Pengaruh Kecepatan Pengadukan dan Kehalusan Gambir Serta Variasi Komposisi Terhadap Beberapa Sifat Fisika dalam Pembuatan Tinta Cetak

Abstract

Ink is a very important element that determines the quality of a printout. One of the potential natural materials that can be used as a raw material for making printing ink is gambier.The objective of this study was to observe the effect of stirring speed and particle size on some physical properties in the printing ink. The ink manufacturing was done in 2 phases, namely the manufacture of color pigment and ink formulation. Pigment ink was made by cleaning the gambier through dilution with hot water, filtration, and precipitation of fitrat. Furthermore the gambier was mashed with particle size variation 40, 60, 80 mesh. The adding saturated FeCl3 compounds in ethanol into the extract gambier slowly with stirring speed 250, 500, 750 rpm for 4 hours. The color of the pigment, viscosity, and the particle size was tested by using the PSA method (particle size analyzer). Manufacture of ink formula with additives propylene glycol 7.5; 10; 12.5 mL and polyethylene glycol 0.1; 0.3; and 0.5 mL for every 30 ml of extract gambier in ethanol. Best pigment was obtained from the use of gambier 60 mesh powder, stirring speed 250 rpm, the smallest pigment particle was 47.54 nm. The best ink formula was using propylene glycol and polyethylene glycol 12.5 mL and 0.5 mL. The characteristics of ink were black colored ink with a density 0.9633 at a temperature of 28-30°C, viscosity 0.9 cP, and surface tension -1 0.2539 Nm . Keywords: