阅读说明：本技术 一种航空级芳纶蜂窝纸及其制备方法 (Aviation-grade aramid fiber honeycomb paper and preparation method thereof ) 是由 符永平 于 2020-06-28 设计创作，主要内容包括：本发明涉及一种航空级芳纶蜂窝纸及其制备方法,所述芳纶蜂窝纸由横截面为“8”字型的间位芳纶纤维制备而得。本发明的芳纶蜂窝纸制成三明治复合材料后,复合材料的蒙皮剥离力高、四点弯曲强度高、韧性好,满足航空复材的标准要求。(The invention relates to aviation-grade aramid fiber honeycomb paper and a preparation method thereof, wherein the aramid fiber honeycomb paper is prepared from meta-aramid fiber with a cross section in a shape of 8. After the aramid honeycomb paper is made into the sandwich composite material, the composite material has high skin peeling force, high four-point bending strength and good toughness, and meets the standard requirements of aviation composite materials.)

1. The utility model provides an aviation level aramid fiber honeycomb paper which characterized in that: the aramid honeycomb paper is prepared from meta-aramid fibers with cross sections in the shape of an 8.

2. The aircraft-grade aramid honeycomb paper as claimed in claim 1, characterized in that: the titer of the 8-shaped meta-aramid fiber is 3-5D.

3. The aircraft-grade aramid honeycomb paper as claimed in claim 1, characterized in that: the longitudinal and transverse orientation ratio of the 8-shaped meta-aramid fiber is close to 1: 1.

4. A preparation method of aviation-grade aramid honeycomb paper comprises the following steps:

the 8-shaped meta-aramid fiber is used as a raw material, and the aviation-grade aramid honeycomb paper is prepared by adopting a negative pressure, low temperature, high temperature and low temperature hot pressing method.

5. The method of claim 4, wherein: the negative pressure is-0.03 to-0.01 MPa.

6. The method of claim 4, wherein: the first low-temperature is-10-20 ℃, and the pressure is 50-100 KN/m.

7. The method of claim 4, wherein: the high temperature is 230-290 ℃, and the pressure is 300-600 KN/m.

8. The method of claim 4, wherein: the second low-temperature is 20-80 ℃, and the pressure is 200-400 KN/m.

Technical Field

The invention belongs to the field of aviation materials, and particularly relates to aviation-grade aramid honeycomb paper and a preparation method thereof.

Background

The aramid fiber honeycomb composite material is widely applied to military fields such as aerospace, aviation and the like due to high specific strength, high specific stiffness, heat insulation, wave transmission and excellent dielectric properties. At present, the prepared aramid fiber honeycomb paper takes O-shaped meta-aramid fiber as a main raw material, cannot meet the use standard of a bearing structural member, and particularly shows that the skin peeling force is low, four-point bending failure is caused, the brittleness is high, the toughness is insufficient after the aramid fiber honeycomb paper is made into a sandwich structure, the aramid fiber honeycomb paper is easy to break in a secondary processing process, and great potential safety hazards exist in the complex use working condition of an airplane structural member.

Disclosure of Invention

The invention aims to solve the technical problem of providing the aviation-grade aramid fiber honeycomb paper and the preparation method thereof.

The invention provides aviation-grade aramid fiber honeycomb paper which is prepared from meta-aramid fiber with a cross section in a shape of 8.

The titer of the 8-shaped meta-aramid fiber is 3-5D.

The longitudinal and transverse orientation ratio of the 8-shaped meta-aramid fiber is close to 1: 1.

The invention also provides a preparation method of the aviation-grade aramid honeycomb paper, which comprises the following steps:

the 8-shaped meta-aramid fiber is used as a raw material, and the aviation-grade aramid honeycomb paper is prepared by adopting a negative pressure, low temperature, high temperature and low temperature hot pressing method.

The negative pressure is-0.03 to-0.01 MPa.

The first low-temperature is-10-20 ℃, and the pressure is 50-100 KN/m.

The high temperature is 230-290 ℃, and the pressure is 300-600 KN/m.

The second low-temperature is 20-80 ℃, and the pressure is 200-400 KN/m.

Advantageous effects

(1) The 8-shaped meta-aramid fiber is adopted to replace the O-shaped meta-aramid fiber, so that the breaking strength and the specific surface area of the fiber are greatly improved; the problem of the internal compactness of the 3-5D fiber is thoroughly solved, so that the technical requirement for preparing the high-compactness fiber for the aramid fiber honeycomb paper can be met; meanwhile, the ratio of longitudinal to transverse orientation approaches 1: 1.

(2) After the aramid fiber honeycomb paper is impregnated with phenolic resin and cured, the aramid fiber honeycomb paper still can keep good toughness and meet the standard requirement of aviation materials; after the composite material is prepared into the sandwich composite material, the skin peeling force of the composite material is high, the four-point bending strength is high, the toughness is good, and the standard requirements of aviation composite materials are met.

Drawings

Fig. 1 is a schematic cross-sectional view of an "O" -shaped meta-aramid fiber and an "8" -shaped meta-aramid fiber;

FIG. 2 is a schematic cross-sectional view and a schematic cross-sectional view of an aramid honeycomb paper made of O-shaped meta-aramid fibers and an aramid honeycomb paper made of 8-shaped meta-aramid fibers;

FIG. 3 is a schematic process flow diagram of the present invention.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.