CN114717700A - Preparation method of alumina continuous fiber sewing thread - Google Patents

Abstract

The application discloses a preparation method of an alumina continuous fiber sewing thread, belonging to the technical field of functional materials. A preparation method of alumina continuous fiber sewing thread comprises the following steps: (1) preparing a sizing agent for the alumina continuous fiber; (2) uniformly coating the impregnating compound on the surface of the alumina continuous fiber, and drying to obtain an alumina continuous fiber base material; (3) twisting every 3-5 strands of the alumina continuous fiber base material to obtain alumina continuous fiber yarns; (4) twisting every 3-8 strands of the alumina continuous fiber yarns to obtain alumina continuous fiber sewing thread blanks; (5) and (3) uniformly coating the impregnating compound on the surface of the alumina continuous fiber sewing thread blank, and drying to obtain the alumina continuous fiber sewing thread. The aluminum oxide fiber reinforced composite material prepared by the method has good flexibility, good heat resistance, high strength and wear resistance, and meets the use requirements of the aluminum oxide fiber reinforced composite material under the high-temperature condition of more than 1000 ℃.

Description

A kind of preparation method of alumina continuous fiber sewing thread

technical field

The application relates to a preparation method of an alumina continuous fiber sewing thread, which belongs to the technical field of functional materials.

Background technique

High-performance ceramic alumina continuous fibers have excellent high temperature oxidation resistance, chemical corrosion resistance and heat resistance, as well as low thermal conductivity, high strength and high modulus, good thermal insulation and other excellent properties, which can be used as reinforced composite Heat-resistant materials and heat-insulating refractory materials can also be twisted and braided to make fiber products such as fiber ropes, fiber mats, and fiber cloths. The types of finished products are rich and can be used in high-tech fields such as aerospace, high-temperature smelting, and composite new materials.

Fiber sewing thread has a wide range of applications, mainly in the fields of stitching composite materials, plastics and leather products. Common sewing thread materials are carbon fiber, aramid fiber, glass fiber sewing thread, etc. However, aramid fibers begin to decompose at temperatures above 500°C, and the maximum service temperature of glass fibers is only 1000°C. Moreover, these fibers do not match the thermal expansion and thermophysical compatibility of alumina fiber-reinforced composite materials, and cannot meet the requirements of 1000°C. Requirements for the use of alumina fiber reinforced composites under the above high temperature conditions.

In order to prepare alumina fiber sewing preforms, alumina fiber sewing thread must be used. However, alumina fibers with small tows do not meet the requirements of direct stitching. When directly stitched, the stitching resistance is large, the alumina fibers are brittle, the yarn is easy to break, the stitching needle or machine wears the fibers greatly, and the performance of the fibers decreases after damage. During the sewing process, the friction loss of the thread is required to be as small as possible, and no knotting or untwisting occurs. In order to solve the above problems, it is urgent to process a high-quality alumina continuous fiber sewing thread with good flexibility, good heat resistance, high strength and wear resistance.

SUMMARY OF THE INVENTION

In view of this, the object of the present invention is to provide a kind of preparation method of alumina continuous fiber sewing thread, which utilizes the smaller kinetic friction coefficient and better antistatic performance of the sizing agent to coat the alumina continuous fiber and sewing thread. The surface of the blank thread gives the fiber better flexibility, smoothness and sewability. The sewing thread is prepared by twisting the alumina continuous fiber.

The invention provides a preparation method of alumina continuous fiber sewing thread, comprising the following steps:

(1) Preparation of sizing agent for alumina continuous fibers;

(2) the sizing agent of step (1) is evenly coated on the surface of the alumina continuous fiber, and dried to obtain the alumina continuous fiber base material;

(3) twisting every 3-5 strands of the alumina continuous fiber base material obtained in step (2) to obtain alumina continuous fiber yarns;

(4) the alumina continuous fiber yarn obtained in step (3) is twisted every 3-8 strands to obtain the alumina continuous fiber sewing thread blank thread;

(5) uniformly coating the sizing agent on the surface of the alumina continuous fiber sewing thread blank thread, and drying to obtain the alumina continuous fiber sewing thread.

