The trough is sealed with a hydraulically clamped lid; double mechanical shaft seals with barrier fluid maintain vacuum integrity at both blade shaft penetrations. Vacuum is applied (−0.85 to −0.98 bar) while blades rotate at 10–60 RPM — rising gas bubbles from the kneaded compound exit through the vacuum line to a cold trap condenser that captures entrained solvent vapour. For solvent-stripping applications, jacket heating (40–120°C) simultaneously drives solvent evaporation while the blades maintain material homogeneity. PLC monitors vacuum level, blade torque, and condenser temperature throughout cycle.
Challenges
Vacuum Integrity at Double Blade Shaft Seals Under Kneading Load
Combined vacuum differential and blade bending load stresses both shaft seals — air ingress.
Lid Seal Failure from High-Viscosity Material Fouling Seating Face
Product extruded into lid gasket groove during kneading prevents full vacuum seal on lid closure.
Solvent Vapour Condensation in Vacuum Pump Oil
Solvent-laden vapour not fully captured by cold trap condenses in vacuum pump oil — pump failure.
Degassing Effectiveness in Ultra-High-Viscosity Material (>500,000 cP)
Bubble rise velocity through >500,000 cP material is near zero — degassing is extremely slow.
CIP of Vacuum Line, Cold Trap, and Condenser
Solvent-contaminated vacuum line and cold trap require validated cleaning between product campaigns.
Solutions
- Double Labyrinth + Double PTFE Lip Seal per Shaft (Independent Vacuum Integrity): Two sealing zones per shaft; barrier fluid circulation maintains vacuum at each seal independently.
- Recessed Lid Gasket Groove with Anti-Extrusion Ring: Groove geometry prevents product from reaching the gasket contact face — sustained vacuum seal.
- Oversized Cold Trap (−40°C, Surface Area 3× Design Duty) Before Vacuum Pump: Cold trap captures >99% of solvent vapour — protects pump oil from contamination.
- Distributed Blade Perforations (2 mm Holes on Hollow Sigma Blade): Blade perforation draws gas bubbles directly from within the kneaded mass — improves degassing rate.
- Dedicated CIP Circuit for Vacuum Line + Hot Solvent Flush of Cold Trap: Automated hot solvent flush of cold trap and vacuum line between campaigns — validated residue removal.
Applications
- Chemical: Reactive adhesive degassing during cure, solvent stripping from rubber compound, void-free sealant.
- Pharmaceutical: Bubble-free ointment and paste kneading, sterile vacuum-degassed base, suppository mass.
- Plastics & Elastomers: Vacuum kneading of moisture-sensitive polymers, degassed silicone compound, void-free encapsulant.
- Food Processing: Vacuum-degassed fondant, bubble-free nougat, aroma-preserved confectionery compound.
- Electronics: Thermally conductive paste, vacuum-degassed potting compound, bubble-free encapsulation resin.
Product Catalogue & Technical Datasheet
Model | Scale | Trough Vol. (L) | Batch Size (kg) | Front RPM | Motor (kW) | Vacuum Level (bar abs.) | Condenser Capacity (kg/h) | Jacket Temp (°C) | Trough L × W × H (mm) |
VSM-001 | Lab | 1 | 0.5–0.8 | 10–60 VFD | 0.75–1.5 | 0.02–0.15 | 0.5 | 0–150 | 500×250×350 |
VSM-005 | Lab | 5 | 2–4 | 10–60 VFD | 2.2–4.0 | 0.02–0.15 | 1 | 0–150 | 700×380×450 |
VSM-025 | Lab/Pilot | 25 | 10–20 | 10–60 VFD | 7.5–11 | 0.02–0.15 | 2 | 0–150 | 1,200×620×720 |
VSM-100 | Pilot | 100 | 40–80 | 10–60 VFD | 18.5–22 | 0.02–0.15 | 5 | 0–150 | 2,100×930×1,050 |
VSM-250 | Production | 250 | 100–200 | 10–50 VFD | 37–55 | 0.02–0.15 | 12 | 0–150 | 3,100×1,250×1,350 |
VSM-500 | Production | 500 | 200–400 | 8–40 VFD | 75–90 | 0.02–0.15 | 25 | 0–150 | 4,200×1,600×1,650 |
VSM-1000 | Large Prod | 1,000 | 400–800 | 5–30 VFD | 110–132 | 0.02–0.15 | 50 | 0–150 | 5,800×2,000×2,000 |
VSM-2000 | Large Prod | 2,000 | 800–1,600 | 5–25 VFD | 185–220 | 0.02–0.15 | 100 | 0–150 | 8,000×2,500×2,500 |