The MPPA Standards Committee has approved a new test method standard for measuring the flow rate of non-free-flowing metal powders using the Carney flowmeter funnel. To date, no Carney funnels have been calibrated for testing flow rate—they have only been supplied for testing the apparent density of non-free flowing metal powders. However, the MPPA Standards Committee has recently approved a standard calibration powder to be used to calibrate Carney funnels. The new calibration powder is a 316L stainless steel screen cut that was tested extensively for stability and repeatability of flow time over an extended period of drying and testing. A master Carney flowmeter funnel has been set aside at Kymera International. The flow time for 150 g of the calibration powder to flow through the master funnel is 31.0 seconds.
Kymera International has 200 g quantities of this standard calibration powder available for purchase. The next step in the development of the Carney flow test method is for companies to acquire this standard calibration powder to check the flow time for the calibration powder through their Carney flowmeter funnels—a new funnel should have a flow time of 31.0 ±0.5 s for 150 g of the powder. Funnels with a flow time of less than 28 s are invalid. The MPPA Standards Committee will be coordinating an interlaboratory test program in 2022 in conjunction with ASTM Committee B09 on Metal Powders and Metal Powder Products to determine the precision of the Carney flow rate test method. A valid flowmeter funnel will be required for participation in the study.
The standard calibration powder is available from Kymera International. Additional details are available at www.kymerainternational.com.