Preferably, based on the total mass of the solid components as 100%, the sizing agent is composed of the following raw materials by mass percentage: 2-20% of organic polymer resin, 0.1-1.0% of lubricant, 0.1-1.5% of surfactant , and the rest are solvents.

Preferably, the preparation method of the sizing agent is as follows: adding the organic polymer resin into the solvent and stirring it evenly, then adding the surfactant and the lubricant in sequence, and stirring it evenly;

Wherein, the organic polymer resin is acrylic resin, styrene-acrylate or polyurethane resin.

The siloxane group introduced into the acrylic resin is on the side chain farther from the main chain of the acrylate, which greatly improves the extension and freedom of the molecular chain, and the viscosity is moderate, which can give the fiber good clustering without causing Fiber bundles are too sticky. Styrene-acrylate uses acrylic acid as a soft monomer to give the polymer emulsion film-forming flexibility and cohesiveness, so that the fibers after sizing have certain flexibility and clustering. The film has a certain strength and hardness, and the mechanical properties of the fiber are improved after sizing. Polyurethane resin contains strong polar urethane bonds. When it is used as a film-forming agent, the hard segment and soft segment in the molecular chain can be adjusted according to the needs of fiber products. Among them, soft polyurethane has a thermoplastic linear structure, so it has excellent The stability, resilience and mechanical properties of the fiber can effectively improve the flexibility and mechanical properties of the fiber.

Preferably, in the step (2), the fineness of the alumina continuous fibers is 45-80Tex, the drying temperature is 80-200°C, and the drying time is 1-5min.

Preferably, in the step (3), the twist of twist is 70-100 twists/m.

Preferably, in the step (4), the twist of twist is 80-250 twists/m.

Preferably, in the step (5), the drying temperature is 80-200° C., and the drying time is 1-5 min.

Preferably, in the step (2), the coating thickness of the sizing agent on the surface of the alumina continuous fiber is 0.2-2.0 μm.

Preferably, in the step (5), the coating thickness of the sizing agent on the surface of the alumina continuous fiber sewing thread blank thread is 0.2-2.0 μm.

Preferably, the solvent is glycerol, water, DMF or styrene;

The lubricant is one or both of hydroxyl silicone oil and amino silicone oil; the lubricant can form a layer of hydrophobic, smooth and flat film on the surface of the fiber, thereby achieving the effect of softening the fiber.

The surfactant is one or both of polysorbate and pentaerythritol fatty acid ester. Adding surfactants to the sizing agent can reduce the surface tension of the sizing agent and increase the affinity between the sizing agent and the fiber surface; question.

In this application, "DMF" means N,N-dimethylformamide.

The beneficial effects of this application include but are not limited to:

1. The preparation method of the alumina continuous fiber sewing thread of the present application, by twisting the alumina continuous fiber to prepare the sewing thread, without performing operations such as filament winding and weaving; using an organic polymer resin solution as the alumina continuous fiber and sewing thread. The raw material of the sizing agent for wire blanks uses the characteristics of organic polymer resins with good wear resistance, strong emulsion stability, and smooth and soft film formation. After sizing the fibers, the alumina continuous fiber monofilaments can be adhered to each other. Endows the fiber with better flexibility, smoothness and sewability, improves the fiber bundle bundle, and also improves the fiber's softness and mechanical properties.

2. The preparation method of the alumina continuous fiber sewing thread of the present application is simple and easy to operate, because only a sizing process is required for the alumina continuous fiber, no weaving and winding is required, and there are fewer devices involved, and the sewing of the alumina continuous fiber can be realized. The continuous production of the line reduces costs and has a competitive advantage in the market.

3. The tensile breaking strength of the alumina continuous fiber sewing thread of the present application can reach 0.317N/Tex, the collusion strength can reach 0.061N/Tex, and the number of times of abrasion can reach 1974.8 times. After coating, the surface of the fiber forms a conductive channel, The electric charges generated by the fibers after friction can be effectively removed, so that the fiber sewing thread has better antistatic properties.

