Uvispeed UV-Curable Halftone Inks
Fujifilm Sericol USA Inc.
Graphics screen printers who need the ability to print large quantities of grand-format signs and displays typically turn to multicolor inline presses to accomplish the task. These printing systems can efficiently handle a variety of substrates, and they offer the flexibility to take on a generous assortment of applications. Another big benefit inline presses present is that most models are designed to print, cure, and transport substrates from start to finish—all without operator intervention.
Fujifilm Sericol developed Uvispeed, its new line of UV-curable halftone inks, to further bolster the advantages of inline presses by enhancing the speed at which operators can run their printing lines and boosting production of large-format four-color-process graphics to more than 500 pieces per hour. According to Fujifilm Sericol, Uvispeed inks feature a unique, quick-release ink rheology that facilitates high-speed printing—even when using screens with fine thread counts. The inks also are designed to combat common issues associated with high-speed screen printing, such as changes in color density and stability, variations in ink coverage and dot consistency, and more.
Uvispeed inks are available in two versions, both of which are billed as non-blocking and able to fully cure with low UV energy. Uvispeed RIGID is formulated to deliver a high-gloss finish and adhere to rigid plastics, polystyrene, board, many vinyls, card stock, and coated paper. Uvispeed FLEX is designed to produce a high-gloss finish on flexible vinyls such as static cling, common vinyl banner stock, top-coated polyesters, and pressure-sensitive materials.
Uvispeed RIGID is supplied with a press-ready viscosity. Thinning is not required or recommended. Fujifilm Sericol notes that Uvispeed RIGID prints and cures well through monofilament polyester screen meshes between 355- to 420-threads/in. The company specifies the use of solvent-resistant stencil materials, as well as the use of a dual-cure or one-pot direct emulsion and thin film stencil (3-6 microns EOM). Standard halftone colors are said to yield a minimum coverage of 2800-3500 sq ft/gal, depending on film thickness.
Fujifilm Sericol reports that accelerated weathering tests indicate an exterior life for Uvispeed RIGID of up to six months in a temperate climate. The use of Extended Life Magenta ink is required for those who wish to extend the exterior life to 12 months. Uvispeed RIGID inks are available in standard and intense halftone colors. Standard halftone colors are matched to SWOP standards, though Fujifilm Sericol explains that the densities are slightly higher than SWOP under most conditions and, therefore, may be adjusted by using halftone extender base. Intense halftone colors are formulated to be considerably higher in density than SWOP standards. Extender base may also be used to adjust their density.
Uvispeed FLEX is supplied with a press-ready viscosity as well. Thinning of the ink is not required or recommended. According to Fujifilm Sericol, these inks are designed to maintain low dot profile, retain flexibility, and perform well in diecutting. Suggested mesh for use with Uvispeed FLEX inks is a low-elongation, monofilament polyester in the range of 355-420 threads/in. The use of a 70- to 85-durometer, UV-ink-resistant squeegee also is recommended. Stencils must be resistant to solvents, and Fujifilm Sericol suggests the use of a dual-cure or one-pot direct emulsion and thin film stencil (3-6 microns EOM). Standard line colors will yield coverage of 2800-3500 sq ft/gal, depending on film thickness.
As is the case with Uvispeed RIGID, accelerated weathering tests indicate that Uvispeed FLEX exhibits an exterior life of up to six months in a temperate climate. Extended Life Magenta is required for applications that call for an exterior life of 12 months. Uvispeed FLEX inks are available in standard and intense halftone colors, both of which may be adjusted for density with way of adding extender base.
For storage and handling, Fujifilm recommends that both Uvispeed RIGID and FLEX formulations be kept in temperatures between 50-77°F. All ink containers should be tightly closed immediately after use, and Fujifilm Sericol suggests disposing of surplus inks from screens at the end of long print runs. For more information, contact Fujifilm Sericol USA Inc., 1101 W. Cambridge Dr., Kansas City, KS 66103, 913-342-4060, 800-255-4562, fax: 913-342-4761, Web: www.fujifilmsericol.com.