Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Introduction:Powder flowability is the ability of a powder to flow in adesired manner in a specific piece of equipment.F...
Flow Patterns:Two flow patterns developed when powder flow from container:Funnel FlowMass FlowFunnel Flow• Side wall ma...
Factors Affecting Powder Flow Properties:The specific properties of a powder that affect its flow are known asflow proper...
Consideration of critical Factor: Particle Size Particle Nature Porosity Bulk Density Moisture Content Interparticle...
Powder Flow Problem:1. Rat-holing2. Arching3. Flooding Prevention of flow problem:Increased outlet diameterReduced fill...
Measurement of Flow Properties:1. Angle of repose: The internal angle between the surface of the pile and the horizontals...
Angle of repose method used interparticulate friction or resistanceto movement between particles.Experimental Variable:...
Avalanching Tester:Used to determine dynamic angle ofrepose.MTA (mean time to avalanche)determine and at the time ofaval...
2. Carr’s Compressibility Index And Hausner Ratio:Both are determined by measuring the bulk volume and thetapped volume o...
3. Flow Through an Orifice:Useful only for free-flowing materials.Two types of flow rate of powder determined:Mass flow...
4. Shear Cell Method:In the shear cell method, the force necessary to shear the powderbed by moving the upper ring is det...
Flow factor index Flowabilityff<1 Non flowing1<ff<2 Very cohesive2<ff<4 Cohesive4<ff<10 Easy flowingff≥10 Free flowingThe ...
5. Cohesion Index:Stable Micro Systems TA.XT Plus textureanalyzer used to determine cohesioncoefficient which is determin...
6. FT4 Powder Rheometer:This methodologies allow measurement of:Flow energyShear propertiesBulk propertiesThe forces ...
Downward Test Mode:It is used to measure the Basic Flow Energy (BFE)Upward Testing Mode:It is used to measure the Specif...
7. PTG-S4 Powder Characterization Instrument:Features:Fully USP <1174>, EP <2.9.36> andISO 4324 (12/83) compliantMeasure...
8. Penetrometry:The pressure of penetration in Pascal was usedto estimate flow rate.Particle size should be in the range...
Control of powder flow1. Mucon Iris Diaphragm Valve2. Powry Valve3. Vacuum Assisted Powder Flow Nozzle4. Funken Continuous...
Importance of Flow Properties in Pharmacy:1. Tablet Manufacturing2. Capsule Manufacturing3. During Drug Delivery4. During ...
Conclusion:Powder flow is a key requirement for pharmaceutical manufacturingprocess.An understanding of the fundamentals...
Reference:1. Jenike, A.W., Storage and Flow of Solids (Bulletin 123 of the UtahEngineering Experimental Station), 53 (26),...
Thanks:
Powder flow testing and control
Upcoming SlideShare
Loading in …5
×

