Extrusion
Micro/Nano Encapsulation
Vibrating nozzle systems produce microcapsules or microspheres with a very narrow size distribution.
Stationary and submerged nozzles produce capsules of oils or aqueous fill materials using waxes or hydrophilic and lipophilic polymers. View high-speed video.
These oil-filled microcapsules were produced with centrifugal coextrusion.
Several particle and fiber extrusion techniques are employed by Southwest Research Institute (SwRI) personnel to solve product performance requirements. Extrusion processes include:
- Stationary nozzle
- Centrifugal extrusion
- Vibrating nozzle
- Submerged nozzle
- Electrohydrodynamics
- Single or twin-screw extrusion
- Microextrusion
Extrusion processes produce matrix or core-shell morphologies, depending on nozzle configuration. Particle extrusion processes produce narrowly distributed particles. SwRI scientists have innovated particle extrusion processes to:
- Produce capsules down to sub-micron sizes with small particle size variances
- Operate with complex thermal profiles
- Support production capacity
Fiber extrusion processes produce single or multiple fibers with diameters down to several hundred nanometers. SwRI personnel have devised fiber extrusion processes to produce:
- Matrix fibers
- Core-shell fibers
- Multilayer, fibrous structures
Extrusion Applications
- Narrow size distributions
- Core-shell morphologies
- Gas, liquid or solid cores
- Variable shell thickness
- Variable payload composition
Extrusion Characteristics
- Sizes from1 micron to 10,000 microns
- These oil-filled microcapsules were produced with centrifugal coextrusion.
- Narrow size distribution
- Material versatility
- Scalability and high production capacity
- Continuous production.
Related Terminology
microencapsulation • nanoencapsulation • extrusion • fiber extrusion • cengrifugal coextrusion • microcapsules • core-shell • particle extrusion
