Posted by on 2/14/2020 to
Inks can be formulated in an infinite number of ways to meet specific application requirements. The inks we carry are standard formulations which are intended to cover most marking applications. Although the application recommendations made on our website are based on tests conducted by our supplier, the customer should conduct performance tests for their specific application to ensure that the inks selected meet their specific application requirements. In all cases, Universal inks are formulated for industrial use only!
We carry two basic solvent types in the manufacture of inks, alcohol and petroleum solvents. There are various grades of solvent within each type, which basically relate to the speed by which the solvents evaporate or dry. In addition to solvent variations, some inks are pigmented, which contain ground solids to impart color to the ink and some are dye type which contain liquid color. It is important to thoroughly understand the characteristics of the various inks prior to making a selection for a particular application. The type of ink selected must be compatible with both the material being marked and the applicator with which the ink will be applied. Although inks designed for non-porous use can be used on porous surfaces, this is generally not recommended since it is more costly and the higher resin content of the non-porous inks may cause unnecessary problems for the consumer.
Stenciling and marking inks dry in one of two ways. Porous surface inks dry through absorption into the material being marked, leaving the pigment or dye color in the material fibers. Corrugated cartons and Kraft paper are good examples of porous surfaced materials. Since inks are not capable of being absorbed into a non-porous surface, such as metal or plastic, non-porous inks dry through evaporation of the ink solvents, leaving the dye or pigment on the surface of the material. Some amount of resin or “binder” is added to the formulation to bind the pigment or dye to the surface once the solvents have dissipated. The amount and type of resin used in the formulation determines the ability of the ink to resist chipping, peeling, weathering and subsequent solvent resistance. It is also important to note that the ambient temperature and humidity in the area where inks are applied can have a dramatic affect on the drying characteristics of inks. Generally speaking, the warmer the ambient temperature and the lower the humidity, the faster the inks will dry.
In applications where resistance to fading is required, generally only pigmented inks will perform satisfactorily. Most dye type inks will fade rapidly when exposed to direct sunlight for prolonged periods. Since pigmented inks contain layers of finely ground solids when applied, they are much more resistant to fading and will perform somewhat like an exterior paint. For fade and weather resistance, it is generally recommended to use a non-porous pigmented ink even on porous surface materials. The additional amount of resin in these ink formulations help to hold the pigments in place under exposure to water spray and abrasion.
Since there are so many types of inks available from various suppliers, it is important to understand the effect different ink solvents can have on the materials used in the ink applicators. In the case of the foam rubber materials used in the production of stencil rollers, pads and coding rollers, the type of foam used, whether synthetic or natural rubber, will determine its compatibility with alcohol or petroleum solvents. There are far too many factors to consider to list them all within the context of this article but we strongly recommend that you consult with our Customer Service for specific recommendations if you have any doubt about applicator/ink compatibility.