The patented blade is a true helix and can be mathematically described, unlike the blades fitted to other powder measuring devices on the market. The helical blade naturally cuts through the column of powder being tested and negates the need for complex torque measuring systems. Repeatably manufactured by CNC machining, it allows Stable Micro Systems to achieve very reproducible, and highly discriminating results from a reliable, simple and lost cost accessory.

Commenting on the patent, Jim Walker, technical director at Stable Micro Systems, said: "The design of the blade is the single most important factor in achieving repeatable powder flow measurements. The non-helical blade used on other instruments is bent from a flat sheet and presents a large flat central area to the powder being tested. It effectively compresses a column of powder beneath the blade during its travel path through the sample. As a consequence, any axial force readings being taken are corrupted and these instruments are forced to rely on torque measurements because of the inadequacies of blade design."

Stable Micro Systems Patented Helical Blade:

STABLE MICRO SYSTEMS LAUNCHES POWDER FLOW ANALYSER

Stable Micro Systems, a leading designer and manufacturer of materials testing instrumentation, has launched its revolutionary Powder Flow Analyser. The new instrument is being hailed as industry's most accurate and reliable method of measuring the flow characteristics of dry and wet powders. It will help manufacturers avoid typical problems such as batch and source variation of ingredients, caking during storage, bridging in hoppers and sticking during production.

The Powder Flow Analyser can be used to assess any product capable of flow - not just free-flowing powders. Samples are conditioned at the beginning to eliminate any variations in loading, and the precision-engineered, patented blade is then rotated through the sample, causing "controlled flow". Sophisticated mixing and testing cycles enable users to test their products in realistic conditions. During a caking test, for instance, compaction of the sample forms a cake-like layer of powder which can then be analysed, giving a good indication of how the sample may flow out of a silo after prolonged storage.

Stable Micro Systems' Powder Flow Analyser is supplied with library tests so manufacturers can start testing quickly and conveniently after straightforward installation and calibration. Users can, however, fully program the instrument to carry out slicing, shearing, compressing, compacting, mixing and aerating cycles in any combination, and in any sequence. Test sequences can be repeated ad infinitum to maximise accuracy and repeatability.

Testing is possible with very small sample volumes, minimising both disruption and expense. These samples are placed in a borosilicate glass sample vessel; allowing users to monitor what is happening to the powder as the sample is displaced. During the test, axial force, time and distance are measured by a sensitive transducer and data is displayed and analysed in real time by 16 or 32 bit software. This allows manufacturers to test characteristics such as mixing kinetics, granule surface friction, resistance to compression and particle cohesion after compaction. The results from different samples can be ranked and compared to assess the impact of external conditions including batch or source variation, humidity and moisture content, surface properties, electrostatic charge and particle or granule size, shape and distribution.

The Powder Flow Analyser is supplied with a renowned texture analyser from Stable Micro Systems. The TA.XT2i and TA.XTplus instruments are already used in over 4000 laboratories worldwide for various texture analysis tests in food, chemicals, pharmaceuticals, personal care, paints and coatings and other manufacturing industries. By simply changing the attachments on the instrument, manufacturers can test semi-finished and finished products. In the food industry, tests on flour, sugar and additives can be followed by analysis of dough and other mixes, then finished products including confectionery and baked goods, meat and dairy products, cereals and snacks. In the pharmaceutical and personal care industries, tests on ingredients can be followed by analysis of finished products such as tablets and capsules, toothpaste and shaving foams. Analysis of compaction and relaxation of powder in a punch and die tabletting system is one such example.

Non-helical blade used on other powder measuring instruments:

From an engineering perspective:
The patented blade is a true helix and can be mathematically described, unlike the blades fitted to other powder measuring devices on the market. The helical blade naturally cuts through the column of powder being tested and negates the need for complex torque measuring systems. Repeatably manufactured by CNC machining, it allows Stable Micro Systems to achieve very reproducible, and highly discriminating results from a reliable, simple and lost cost accessory.

Commenting on the patent, Jim Walker, technical director at Stable Micro Systems, said: "The design of the blade is the single most important factor in achieving repeatable powder flow measurements. The non-helical blade used on other instruments is bent from a flat sheet and presents a large flat central area to the powder being tested. It effectively compresses a column of powder beneath the blade during its travel path through the sample. As a consequence, any axial force readings being taken are corrupted and these instruments are forced to rely on torque measurements because of the inadequacies of blade design."

TTC adds that a blade with a flat section absolutely prevents the ability to move through a powder column without disturbing it's condition. So if a powder is compacted for a caking study, for example, simply coming out of the powder to compact it a second time will disturb and undo the impact of the original compaction. Likewise you could not instruct the blade to slip to the bottom of a powder column and then lift up, because the probe would distrub the powder sample on the downward path.