Depth Filtration
Glass Micro Fiber

Depth filtration categorizes filter media that traps particulate within the random matrix of fibers found within the thickness of the media. The efficiency rating of the filter is characteristic of the complex pore structure that develops as the fibers over-lap. The fibrous material within the filter is commonly glass micro fiber or poly-propylene.In depth filters such as glass micro fiber, the purity of the filter is dictated by the presence of, if any, binder material that acts as a strengthening agent and aids in holding the fibers together.

Because of the characteristically high flow rates of depth filters, they are generally used in applications such as single and multi process removal of sediment and course particulate. Glass micro fiber filters are available without binders,making the inertmatrix an ideal medium to entra-psediment for further analysis and counting. Also, depth filtration media is commonly used as pre-filtration prior to surface filtration substrates such as membranes.

GRADE A- Fine porosity, fast flow rate, with a 1.6µm size particle retention. Frequently used in the filtration of precipitatedproteins and cells. Ideally suited for use as a filter for radioimmuno assay of weak beta emitters by scintillation counting and gravimetric determination of airborne particulate. Binderless borosilicate glass micro fiber.

GRADE B - Fine porosity, medium to fast flow rate, with a 1.0µm size particle retention. Ideally suited for the collection of biochemical polymers that have been precipitated by denaturation. This material is twice as thick as Grade A with a higher loading capacity. May also be used as a solid particulate filter for gasses or as a prefilter. Binderless borosilicate glass microfiber.

GRADE C - Fine porosity, fast flow rate, with a 1.2µm size particle retention. Primarily used for RIA procedures and harvesting lymphocytes. Binderless borosilicate glass microfiber.

GRADE D - Coarse porosity, fast flow rate, with a 2.7µm size particle retention. Well suited for higher volume and repetitive laboratory filtering. Also ideally used as a general pre-filter to extend primary filter life. Binderless borosilicate glass microfiber.

GRADE E - Fine porosity, fast flow rate, with a 1.3µm size particle retention. This material is an economical media for suspended particle analysis in water, cell harvesting, pre-filtration and air monitoring applications. Binderless borosilicate glass microfiber.

GRADE F - Fine porosity, medium flow rate, with a 0.7µm size particle retention. Frequently used with Grade D to filter diluted aqueous solutions containing strong oxidizing, acidic, or alkaline components prior to laser spectroscopy. May also be used for TCLP analysis and collecting extremely fine precipitated proteins, including immunoglobulins. Binderless borosilicate glass microfiber.

934-AH® - Fine porosity, fast flow rate, with a 1.5µm size particle retention. This material is the standard for volatile suspended solids content and related measurements (Standard Methods 2540D and EPA Method 160.2). Also widely used in cell harvesting applications and RIA scintillation counting. Binderless borosilicate glass microfiber enables use up to 550°C.

GRADE A-E - Fine porosity and fast flow rate, with a 1.0µm size particle retention. Binderless borosilicate glass microfiber. DOP efficiency is 99.98%. Primarily used in suspended solids and air monitoring.

QUARTZ A - Fine porosity with a 99.999% efficiency in air filtration for the retention of 0.6µm particles in air at a flow rate of 5cm/second. Primarily used in air pollution monitoring, atomic absorption spectroscopy, flame emission spectrometry and other applications where an extremely critical analysis is needed. Effective temperature range of up to 1000 °C. Binderless quartz micro fiber.

The trademark 934-AH® Is owned by Whatman Inc. and used under license