ZKMD-18798c Portable Bulk Density Tester for Instant Tea (Free-Flowing Powders)

Overview

The ZKMD-18798c Portable Bulk Density Tester is a purpose-engineered instrument designed to determine the bulk density of free-flowing, dry particulate materials—specifically optimized for instant tea granules, soluble coffee powders, powdered dairy blends, and other hygroscopic food-grade powders. It operates on the principle of gravitational settling and volumetric displacement: a known mass of dried sample is gently poured into a calibrated cylindrical cup under standardized conditions (controlled height, funnel geometry, and orifice diameter), allowed to settle freely without vibration or compaction, and the resulting volume is measured to calculate bulk density (g/mL or kg/m³). Unlike true density testers that rely on gas pycnometry or liquid displacement, this instrument measures *apparent* or *loose* bulk density—the critical parameter governing flowability, packaging efficiency, dosing accuracy, and reconstitution behavior in industrial food processing lines.

Key Features

• Portable, benchtop-ready design with integrated calibration cup (25 mL nominal volume) and precision stainless-steel funnel assembly compliant with GB/T 4676 and ASTM D1895–22 geometry specifications.
• Non-destructive, operator-independent measurement protocol minimizing inter-user variability—no tapping, vibration, or manual consolidation required.
• Pre-calibrated mass balance interface (compatible with external analytical balances up to 0.001 g resolution) ensures traceable mass input per test cycle.
• Dust-resistant housing and smooth-surface cup facilitate rapid cleaning between samples—critical for cross-contamination control in multi-product QA labs.
• No electrical power requirement for core measurement function; optional battery-powered digital display module available for field use.
• Designed for ambient temperature operation (15–30°C) and relative humidity ≤60% RH to maintain sample integrity during testing.

Sample Compatibility & Compliance

The ZKMD-18798c is validated for free-flowing, non-cohesive, dry particulates with particle size distributions typically ranging from 100 µm to 2 mm. Instant tea granules—produced via spray-drying or agglomeration—fall within this operational envelope when conditioned to ≤5% moisture content (as verified per GB/T 8304 or AOAC 925.09). Sample preparation strictly follows GB/T 4676: representative sampling, homogenization, and drying at 110°C for 1 hour followed by desiccator cooling to ambient temperature prior to testing. The instrument supports GLP-aligned documentation workflows; raw data (mass, volume, calculated density) can be recorded manually or linked to LIMS via external balance output (RS-232/USB). While not certified for regulatory submission per se, its methodology aligns with ISO 60:2023 and ASTM D1895–22, enabling comparability across international R&D and QC laboratories.

Software & Data Management

The ZKMD-18798c operates as a hardware-only platform—no embedded firmware or proprietary software is included. This architecture eliminates validation overhead associated with electronic records and ensures full compliance with FDA 21 CFR Part 11 when used in conjunction with validated external balances and documented manual entry procedures. Users may integrate results into existing ELN or LIMS systems using standard CSV export from connected balances. Audit trails, user authentication, and electronic signatures are managed at the enterprise software level—not at the instrument layer—supporting GMP-compliant environments where instrument simplicity and procedural transparency are prioritized over automation.

Applications

• Quality control of instant tea manufacturing: monitoring batch-to-batch consistency in granule morphology and flow behavior.
• Formulation development: evaluating excipient compatibility and drying process impact on powder density and dissolution kinetics.
• Packaging line optimization: correlating bulk density with fill volume accuracy and headspace management in stick-packs or sachets.
• Supplier qualification: verifying incoming raw material density against agreed technical specifications (e.g., 0.35–0.48 g/mL for agglomerated green tea extract).
• Research on reconstitution performance: linking low bulk density to improved wettability and reduced clumping in hot water.

FAQ

Is this instrument suitable for measuring tapped density?
No—the ZKMD-18798c is specifically configured for *free-flowing* (loose) bulk density only. Tapped density requires mechanical vibration per ASTM D4781 or USP <616>; a separate tap density tester is recommended.
Can it be used for wet or high-moisture powders?
No. Samples must be dried to ≤5% moisture content prior to testing, as specified in GB/T 4676 and confirmed via orthogonal methods (e.g., XFSFY-50A moisture analyzer). Hydration alters particle cohesion and invalidates free-flow assumptions.
Does it comply with ISO/IEC 17025 requirements?
The instrument itself is not accredited, but its test method (per GB/T 4676 + ASTM D1895) is technically validatable. Laboratories may include it in their scope of accreditation when paired with calibrated balances, documented SOPs, and uncertainty budgets.
What maintenance is required?
Annual verification of cup volume (via water displacement at 20°C) and funnel orifice diameter (with optical comparator) is recommended. No routine calibration certificates are issued—users perform in-house verification per internal SOPs.