Powder flow testing and control

14,484 views

Published on

Published in: Technology, Business

Powder flow testing and control

  1. 1. Introduction:Powder flowability is the ability of a powder to flow in adesired manner in a specific piece of equipment.Flow of powders may be:Free-flowing Non-flowing or CohesiveManufacturing of tablets, capsules, filling of powder in containerinvolves several powder handling steps, including blending,transfer, storage, and feeding to a press or a dosator.The inability to achieve reliable powder flow during these stepscan have a significant adverse effect on the manufacture andrelease of a product to market.
  2. 2. Flow Patterns:Two flow patterns developed when powder flow from container:Funnel FlowMass FlowFunnel Flow• Side wall materialstagnant whereas flowof funnel- shapedmaterial take place• First-in-last-out• Chance of powdersegregation• Suitable only for freeflowing powderMass Flow• All of the material is inmotion• First- in-frist-out• Minimize segregationand prevent rat-holing
  3. 3. Factors Affecting Powder Flow Properties:The specific properties of a powder that affect its flow are known asflow properties.These flow properties depend upon:Collectiveforces acting onindividual particlesParticle variableEnvironmentalconditionPowder or Particlevariables:• Particle size, Sizedistribution, Shape, Surfacetexture, Cohesively, Surfacecoating, Particleinteraction, Wear or attritioncharacteristic, Propensity toelectro-staticcharge, Hardness, Stiffness, Strength, Fracture toughnessExternal Factorsinfluencing PowderBehaviour:• Flow rate, Compactioncondition, Humidity, Electro-static charge, Aeration,Transportation experience,Container surface effects,Storage time
  4. 4. Consideration of critical Factor: Particle Size Particle Nature Porosity Bulk Density Moisture Content Interparticle forceVan der WaalsElectrostaticSurface tensionInterlockingFriction, etcDuring Storage and TransportationCaking and bridgingPackaging conditionHigh to low aerationDe-aerationConsolidation by tapping
  5. 5. Powder Flow Problem:1. Rat-holing2. Arching3. Flooding Prevention of flow problem:Increased outlet diameterReduced filling height powderEquipment capacity can be reducedReduced cohesive strength of powderAgitation or mechanical assistance can be utilized
  6. 6. Measurement of Flow Properties:1. Angle of repose: The internal angle between the surface of the pile and the horizontalsurface is known as the angle of repose.Angle of repose depends upon: Density Surface area Shapes of the particles The coefficient offriction of the material This angle is in the range0 –90 .Flow Property Angle of repose (Degrees)Excellent 25–30Good 31–35Fair—aid not needed 36–40Passable—may hang up 41–45Poor—must agitate, vibrate 46–55Very poor 56-65Very, very poor ≥ 65
  7. 7. Angle of repose method used interparticulate friction or resistanceto movement between particles.Experimental Variable:Segregation of materialConsolidationAerationMethods for determining the static angle of repose :Fixed height methodFixed base diameter methodTilting box methodMethods for determining the dynamic angle of repose:Revolving cylinder method
  8. 8. Avalanching Tester:Used to determine dynamic angle ofrepose.MTA (mean time to avalanche)determine and at the time ofavalanching image was captured.Aero-Flow™ AutomatedPowder FlowabilityAnalyzer
  9. 9. 2. Carr’s Compressibility Index And Hausner Ratio:Both are determined by measuring the bulk volume and thetapped volume of a powder.CompressibilityIndex (%)Flow Character Hausner Ratio≤10 Excellent 1.00-1.1111-15 Good 1.12-1.1816-20 Fair 1.19-1.2521-25 Passable 1.26-1.3426-31 Poor 1.35-1.4532-37 Very poor 1.46-1.59≥37 Very, very poor ≥1.60
  10. 10. 3. Flow Through an Orifice:Useful only for free-flowing materials.Two types of flow rate of powder determined:Mass flow rateVolume flow rateExperimental variable:The type of containerThe size and shape of the orifice usedHeight of the powder bedGeneral guidelines for dimensions of the cylinder are as follows:Diameter of opening > 6 times the diameter of the particlesDiameter of the cylinder > 2 times the diameter of the opening
  11. 11. 4. Shear Cell Method:In the shear cell method, the force necessary to shear the powderbed by moving the upper ring is determined.Types of shear cell method:Cylindrical shear cellAnnular shear cellPlate-type shear cell4.1 Brookfield PFTChoice of Test Options:Flow FunctionTime ConsolidationTest with Flow FunctionWall FrictionData Output:Flow factor IndexArching DimensionRat-hole DiameterHopper Half AngleWall FrictionBulk Density Curve
  12. 12. Flow factor index Flowabilityff<1 Non flowing1<ff<2 Very cohesive2<ff<4 Cohesive4<ff<10 Easy flowingff≥10 Free flowingThe standard classification of powderflowability uses the flow factor index (ff):It is ideal for manufacturers who process powders daily and want tominimize or eliminate downtime and expense that can occur whenhoppers discharge erratically or fail to discharge altogether.Consolidation stress
  13. 13. 5. Cohesion Index:Stable Micro Systems TA.XT Plus textureanalyzer used to determine cohesioncoefficient which is determined byintegrating the negative areas underthe force displacement curve.Cohesion Index Flow behaviour≥19 Hardened, extremelycohesive16-19 Very cohesive14-16 Cohesive11-14 Easy flowing≤11 Free flowingA low cohesion index is associated withnon-cohesive free-flowing powders.
  14. 14. 6. FT4 Powder Rheometer:This methodologies allow measurement of:Flow energyShear propertiesBulk propertiesThe forces causing the deformation and flow is measured.FT4 flowmeter Downward testing mode Upward testing modeCalibration and Data Analysis:The variables are force, torque, height, and rotational and linearvelocities, flow properties determined via extrapolation.
  15. 15. Downward Test Mode:It is used to measure the Basic Flow Energy (BFE)Upward Testing Mode:It is used to measure the Specific Energy (SE) which is the flow energyper gram of powder tested.
  16. 16. 7. PTG-S4 Powder Characterization Instrument:Features:Fully USP <1174>, EP <2.9.36> andISO 4324 (12/83) compliantMeasure flow-time, cone angle,flowabilityPTG-ER stirrer includedIntegrated analytical balance cellIntegrated dust protection bonnetBuilt-in printer
  17. 17. 8. Penetrometry:The pressure of penetration in Pascal was usedto estimate flow rate.Particle size should be in the range of0.250-0.630 mm.Used for non-consolidated pharmaceuticalpowder excipients: sodium chloride,sodium citrate, boric acid, and sorbitol.A polynomial quadratic equation was generated using the ratio ofpenetration pressure to bulk density, from which the flow rates for thegroup of all tested powders could be estimated.
  18. 18. Control of powder flow1. Mucon Iris Diaphragm Valve2. Powry Valve3. Vacuum Assisted Powder Flow Nozzle4. Funken Continuous Auto Feeder5. Fluidizing Hopper Flow Control ValveMucon ValvePowry Valve
  19. 19. Importance of Flow Properties in Pharmacy:1. Tablet Manufacturing2. Capsule Manufacturing3. During Drug Delivery4. During Mixing and Sieving5. During Unloading of Packs6. During Transportation Through Conveyers7. During Filling of Powders, Dry Suspension and Dry Syrup
  20. 20. Conclusion:Powder flow is a key requirement for pharmaceutical manufacturingprocess.An understanding of the fundamentals of powder flow can steerone in the right direction to achieve reliable powder flow. Continuous and even flow of powder during tablet and capsulemanufacturing reduced weight variation, content uniformity (alsohardness in tablet).Powder flow is also crucial during mixing, packaging, and transportationReduction in process costs and maintaining the quality and consistencyof the final product
  21. 21. Reference:1. Jenike, A.W., Storage and Flow of Solids (Bulletin 123 of the UtahEngineering Experimental Station), 53 (26), (1964, revised 1980).2. Prescott, J.K., and Barnum R.A., On powder flowability, PharmaceuticaTechnology, October 2000, pp. 60-84 and 236.3. Prescott, J. K. and Hossfeld, R. J., Maintaining product uniformity anduninterrupted flow to direct compression tablet presses.Pharmaceutical Technology, 18 (6), 1994, pp. 99-114.4. Baxter, Thomas J., “When Powders Flow Like Water: AddressingTwo-Phase Flow Effects in Tablet Press Feed System”, Tablets &Capsules, March 2009, Volume 7, No. 2, pp. 26-32.5. Barnum, Roger, Ebb and Flow: Understanding Powder Flow Behavior,Pharmaceutical Processing, March 2009, pp. 18-21.
  22. 22. Thanks:

×