4. The alumina continuous fiber sewing thread of the present application has a retention rate of 94.41% of the strength of the monofilament after being kept at 1100 ° C for 2 hours, and the retention rate of the strength of the bundled filaments can reach 89.7% after being left to stand for 24 hours at 1mol/LH ₂ SO ₄ . , 2mol/L KOH after standing for 24 hours, the retention rate of filament strength can reach 78.7%. The alumina continuous fiber sewing thread prepared in the experiment has strong wear resistance, good temperature resistance and chemical corrosion resistance.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments. It is pointed out that the following embodiments should not be construed as limiting the scope of protection of the present invention. Those of ordinary skill in the art make some simple replacements or adjustments according to the content of the present invention, which are all within the scope of the present invention. within the scope of protection.

Example 1

A preparation method of alumina continuous fiber sewing thread, comprising the following steps:

(1) To formulate a sizing agent for alumina continuous fibers, the sizing agent is composed of the following raw materials by mass percentage based on the total mass of the solid component: 2% of acrylic resin, 0.2% of hydroxy silicone oil, 0.3% of polysorbate , the rest is water;

The preparation method of the sizing agent is as follows: adding 2% acrylic resin into water and stirring uniformly, then adding 0.3% polysorbate and 0.2% hydroxy silicone oil in sequence, and stirring uniformly.

(2) Selecting alumina continuous fibers with a fineness of 45Tex, uniformly coating the surface of the alumina continuous fibers with the sizing agent of step (1), with a coating thickness of 2.0 μm, drying at 80° C. for 5 min to obtain continuous alumina fibrous substrate;

(3) Twisting the alumina continuous fiber base material obtained in step (2) every 4 strands to obtain an alumina continuous fiber yarn, the twisting twist is 70 twists/m, and then the alumina obtained by twisting The continuous fiber yarn is evenly divided into 4 segments;

(4) every 5 strands of the alumina continuous fiber yarn obtained in step (3) are twisted to obtain an alumina continuous fiber sewing thread blank, and the twisted twist is 80 twists/m;

(5) Coat the sizing agent evenly on the surface of the alumina continuous fiber sewing thread blank thread, the coating thickness is 2.0 μm, and after drying at 80° C. for 5 minutes, the alumina continuous fiber sewing thread is obtained.

Example 2

A preparation method of alumina continuous fiber sewing thread, comprising the following steps:

(1) The sizing agent for alumina continuous fibers is prepared, and the total mass of the solid component is 100%. The sizing agent is composed of the following raw materials by mass percentage: 20% of styrene-acrylate, 1% of amino silicone oil, pentaerythritol fatty acid Ester 1.5%, the rest is water;

The preparation method of the sizing agent is as follows: adding 20% styrene-acrylate into water and stirring evenly, then adding 1.5% pentaerythritol fatty acid ester and 1% amino silicone oil in sequence, and stirring evenly;

(2) Selecting alumina continuous fibers with a fineness of 80Tex, uniformly coating the sizing agent of step (1) on the surface of the alumina continuous fibers, with a coating thickness of 0.2 μm, and drying at 200° C. for 2 minutes to obtain continuous alumina fibrous substrate;

(3) Twist every 5 strands of the alumina continuous fiber base material obtained in step (2) to obtain an alumina continuous fiber yarn with a twist of 100 twists/m, and then twist the alumina obtained by twisting The continuous fiber yarn is evenly divided into 4 segments;

(4) every 8 strands of the alumina continuous fiber yarn obtained in step (3) are twisted to obtain an alumina continuous fiber sewing thread blank thread, and the twisted twist is 250 twists/m;

(5) Evenly coat the sizing agent on the surface of the aluminum oxide continuous fiber sewing thread blank thread, the coating thickness is 0.2 μm, and after drying at 200° C. for 2 minutes, the aluminum oxide continuous fiber sewing thread is obtained.

