Capsule filling machine filling volume difference

The NJP series represents an integrated electromechanical-pneumatic automation system. Driven by a main motor through a indexing box and cam-linkage mechanism, it coordinates multiple stations to achieve capsule separation, material filling, waste removal, capsule closing, product ejection, and mold cleaning. Key features include:

• Compact structural design

• Advanced automation level

• High operational availability

  Dosing accuracy ≤±3%

• Material recovery rate ≥99.5%

• Quick mold changeover (<15 min)

• Low noise operation (<75 dB(A))

Dosing accuracy serves as the critical performance indicator. Our machine employs a ‌plug-type dosing mechanism‌ where filling volume is determined by the diameter (Φ2.5-Φ12mm) and thickness (3-15mm) of measuring disc holes, correlated with material bulk density (0.4-1.2 g/cm³). Notably, dosing precision is influenced by both machine parameters and environmental/material factors.

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I. Production Environment Requirements‌

Critical Control: Maintain environmental stability to prevent material adhesion to punches, which may cause weight variation exceeding ±5%.

‌II. Material Characteristics‌

‌Optimal Specifications‌:

• Particle size: 80-100 mesh

• Uniform granulation (CV <5%)

• Homogeneous density (RSD <3%)

• Moisture content: <3% w/w

• Flowability: 25-35° angle of repose

• Anti-static properties

• Compactibility index: 0.8-1.2

Process Recommendation: Adjust formulation excipients (e.g., add 0.5-1% colloidal silica) to approach these parameters when pharmaceutically permissible.

‌III. Structural Factors & Adjustments‌

‌1. Surface Finish of Mold Components‌

• ‌Critical Inspection Points‌:

• Measuring disc holes (Ra ≤0.4μm)

• Filling rod tips (Ra ≤0.2μm)

• ‌Acceptance Criteria‌: No visible scratches, dents, or foreign particles under 10× magnification

• ‌Optimization‌: Electrolytic polishing can reduce material adhesion by 30-40%.

‌2. Clearance Control‌

Technical Note: Maintain contact surface finish (Ra ≤0.8μm) to prevent powder leakage exceeding 0.5% of batch weight.

‌3. Filling Rod Pressure Consistency‌

‌Verification Protocol‌:

1. Clean rod seats (ultrasonic cleaning recommended)

2. Spring force test:

• Vertical droop deviation: <1mm

• Swing amplitude variance: <15%

3. Replace springs with >10% force variation

‌4. Material Level Control in Powder Ring‌

• ‌Sensor Calibration‌: 5-8mm detection range with 0.1mm repeatability

• ‌Feeding Strategy‌:

• Delay time: 1-3s (adjustable via HMI)

• Frequency: 8-12 feeds/min

• ‌Material Flow Aids‌:

• Install agitator discs (rotation speed: 15-30 rpm)

• Optimize machine speed: 2,000-2,800 cph

‌5. Compacted Column Characteristics‌

‌6. Material Adhesion Mitigation‌

‌Corrective Actions‌:

1. Environmental control:

• Dehumidify to ≤35% RH for hygroscopic materials

• Cool to 18-20°C for fatty compositions

2. Mechanical adjustments:

• Cam phase optimization (±5°)

• Implement scraping mechanism (0.05-0.1mm clearance)

‌7. Weight Deviation Analysis‌

Utilize dual-channel weighing system (accuracy: ±0.1mg) to:

• Detect front/rear row variations (>±3% indicates alignment issues)

• Identify left/right deviations (>±2% suggests uneven compression)

‌IV. Dosing Accuracy Principles‌

1. Finer disc holes offer better stability than coarser ones

2. Thinner discs (3-8mm) outperform thick discs (>10mm)

3. High bulk density materials (≥0.8g/cm³) show 40% lower CV

4. Maintain powder level ≥80% ring height

5. Surface flatness tolerance: ≤1mm/m²

6. Level fluctuation should be controlled within ±3mm

‌Conclusion‌: Capsule weight uniformity (typically RSD 1.5-4.5%) is collectively determined by equipment condition (40%), environmental control (30%), and material properties (30%). Comprehensive process validation (≥3 consecutive batches) is recommended for critical formulations.