Extrusion
Micro/Nano Encapsulation

image: Vibrating nozzle systems produce microcapsules or microspheres with a very narrow size distribution.

Vibrating nozzle systems produce microcapsules or microspheres with a very narrow size distribution. 

 

image: Stationary and submerged nozzles produce capsules of oils or aqueous fill materials using waxes or hydrophilic and lipophilic polymers.

Stationary and submerged nozzles produce capsules of oils or aqueous fill materials using waxes or hydrophilic and lipophilic polymers. View high-speed video.

 

image: These oil-filled microcapsules were produced with centrifugal coextrusion.

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

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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 10 technical divisions.
04/21/14