Fumasep® FAB-PK-75 is a PK-reinforced anion exchange membrane with high proton blocking capability, high selectivity, and high mechanical stability. It offers excellent stability in both acidic and caustic environments (pH 1–14).

This membrane is designed for electrodialysis and electrodialysis with bipolar membranes, including applications involving the concentration and processing of acidic or caustic solutions.

Key Features:

Type: PK-reinforced Anion Exchange Membrane
Stability Range (pH) at 25°C: 1 – 14
Thickness (dry): 60 – 90 µm (2.4 – 3.5 mil)
Available Sizes: 10 cm × 10 cm and 20 cm × 30 cm

Fumasep FAB-PK-75 Technical Specification Sheet

Note on Sizing & Handling: Fumatech membranes are sensitive to humidity. Actual sheet dimensions may vary by approximately ±0.5 cm from the nominal cut size. Wrinkles may appear due to moisture content but typically flatten out when the membrane is soaked in deionized water.

Handling: Keep the membrane package closed/sealed when unused. Store, handle, and process the membrane in a clean and dust-free area. Use only new and sharp knives or blades when cutting. Always wear protective gloves. Handle with care — do not puncture, crease, or scratch the membrane. All surfaces in contact with the membrane must be smooth and free of sharp edges.

Storage:

Dry form: Store in a sealed container for long-term storage (> 12 months).
Wet form: For short to medium-term storage, keep in 0.5 – 1.5 wt% NaCl solution or a comparable neutral electrolyte. For extended wet storage, use a sealed container with 1 – 3 wt% sodium sulfite (Na₂SO₃) as a biocide.

Pre-Treatment and Conditioning: The membrane is supplied dry in the bromide (Br⁻) form. It can be used dry or wet depending on the application.

For wet assembly or optimum performance, condition the membrane as follows: Place the membrane between stabilizing meshes/spacers and soak in 0.5 M NaCl solution at 25 °C for 72 hours, exchanging the solution several times. Do not allow the membrane to dry out after wetting.

If additional cleaning is needed, rinse the membrane in deionized water or the process solution as required.

Note: Customers should validate the membrane’s suitability and any required ionic form conversion for their specific application. If you have questions regarding pretreatment or storage, please contact us.

Please note that a current lead time of one to two weeks is to be expected.

Membrane Properties
Membrane	Anion Exchange Membrane
Thickness	60 - 90 µm (microns)
Appearance / Color	Brown
Backing Foil	None
Delivery Form	Dry
Reinforcement	PK
Counter Ion	Bromide (Br-)
Density	10 - 13 mg•cm-2
Specific Area Resistance	< 4 Ω cm² (in Cl⁻ form)
Specific Conductivity	High (area resistance < 4 Ω cm² in Cl⁻ form)
Selectivity	93 - 98 %
Proton Transfer Rate	< 700 nmol min⁻¹ cm⁻²
Ion Exchange Capacity	0.7 - 1.0 (in Cl- form) meq•g-1
Dimensional Swelling in H2O at 25°C	0 - 1 %
Uptake in H2O at 25°C	5 - 15 wt %
Non-Std Modulus (MPa)	> 1000 MPa
Tensile Strength - max. (MPa)	> 40 MPa
Yield Strength at 23°C / 50 % R.H.	20 - 30 MPa
Elongation to Break (%)	> 15 %
pH Stability Range at 25°C	0 - 14 pH
Bubble Point Test in Water at 25°C	> 3 bar