Macherey-Nagel MN GF-3 round glass fibre filter, binder-free, 0.6 µm (Ø 25 mm – 270 mm)

Macherey-Nagel MN GF-3 glass fibre circular filters represent a materials science-optimised and extremely high-performance system solution for demanding clarification, ultra-fine filtration and sample preparation in day-to-day laboratory work. Available in a wide range of diameters, from 25 mm for smaller syringe-top systems up to large-area 270 mm for high-volume funnel filtration, this filter series covers all scales of modern analytical work. Whether for the process-related monitoring of environmental parameters, the precise determination of suspended solids in wastewater analysis or biochemical separation processes, the structural purity of the filter medium is the primary criterion for ensuring gentle handling of materials, contamination-free operation and process reliability.

Maximum retention and filtration kinetics thanks to binder-free borosilicate

The technological foundation of the MN GF-3 filters is based on pure borosilicate glass fibres, which are processed into a homogeneous non-woven fabric entirely without any organic or inorganic binders. This mechanical structure achieves an extremely fine nominal retention capacity of 0.6 µm (micrometres). Despite this high retention rate for the finest precipitates and microparticles, the three-dimensional depth filtration structure is characterised by an excellent fluid-mechanical flow rate (filtration time) and a remarkable loading capacity. The risk of transient filter clogging (blockage of the flow path) in highly particulate-laden sample media is significantly minimised compared with conventional membrane filters.

Universal chemical inertness and extreme thermal stability

From a chemical perspective, the pure glass fibres are completely inert towards a wide range of highly aggressive media, organic solvents, acids and alkalis (with the exception of hydrofluoric acid and highly concentrated, hot alkalis). The non-porous surface structure of the fibres prevents irreversible adsorption effects of sample components and ensures excellent gravimetric stability. An invaluable advantage for thermal analysis: the filters remain absolutely dimensionally stable and biochemically unchanged up to a temperature of 500 degrees Celsius. This allows for the reliable ashing of filter residues or intensive hot-air sterilisation cycles in a drying oven.

Validated standards for standards-compliant environmental analysis

The infrastructural validity of the MN GF-3 round filters is particularly evident in their suitability for standardised test procedures. The quality is perfectly tailored to the demanding determination of filterable substances (suspended solids) in water and wastewater in accordance with the European standard DIN EN 872. For laboratory managers and quality management officers in a regulated environment, this compliance with standards provides a reliable basis for validation, ensuring that regulatory audits under GLP and GMP guidelines are passed with confidence.

Technical details

Material Science & Filter Structure

• Filter type: Glass fibre depth filter / circular filter
• Material composition: 100 per cent purest borosilicate glass fibres
• Binder status: 100 per cent binder-free (free from organic additives)
• Nominal retention capacity: 0.6 µm (micrometres)
• Basis weight: approx. 50 g/m² (grams per square metre)
• Filter thickness: approx. 0.28 mm (millimetres)

Dimensions & scalability

• Available diameter range: 25 mm to 270 mm
• Common intermediate sizes in the range: 25 mm, 37 mm, 45 mm, 47 mm, 55 mm, 70 mm, 90 mm, 110 mm, 125 mm, 142 mm, 150 mm, 185 mm, 240 mm, 270 mm
• Cutting: Geometrically precise, fibre-free circular cut

Resilience & kinetics

• Thermal resistance: Up to 500 degrees Celsius (completely non-flammable)
• Chemical resistance: Universally inert to organic solvents, acids and typical laboratory chemicals
• Filtration rate: Very fast whilst maintaining high particle retention
• Sterilisability: Fully autoclavable (up to 121 degrees Celsius) and suitable for hot-air sterilisation

Standards & Compliance

• Environmental analysis: Ideally suited for the determination of suspended solids in accordance with DIN EN 872
• Quality management: Supports residue-free gravimetric analyses in accordance with GLP guidelines

Contents

• 1 x pack of Macherey-Nagel glass fibre round filters, grade MN GF-3 (standard contents: 100 pieces per box) in the diameter selected by the customer (25 mm to 270 mm).

Individual requirements & accessories

To ensure the optimal integration of Macherey-Nagel glass fibre filters into your daily analytical routine, we stock a comprehensive range of complementary laboratory equipment. For traditional vacuum or Büchner filtration, we offer suitable porcelain Büchner funnels, robust suction flasks made of borosilicate glass, and complete multi-vacuum filtration units. For gentle, contamination-free handling of wet or dry filter discs, our range includes flat-tipped filter tweezers made from high-alloy stainless steel. For subsequent drying until a constant weight is achieved, we also offer chemically inert desiccators and Petri dishes. Please make use of our technical procurement service to design your filtration workstations to suit your specific requirements.