Hardened Highly Pure Filter Papers for Qualitative Analysis

Hardened highly pure filter papers (ash content approx. 0.05%) with extremely high chemical and mechanical resistance, especially recommended for vacuum and pressure filtration, and for the use of acidic and alkaline solutions.

  • Made of super-refined cotton linters and cellulose
  • alpha-cellulose content above 95%, therefore high stability and durability
  • High wet strength; easy to scrap off or wash off precipitates, no fibre release
  • Hardened by small quantities of nitrogen-containing resin, which does not introduce significant impurities into the filtrate
  • Very low content of minerals (approx. 0.05% ash)
  • High resistance to aggressive chemical components, like sulphuric and nitric acids (up to 40% at 50° Celsius) and alkalis (up to 10% at 20° Celsius) and alkalis (up to 10% at 20° Celsius).

 

These filters are available as filter circles with the following sizes (in mm):

47 – 55 – 70 – 90 – 110 – 125 – 150 – 185 – 240.

Other sizes, sheets, rolls and special cuts are available on request.

Grade Properties Filtration Herzberg [s] Retention rate* [μm] weight [g/m²] Thickness [mm]
1573 fast 50 12 – 25 88 0,17
1574 medium 170 7 – 12 90 0,16
1575 slow 600 ** 2 90 <0,14
1577 slow 650 ** ≤ 2 81 0,12

* Approximate values ** Measured with 150 mm water column instead of 50 mm: