Plastisol is best stored outside of the traffic area of a shop where it can be staged on shelves that make it easy to find what you need instead of having to sort through ink containers to find what is needed. Shelving that is only one container deep works best as it keeps inks from being hidden. The coolest part of the shop is the best storage area. Ink should not be stored near dryers and flash-cure units. At the same time, cold winter weather can be an issue with using inks, especially opaque whites and other opaque inks. Many printers will have a temporary holding area for these heavier inks that is heated even when the shop is closed. A heated office or corner of a screen room can suffice to make these heavier inks useable at the start of business in the cooler seasons.
It is a good idea to stir plastisol before each use. Plastisol has a characteristic called “false body” where the ink will take on a thicker viscosity when it sits, even for one day, which is broken down by stirring. Printers will sometimes add unnecessary viscosity reducers when they do not stir first to break down the false body. Also, when plastisol has been sitting for a very long time, there can be a separation of plasticizer (clear liquid portion of the ink) from the heavier components of pigment and resin. By stirring first, the ink is rebalanced before use.
Union plastisols are made to extremely high standards with state of the art dispersing equipment. Fully dispersed plastisol allows for a finer texture which eliminates “lumps and chunks” in our ink. In addition, all Union Inks are made in controlled batches. This batch process does have the benefit of extremely tight quality control whether it’s a small or large batch. Our goal is to provide you with consistent batch to batch product.
When plastisol ink builds up on screens, it can be caused by several reasons. The most common cause is too much ink. That is, you are printing more of a color than the substrate can handle. This situation can be caused by screen mesh too low, squeegee too slow, mesh not tensioned high enough, ink too heavy for the application, and even the nature of the ink itself. Heavier more opaque inks have a very high solids component that is more prone to build up than lighter medium opacity and transparent plastisols. The most common reason for build-up is probably screen mesh that is too low for the given substrate and ink. Modern plastisols, especially Union Ink, are dispersed to a very small particle size which allows them to be printed through high mesh counts. When printed through low mesh counts, too much ink can be printed. A good frame of reference here is to remember that a 160 threads/inch mesh uses 42% less ink than a 110 threads/inch mesh screen and a 230 threads/inch screen uses 34% less ink than a 160 threads/inch screen.
Shirts prepared for discharge must be reactive dyed 100% natural fiber fabrics. 100% cotton reactive dyed is best. Most major brands of cotton shirts discharge very well and most garment manufacturers will also provide a list of colors of their shirts that are best for discharge. It should also be noted that the fresher the fabric you are trying to discharge is, the better. Shirts that have been stored for a long period of time (more than a year) will not discharge as well as garments that have been recently made. Pigment dyed shirts do not discharge well as these dyes are not reactive.
Dye migration is the result of the sublimation of polyester dyes out of the fabric and into the ink. Plastisol will very happily accept these dyes and the result is discolored inks. Unfortunately, there is no easy answer to this question but the biggest factor in controlling dye migration is to use the right inks. Low bleed inks for blend fabrics and Poly inks for 90-100% poly fabrics. The difference between standard low-bleeds and poly inks is the amount of blocking agents that are present. When dye migration is still an issue try using PLHE1500, Low Bleed Barrier Grey.
Being about to control what fabrics you print on is most ideal, but in the real world, most printers do not have that control. Testing of substrates is recommended so that you know what you are up against before you start printing a production run.
Crocking is a condition where ink can actually be rubbed off of a cured print. With plastisol, it is usually caused by using an ink that has too much pigment for the application. It is most commonly found with red pigment opaque inks such as the Maxopake series. The solution is to use an extender base such as MIXE-9070 Soft Hand Extender to lower the opacity. In fact, Mixopake inks should always be extended when used on lighter fabrics or on an under base. They are only needed full strength on darks fabrics without an under base.
Plastisol transfers can be made with just about any plastisol but the best results will be achieved with plastisols that have been modified to increase their adhesion. In the Union Ink line, the Mixetrans series is optimized for transfers. There are also two methods for increasing adhesion when using standard plastisols. The first is to dust the finished transfers with Union Unilon transfer adhesive powder. There are three different powders available depending on the application. The second way to increase adhesion is to print a printable adhesive as the last screen. The adhesive PLUE-9040, is a clear adhesive plastisol.
We are constantly striving to improve formulations. Through input from printers and our own research, it is a continuous process. In addition, Pantone changes the paper that they use for their color swatches. As a result, quite a few colors shifted slightly in shade.
The Union RGCC ink mixing software has an ink usage calculator in it. Even if you are not using a color match for your print you can still access the software and calculate your approximate usage. You need to know the mesh counts to be used, the dimensions of the print, and the number of units to be printed. Mesh is a huge factor in ink consumption. A 156 threads/inch mesh will use approximately 42% less ink than a 110 threads/inch mesh.
Metallic pigments have a wonderful appearance. Unfortunately, they also tend to dull quite quickly(tarnish). This is caused by the interaction of the environment (washing, drying, and exposure). It is most common with silver metallic as the metal used to create the look is usually aluminum. Aluminum is highly affected by laundry soap and dulls after only a few washes.Your best solution is to use shimmer inks which utilize a coated metal flake that is less susceptible to environmental conditions (tarninshing). And, while the flake is slightly larger, the end result is still quite attractive.
Cool and Warm grays are listed after the Pantone numeric pantone colors in the ink mixing database. In addition most of the Union standard colors can be found at the end of the list also.