Asst. Prof. Dr. Juntira Komasatitaya, (Material Engineering), Lecturer and printing ink researcher, King Mongkut’s University of Technology Thonburi, Thailand.
The Study of Eco-friendly Printing Ink Composed of Starch/PVA Blend for Printing On Cardboard
Juntira Komasatitaya, King Mongkut’s University of Technology Thonburi
Cardboard cartons such as corrugated board are secondary packaging that holds together the individual units of a good to deliver mass quantities of the good. Many trashes of cartons are disposed to environment, brought to making recycled paper. Purpose of this research was to identify natural resource materials to develop an environmental friendly flexographic ink that can be safety recycled or decomposed in landfills. Because starch was a resin derived from natural resource, non-toxic, and less pollution, so it was used as a natural binder for making water based printing ink. The solution of starch was blended with polyvinyl alcohol (PVA) solution by shear mixing. PVA was mixed into starch solution to improve flowing behavior, film formation and flexibility of the ink.
This work presents the study of water based flexographic printing inks composed of solution blending of starch and PVA. Blending variance of different starches were evaluated for the best printed quality and ink performances, against a typical synthetic water based flexographic ink The starch/PVA inks prepared from cassava, rice, or corn starches were compared on their properties and print density. Next, the cassava starch/PVA ink was printed on a corrugated board as a substrate, printing by a flexographic printing machine. Print quality was compared to that of a typical flexographic ink composed of a synthetic binder. These studies were concluded that the ink properties: viscosity, pigment dispersion, and fastness of the starch/PVA inks were suitable for flexographic printing on corrugated cardboard. Print quality showed good print density, good sharpness of printed text and line, but % dot gain of halftone screen on the printed samples was more than that of the typical flexographic ink.