Superabsorbent Polymer (SAP) Testing Methods
Independent SAP testing to support confident material decisions.
Whether you are qualifying a new supplier, comparing SAP materials, or investigating a performance difference, get the objective data you need to move forward.
Included Tests
Controlled comparison of raw and recovered SAP across key performance properties:
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Free Swell Capacity (FSC) -- Raw & Recovered
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Centrifuge Retention Capacity (CRC) -- Raw & Recovered
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Absorption Against Pressure (AAP, 0.3 & 0.7 psi) -- Raw & Recovered
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Moisture Content -- Raw only
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pH -- Raw only
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Polymer Vortex Speed -- Raw only
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Controlled recovery of SAP from finished product
SAP Test Methods
Absorption & Retention
NWSP 240.0 — Free Swell Capacity (FSC)
Determines the amount of saline solution absorbed by a superabsorbent polymer under free-swelling conditions, without an applied load.
NWSP 241.0 — Centrifuge Retention Capacity (CRC)
Determines the amount of saline solution retained by a superabsorbent polymer following centrifugation.
NWSP 242.0 — Absorption Against Pressure (AAP)
Determines the amount of saline solution absorbed by a superabsorbent polymer under a specified applied pressure.
Available applied loads:
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0.7 psi: Standard applied pressure per NWSP 242.0.
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0.3 psi: Modified applied pressure available upon request.
NWSP 243.0 — Permeability Dependent Absorption Under Pressure (PDAUP)
Determines the absorption capacity of a superabsorbent polymer under applied pressure, where permeability is a significant controlling factor.
Absorption Time
APS-108 — Polymer Vortex Speed (PVS)
Determines the time required for superabsorbent polymer to absorb saline solution and form a gel, as indicated by the disappearance of the vortex.
Physical Characterization
NWSP 220.0 — Particle Size Distribution (PSD)
Determines the particle size distribution of superabsorbent polymer using sieve shaking.
NWSP 230.0 — Moisture Content
Determines the moisture content of superabsorbent polymer by measuring mass loss upon heating.
NWSP 200.0 — pH
Determines the pH of a saline solution containing superabsorbent polymer.
NWSP 251.0 — Bulk Density & Flow Rate
Determines the bulk density and mass flow rate of superabsorbent polymers.
Testing requirements and applicable method references are confirmed during project review.
Deliverables
Comparative report with side-by-side raw and recovered SAP results and performance assessment notes highlighting notable observations
