Plan a trial for your application
Water-soluble adhesives
At fixed solids and drying conditions, compare tack, dry film strength and undissolved particles.
Film formation and sizing
At equal film thickness, record coating behavior, dry film water uptake and adhesion.
| Form or grade | Suitability and verification |
|---|---|
| Partially hydrolyzed | Verify dissolution and adhesion at the actual temperature for the degree of hydrolysis and polymerization. |
| Highly or fully hydrolyzed | Confirm dissolution procedure, water resistance and film-forming characteristics. |
Purchase specifications and incoming inspection
Include the intended grade or current specification in the enquiry. Use the table to compare selection criteria and inspection conditions. The specification agreed by both parties defines the contractual limits. Kuraray · PVOH grades and measurement conditions ↗
| Property | Unit | Published or agreed specification | Test conditions and checks |
|---|---|---|---|
| Aqueous solution viscosity | mPa·s | Request a separate range for the offered grade. | Kuraray compares grades in a 4% aqueous solution at 20 °C. Request concentration and method on the COA. |
| Degree of hydrolysis | mol % | Confirm whether fully or partially hydrolyzed. | Request the result for the grade concerned. Compare the reference and production material on the same basis. |
| Nonvolatile content | % by mass | Confirm for the PVA grade under evaluation. | Calculate adhesive mix proportions on a dry basis and note drying temperature and duration. |
When approving a sample, record the grade, methods, limits and specification revision. On receipt, match the packing lot number to the lot-specific COA and record the measured values and release decision.
From samples to commercial delivery
Packaging and receiving
Specify particle size, moisture protection and net weight for powder or granules. Sample and commercial bags must identify the same degree of hydrolysis.
Storage and handling
Request the dissolution conditions. Viscosity code alone does not establish equivalence between fully and partially hydrolysed grades.
Sample and order lead times
State processing equipment, trial batch size and monthly demand. Confirm same-grade samples, first-order MOQ, staged deliveries and arrival date.
Questions from the plant
Why did dissolution time change on switching to another PVA of the same viscosity grade?
Compare clarity, gel particles and dry film using the current dissolution process.
What should we check when clear gel particles remain in the mixing vessel?
Check degree of hydrolysis, particle size and dissolution records. Measure filter residue and viscosity at the specified concentration.
Report a delivery or batch issue
Include the order number, lot number from the package, label photos and inspection records for the affected lot. When retesting, check Degree of hydrolysis, solution viscosity and test conditions, residual volatiles.
Request documents for your application
TDS · Technical data sheet
For grade selection and sample approval, specify the grade and revision required.
SDS · Safety data sheet
Specify the country or region of use and the required language.
COA · Certificate of analysis
Request a sample COA during supplier review. For incoming inspection, provide the actual lot number.