Example 3

A preparation method of alumina continuous fiber sewing thread, comprising the following steps:

(1) The sizing agent for alumina continuous fibers is prepared, and the total mass of the solid component is 100%. The sizing agent is composed of the following raw materials by mass percentage: 5% of polyurethane resin, 0.4% of hydroxy silicone oil and amino silicone oil, polysorbate Esters and pentaerythritol fatty acid esters 0.5%, the rest is DMF;

The preparation method of the sizing agent is as follows: adding 5% polyurethane resin into DMF and stirring evenly, then adding 0.5% polysorbate and pentaerythritol fatty acid ester and 0.4% hydroxy silicone oil and amino silicone oil in sequence, and stirring evenly;

(2) Selecting alumina continuous fibers with a fineness of 60Tex, uniformly coating the surface of the alumina continuous fibers with the sizing agent of step (1), the coating thickness is 1.0 μm, and drying at 115° C. for 2.5min to obtain alumina continuous fiber substrate;

(3) Twist the alumina continuous fiber base material obtained in step (2) every 3 strands to obtain an alumina continuous fiber yarn, and the twisted twist is 80 twists/m, and then twist the alumina obtained by twisting The continuous fiber yarn is evenly divided into 4 segments;

(4) every 3 strands of the alumina continuous fiber yarn obtained in step (3) is twisted to obtain an alumina continuous fiber sewing thread blank thread, and the twisted twist is 140 twists/m;

(5) Coat the sizing agent evenly on the surface of the alumina continuous fiber sewing thread blank thread, the coating thickness is 1.0 μm, and after drying at 95° C. for 5 minutes, the alumina continuous fiber sewing thread is obtained.

Comparative Example 1

The difference from Example 3 is that the surface of the alumina continuous fibers in step (2) is not coated with sizing agent.

Comparative Example 2

The difference from Example 3 is that no sizing agent is applied to the surface of the aluminum oxide continuous fiber sewing thread blank thread in step (5).

Comparative Example 3

The difference from Example 3 is: the surface of the alumina continuous fiber in step (2) and the surface of the aluminum oxide continuous fiber sewing thread blank thread in step (5) are not coated with sizing agent, and the alumina continuous fiber in step (3) is not coated with sizing agent. The surface of the yarn is coated with sizing agent, and the coating thickness is 2.0 μm.

Comparative Example 4

The difference from Example 3 is that the polyurethane resin was replaced with a polyurethane resin.

Test example

Strength test method: refer to national standard GB/T7690.3-2013 for bundle strength, national standard ASTMD3721-2001a for collusion strength, and national standard FZ/T01058-1999 for wear-resistance test method for yarns with reciprocating grinding roller method.

Test method for wear resistance: keep one end fixed, lower the fixture to perform reciprocating motion to test the dynamic friction coefficient of the sewing thread. In the experiment, a 150mm long sewing thread sample was intercepted, and one end of the sewing thread was fixed with a screw, and a 70g weight was hung on the other end of the sewing thread to fix the sewing thread sample. Setting parameters: the spacing between the ceramic holes on both sides of the lower fixture is 35mm, the normal loading force is 0.4N, the working frequency is 3Hz, and the reciprocating friction stroke is 3mm. Five sets of each sewing thread sample were tested, and the average coefficient of kinetic friction was calculated.

Conductivity test method: high resistance meter four-probe method.

Strength retention rate test after treatment: The strength test method after treatment is the same as the strength test method before treatment, and is calculated according to M=M'/M ₀ ×100%, where M ₀ is the strength before treatment, M' is the strength after treatment strength, M is the strength retention rate.

The test results are shown in Table 1.

