Freeness Converter: CSF (mL) ↔ Schopper-Riegler (°SR)

Freeness Converter: CSF (mL) ↔ Schopper-Riegler (°SR)

Refining degree is read two ways: Canadian Standard Freeness in mL (ISO 5267-2 / TAPPI T227) and Schopper-Riegler in °SR (ISO 5267-1). They move inversely — more refining lowers CSF while it raises °SR. This tool gives an engineering approximation for quick cross-reading; always confirm against a bench test.

Typical grade targets

Grade	Approx. °SR	Approx. CSF mL
Tissue	20–40	~700–450
Printing & writing	30–45	~500–350
Packaging / liner	35–50	~450–300
Greaseproof / glassine	80–90	~90–40

Approximation only. A calibrated CSF tester discharges 880–890 mL on a distilled-water check at 20 °C; the 300–500 mL range shows the most lab-to-lab variation. For furnish-specific freeness targeting, request a plate-pattern recommendation from Henan Zejiang Paper Machinery.