GBPI W812 – Gravimetric Water Vapor Permeability Analyzer (Cup Method)
- High-throughput 12-station gravimetric method water vapor permeability analyzer for barrier films, sheets, and paperboards
- Full testing compliance with ASTM E96 (Desiccant & Water Methods), ISO 2528, DIN 53122-1, ASTM D1653, and GB/T 1037
- Broad testing range from 0.05 to 10,000 g/(m²·24h) with balance resolution of 0.0001 g/(m²·24h)
- High-precision automated weighing system with internal 0.1 mg analytical balance (0.01 mg optional)
- 12 independent rotating test stations enabling rapid high-volume testing cycles without manual intervention
- Automated environmental control from 10 °C to 50 °C (±0.1 °C) and 5% to 90% RH (±2% RH)
- Supports both weight-gain (desiccant) and weight-loss (water) gravimetric permeation testing modes
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The GBPI W812 is an advanced, automated gravimetric water vapor permeability analyzer engineered for high-throughput cup method moisture transmission testing of plastic films, barrier sheeting, paper, cardboard, textiles, and composite packaging materials. Built in full conformance with standardized gravimetric protocols including ASTM E96, ISO 2528, DIN 53122-1, ASTM D1653, and GB/T 1037, this multi-station instrument provides packaging testing laboratories with primary, direct gravimetric measurement accuracy.
The cup method represents the historical and universally accepted referee benchmark for moisture barrier evaluation. The GBPI W812 gravimetric water vapor permeability analyzer operates by establishing a constant vapor pressure difference across the test specimen sealed onto a specialized permeation cup containing desiccant (weight-gain method) or distilled water (weight-loss method). As water vapor diffuses through the specimen under precisely regulated temperature, humidity, and airflow velocity conditions, the system automatically indexes each cup to an internal high-precision analytical balance at scheduled intervals, recording weight variations over time to establish a linear steady-state transmission slope.
Twelve-Station High-Throughput Rotary Chamber
Unlike conventional manual cup testing that demands labor-intensive weighing and opens testing chambers to ambient fluctuations, the GBPI W812 houses twelve automated testing stations within an insulated, environmentally sealed test chamber. A computer-controlled Geneva mechanism smoothly positions each test dish onto the internal electromagnetic balance without disturbing the internal micro-climate or interrupting test conditions.
Precision Weighing & Thermal Fluid Control
Equipped with an internal 220 g analytical balance with 0.1 mg graduation (expandable to 0.01 mg), the system guarantees repeatable micro-mass readings. The testing environment features circulating horizontal airflow with adjustable velocities from 0.3 to 2.5 m/s, paired with thermal control spanning 10 °C to 50 °C (±0.1 °C) and humidity regulation between 5% and 90% RH.
The system is managed through dedicated PC control software that automates intermittent weighing sequences, calculates real-time WVTR values, plots weight-versus-time curves, and exports standardized test certificates with full audit trail compliance.
GBPI W812 Gravimetric Cup Method WVTR Analyzer – Technical Specifications
| Technical Parameter | Specification Details |
|---|---|
| Testing Principle | Gravimetric Cup Method (Weight Gain / Weight Loss Method) |
| Applicable Standards | ASTM E96, ISO 2528, DIN 53122-1, ASTM D1653, TAPPI T464, GB/T 1037 |
| Testing Range | 0.05 ~ 10,000 g/(m²·24h) |
| Measurement Resolution | 0.0001 g/(m²·24h) |
| Number of Test Stations | 12 automated rotating test stations |
| Integrated Balance Capacity & Precision | 220 g range; 0.1 mg graduation (0.01 mg high-sensitivity balance optional) |
| Temperature Control Range | 10 °C ~ 50 °C (±0.1 °C accuracy) |
| Humidity Control Range & Accuracy | (5 ~ 90)% RH (±2% RH accuracy) |
| Chamber Wind Speed | 0.3 ~ 2.5 m/s (Standard); 0.03 ~ 0.5 m/s (Optional) |
| Effective Permeation Area | 33 cm² per test dish |
| Specimen Dimensions | Φ74 mm diameter; Specimen thickness ≤ 3 mm |
| Gas Source Requirement | Clean compressed air; Gas pressure ≥ 0.6 MPa |
| Dimensions & Net Weight | 830 mm × 670 mm × 440 mm; 75 kg |
| Power Supply & Rating | AC 220 V ±10%, 50 Hz; Rated Power: 800 W |
Key Features & Engineering Innovations
- 12 Independent Automated Test Dishes: High capacity rotary carrousel allows simultaneous testing of up to 12 dishes, drastically reducing multi-day testing cycles.
- Internal Automatic Indexing Balance: Eliminates human error and thermal disruption by automatically weighing each cup inside the sealed testing chamber without opening doors.
- Broad Measurement Dynamic Range: Spanning 0.05 to 10,000 g/(m²·24h), easily testing everything from high-barrier films to breathable textiles and non-wovens.
- Dual Desiccant & Water Methods: Accommodates standard cup testing under dry desiccant absorption (water vapor absorption) or wet cup evaporation (water loss).
- Precision Wind Flow Control: Regulated laminar airflow velocities (0.3 to 2.5 m/s) comply strictly with ASTM E96 standard boundary layer specifications.
- Intelligent PC Software Analytics: Automated steady-state recognition, automatic weight curve slope regression, and GMP compliant data auditing.
Standard Scope of Delivery
| Item | Description | Quantity |
|---|---|---|
| 1 | GBPI W812 Gravimetric WVTR Analyzer (12 Test Stations) | 1 Unit |
| 2 | Integrated 0.1 mg High-Precision Analytical Balance (Internal) | 1 Set |
| 3 | Standard Stainless Steel Permeation Test Cups | 12 Pcs |
| 4 | Precision Specimen Punch Template (Φ74 mm) & Cup Sealing Ring | 1 Set |
| 5 | GBPI Gravimetric Data Acquisition and Curve Analysis Software | 1 License |
| 6 | Standard Calibration Weight (Class F1) & Communication Cables | 1 Set |
Standard Compliance
- ASTM E96 / E96M: Standard Test Methods for Water Vapor Transmission of Materials (Desiccant Method and Water Method)
- ISO 2528: Sheet materials — Determination of water vapour transmission rate — Gravimetric (dish) method
- DIN 53122-1: Testing of plastics and elastomers — Determination of water vapour transmission rate — Part 1: Gravimetric method
- ASTM D1653: Standard Test Method for Water Vapor Transmission of Organic Coating Films
- TAPPI T464: Water vapor transmission rate of paper and paperboard at high temperature and humidity
- GB/T 1037: Test method for water vapor transmission of plastic film and sheet — Cup method
Target Materials
- Barrier Films & Sheets: PE, PP, PET, biodegradable PLA, and multilayer barrier structures.
- Paper & Paperboard: Coated paper packaging, corrugated paperboard, and barrier liner boards.
- Textiles & Nonwovens: Waterproof breathable fabrics, medical protective garments, and geotextiles.
- Construction & Building Foils: Vapor barrier membranes, roofing underlayments, and insulation materials.