Powder flowability improvement

Increase solids mixing. Improve powder flowability of feed. Increase agitation intensity (e g., impeller speed, fluidization gas velocity, or rotation speed). 

Increase powder flowability. Powder feed rates improve with decreasing powder cohesive strength, increasing flow gaps, and increasing bulk permeability. See Solids Handling Bulk Solids Flow Characterization. ... 

A glidant does not always improve the powder flowability, for example when the active substance is micronised. The cohesion forces between the small particles may be too large to be overcome by a glidant. Moreover, when the poor flow properties of the powder are due to irregular particle shapes, a glidant will not have much effect either. 

For products of 2 gm and below, various precipitation processes have always been preferred by the key end market - cable sheathing. In cable sheathing based on various rubbers and/or polyethylene copolymers, a small particle size ATH is required in order to give maximum tensile strength. The major developments over recent years have been improvements in the chemical purity, particularly soluble ionic surface impurities such as sodium, and improvements in the bulk handleability of such fine powders (flowability etc.). 

Custom-made SFD towers and apparatuses have been designed, built and improved to produce nearly monodisperse, low-density lyophilisate powders suitable for pulmonary dmg delivery. Spray-freeze-dried particles were characterized regarding their mean geometric particle size, aerodynamic behaviour, surface morphology and interior structure, API (protein) stabihty, powder flowability and reconstitution characteristics. 

Uses Antifoam for incorporation into powdered detergents such as phosphate-based and phosphate-free laundry detergents Features Ready to use improved powder flowability good storage stability high flowability unaffected by a wide range of temps. 

Because particle size is so intimately intertwined with powder performance, it is one of the prime considerations in selecting excipients to develop or improve a formulation. This is particularly important with direct compression formulations where excipient flowability and compaction performance are critical. Typically, excipients for these applications exhibit narrow size distributions with moderate-to-coarse particle size, having a mean size from 100 to 200 pm. 

Solids of group C are very fine-grained, cohesive powders (e.g. flour, fines from cyclones, and electrostatic filters) that virtually cannot be fluidized without fluidization aids. The adhesion forces between particles are stronger than the forces that the fluid can exert on the particles. Gas flow through the bed forms channels extending from the grid to the top of the bed, and the pressure drop across the bed is lower than the value from cq 1. Fluidization properties can be improved by the use of mechanical equipment (agitators, vibrators) or flowability additives such as Aerosil. 

If a powder flows poorly, the vibrator can be used, but it also causes powder segregation and stratification. The addition of glidant (occasionally lubricant) in the powder mixtures can readily increase flowability at the low concerntration. Talc or fumed silicon dioxide is an example of a glidant. If this is not sufficient to improve the flow, other means of flow improvement are necessary. There are two main factors that affect powder flow particle size and particle shape. The more spherical a particle is, the better it flows. Small particles are very cohesive and hence do not flow well, but increasing the particle size will improve flow. With the aid of spray drying or spheronizers, particles become spherical. 

Elemental sulfur is an acaridde and fungicide widely used on orchard, ornamental, vegetable, grain, and other crops. It is prepared as dust in various particle sizes and applied as such, or it is formulated with various minerals to improve flowability, or is applied as an aqueous emulsion or wettable powder. 

---