Macherey-Nagel MN 85/90 BF round glass fibre filter, binder-free, 0.5 µm (Ø 5 mm – 270 mm)

Macherey-Nagel MN 85/90 BF glass fibre round filters represent a high-purity, matrix-stable system solution for demanding filtration processes, gravimetric analyses and the highly efficient separation of ultrafine particles in laboratories, environmental analysis and industrial quality control. Manufactured from 100% pure borosilicate glass fibres without any organic or inorganic binders (BF=binder-free), these depth filters guarantee absolute chemical inertness and contamination-free analytical results. The wide range of available diameters, from a delicate 5 mm up to a large-area 270 mm, enables perfect scalability for all standard Nutsch, extraction and micro-weighing equipment.

Material-science purity and binder-free structure

The process-engineering heart of the MN 85/90 BF filters is their binder-free fibre architecture. As no chemical additives or acrylic resins are used at all during manufacture, the filter matrix remains absolutely stable even when filtering highly aggressive organic solvents, strong acids or alkaline media. Any leaching of foreign substances from the material into the filtrate – which could interfere with sensitive downstream detection methods (such as HPLC, GC or ion chromatography) – is reliably prevented in a manner that is gentle on the material and ensures process reliability. Furthermore, the high purity of the borosilicate fibres ensures complete biological inertness, which makes them ideal for use in microbiology and cell culture filtration.

Excellent retention capacity and outstanding fluid dynamics

With a nominal retention capacity of 0.5 µm in liquid media, these glass fibre filters are ideally suited for the separation of the finest precipitates, colloidal suspensions and proteins. The three-dimensional depth filter structure not only traps particles on the surface but also traps them within the fibre mesh. This results in an exceptionally high dirt-holding capacity and prevents premature clogging of the filter, even with samples containing high levels of matrix material such as wastewater, slurries or extracts. At the same time, excellent flow rates are achieved, which significantly reduces filtration times in multi-user operation.

Extreme thermal resilience and versatile environmental analysis

From a thermodynamic perspective, the MN 85/90 BF round filters are characterised by outstanding temperature resistance of up to 500 degrees Celsius. This thermal stability makes them ideal for standard gravimetric methods, such as the determination of filterable substances (dry residue) and loss on ignition in accordance with national and international environmental standards. The filters can be dried in a drying oven or ashed in a muffle furnace without any risk of the fibre structure collapsing. Typical areas of application include not only wastewater and drinking water monitoring but also air pollution control, the protection of membrane filters against clogging (pre-filtration) and the clarification of viscous phases.

Technical details

Metrology & Filter Specifications

• Filter type: Glass fibre round filter / depth filter
• Quality / Grade: MN 85/90 BF
• Binder: 100% binder-free (BF)
• Nominal retention capacity (liquid): 0.5 µm
• Retention capacity (air/gas): Higher (due to diffusion and interception mechanisms)
• Filtration characteristics: Very high flow rate with maximum particle retention

Material properties & resilience

• Base material: High-purity borosilicate glass fibre mesh
• Chemical resistance: Universally resistant to organic solvents, acids and mild alkalis
• Thermal stability: Up to 500 degrees Celsius (completely incinerable/refractory)
• Biological reactivity: Inert (no breeding ground for microorganisms)

Dimensions & Range of Variants

• Available diameters: 5 mm to 270 mm (selectable according to application)
• Filter shape: Round filters (pre-cut, flat)
• Packaging: Usually supplied in a handy cardboard box (quantity varies depending on diameter, usually 100 pieces)

Contents

• 1 x pack of Macherey-Nagel MN 85/90 BF round glass fibre filters in the selected diameter variant
• 1 x batch-specific quality certificate from the manufacturer

Important note: Vacuum filtration units, Büchner funnels, suction flasks and suitable rubber sleeves (Guko) are not included in the scope of delivery and must be selected separately to suit the specific workstation.

Individual requirements & accessories

To realise the full potential of the Macherey-Nagel MN 85/90 BF filters, their use in professional vacuum filtration set-ups is recommended. Our laboratory range includes suitable porcelain and stainless steel Büchner funnels, as well as glass filtration apparatus with frit supports. For the precise handling of damp round filters without damaging the fibre structure, we recommend the use of rounded stainless steel laboratory tweezers. Should you require filters with a different retention capacity or integrated organic binders for your analytical work, we also offer the complete Macherey-Nagel filter range (e.g. MN 85/70 or membrane filters). Please make use of our technical procurement service to design your filtration workstations to suit your specific requirements.