Powder loose packing density meterIt is a precision instrument used to determine the mass per unit volume of powders or particles in their natural accumulation state, widely used in fields such as powder metallurgy, chemical engineering, pharmaceuticals, food processing, battery materials, etc. It is based on the principle that materials naturally fill standard measuring cups under the action of gravity in a free flowing state. The material falls freely into the measuring cup through the funnel, and after filling, the excess material is scraped flat with a scraper. After weighing the mass of the material in the measuring cup, the loose density (unit: g/cm ³ or kg/m ³) is calculated by the ratio of mass to volume.
Powder loose packing density meterOperation steps:
1、 Preparation work
Instrument inspection
Confirm that the funnel, measuring cup, balance, scraper and other components are clean and dry, with no residual powder.
Check whether the funnel aperture (such as 2.5mm or 5.0mm) and measuring cup volume (such as 25ml ± 0.03ml) meet the standards.
Adjust the instrument level to ensure stable placement and keep it away from vibration sources.
Powder pretreatment
According to the characteristics of the powder (such as easy moisture absorption and oxidation), it should be dried or treated with inert gas protection.
For powders that are prone to bridging or have strong adhesion, a soft bristled brush or vibrator can be used in advance to assist in flow.
2、 Fill powder
bucket fill
Scott volumetric method: Pour the powder into the sieve of the upper combination funnel, and flow it into the measuring cup through the fabric box and square funnel.
Standard funnel method: Block the funnel outlet with your fingers, fill the powder into the funnel, and release your fingers to allow the powder to fall freely into the measuring cup.
Vibration funnel method: Start the vibration device, adjust the amplitude (such as 100 ± 15 μ m) and frequency (such as 100Hz), so that the powder flows evenly into the measuring cup.
Control the filling amount
Stop filling when the measuring cup is full and the powder overflows.
Avoid compressing or removing powder from the measuring cup to ensure a stable filling process.
3、 Scraping and compacting
Scrape the surface flat
Use a non-magnetic ruler or scraper to scrape off excess powder at a 45 ° angle along the top of the measuring cup, ensuring a smooth surface.
Avoid squeezing or vibrating the measuring cup during operation to prevent changes in powder density.
Lightly tap and compact
After scraping flat, gently tap the measuring cup to make the powder slightly compacted, avoiding powder loss when moving.
Ensure that there is no residual powder on the outer wall of the measuring cup to prevent weighing errors.
4、 Weighing and Calculation
Weigh the mass of the powder
Pour the powder from the measuring cup into a clean container, weigh it with a high-precision balance (accuracy ± 0.01g), and record the mass (m).
Repeat the measurement three times and take the average to improve accuracy.
Calculate loose packing density
Calculate the loose density according to the formula ρ=m/V, where:
ρ: Loose density (g/cm ³)
m: Powder mass (g)
V: Measuring cup volume (cm ³, such as 25cm ³)
Keep the result to two decimal places (e.g. 0.01g/cm ³).
5、 Cleaning and maintenance
Clean the instrument
Use a soft bristled brush or vacuum cleaner to clean the funnel, measuring cup, and workbench to prevent powder residue.
For easily corrosive powders, wipe the parts with specialized cleaning agents to avoid rusting.
periodic calibration
Check whether the funnel aperture and measuring cup volume are worn, and replace the components if necessary.
Regularly calibrate the balance with standard weights to ensure weighing accuracy.
6、 Precautions
Powder characteristic adaptation
For powders with poor flowability (such as sub sieve grade powders), vibration funnel method or Scott volumetric method should be preferred.
Avoid using easily broken powders (such as agglomerated particles, fibrous powders) for vibration testing.
environmental control
Maintain stable laboratory temperature (e.g. 20-25 ℃) and humidity (e.g. ≤ 65%) to reduce the impact of environmental factors on measurement results.
Stay away from airflow interference to prevent powder from flying and affecting weighing.
Operating Specifications
When smoothing the powder, ensure that the ruler or scraper is non-magnetic and free of static electricity to avoid adsorbing the powder.
In the vibration funnel method, the cup holder and vibration device need to be isolated to prevent vibration transmission from affecting the results.