Whatman 989810112 Grade 4 125mm PYRAMID 1000/Pk
Whatman SKU: 989810112

Qualitative Filter Paper - 989810112

Gravity filtration methods for removing suspended solids require filter paper that seats cleanly in funnels and retains particles consistently. Standard basis weight specifications provide predictable filter packing density for volumetric displacement calculations in funnel assemblies. In turn, from fiber selection through final inspection, the manufacturing process ensures every sheet meets the performance specifications of its grade.

Key Filter Paper Characteristics

• Particle retention rating of 25um defines the separation threshold for the application, determining which solids are captured and which pass through.
• Non-hardened cellulose delivers the flow rates and retention that routine methods require at practical cost per determination.
• Untreated cellulose provides the natural wicking and absorption properties that gravity filtration methods utilize.
• Wet strength sufficient for gentle handling during precipitate transfer while maintaining the rapid flow rates of qualitative grades.
• Medium porosity cellulose matrix captures suspended solids while maintaining the throughput needed for efficient batch processing.

Scaling your method from development to routine production requires paper consistency at every lot, and the specifications above provide that assurance. In these cases, consistent sheet-to-sheet performance reduces the variability your operators encounter during high-volume daily filtration workflows. Make the decision for consistency and reliability, ensuring that your laboratory maintains its reputation for high-quality, error-free output.

Diameter

125mm

Flow Speed

Fast

Folded/ Fluted/ Pleated

Yes

Grade

4

Hardened (Yes/ No)

No

Material

Cellulose Fiber

Nominal Ash Content (%)

0.06%

Nominal Basis Weight (g/ m²)

92g/m²

Particle Retention

25um

Qualitative/ Quantitative

Qualitative

Sterility

Nonsterile

Wet Strengthened (Yes/ No)

No

Wettability

Hydrophilic

• General Clarification - Removes suspended solids from aqueous solutions by gravity filtration for routine sample preparation.
• Teaching Laboratory - Provides consistent and economical filtration media for student exercises in analytical and general chemistry.
• Precipitation Recovery - Collects insoluble reaction products on the paper surface for subsequent washing and downstream analysis.
• Enzyme Clarification - Removes particulates from enzyme solutions before activity assays in biochemistry and industrial testing.
• Pigment Screening - Separates undispersed colorant particles from coating formulations during color development and QC testing.
• Paint and Coatings QC - Removes gels and undispersed pigment from coating samples prior to color measurement and viscosity testing.