PLA granulation, crystallization, drying, stirring, dehumidification

PLA Crystallization & Drying Unit

**PLA Thermal Crystallization Dryer: Technical Overview**  

**PLA Water Crystallization, Stirring & Dehumidification System**  

A specialized industrial solution for comprehensive PLA biopolymer conditioning, integrating three critical processes to optimize material stability and processability. This system ensures precise control over moisture removal, crystal structure development, and thermal uniformity for high-performance PLA processing.

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### **System Architecture**  

1. **Water Crystallization Module**  

  - **Dynamic Hydration Control**: Adjusts pellet surface moisture (0.5–2.5% w/w) to nucleate crystal growth during heating phases.  

  - **Multi-Stage Heating**: Programmable temperature ramps (60°C → 100°C → 80°C) induce α-crystal formation (orthorhombic structure) while preventing hydrolysis.  

2. **High-Efficiency Stirring Unit**  

  - **3D Helical Agitator**:  

    - Rotation speed: 5–25 RPM (variable frequency control)  

    - Mixing homogeneity: ≤±1.5% temperature variance across batch  

    - Self-cleaning PTFE blades prevent material buildup  

3. **Triple-Stage Dehumidification**  

  - **Pre-Drying**: Ambient air desiccation to -20°C dew point  

  - **Molecular Sieve Adsorption**: Zeolite towers with auto-regeneration (cycle time: 15 min)  

  - **Vacuum-Assisted Drying**: Final moisture reduction to ≤30 ppm (0.5 bar absolute pressure)  

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### **Technical Specifications**  

| Parameter | Value |  

|-----------|-------|  

| Capacity | 200–10,000 kg/batch |  

| Drying Time | 2–6 hrs (material-dependent) |  

| Energy Consumption | 0.18–0.32 kWh/kg |  

| Residual Moisture | ≤50 ppm (ISO 15512 compliant) |  

| Crystallinity Range | 15–45% (DSC-verified) |  

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### **Key Innovations**  

- **Moisture-Crystallinity Coupling Algorithm**: Real-time adjusts drying parameters based on PLA viscosity (η) and glass transition (T_g) data.  

- **Anti-Static Chamber Design**: Reduces fines generation by 60% through ionized airflow.  

- **Closed-Loop Nitrogen Purging**: Maintains O₂ < 200 ppm for oxidation-sensitive grades.  

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### **Industrial Performance**  

- **Fiber Spinning**: Reduces yarn breakage from 12% to 3.5%  

- **3D Printing Filament**: Improves dimensional stability to ±0.05 mm  

- **Film Blowing**: Enables 8–10 μm thickness consistency  

Certified to UL 61010-1 safety standards, this system achieves 99.7% moisture removal efficiency while cutting energy costs by 40% versus conventional hot-air dryers. (Word count: 298)

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