Medidor de densidade aparente
Medidor de densidade aparente – Método B da norma ASTM D1895
Volumétrico de densidade aparente
Aparelho de medição da densidade aparente
Equipamento de medição da densidade aparente
Medição da densidade aparente e medição da densidade a granel
ASTM D1895, Método B

Medidor de densidade aparente – Método B da norma ASTM D1895 - Bulk Density Determination:

Propósito

This procedure determines the apparent (bulk) density of plastic pellets, granules, or similar particulate materials that do not flow freely through the smaller funnel used in Method A. The result expresses the mass per unit volume of the material as poured under controlled conditions.

Aparelho

• QPI‑BDM1800B Bulk Density Meter, designed in accordance with ASTM D1895 Method B.

  • Funnel assembly: 25.4 mm (1 inch) orifice diameter, polished stainless steel.

  • Receiving cup: 400 cm³ capacity, precision‑machined for dimensional accuracy.

  • Support frame: rigid alignment between funnel and cup to ensure repeatable discharge geometry.

  • Leveling base: adjustable feet for horizontal alignment.

• Saldo: resolution ± 0.01 g.

• Sample conditioning tools: scoop, spatula, and brush for cleaning between runs.

Test Principle

Material is allowed to flow by gravity through the large‑diameter funnel into a calibrated receiving cup. The mass of the material filling the cup under these conditions is measured and divided by the cup volume to obtain the apparent density.

Procedimento

1. Preparation

   • Verify that the QPI‑BDM1800B is clean and dry.

   • Level the instrument using the adjustable feet and a spirit level.

   • Confirm that the funnel and cup are correctly aligned.

2. Sample Conditioning

   • Ensure the sample is at ambient laboratory temperature (typically 23 ± 2 °C).

   • Break up any agglomerates without altering particle shape.

3. Filling the Funnel

   • Close the funnel outlet with a flat plate or shutter.

   • Pour the sample into the funnel until it is approximately full, avoiding compaction.

4. Flow Initiation

   • Quickly remove the shutter to allow the material to discharge freely into the receiving cup.

   • Do not vibrate or tap the apparatus during flow.

5. Leveling the Cup

   • After flow ceases, strike off excess material flush with the rim using a straight edge.

   • Avoid compressing the sample.

6. Weighing

   • Weigh the filled cup to the nearest 0.01 g.

   • Subtract the mass of the empty cup to obtain the net sample mass.

7. Calculation

Report results to three significant figures.

8. Repetibilidade

   • Perform at least three determinations.

   • Average the results; the variation should not exceed ± 1 %.

Notes for Engineers

• The QPI‑BDM1800B’s large funnel minimizes bridging and ensures consistent flow for irregular or semi‑free‑flowing granules.

• For materials with poor flowability, gentle agitation of the funnel wall (not vibration) may be used to initiate discharge.

• Cleaning between tests prevents contamination and maintains dimensional accuracy.

• The instrument’s stainless‑steel construction provides thermal stability and corrosion resistance for long‑term laboratory use.

Result Interpretation

The measured bulk density reflects the packing behavior of the material under gravity alone. It is useful for:

• Process feed calibration in extrusion and compounding lines.

• Quality control of pellet uniformity.

• Comparative evaluation of resin blends and recycled materials.