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Ashless Filter Paper

Our Ashless Filter Papers our made under the strictest requirements of quality not only of the raw materials used but also of the conditions in which the production takes place. The Ashless filter paper grades are made with 100% cotton linter fibres. Cellulose fibres in their natural state contain small quantities of organic and inorganic impurities. As quantitative analysis requires a high purity, these papers have been washed out with acid and finally cleaned with demineralized water to provide an ash content of 0.007%. The papers also become highly resistant to the moist state. These standard Ashless grades are very pure filters suitable for routine quantitative gravimetric techniques and in the preparation of samples for use in analysis involving instrumental techniques. Because of all this, these filters are especially suitable for filtration with Buchner funnels in Quantitative Analysis since they meet the requirements of international standards with regards to Ash content. Johnson Test Papers offers a complete range of Ashless Quantitative Cellulose Filter Papers with a choice of pore size, filtration speeds, and filter thicknesses. They are available in different Filter sizes from small circle formats to large sheets. We can also make custom sized filters to meet your specific needs.


Click on a Grade to find out more...

Grade 351

- Very Slow Filtering
Application :

fine pores filter paper used for extremely difficult filtration conditions such as cold barium sulphate, metastannic acid, cuprouse oxide.

Grade 352

- Medium Filtering
Application :

Medium pore filter paper used foor fine precipiates, such as magnesium ammonium phosphate, calcium oxalate, magnesium ammonium arsenate, coarser forms of barium sulphate

Grade 353

- Medium fast filtering
Application :

Most commonly used grade for coarser precipitates such as lead, iron and silver sulphide, alcali carbonates, lad chromate, arsenic, antimony, cadmium, foodstuffs.

Grade 354

- Fast Filtering
Application :

Wide pore filter paper used for coarse and voluminous precipitates such as iron, aluminium and chromium hydrixides, Si-determination in steel and pig iron analysis.

Available Grades
Grade Whatman Equivalent Speed Thickness (mm) Pore Size (μM) Weight (g/m²) Filtration Speed (sec*) Burst Strength (kg/cm²)
351 = No.42 Very Slow Filtering 0.14 2-3 84 180 > 0.20
352 = No.40 Medium Filtering 0.16 5-8 84 50 > 0.20
353 = No.43 Medium fast filtering 0.17 8-12 84 20 < 0.20
354 = No.41 Fast Filtering 0.18 12-15 84 10 > 0.20