PTG-S4 Automated Powder Flow Analyzer

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PTG-S4 Automated Powder Flow Analyzer

The PTG-S4 automated powder flow analyzer is used to measure the flow behavior of granules and powders in compliance with the EP [2.9.36], USP [1174] Pharmacopoeia and ISO 4324 standards. This instrument determines the powder flow time, the powder cone angle of the collected powder mound, the weight, the density and the volume of the powder cone. Furthermore the EP "flowability" result is calculated by measuring the flow time of 100g of sample through a specified pouring nozzle. The PTG-S4 is equipped with a clear view dust hood, made from anti-static material, to protect the user from most of the dust during the powder analysis. This hood can easily be opened and removed completely for cleaning.

PTG S4 Automatied Powder Flow Analyzer

Why Measure the Flow Properties of Powders?
It has been estimated that over 50% of the materials used in all industrial applications were at some stage in a powder form. These powders need to be transported, injected, propelled and be able to pass through various process stages before they achieve their final form. This final form may be a tablet, a suspension or indeed a powder formulation. The need to be able to measure, control or test for reproducible powder flow has been well established in many industrial applications.

Powder flow characteristics are important for:

  • Reduction in cost of raw process materials: reject bad batches before processing
  • Maintenance of the optimum formulation for the process concerned
  • Reduction in process costs
  • Maintaining the quality and consistency of the final product
  • Maintaining process efficiency and costs by optimization of product storage, packing, handling and transportation
  • Maintaining powder quality from different suppliers or from the same supplier over a long time period
  • Development of new processes where powders are required to be formulated into end products
  • Checking moisture effects: use of powders in open systems in different climates
  • Investigating and maintaining the quality of dry mixes

Process Behaviour
In processes, which rely on powder and / or powder, mix integrity, the need to have the correct powder flow characteristics is paramount. These powder mixes have to be formulated, mixed and certainly transported. Transportation, even over small distances an easily lead to classification of sorts such that "fines" may drop out and alter the particle size distribution and hence the flow characteristics.

For example we can look at formulated mixtures, which are fed into tableting machines: these powders need to flow in exactly the same way from batch to batch. Generally, the active ingredients are materials that have no natural flow properties. They are sticky (cohesive) and prone to agglomeration. Additionally, the requirement of active material in ever decreasing dosages means that the active must be able to be dispersed in a non-active medium (normally made up of well-established and mainly natural products) in a reproducible way in the mixers prior to the introduction of the formulation into the tablet press.

Areas Where Powder Flow Characterisation is Commonly Used
AreaUse for Powder Flow Characterization
PharmaceuticalsGranulation, micronizing, tablets and other solid dosage forms
AbrasivesCeramics, metallic powders and grinding pastes
CatalystsPowders for extrudates, catalyst rings, and finely divided metals
ChemicalsBulk chemicals, fine chemicals
PrintingPigments, toners and binders
Washing PowdersPowdered surfactants, bulking agents and granulates
FertilizersExtrudates, granulates, powdered pesticides

Operating Principle of the PTG-S4
The PTG-S4 is widely used to compare batches of powders perhaps supplied by the same manufacturer over a period of time or for similar materials provides by different suppliers. The flow characteristics can be easily and quickly determined as a QC tool for inter- batch reproducibility, as this may have a distinct bearing on the ease of production especially if powders are capable of agglomeration and cohesion over time.

The design is compliant to the ISO 4324 (12/83) standard, EP [2.9.36], and USP [1174]. A conical funnel, which can be equipped with different pouring nozzles, takes the sample to be tested. A built-in analytical Sartorius balance cell takes the product collecting dish. The PTG-ER electrical stirrer may be used for powders, which do not flow well. Most pharmaceutical material contains such a high amount of fine particles that it will not start to flow without assistance.

Enter product information using the alphanumeric keyboard of the instrument. Select the test program you want to use:

  • Flow time
  • Cone angle
  • Volume
  • Flow-chart
  • Density
  • Flowability

Then start the test. Depending on the powder the PTG-ER stirrer may be used. When the test is started the funnel is opened and two IR sensors detect the powder flow, this will start the timer to measure the flow time and to record the flow chart. The product itself is collected on a 100mm diameter dish and forms a cone. Once the powder flow stops, the funnel is closed and the movable measuring arm which holds the two infra-red sensors starts to measure the height of the cone up to the tip. Since the surface of the collecting dish is completely filled, the cone angle can be calculated and displayed.

The test should be repeated (in accordance to the ISO 4324 five times) and the deviation of results should not exceed 5%. The test results are displayed at the LCD display of the PTG-S4. Using the built-in thermal printer a test report and powder flow-chart will be printed including descriptive information of the product.

To measure the flowability as per EP [2.9.36] and USP [1174] Pharmacopoeia the test is automatically stopped as soon as 100mg of sample have been collected inside a suitable plastic beaker. In addition to the flowability factor (100mg/t) the powder flow chart can be printed.

