1. Project Background
Polyimide (PI) is widely recognized as “Golden Plastic” due to its exceptional thermal stability, chemical resistance, and mechanical properties. In sectors such as microelectronic packaging, high-performance coatings, and aerospace composites, the particle size distribution (PSD) of PI powder is critical to the quality of the final product.
A leading polymer material manufacturer sought to process raw PI feedstock from 80 mesh down to a micron-level fineness, requiring a narrow and consistent particle size distribution.
2. Core Challenges
- Material Toughness: Polyimide is inherently tough and impact-resistant, making it difficult to pulverize using conventional milling equipment, which often suffers from low efficiency and heat buildup.
- Stringent Fineness Requirements: The target D90 must be strictly controlled within the 4–6μm range.
- Purity Maintenance: To preserve the material’s dielectric properties, it is essential to prevent any metallic contamination during the grinding process.
3. Technical Solution
To meet these requirements, the company utilized the Epic Powder Air Jet Mill for polyimide.
Key Equipment Advantages:
- Self-Grinding Principle: The system utilizes high-speed supersonic airflow to cause particles to collide with each other. This “particle-on-particle” impact minimizes equipment wear and prevents material contamination.
- High-Precision Classification: Equipped with an integrated horizontal turbine classifier, the mill allows for precise control of the “cut point,” ensuring the D90 stays within specifications.
- Cold Processing: The adiabatic expansion of compressed air absorbs heat, maintaining a low temperature in the grinding chamber and preventing thermal degradation of the PI polymer.
4. Experimental & Production Data
By optimizing the feed rate, grinding pressure, and classifier speed, the production results achieved a high degree of precision.
| Parameter | Technical Requirement | Actual Result |
| Feed Size | 80 Mesh | 80 Mesh |
| Target Size (D90) | 4 – 6 μm | 4.8 μm |
| Equipment | Epic Powder Air Jet Mill | Stable continuous operation |
5. Conclusion & Application Results
The processing via the Epic Powder Air Jet Mill for polyimide successfully achieved a D90 of 4.8μm, with a highly symmetrical particle size distribution curve.