Inkjet Inks Filtration

Inkjet inks are manufactured in a variety of formulations. Some of the main variants include the carrier fluid - aqueous or solvent based as well as the colorant itself - pigment or dye based.  Cleanliness of the ink is required to avoid plugging of the print head or nozzle to ensure printer performance and longevity.

Manufacturers of pigment based inks are seeking filtration that achieves highly selective (classifying) particulate removal. These filters must remove oversized pigments, gels, agglomerates and other contaminant, while allowing the desirable sized pigments to pass through the filter and remain in solution  For this application Graver recommends multistage filtration with absolute rated QXL™ Series filters. Graver offers specially formulated inkjet grades with a multilayer structure that achieves fine dispersion classification along with reliable gel retention to meet the demands of inkjet formulators.

For dye based inks, the colorant is actually dissolved in the solution and so the goal of filtration is to remove gelatinous residues, insoluble dyes, and other contaminant.  In this case two stage filtration is recommended with a 0.5 micron absolute QXL Series filter selected as the prefilter followed by a 0.2 micron absolute rated WaterTEC™ P as a final filter.

Be sure to check for chemical compatibility when selecting filters for solvent based ink applications. In some instances the glass media in the Graver GFC™ Series may be the more appropriate choice.

Inkjet ink filters must:

  • Precisely classify particle sizes to assure removal of oversized agglomerates
  • Remove deformable or gelatinous contaminant
  • Protect fine nozzles from plugging

Graver Product Selection -- Pigment Based Inks

Product Application Area
QXL™ Series hybrid pleated/depth filters Depending on ink color and pigment size, a single or multistage filtration process may be required utilizing Graver QXL series filters. The multilayered QXL filter features thick, lofty media for capturing deformable particulate.
GFC™ and GFP™ Series microfiberglass filters For solvent based inks, the microfiberglass media utilized in the GFC and GFP products may be the preferred choice.  Available in optional polypropylene hardware (GFC) or polyester hardware (GFP)

Graver Product Selection -- Dye Based Inks

Product Application Area
QXL™ 0.5 micron QXL series filters are specially formulated for dye based inkjet ink prefiltration
WaterTEC™ Series polyethersulfone membrane filters 0.2 micron, absolute rated WaterTEC™ P membrane filters provide precise removal of unwanted contaminants in the final filtration stage


Application Case Study