Table 1

It can be seen from Table 1 that the coating of the sizing agent on the surface of the alumina continuous fiber can improve the surface state of the fiber, modify the surface defects of the fiber, and achieve the effects of protecting, bundling and lubricating the fiber. After that, the sizing agent is applied on the surface of the sewing thread blank, one is to enhance the clustering between fiber yarns and the cohesion between the yarns, and the other is to enhance the abrasion resistance and mechanical properties of the sewing thread. It can be seen from the comparative examples 1-3 that the coating of the raw fiber and the sewing thread blank is indispensable, and the coating of the sizing agent on the surface of the yarn is not conducive to the relative sliding between the fiber bundles when the fibers are subjected to stress. , resulting in the fiber being prone to stress concentration, resulting in a decrease in the mechanical strength of the fiber. It can be seen from Examples 1-3 and Comparative Example 4 that not all organic polymer resins can be added to the sizing agent. The flexibility, heat resistance, strength and Wear resistance is the result of a combination of various preparation conditions and process parameters. The alumina continuous fiber sewing thread prepared by the preparation method of the alumina continuous fiber sewing thread of the present application has good flexibility and heat resistance, high strength and wear resistance, and can meet the requirements of alumina fiber reinforced composite materials under high temperature conditions above 1000°C. usage requirements.

The above are only the embodiments of the present application, and the protection scope of the present application is not limited by these specific embodiments, but is determined by the claims of the present application. Various modifications and variations of this application are possible for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the technical ideas and principles of the present application shall be included within the protection scope of the present application.

Claims (10)

1. a preparation method of alumina continuous fiber sewing thread, is characterized in that, comprises the steps: (1) Preparation of sizing agent for alumina continuous fibers; (2) the sizing agent of step (1) is evenly coated on the surface of the alumina continuous fiber, and dried to obtain the alumina continuous fiber base material; (3) twisting every 3-5 strands of the alumina continuous fiber base material obtained in step (2) to obtain alumina continuous fiber yarns; (4) the alumina continuous fiber yarn obtained in step (3) is twisted every 3-8 strands to obtain the alumina continuous fiber sewing thread blank thread; (5) uniformly coating the sizing agent on the surface of the alumina continuous fiber sewing thread blank thread, and drying to obtain the alumina continuous fiber sewing thread. 2. the preparation method of alumina continuous fiber sewing thread according to claim 1, is characterized in that, according to the total mass of solid component is 100%, described sizing agent is made up of the raw material of following mass percentage: organic macromolecule Resin 2-20%, lubricant 0.1-1.0%, surfactant 0.1-1.5%, and the rest is solvent. 3. the preparation method of alumina continuous fiber sewing thread according to claim 2, is characterized in that, the preparation method of described sizing agent is: organic macromolecule resin is added in solvent and stirs, then adds surfactant and Lubricant, stir evenly; Wherein, the organic polymer resin is acrylic resin, styrene-acrylate or polyurethane resin. 4. The preparation method of alumina continuous fiber sewing thread according to claim 1, characterized in that, in the step (2), the fineness of the alumina continuous fiber is 45-80Tex, and the drying temperature is 80-200°C , the drying time is 1-5min. 5. The preparation method of alumina continuous fiber sewing thread according to claim 1, characterized in that, in the step (3), the twist of twisting is 70-100 twists/m. 6 . The preparation method of alumina continuous fiber sewing thread according to claim 1 , wherein, in the step (4), the twist of twist is 80-250 twists/m. 7 . 7 . The preparation method of alumina continuous fiber sewing thread according to claim 1 , wherein, in the step (5), the drying temperature is 80-200° C., and the drying time is 1-5 min. 8 . 8 . The preparation method of the alumina continuous fiber sewing thread according to claim 1 , wherein in the step (2), the coating thickness of the sizing agent on the surface of the alumina continuous fiber is 0.2-2.0 μm. 9 . 9. The preparation method of alumina continuous fiber sewing thread according to claim 1, wherein in the step (5), the coating thickness of the sizing agent on the surface of the alumina continuous fiber sewing thread blank thread is 0.2 -2.0μm. 10. The preparation method of alumina continuous fiber sewing thread according to claim 3, characterized in that, the solvent is glycerol, water, DMF or styrene; the lubricant is hydroxy silicone oil and amino silicone oil One or both; the surfactant is one or both of polysorbate and pentaerythritol fatty acid ester.