Preoxidized Pan pulp (PAN-based pulp) is a fiber-reinforced material made of polyacrylonitrile (PAN) fiber as raw material, which is preoxidized, surface fibrillated and ground. Its core component is polyacrylonitrile preoxidized pan fiber, which forms a porous, high specific surface area microfiber structure through a special process, giving it excellent grip and dispersibility.
Preoxidized Pan pulp Production process
The preparation process of pre-oxidized pan pulp mainly includes the following steps:
1.Pre-oxidation treatment: Polyacrylonitrile precursor is oxidized in an air environment at 250-280℃ to form a partially cyclic structure and improve thermal stability.
The heating rate (8-10℃/min) needs to be controlled during the preoxidation process to avoid fiber embrittlement.
2.Surface modification and fibrillation:
Additives such as zinc borate and zinc oxide whiskers are used for surface treatment to enhance the bonding between the fiber and the matrix. Through mechanical grinding or air-laid technology, the fiber fibrillation is transformed into a microfiber structure to increase the specific surface area.
3.Post-treatment:
Drying is completed in two steps: pre-drying (80-90℃) and baking (160-170℃) to improve fiber density and uniformity.
In some processes, it is necessary to compound with supporting fibers such as polyester to make core-spun yarn to enhance mechanical properties.
Pre-oxidized Pan pulp Performance characteristics
Physical and chemical properties:
High flame retardancy: Limiting oxygen index (LOI)>50%, no melting and no dripping during combustion, and it is a quasi-non-combustible material.
High temperature resistance: Long-term use temperature reaches 220℃, short-term resistance to high temperature of 1000℃.
Corrosion resistance: Acid, alkali, organic solvents and radiation resistance, suitable for harsh environments.
Mechanical properties:
High strength and high modulus: Tensile strength can reach more than 60 GPa, modulus 1.5 MPa.
Low brittleness: Improve the cohesion between fibers through fibrillation treatment and reduce the risk of breakage.
Processing performance:
Easy to compound with rubber, resin and other matrices, suitable for molding, injection molding and other processes.
Fiber length and diameter are controllable and adaptable to different application requirements.
| Technical Parameters |
Value |
| Fiber diameter |
8m |
| Limiting Oxygen Index (LOI) |
≥45% |
| Decomposition temperature |
640℃ |
| Tensile Strength |
1.4-2.8 cN/dtex |
| Elongation |
23%-30% |
| Modulus |
5-10Gpa |
| Moisture content |
≤0.3% |
| Moisture regain |
9% |
Pre-oxidized Pan pulp application fields
Friction and sealing materials: Brake pads/clutch linings: Replace asbestos and improve the stability of friction coefficient.
Sealing gaskets: Used in high-temperature sealing scenarios of automobiles and machinery.
Protective materials: Fireproof clothing/welding blankets: Use flame retardancy to protect high-temperature workers.
Aviation/rail transportation materials: Used for engine insulation layer and seat fireproof layer.
Industrial products:
Wear-resistant fillers: Enhance the wear resistance of rubber and plastics.
Insulating materials: Used for motor slot insulation and inter-turn insulation.
Emerging fields:
Carbon fiber intermediates: Pre-oxidized pan fibers can be further carbonized to prepare high-performance carbon fibers.
New energy field: used for battery separators and thermal insulation layers of energy storage equipment.
Pre-oxidized Pan pulp development trends
Technological innovation: Develop modified pulp with higher strength and lower brittleness, such as introducing nano zinc oxide whiskers.
Green manufacturing: Optimize the energy consumption of pre-oxidation process and promote bio-based additives (such as casein).
Application expansion: Extend to high-end fields such as new energy vehicles and aerospace, replacing traditional asbestos and inorganic materials.
Pre-oxidized pan pulp has shown irreplaceability in multiple industrial fields due to its unique performance combination, and future technological upgrades will further promote its market growth.
