High-density carbon fiber needled felt and preparation method thereof
阅读说明：本技术 一种高密度碳纤维针刺毡及其制备方法 (High-density carbon fiber needled felt and preparation method thereof ) 是由 缪云良 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种高密度碳纤维针刺毡,所述针刺毡由碳纤维网胎和碳纤维展宽织物组成的结构单元经叠层针刺成型。本发明采用展宽纤维制备的碳纤维布替代了常用碳纤维布,降低了碳纤维布厚度,并减少了针刺过程中由于碳纤维之间的空隙引起的回弹现象,从而提高了碳纤维针刺毡的整体密度和机械强度。此外,本发明有利于高密度碳纤维针刺毡刺针寿命的延长。(The invention discloses a high-density carbon fiber needled felt which is formed by laminating and needling a structural unit consisting of a carbon fiber net tire and a carbon fiber widening fabric. The carbon fiber cloth prepared by the widening fibers replaces the common carbon fiber cloth, the thickness of the carbon fiber cloth is reduced, and the rebound phenomenon caused by gaps among the carbon fibers in the needling process is reduced, so that the overall density and the mechanical strength of the carbon fiber needled felt are improved. In addition, the invention is beneficial to prolonging the service life of the high-density carbon fiber needled felt.)
1. The high-density carbon fiber needled felt is characterized in that a structural unit consisting of a carbon fiber net tire and a carbon fiber widening fabric is subjected to laminated needling molding.
2. The high-density carbon fiber needled felt according to claim 1, wherein the carbon fiber spread fabric is a spread carbon fiber single cloth, a spread carbon fiber plain cloth, or a spread carbon fiber satin cloth.
3. The high-density carbon fiber needled felt according to claim 1, wherein the carbon fiber gauge used for the carbon fiber stretch fabric is 3K, 6K, 12K, 18K, 24K, 48K or 50K.
4. The high-density carbon fiber needled felt according to claim 1, wherein the carbon fiber spread fabric adopts a carbon fiber spread yarn size of 4cm, 8cm, 10cm, 12cm, 16cm, 20cm, 24cm or 30 cm.
5. The high-density carbon fiber needled felt according to claim 1, wherein the areal density of the carbon fiber splayed fabric is 40g/cm2、60g/cm2、80g/cm2、100g/cm2、120g/cm2、160g/cm2、200g/cm2Or 240g/cm2。
6. The high-density carbon fiber needled felt according to claim 1, wherein the carbon fiber web has an areal density of 30-100g/cm2。
7. A method of making the high density carbon fiber needled felt of claim 1, comprising the steps of:
(1) preparing carbon fiber widening yarns;
passing carbon fiber through a constant temperature region with the temperature of 80-120 ℃ at the speed of 5-25 m/min, sequentially passing through a compressed air injection region and a vacuum adsorption region to form a widened carbon fiber belt with the thickness of 4-20mm, and then spraying resin for shaping;
(2) preparing carbon fiber widening fabrics and net tires;
weaving a carbon fiber widening fabric by using the carbon fiber widening belt as warp yarns and the carbon fiber widening belt or thermoplastic resin fibers as weft yarns; chopping carbon fibers, and forming a net bed layer after humidifying, opening, carding and lapping;
(3) needle punching formation
The carbon fiber widening fabric and the net tire form structural units according to the setting, the structural units are overlapped together along the thickness direction, and then the structural units are formed by needle punching according to the designed needle punching parameters.
8. The production method according to claim 7, wherein the carbon fiber is passed through the compressed air injection zone in the step (1) by: spraying compressed air to the surface of the fiber, and scattering the fiber bundle while bending by means of the jet air flow perpendicular to the fiber direction; the jet speed of the compressed air is 5-50m/s, and the distance between the carbon fiber and the jet orifice is 5-50 mm; the method for making the carbon fiber pass through the vacuum adsorption zone comprises the following steps: the carbon fiber is made to pass through the vacuum adsorbing port at constant speed, and the fiber is re-dispersed and shifted in the width direction to spread the fiber bundle.
9. The method according to claim 7, wherein the thermoplastic resin fibers in the step (2) are low-melting thermoplastic resin fibers, and the thermoplastic resin fibers are one or more of polyethylene fibers, polypropylene fibers, polyester fibers and polylactic acid fibers.
10. The method of claim 7, wherein the thermoplastic resin fiber is less than 100 tex.
Technical Field
The invention relates to the technical field of needled felts, in particular to a high-density carbon fiber needled felt for carbon/carbon composite materials and carbon/ceramic composite materials.
Background
The carbon fiber has high strength, high modulus, excellent thermal property, excellent oxidation resistance and the like, and is widely applied to the fields of aerospace, transportation and the like. The carbon fiber preform (needle felt) is a preformed part which is formed by laying carbon fibers into a textile structure by adopting a textile process method, and is a framework of composite materials such as carbon/carbon composite materials, carbon/ceramic composite materials and the like. There are many types of structures of the preform, whichIn the middle, the needled carbon fiber preform has the advantages of strong structural design, uniform gap distribution, easy compact forming and the like, overcomes the defects of poor bonding strength between two-dimensional ply preform layers, long processing period of a three-dimensional preform, high cost and the like, and becomes a multipurpose preform with high technical content which is disputed by various countries. At present, the carbon fiber needling preform is mainly formed by a net tire and carbon cloth lamination needling process, and the volume density range of the carbon fiber needling preform is mainly 0.1-0.65g/cm3. When the volume density of the carbon fiber needling preform is more than 0.6g/cm3In the process, the preparation difficulty is high, the felting needle is easy to damage, and a high-quality high-density carbon fiber needled preform is difficult to form.