The standard instrument comes with all attachments to measure flow-time, cone angle and flowability in compliance to the current EP/USP Pharmacopoeia. Different pouring nozzles from 4 - 10 mm can be used to test the product. A stirrer can be used to force non-flowing product through the selected pouring nozzle.

The PTG-S4 powder testing system includes a built-in analytical Sartorius balance cell, which extends the instrument use to test powder flowability, density and volume. Additionally, a graph can be plotted on the built-in printer showing the flow behavior of the sample under test.

Using the conical stainless steel funnel as described in the current EP/USP monograph and use the changeable nozzles of 10, 15 and 25mm, the cone angle can also be tested. If smaller diameter nozzles are to be used, an adapter ring which allows the use of pouring nozzles from 4 to 10mm is available.

Up to 10 tests can be performed and used to calculate statistics including mean values of all selected test parameters. The data and results are displayed on the LC-display, presented as hard copy on the built-in printer or transmitted via RS-232 interface to any external data collection system.

Testing Smaller Volumes
For smaller volumes a 10ml funnel and a smaller sample collecting dish are available. This optional accessory can be used with pouring nozzles from 4 to 10mm diameter. A suitable stirring shaft completes the set.

The PTG-S4 Analysis
The PTG-S4 determines the following results:

  • Powder flow time of a pre-defined mass
  • Powder cone volume
  • Powder cone density
  • Cone angle (angle of repose according to EP [2.9.36], USP [1174])
  • Flowability of 100mg of product (according to EP/DAB [2.9.36], USP [1174])
  • Amount of sample (mg in a preset time)
  • Flow chart of sample (mg/time)

Instrument Qualification Program
The PTG-S4 features an in-built qualification program to:

  • Validate the angle measurement
  • Validate the timer
  • Set current time and date
  • Show actual firmware version installed

  • Fully USP [1174], EP [2.9.36] and ISO 4324 (12/83) compliant
  • Measure flow-time, cone angle, flowability, cone density and cone volume
  • PTG-ER stirrer included
  • Integrated analytical balance cell
  • Integrated dust protection bonnet
  • Built-in printer

  • Reduce process costs
  • Improve product consistency from batch to batch
  • Keep tight control of component powders, especially if they are natural products
  • Compare sources of powdered products
  • Provides an easy method to achieve quality control on bulk incoming component products
  • Provides an easy method for the control of dry and wet mixing, tableting, granulating, and capsule filling
  • Predict powder transport through conveyors, air lifts and in silos
  • Predict powder suitability for capsule and bottle filling
  • Predict product settling during transport, so called classification
  • Predict powder influence on tablet hardness and solid dosage form stability
  • Predict powder influence on tablet disintegration and friability
  • Integrated clear view dust protection dust protection hood

Technical Specifications

Data EntryAlpha-numerical keyboard and function keys
Product Data12 digit product code, 12 digit batch number
Cone VolumeApprox. 450ml
Cone MaterialStainless Steel
Range for Cone Angle Test1.0˚ to 65.0˚
Range for Flowability Test0.1 sec. to 999 sec. - mass: 100g
Range for Flow Time Test0.1 sec. to 999 sec.
Range for Cone Density0.000g/ml-1 to 6.0g/ml-1
Range for Cone Weight1mg to 325g
Range for Cone Volume0.1ml to 275ml
PrinterBuilt-in thermal printer or external parallel printer port
Instrument HousingStainless steel to meet GLP requirements
Instrument DimensionsApprox. 50cm x 55cm x 90cm (width x depth x height)
Packaging DimensionsApprox. 90cm x 67cm x 80cm (width x depth x height)
Net / Gross WeightApprox. 35 / 50 kg
CertificationAll components certified to USP / EP requirements
CE / EMC CertificationAll CE / EMC Certification provided
ValidationAll IQ & OQ documents included

We reserve the right to make technical changes without any prior notice.

Included in the Standard Supply Scope

The PTG-S4 comes ready to use with the following standard scope of supply:

  • PTG-ER stirrer
  • Integrated clear view dust protection hood
  • Integrated Sartorius balance cell
  • Integrated thermo printer
  • Pouring nozzles size 6, 8, 10, 15, 25mm
  • 600ml beaker
  • 30˚ angle calibration cone
  • Comprehensive documentation folder including:
    • User Manual
    • DQ/QC instrument compliance test certificate
    • IQ documentation
    • OQ documentation
    • Instrument logbook

Brochure PTG S4


In addition to the standard scope of supply Pharma Test offers a broad range of accessories and options including:

  • 10ml small volume test set, includes POM funnel, stirrer, sample collecting dish, validation cone
  • Hand scoop to fill in powder
  • Full range of certified validation tools available

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