A side-vented perforated pan coater is a closed, horizontal-axis rotating drum with a perforated coating zone through which conditioned process air passes directly across the tablet bed. The exhaust plenum sits beneath the cascading bed, so drying air is drawn through the tablets rather than over them. Built for 5–1,000 kg batches, it applies aqueous and organic film, enteric, and modified-release coats with weight-gain RSD below 3% under full PLC recipe control.
Tablets are charged at 60–70% brim fill and the pan, fitted with mixing baffles, lifts and cascades the bed at 2–22 RPM. Air-atomizing spray guns deliver coating dispersion onto the moving bed surface while heated, HEPA-filtered inlet air (40–80°C) passes through the bed and leaves through the perforated exhaust plenum. Spray rate, bed temperature, and pan pressure (−10 to −25 Pa) run in closed loop. Reverse pan rotation discharges the batch with >99% recovery.
Challenges
Twinning and Sticking
Over-wetting at high spray rates bonds tablets together and picks film off logos and edges.
Spray Drying Losses
Excessive inlet temperature or gun-to-bed distance dries droplets before impact, reducing coating efficiency.
Core Edge Erosion
Friable cores chip and erode at edges during early rotation before the film seal forms.
Inter-Tablet Coating Variability
Poor bed exchange gives weight-gain non-uniformity, critical for enteric and modified-release coats.
Perforation Blinding
Fines and overspray plug pan perforations, lowering airflow and drying capacity.
Solutions
- Spray Rate and Temperature Interlock: PLC links spray rate to exhaust temperature, holding the bed within a 38–45°C window.
- Adjustable Gun Manifold: Gun-to-bed distance (150–250 mm) and angle are set per recipe for coating efficiency above 90%.
- Jog and Slow-Start Profile: Low-RPM pre-warm and jog cycle protects cores until the initial film seal forms.
- Profiled Mixing Baffles: Anti-slip baffles drive axial bed exchange for weight-gain RSD below 3%.
- WIP Spray Nozzles + Drainable Pan: Automated wash-in-place clears perforations between batches; tilted drain ensures full drying.
Applications
- Pharmaceutical: Aqueous film coating, enteric and sustained-release functional coats, taste masking under GMP.
- Nutraceuticals: Multivitamin, herbal, and probiotic tablet coating with moisture-barrier films.
- Food & Confectionery: Compressed mints, chewing gum pellets, and supplement tablet film finishing.
- Veterinary: Bolus and feed-additive tablet coating for palatability and stability.
Models & Capacities: Laboratory to Large Production
| Model | Scale | Pan Ø [mm] | Batch Size [kg] | Brim Vol. [L] | Pan Speed [RPM] | Spray Guns | Inlet Air [CMH] | Heater [kW] | Overall L×W×H [mm] | Weight [kg] |
|---|---|---|---|---|---|---|---|---|---|---|
| APC-005 | Lab | 470 | 3–5 | 9.5 | 4–22 | 1 | 200 | 4 | 1200×900×1550 | 340 |
| APC-010 | Lab | 570 | 6.5–10 | 19 | 4–20 | 1 | 340 | 7 | 1350×1000×1650 | 510 |
| APC-015 | Pilot | 640 | 9.5–15 | 30 | 4–19 | 2 | 460 | 9 | 1450×1050×1750 | 640 |
| APC-025 | Pilot | 740 | 16–25 | 50 | 4–18 | 2 | 670 | 13 | 1650×1200×1850 | 870 |
| APC-040 | Pilot | 840 | 25–40 | 75 | 3–16 | 3 | 950 | 19 | 1800×1300×1950 | 1,150 |
| APC-060 | Production | 940 | 40–60 | 120 | 3–16 | 3 | 1,300 | 25 | 1950×1400×2050 | 1,450 |
| APC-080 | Production | 1,020 | 50–80 | 150 | 3–15 | 4 | 1,600 | 30 | 2100×1450×2100 | 1,700 |
| APC-100 | Production | 1,090 | 65–100 | 190 | 3–14 | 4 | 1,900 | 40 | 2200×1550×2200 | 1,950 |
| APC-150 | Production | 1,220 | 95–150 | 290 | 3–14 | 5 | 2,550 | 50 | 2400×1700×2300 | 2,500 |
| APC-200 | Production | 1,320 | 130–200 | 380 | 3–13 | 6 | 3,200 | 65 | 2550×1800×2400 | 2,950 |
| APC-250 | Production | 1,410 | 160–250 | 480 | 3–13 | 7 | 3,750 | 75 | 2700×1900×2500 | 3,400 |
| APC-350 | Production | 1,550 | 220–350 | 670 | 2–12 | 8 | 4,850 | 95 | 2950×2050×2650 | 4,150 |
| APC-500 | Large Prod | 1,710 | 310–500 | 960 | 2–12 | 10 | 6,350 | 130 | 3200×2200×2800 | 5,100 |
| APC-750 | Large Prod | 1,920 | 470–750 | 1,450 | 2–11 | 12 | 8,600 | 170 | 3500×2400×3000 | 6,450 |
| APC-1000 | Large Prod | 2,080 | 630–1,000 | 1,900 | 2–10 | 14 | 10,700 | 210 | 3800×2600×3200 | 7,650 |