Table 5.
Coating Techniques | Advantages | Disadvantages |
---|---|---|
Physical Method | ||
Rotary Drum | • Can be a continuous process, low operating cost, easily scaled | • Requires a large number of materials to achieve a uniform coating |
Pan Coating | • Can be a continuous process, low operating cost, easily scaled | • High air temperature for drying • Poor maintenance of humidity level results in a defective structure |
Fluidized Bed | • Can be a continuous process, low operating cost, easily scaled • Can achieve a more uniform coating • A more extensive selection of materials |
• Expensive equipment • Long residence time • Prone to filter blocking • Higher chance of solvent explosion • Lower performance with larger granule size |
Melting and Extrusion | • Solvent-free • Simple and cheap |
• Hot melts are involved • Expensive equipment |
Chemical Method | ||
Solution Polymerization/crosslinking | • Solvent reduces viscosity which makes it easier to process. • Crosslinking density can be controlled by varying monomer, initiator and cross-linking agent content |
• Lower rate of reaction results in possible loss of compound • Difficult to recover solvent from its final form. |
Inverse Suspension Polymerization | • Crosslinking density can be controlled by varying monomer, initiator and cross-linking agent content • Higher efficiency due to high reaction rate • The solvent can be recovered which reduces the cost |
• Prone to contamination by the suspension • Must perform separation to purify polymer |
Microwave Irradiation | • Simple and low energy consumption | • Not widely implemented in CRF preparation |