ratio is 5 times, the setting temperature is 190 ℃, and the strength of the obtained monofilament is the highest and is 2.5 cN/dtex.

The strength of the obtained PFA monofilament with large diameter is as follows: not less than 1.5cN/dtex, diameter: 0.08-3.0mm, fluidity index: MFR =2-40g/10min (372 ℃/2.16kg load, ASTM).

The method is simple and convenient, and can effectively improve the strength of the PFA monofilament with large diameter.

The present invention will be further described with reference to the following examples.

Detailed Description

A large diameter PFA monofilament having a strength of: not less than 1.5cN/dtex, diameter: 0.08-3.0mm, fluidity index: MFR =2-40g/10min (372 ℃/2.16kg load, ASTM).

The preparation method comprises the following steps:

(1) preparing materials: taking the following raw materials in percentage by mass:

PFA 100%；

(2) feeding the raw materials into a single-screw extruder for melt extrusion, and adding an auxiliary agent for reaction in the melt extrusion process, wherein the reaction time is 30 seconds-5 minutes; the screw diameter of the single screw extruder is 36-53 mm, the screw temperature is 330-.

The auxiliary agent is prepared by compounding a lubricant and a strength-improving additive according to the mass ratio of 1:

the lubricant comprises: two or more of polyethylene wax, stearic acids (calcium stearate, zinc stearate, barium stearate, etc.), fatty acids (n-butyl stearate, stearamide, oleamide), silicone oils, etc., and the amount (mass) of each lubricant is the same; some additives can be used as internal lubricants, and the internal lubricants can be uniformly dispersed among molecular chains, so that the internal friction of the molecular chains is reduced, and the fluidity of the polymer is improved; some additives may act as external lubricants which act to reduce friction between the polymer melt and the barrel wall of the screw machine, so that when two or more internal and external lubricants are used in combination, the effect is better, the PFA melt in the screw is more fluid, and the resulting filaments are smoother.

The strength-enhancing additives include: nano additives (nano silicon dioxide, nano titanium dioxide or nano calcium carbonate, etc.);

the total dosage of the auxiliary agent is 5-15% of the dosage of the raw material in the step (1).

(3) And filtering, water cooling, hot water tank stretching, hot air stretching, shaping, winding and packaging after single screw extrusion to obtain the large-diameter PFA monofilament. Wherein the spinning temperature is 330-. The optimal process parameters are as follows: the spinning temperature is 380 ℃, the liquid cooling temperature is 60 ℃, the hot water drawing temperature is 90 ℃, the hot air drawing temperature is 170 ℃, the drawing ratio is 5 times, the setting temperature is 190 ℃, and the strength of the obtained monofilament is the highest and is 2.5 cN/dtex.