The pigment solids that are the basis of these inks need to be small enough to avoid clogging printhead openings. The pigment solids also should be evenly dispersed through the ink for consistent, high quality thermal printing. Filters both remove larger particles and agglomerates and contribute to the mixing process that assures full dispersion.
Dyes are chemical colorants as opposed to solid pigments. Print color is achieved by the dye molecules adhering to the substrate. Printer performance depends on lack of particles and even organic contaminants in the ink. Therefore, filters are used to remove undissolved dye components and gels that may clog printheads. Depending on the ink carrier, bacteria and other organisms may even grow in dye based inks, so they should be removed by product filtration.
Many inks are water based, but industrial print systems may use inks that are based on non-aqueous solvents. The filtration goals described above for pigment and dye based inks still apply, but the filter media chosen must be compatible with the solvent to assure desired filter performance. Critical Process Filtration offers filter media in multiple materials for chemical compatibility.
UV Curable Inks
Inks incorporating UV curable elements can provide a bright, long-lasting image. Most UV curable inks are high viscosity liquids, so choosing a filter media requires consideration of the pressure drop of the media. Critical Process Filtration filter system sizing tools account for liquid viscosity and can help you choose the right filter media and quantity of filters.
Filters for Colorants
As with any formulation process, the raw ingredients should be filtered to assure that no contaminants are inadvertently introduced into the process. Filtering both colorants and the ink carrier will help safeguard final product quality and performance.
Common Filtration Steps in Ink Jet Ink Formulation
Assuring the quality of printing is critical to the success of any manufacturer of ink jet inks, and filtration is key to the quality of the ink. Building cost effective filtration systems will help both the print quality and the profitability of the manufacturer.
Water based inks must be created with high quality water. Reaching and maintaining that quality is more complex than simply installing a filter or even a reverse osmosis and deionization system.
Critical Process Filtration has decades of experience with water filtration and water treatment. From removing chlorine from drinking water to helping transform river water to ultrapure water, Critical Process Filtration has the filters to make your treatment system run smoothly and reliably and deliver the right quality for all your processes.
Removing unwanted large particles from the liquid ingredients of inks makes the mixing processes more efficient and the quality of the final product better. How much filtration is required to assure a high quality outcome depends on the initial quality of the materials.
Colorants are often a relatively small portion of the ink volume, but the quality of the colorant has an obvious impact on quality of the end product. Incoming colorant quality depends on a number of factors, including the storage system, the distribution and dispensing equipment and the environmental conditions at your facility. Critical Process Filtration has a wide range of media and device options to filter ingredients and help assure high quality results.
The largest portion of the ink is the carrier, so the quality is obviously as important as the colorant to end product quality. Water is a common carrier and filtration can assure water ingredient quality. Non-aqueous solvents are usually fast drying carriers, so printing with solvent based inks can be a very fast process. The image made with solvent based inks may also be waterproof, which is an advantage in many applications on a wide range of surfaces.
Critical Process Filtration has multiple filtration media that are compatible with water and solvents used in inks. The depth filters used for large particle removal are available in polypropylene, nylon and fiberglass. Critical Process Filtration membrane filters that can remove sub-micron particulates are available in many materials from PES to nylon to PTFE. We can help you find the filtration solution that will deliver the print quality your customers need.
Filling and emptying tanks requires air to either exit the tank or enter the tank. Using a filter to block potential environmental contaminants like dust or even bacteria from entering the tank helps protect the quality of the tank contents and your final product.
For tank vent applications, using filter products made with either hydrophobic depth media or hydrophobic membranes can help assure cost effective operation and product purity.
The most critical process in any ink manufacturing operation is the protection of final product quality. Filtration is the key to assuring that the ink is free from large particles, gels and agglomerates, will flow freely during printing, and create the desired image on printed material. Critical Process Filtration depth filters are used for large particle removal. Critical Process Filtration membrane filters may be used to remove sub-micron particulates or even bacteria for the highest quality printing applications. The filters chosen must be compatible with the ink formulation, remove the target contaminants, but cannot adversely affect any other characteristics of the ink. Critical Process Filtration can help you find the filtration solution that delivers the quality you need.
Laboratory to Production
With configurations ranging from 13mm disc filters to 40” cartridge filters, all made with the same attention to quality and cost, process scale up can be easily accomplished using Critical Process Filtration products and support. Whether evaluating the filtration of solvents or testing filterability of finished formulations, Critical Process Filtration will work with you to create the most cost effective processes possible.
To estimate the number of filters you will need for your application, use our unique sizing tools.
Contact Critical Process Filtration to learn how we can evaluate your facility and recommend cost effective filtration that will safeguard chemical quality.