Synder Introduces New Nanofiltration Membrane for Dye Desalting Applications

Synder Filtration is pleased to announce the release of NDX, a new nanofiltration membrane designed specifically for use in dye concentration and desalting applications throughout the textile industry. NDX has a molecular weight cut-off of 800-1,000Da and offers comparable flux and rejection performance compared to other membranes for dye desalting currently available on the market. The removal removal of salts in the dye manufacturing process is essential in the preparation and purification of the final dye product, and the use of NDX has been shown to be an ideal membrane for this process as described the case study detailed below. Additional field trials have shown that Synder’s NDX membrane is capable of providing equivalent, if not superior, performance with respect to dye rejection, dye purity, and flux compared to that of the leading competitor.

Case Study Summary
Synder NDX 2540 elements were tested in a simulated feed stream was comprised of 3wt% Reactive Red 195 dye and 5wt% NaCl, and testing was performed through 6x volume concentration factor (VCF). Dye rejection of NDX was consistent at >99.9% for all tested concentration factors. Sodium rejection was observed to increase slightly over the duration of testing but remained less than 22% by the end of the study, without the use of diafiltration. Overall, NDX exhibited consistently high dye rejection and high salt passage rates through 6x VCF, as well as solid flux performance under relatively low operating pressures. These results indicate that the use of NDX is effective for removing salts, increasing dye purity, and improving product value.
Read full case study here

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With over 25 years of experience in the membrane filtration industry, Synder continues to focus on specialty process applications and provide exceptional lead times and responsiveness. The addition of NDX to our nanofiltration membrane line provides a wider range of options for customers looking to use nanofiltration for specialty process applications. For more information about our membranes, please visit our website at or email us at
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