Terahertz applications in ceramic industry

High Speed Linear Terahertz Scanning system developed and manufactured by TeraSense for conveyor belt applications is a perfect solution for non-destructive test and quality control of different materials in an industrial environment. On of the key benefits of the TeraSense THz imaging technology is its high sensitivity to different features and inclusions in the volume of non-metallic materials (ceramics, plastics, wood). One of the most distinguished applications of the system is an evaluation of density and humidity variations in the pressed powders (‘green tiles’ and kiln fired tiles in ceramic industry, pills, caplets, and tablets in pharmaceutical industry, etc.).

In ceramic tile industry, it is important to control density gradients in ‘green’ tiles right after being formed in a press and inspect finished tile for various defects. TeraSense THz imaging technology, unlike X-Ray one, is highly sensitive to variations of density and, especially, humidity of the ceramic samples. TeraSense technology allows to control density variations of the tile after the press and provide a feedback necessary for a powder feeding machine operation.

Advantages of the THz imaging system

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  • Extremely high image acquisition rate (up to 5000 fps)

  • Non-destructive (no ionizing radiation)

  • Powerful tool for defects inspection in dry tiles

  • Powerful tool for measuring density or humidity variations in wet tiles

  • Low cost solution

High Speed Linear Terahertz Scanner
with Type II sub-THz Source.
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System set up

Basic specifications of the system Type II

Camera

  • Operation frequency: 100 GHz
  • Image acquisition rate: up to 5000 lines per second
  • Image width and number of pixels: custom (typical 384 x 3 mm2, 256×1 pixel)
  • Pixel pitch: 1.5 mm
  • Spatial resolution: 3 mm
  • Fits conveyor belt running speed up to 15 m/s
  • Original software: TeraFast® Viewer
  • Interface: mini-USB
  • Power supply: 24V / 20W

Source

  • Operation frequency: 100 GHz
  • Power per camera pixel: 140 µW
  • Reflection beamforming optics
  • Protective isolator for enhanced stability

Defect detection and humidity measurements

Proven
by factory tests

TeraSense TeraFAST imaging system can detect various defects, such as:

  • Cracks
  • Holes, voids D > 3 mm
  • Scratches > 3 mm deep
  • Inclusions (especially metallic)
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Measurement of moisture gradient in a sample of ‘green’ tiles with a moisture content of 0 to 3%.
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THz transmission image of a cracked ‘green’ tile with humidity gradient: 1.5 – 2.2%. Cracks, hidden defects
and moisture gradient of the tile are clearly detectable.
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THz transmission image of a tile with scratched text on it. Text seems “dark” due to sub-THz radiation
scattering on scratches.
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THz transmission image of a dry ceramic tile. Holes and scratches can be clearly seen.
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THz transmission image of 13 mm, 19.5 mm and 26 mm thick ceramic tile
(2, 3 and 4 layers of 6.5 mm thick tile accordingly).
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Sub-THz signal attenuation at 100 GHz for ceramic tiles of different thickness and humidity.

Terahertz imaging of ceramic tiles defects

Demonstration of THz food imaging

Have any questions? Please contact us.