Density / TAP density

The density of a body is basically defined as the ratio of its mass m to its volume V. Depending on the application or further processing, various “density properties” are of interest for powders, including:

• True density: Density of a substance that only takes into account the material content, i.e., without the volume of any cavities that may be present; determined for solids using gas pycnometry (DIN 66137-2:2004-12)
• Bulk density: Density of a mixture of a powdery or granular material and a medium (usually air) that fills the spaces between the bulk material; determined using standardized bulk density measuring devices.
• Tap density: Density of a filled powder that has been compacted by (usually defined) tapping or vibration (DIN EN ISO 787-11); determined using tap density testers equipped in accordance with the standards

Closed cell content is a parameter that is particularly important in foam materials: it indicates the proportion of bubble-shaped polymer cells in such a material that are completely closed.

True density- Gas pycnometry

In gas pycnometry, a known sample vessel volume and an inert measuring gas (usually helium) are used to determine the volume displaced by the sample to be measured (powder, solid). The pure density is calculated from the previously determined sample weight. 3P Instruments offers two device series depending on the application:

BetterPyc 380 series Density gas pycnometer (DIN 66137-2:2004-12) Measuring cell volume: 10 – 100 cm3 Fully automatic, operated via PC and SOP-based software	3P densi series Density gas pycnometer (DIN 66137-2:2004-12) Measuring cell volume: 1 – 100 cm3 Fully automatic, touchscreen operation

Bulk density

The bulk density of a material is determined using different setups defined in the relevant standards, depending on the industry. 3P Instruments offers the following systems:

BeDensi B1 Bulk density determination of non-metallic powders Compliant with GB/T 16913	BeDensi B1-S Scott volumeter for determining the bulk density of metal powders and granulates Compliant with ISO 3923-2, ASTM B329-14	BeDensi P Bulk density determination of powders in the field of polymers and molding compounds Compliant with ISO 60	HFlow-1 Bulk density and flowability determination for pharmaceutical and metal powders available as Hall, Carney, and Gustavsson models Compliant with ISO 4490, ASTM B213-13

Tap density

The tap density of a powder or granulate is determined according to industry-specific conditions defined in the relevant standards. 3P Instruments offers the BeDensi T Pro series devices with a choice of 1, 2, or 3 measuring cylinders:

BeDensi T Pro series Determination of the tap density of powders or granulates TAP speed: 100–300 taps/min Compliant with DIN EN ISO 787-11; USP <616>; Ph.Eur.2.9.34; ASTM D7481; ASTM B527, among others

Closed cell content – Gas pycnometry

The closed cell content of a foam material is determined using gas pycnometry, whereby a sample of known geometric volume is tested for its “closed” volume using an inert measuring gas (usually helium). In principle, the closed cell content is then calculated from the ratio of closed to geometric volume. 3P Instruments offers two device series depending on the application:

BetterPyc 380 series Closed cell content with gas pycnometry (DIN ISO 4590) Measuring cell volume: 10 – 100 cm3 Fully automatic, operated via PC and SOP-based software	3P densi series Closed cell content with gas pycnometry (DIN ISO 4590) Measuring cell volume: 1 – 100 cm3 Fully automatic, Touchscreen operation