Yuelian PW-212 Cobb Absorbency Tester for Paper and Paperboard
| Brand | Yuelian / PW |
|---|---|
| Origin | Guangdong, China |
| Manufacturer Type | Authorized Distributor |
| Origin Category | Domestic (China) |
| Model | PW-212 |
| Pricing | Upon Request |
| Test Area | 100 ± 0.2 cm² |
| Specimen Area | 122.718 ± 0.2 cm² |
| Liquid Height | 10 mm (standard) |
| Water Volume | 100 ± 5 mL |
| Roller Length | 200 ± 0.5 mm |
| Roller Mass | 10 ± 0.5 kg |
| Cup Material | Full 304 stainless steel |
| Lid Material | Anodized magnesium-aluminum alloy (fully sealed, acid/alkali resistant) |
| Sealing Ring | Pure silicone |
| Lid Knob Sleeve | High-strength machined copper |
| Rotational Locking Mechanism | Copper alloy, wear-resistant |
| Dimensions (W × D × H) | 396 × 315 × 300 mm |
| Weight | 28 kg |
Overview
The Yuelian PW-212 Cobb Absorbency Tester is a precision-engineered instrument designed specifically for quantifying the surface liquid absorption behavior of paper and paperboard substrates under standardized conditions. It operates in strict accordance with the gravimetric Cobb method—a widely accepted physical test principle that measures the mass gain of a specimen after controlled contact with water for a defined duration (typically 60 or 120 seconds). This measurement directly reflects the degree of surface sizing, internal sizing uniformity, and overall hydrophobic barrier integrity of fibrous packaging materials. As such, the PW-212 serves as a critical quality control tool in paper mills, corrugated board converters, and packaging R&D laboratories where consistent moisture resistance is essential for printability, structural stability, and end-use performance.
Key Features
- Full 304 stainless steel cup construction ensures long-term corrosion resistance against repeated exposure to aqueous media and cleaning agents.
- Anodized magnesium-aluminum lid with full-seal design provides superior mechanical rigidity and chemical inertness—validated for compatibility with acidic and alkaline test solutions beyond standard water.
- Pure silicone sealing ring guarantees repeatable, leak-free interface between specimen and test cup across thousands of operational cycles.
- Machined copper knob sleeve and copper-alloy rotational locking mechanism deliver precise, backlash-free positioning and exceptional wear resistance over extended service life.
- Calibrated 10 kg roller with 200 mm length applies uniform, traceable pressure to ensure consistent specimen flattening and interfacial contact prior to immersion.
- Accurately defined test area (100.0 ± 0.2 cm²) and specimen cutout (122.718 ± 0.2 cm²) conform to dimensional tolerances specified in ISO 535 and GB/T 1540–2002, minimizing edge-effect variability.
Sample Compatibility & Compliance
The PW-212 accommodates standard sheet specimens measuring ≥ 150 mm × 150 mm, compatible with all common paper grades—including kraft linerboard, testliner, bleached and unbleached board, coated and uncoated offset papers, and food-grade packaging substrates. Its mechanical configuration satisfies the geometric and procedural requirements of ISO 535:2014, GB/T 1540–2002, and QB/T 1668–2012. When operated within documented SOPs—including pre-conditioning per ISO 187, calibrated analytical balance use (0.001 g resolution), and environmental control (23 ± 1 °C / 50 ± 2 % RH)—the system supports GLP-compliant data generation. While not intrinsically 21 CFR Part 11 certified, its deterministic mechanical operation and manual data recording workflow are fully auditable in regulated packaging QA environments.
Software & Data Management
The PW-212 is a manually operated, non-digital instrument; it does not incorporate embedded firmware, touchscreens, or automated data logging. All measurements are recorded externally using calibrated laboratory balances and standardized reporting templates. This architecture eliminates software validation overhead while preserving full traceability through handwritten or LIMS-integrated entry of specimen ID, ambient conditions, immersion time, initial/final mass, and calculated Cobb value (g/m²). Laboratories implementing electronic records may integrate PW-212 results into validated QMS platforms via structured CSV upload or direct API ingestion—provided metadata fields (operator, date/time, instrument ID, calibration status) are maintained per ALCOA+ principles.
Applications
- Verification of rosin, AKD, ASA, and starch-based sizing efficacy during paper machine optimization.
- Comparative evaluation of surface treatments (e.g., plasma, corona, or coating) on recycled fiberboard.
- Batch release testing for pharmaceutical cartons requiring compliance with USP moisture barrier specifications.
- Troubleshooting delamination or blistering in laminated packaging structures.
- Research into nanocellulose-reinforced barriers and bio-based hydrophobic coatings.
- Supplier qualification audits where Cobb values serve as contractual KPIs for moisture resistance.
FAQ
What standards does the PW-212 comply with?
ISO 535:2014, GB/T 1540–2002, and QB/T 1668–2012.
Is the instrument supplied with calibration documentation?
Yes—each unit ships with a factory-verified dimensional certificate covering test area, specimen area, roller mass, and liquid volume tolerances.
Can the PW-212 be used with liquids other than water?
Yes—its chemically resistant materials support testing with glycerol/water mixtures, ethanol solutions, or pH-adjusted aqueous media, provided safety protocols and material compatibility are verified.
What maintenance is required?
Routine cleaning with deionized water and soft lint-free cloths; periodic inspection of silicone seal integrity and copper mechanism lubrication per manufacturer’s maintenance schedule.
Does the system include sample cutting dies or balances?
No—these are specified as optional accessories; users must supply ISO-compliant circular cutters (Ø125 mm) and analytical balances meeting OIML R76 Class I requirements.
