1. Are pad printing inks available in any color I want?
2. How do I determine what type of ink to use?
3. What about the environmental impact of pad printing inks?
4. What does hardener (catalyst) do to the ink?
5. Could I mix different brands or series of inks and thinners together?
6. How much thinner should be added to pad printing ink? Can I omit the thinner?
7. How much ink does pad printing consume?
8. What is retarder used for?
1. Are pad printing inks available in any color I want?
Visprox inks (available from Printex) come in over thirty standard colors. Twelve of those colors compose a Pantone color matching system (Colormatic System) which can be used to reproduce any of the Pantone coated series colors, well over 1,000 colors total. Our customers can purchase this system to do their own color blending, or purchase them by the liter size container from Printex. In addition, Printex can provide custom color formulations by the liter. We can also blend some Day-Glo colors, metallized and perlescent colors. Metallic pad printing inks look like metallic paint, lacking the luster of foils, and limited by their particle size availability suitable for pad printing.
back to top
2. How do I determine what type of ink to use?
Printex has an applications table called Substrate Compatibility Chart to recommends a suitable ink for most common substrates. When in doubt, test it out, or simply contact our Customer Service or Technical Support team to send us your sample part in order for us to conduct an ink compatibility test at our Headquarters in Poway and provide you conclusive results free of charge.
back to top
3. What about the environmental impact of pad printing inks?
Pad printing inks are solvent-based, and are considered paint-related materials by the Department of Transportation (DOT) and the Environmental Protection Agency (EPA). The solvent content means that they are flammable and they release Volatile Organic Compounds (VOCs) into the atmosphere. These inks must be handled shipped and stored properly. Disposal must be handled in the proper manner according to all applicable regulations. See our Material Safety Data Sheets (MSDS) for more information.
The advent of sealed inking systems (as featured in Printex machines) has greatly reduced VOC emissions on the pad printing press.
back to top
4. What does hardener (catalyst) do to the ink?
Hardener, which is also known a catalyst, reacts (cross-links) with ingredients in the ink to polymerize it. Practically speaking, this is usually done to make the ink adhere to a substrate. It also makes fully dried and cured ink more resistant to scratching, rubbing and solvents. Hardener can only be used in an ink that is designed to work with it. A result of using hardener is a limited working life (pot life) once blended. After use, the cup must be cleaned, and the remaining ink must be disposed of.
back to top
5. Could I mix different brands or series of inks and thinners together?
Some ink series "share" their thinner systems as in Visprox 2000 and 8000 series. It is not recommended to mix various manufacturers inks and thinners without conducting conclusive tests as to the behavior and results of this mix. Printex knows from experience that blending Visprox inks with anything other than Visprox thinners (of the same series) will result in unpredictable performance. Certain third-party pigments and additives will work in some pad printing inks, but it is always best to consult your ink supplier before trying.
back to top
6. How much thinner should be added to pad printing ink? Can I omit the thinner?
There is an exact amount of thinner that should be added to Visprox pad printing inks prior to use. Typical for most applications is 30% thinner to ink batch weight ratio measured by weight and mixed thoroughly. Depending upon the application, the amount of thinner could be as little as 20%, and as much as 35%. As a general rule, the finer/smaller the artwork to be printed is, the higher the thinner percentage (over 30%) will need to be. Inversely, with large solid fills and bold lines, 20-30% will be correct. Too much thinner will result in a pale, spotty print. All pad printing inks have to be blended with some amount of thinner, as they are usually too thick straight out of the can to be used for pad printing.
back to top
7. How much ink does pad printing consume?
This varies by the nature of the artwork being printed, but in any case the answer is: next to nothing. Ink consumption could actually be measured by printing a part with the image, weighing the printed part using an extremely sensitive scale, and comparing that weight to the unprinted weight of the same part. A scale with 0.01 of a gram sensitivity would be the minimal required for such a test. Even if such a device were available, the results would still be approximate, because it would not take into account factors like: solvent evaporation, ink loss during plate changes, cleaning and pot life which all contribute to ink consumption.
back to top
8. What is retarder used for?
Retarder is a type of thinner with a very slow evaporation rate. It is used to extend the evaporation (flashing) time of the ink and counteract premature drying. Typical reasons for using retarder would be very hot and/or dry climatic conditions, a slow machine cycle time, or the need to reproduce very fine details (which tend to dry quickly on the printing plate). Retarder should be added carefully in small amounts, as a little retarder tends to have a big effect on ink dry time. Since retarder also acts as a thinner, it lowers the viscosity of ink just like regular thinner. When it is needed, it should be used in lieu of the same amount of the thinner content. Under most conditions, the amount of retarder needed will not exceed 15% ratio.
back to top |
