Aramid honeycomb is mainly composed of a honeycomb core made of aramid pape. Aramid paper has extremely high strength-to-weight ratio and good heat resistance, while honeycomb structures provide excellent stiffness and stability. The manufacturing process of aramid honeycomb materials mainly includes the preparation of honeycomb cores and the forming of composite material skins. Through high-temperature and high-pressure curing, aramid honeycomb materials are finally formed.
What is Kevlar and what is Nomex?
Aramid fibers are mainly divided into two types: "para" aramid fibers (PPTA) or Aramid 1414 and "meta" aramid fibers (PMIA) or Aramid 1313. The molecular formula difference of aramid 1313 and aramid 1414 lies in the position of the amide group, which is in the meta position in aramid 1313 and in the para position in aramid 1414. DuPont's para-aramid brand is called KEVLAR, and the meta-aramid brand is called NOMEX.
What are the advantages of Kevlar fiber?
Kevlar has excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, light weight, insulation, aging resistance, and long life cycle. Its strength is 5 to 6 times that of steel wire, and its modulus is 2 to 3 times that of steel wire or glass fiber. The toughness is twice that of steel wire, and the weight is only about 1/5 of steel wire. It does not decompose or melt at a temperature of 560 degrees. Kevlar has a wide range of applications in military, bulletproof vests, aerospace, and other fields. For example, composite armor for tanks, armored vehicles, bulletproof vests, helicopter cockpits and driver's seats, etc., can effectively improve protection and mobility. In addition, Kevlar is also used in industrial applications such as fiber protection films and non-asbestos gasket materials.
What are the advantages of Nomex fiber?
Nomex aramid has good flame retardancy and heat resistance. (It can maintain 80% of the original strength at 200 °C, and can maintain 65%-70% of the original strength after 100 hours of continuous use at 260 °C) electrical and mechanical properties. In addition, it can withstand the action of most acids and has good stability to alkalis. Widely used in military industry and electrical industry, it is an excellent insulation material of Class H. Specific applications include racing suits, electrical equipment insulation, drive motor insulation, power battery pack fire safety, etc.
What are the two common honeycomb materials? What is honeycomb Kevlar and what is honeycomb Nomex?
According to the different raw materials of aramid paper, aramid honeycomb can be divided into para-aramid (Kevlar) honeycomb and meta-aramid(Nomex) honeycomb. The para aramid paper honeycomb has better mechanical properties than the meta aramid paper and honeycomb.
What are the advantages and disadvantages of Kevlar honeycomb and Nomex honeycomb?
Here are the specific differences between the two types of aramid honeycomb:
|
Comparison dimensions |
Para-aramid honeycomb |
Meta-aramid honeycomb |
|
Raw materials and molecular structure |
Made of para-aramid paper. The amide group in the molecular chain is located in the para position (1, 4 positions) of the benzene ring, making the molecular chain more strong. |
Made of meta-aramid paper. The amide group in the molecular chain is located in the meta-position (1,3) of the benzene ring, and the molecular chain rigidity is relatively weak. |
|
Mechanical properties |
The performance is better. Due to the stronger rigidity of the molecular structure, para-aramid honeycomb has higher tensile, compressive, and shear strength, and its overall mechanical properties are far superior to meta-aramid honeycomb. |
The performance is relatively low. The main mechanical properties (such as compressive strength, shear modulus, etc.) are significantly lower than those of para-aramid honeycomb. |
|
Application areas |
With its excellent mechanical properties, it is widely used in the aerospace field with strict performance requirements, such as the wings and fuselages of advanced military aircraft and high-end civil aviation aircraft. |
It is commonly used in civil aviation aircraft under the premise of meeting basic usage requirements. (door, bulkhead, tail, floor, radar cover, luggage rack, ceiling, etc.), rail transit (car side panels, roof panels, seats, partitions, luggage racks, sunroof panels, etc.) Manufacturing of ships, yachts, sports equipment, electrical insulation, and communication equipment. |
In summary, the fundamental difference between para-aramid honeycomb and meta-aramid honeycomb lies in their chemical structure. This difference determines that para-aramid honeycomb is a higher-end aerospace-grade material, while meta-aramid honeycomb is more widely used in industrial fields with slightly lower performance requirements.