Information for users of other powder testers or flowability testers
You already have a powder tester, a shear tester or another type of tester? Even for you our Ring Shear Testers probably are an advantageous alternative::
Assumed that you are working with a powder tester, which is no shear tester (for shear testers see here):
- With a Ring Shear Tester you determine clearly defined physical quantities, e.g. the flowability, the strength of the powder, the internal friction, and the bulk density. With many so-called "simple testers" device-dependent quantities are determined, which neither can be applied quantitatively nor result on the flowability only. Thus misinterpretations can follow from these types of test devices.
- The flowability, as measured with a Ring Shear Tester, is the ratio of the consolidation stress and the strength of the powder following from the applied consolidation stress. This definition of flowability covers the usual practical problem: To initiate flow of a resting powder, e.g. in a silo or a dosage system.
- With our Ring Shear Testers of the series RST-01 powders and bulk solids with a particle size of up to 5 - 10 mm (dependent on the particle size distribution) can be tested: The range covers highly-disperse powders like carbon black or titanium dioxide, cement, plastics granules, and also moist products like sewage sludge or clay. The Ring Shear Tester RST-XS is appropriate for fine-grained powders (particle size up to 0.5 .. 1 mm).
- Our Ring Shear Testers are real shear testers. Shear testers are the standard test devices in the powder and bulk solids technology.
- The automatic Ring Shear Tester performs not only the test automatically, but also the evaluation of the results. Thus, only the results have to be read from the computer screen, saved or printed after the test. The software RST-CONTROL 95 contains the experience of many years of powder testing with different marterials and testers. Thus even after minimal training applicable test results can be obtained.
- The flow properties can be tested at that stress level which represents the stresses of the application (e.f. silo, big-bag).
- Measurement of the time consolidation (caking), i.e. the increase in strength during storage at rest. .
- Wall friction tests (friction between a bulk solid an a wall material, e.g. aluminum, stainless steel, coatings...).
Assumed that you already have a shear tester:
- With our Ring Shear Testers a flowability test (yield locus test) typically requires 10 to 20 minutes, whereby this time is product dependent. The RST-01.01 requires the operatuor during the whole test period (weight pieces have to be handeld, the motor drive has to be switched on and off), whereby the automatic Ring Shear Testers RST-01.pc and RST-XS perform the test and the evaluation automatically.
- With our Ring Shear Testers of the series RST-01 powders and bulk solids with a particle size of up to 5 - 10 mm (dependent on the particle size distribution) can be tested: The range covers highly-disperse powders like carbon black or titanium dioxide, cement, plastics granules, and also moist products like sewage sludge or clay. The Ring Shear Tester RST-XS is appropriate for fine-grained powders (particle size up to 0.5 .. 1 mm).
- Not only flowability, but also wall friction, time consolidation (caking). compressibility and attrition can be measured with a Ring Shear Tester.
- The Ring Shear Tester does not require a manually pre-consolidation of the powder sample (e.g. "twisting"). Steady-state flow will be attained after sufficient shear, and the shear displacement is not limited as with certain other devices on the market. Overconsolidation of a sample is not possible, because the powder speciman is just filled in loosely without any pre-consolidation. This time-consuming preliminary tests for searching the right degree of pre-consolidation are not necessary. This yields not only a drastic reduction of the time for testing, but also a clearly better reproducibility.