The new, Hosokawa Viblette VBL-F, wet sieve analyzer is launched this month and is seen as the modern standard to replace conventional wet sieving methods in dry particle size analysis.
The simple to use Viblette VBL-F offers sieving times a third less than conventional sieving methods whilst using only 1/6th the liquid to produce accurate and reproducible particle size analysis required in quality control operations. The unit offers a 5 micron,non-filming screen wet sieving capability.
Wet sieving is an established method where cohesive or highly electrostatic powders are to be analysed and where small amounts of coarse powders are to be isolated – which is difficult to detect by laser diffraction- scattering methods or dry sieving.
Enhanced vibration allows rapid analysis and unique shower nozzles deliver effective powder wetting with little liquid waste. Liquid is sprayed through shower nozzles onto the powdery sample on the sieve. The sprinkler is rotated by liquid pressure evenly wetting the powder.The problem of fine screen filming that can occur in wet sieving is avoided using enhanced vibration force, allowing both fine particles and liquid to pass through the screen and shortening the measuring time. Manual intervention is not required during sieving.
Options are available for ultrasonic operation for high cohesive, superfine powders; for organic solvents as well as a series of control options of spray timing, flow volume, rotational speed of sprinkler, process time and vibration on/off timing.
Typical powder applications include, carbon black, calcium carbonate,graphite, silica, plastic, food, abrasives, ceramic fine powders.