Disclosure of Invention
In view of the above problems in the prior art, the applicant of the present invention provides a high-density carbon fiber needled felt and a preparation method thereof. The carbon fiber cloth prepared by the widening fibers replaces the common carbon fiber cloth, the thickness of the carbon fiber cloth is reduced, and the rebound phenomenon caused by gaps among the carbon fibers in the needling process is reduced, so that the overall density and the mechanical strength of the carbon fiber needled felt are improved. In addition, the invention is beneficial to prolonging the service life of the high-density carbon fiber needled felt.
The technical scheme of the invention is as follows:
the high-density carbon fiber needled felt is formed by laminating and needling structural units consisting of a carbon fiber net tire and a carbon fiber widening fabric.
The carbon fiber widening fabric is widening carbon fiber single cloth, widening carbon fiber plain cloth or widening carbon fiber satin cloth.
The carbon fiber specification adopted by the carbon fiber widening fabric is 3K, 6K, 12K, 18K, 24K, 48K or 50K.
The specifications of the carbon fiber widening yarns adopted by the carbon fiber widening fabric are 4cm, 8cm, 10cm, 12cm, 16cm, 20cm, 24cm or 30 cm.
The areal density of the carbon fiber widening fabric is 40g/cm2、60g/cm2、80g/cm2、100g/cm2、120g/cm2、160g/cm2、200g/cm2Or 240g/cm2。
The surface density of the carbon fiber net tire is 30-100g/cm2。
A preparation method of a high-density carbon fiber needled felt comprises the following steps:
(1) preparing carbon fiber widening yarns;
passing carbon fiber through a constant temperature region with the temperature of 80-120 ℃ at the speed of 5-25 m/min, sequentially passing through a compressed air injection region and a vacuum adsorption region to form a widened carbon fiber belt with the thickness of 4-20mm, and then spraying resin for shaping;
(2) preparing carbon fiber widening fabrics and net tires;
weaving a carbon fiber widening fabric by using the carbon fiber widening belt as warp yarns and the carbon fiber widening belt or thermoplastic resin fibers as weft yarns; chopping carbon fibers, and forming a net bed layer after humidifying, opening, carding and lapping;
(3) needle punching formation
The carbon fiber widening fabric and the net tire form structural units according to the setting, the structural units are overlapped together along the thickness direction, and then the structural units are formed by needle punching according to the designed needle punching parameters.
The method for making the carbon fiber pass through the compressed air injection area in the step (1) comprises the following steps: spraying compressed air to the surface of the fiber, and scattering the fiber bundle while bending by means of the jet air flow perpendicular to the fiber direction; the jet speed of the compressed air is 5-50m/s, and the distance between the carbon fiber and the jet orifice is 5-50 mm; the method for making the carbon fiber pass through the vacuum adsorption zone comprises the following steps: the carbon fiber is made to pass through the vacuum adsorbing port at constant speed, and the fiber is re-dispersed and shifted in the width direction to spread the fiber bundle.
In the step (2), the thermoplastic resin fiber is a low-melting-point thermoplastic resin fiber, namely one or more of polyethylene fiber, polypropylene fiber, polyester fiber and polylactic acid fiber. The thermoplastic resin fibers are less than 100 tex.
The beneficial technical effects of the invention are as follows:
the high-density carbon fiber needled preform (needled felt) is essentially a carbon fiber preform which adopts carbon fiber widening fabric with low surface density to replace common carbon cloth to improve the overall density. Wider carbon fiber bundles are obtained through a widening process, so that carbon fiber monofilaments are arranged in parallel as much as possible, adjacent fiber bundles are easily and tightly arranged together, gaps between the fiber bundles are reduced, and fibers with high orientation degree are obtained; in the preparation process of the carbon fiber fabric, the interweaving times of the carbon fiber bundles in unit area are reduced, so that the overall thickness of the carbon fiber fabric is reduced, and the surface flatness of the fabric is improved. Due to the reduction of the thickness of the carbon fiber stretched fabric and the improvement of the surface flatness, the number of layers of the net tire and the fabric in unit thickness is increased, and the volume density of the carbon fiber preform is improved; compared with the common carbon fiber preform, the rebound of the carbon fiber preform after needling is weakened due to the reduction of the pores among the fibers and the fiber bundles after the fibers are widened and the improvement of the surface flatness of the fabric, so that the carbon fiber needled preform with high density can be obtained.
In addition, the contact area between fiber warps and wefts is increased, so that the sliding resistance between fiber bundles is increased, the strength of the fabric is improved, and the mechanical property of the fabric is superior to that of the traditional carbon fiber fabric. The carbon fiber thickness of the interweaving position is reduced, the carbon fiber is uniformly dispersed, and the damage to the felting needle due to high carbon fiber content and high rigidity in the process of pricking the felting needle into the interweaving position is reduced, so that the service life of the felting needle is prolonged.
Drawings
FIG. 1 is a schematic view of a conventional needled felt;
wherein, 1 is a net-shaped bed course, 2 is a carbon cloth layer.
FIG. 2 is a schematic view showing a partial structure of a needle felt in example 1 of the present invention;
wherein, 1 is a net tyre layer, and 2 is a widening fabric layer.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings and examples.