Dyne inks

The ink for inkjet printers is essentially colored water, and the current formulation of ink is about 75% water, plus dye and glue (Kang 1991, Le 1998, Pond 1999). The ink should flow readily from ihe inkwell to the nozzle, and then to the paper, without dripping or clogging. The viscosity of current inkjet ink is from 2 to 8 cP. The droplets formed should be very uniform in size, and should be as small as possible to increase the resolution. When the droplet hits the paper, the droplet should penetrate the fibers without splatter, which would increase the diameter of the dot on the printed text or picture. The surface tension of current ink is around 45 to 50 dynes/cm, which is much lower than water at 70 dynes/cm. It is believed that if the surface tension is raised from 45 to 65 dynes/cm, the spread (or ratio of diameter of spot on paper/diameter of droplet) would decrease from 3.3 to 1.1. Much higher resolutions... 

EarthFirst film for packaging flowers or herbs is amenable to ink and has a high natural dyne level making floral sleeves more colourful and presentable. 

The surface tension of the ink is a primary factor determining droplet formation and spreading on the substrate upon contact. The surface tension can be controlled by using surfactants and by selecting proper solvent compositions. For example, adding propanol to water win cause a large decrease in surface tension, from 72.8 dyne/cm to below 30 dyne/cm, depending on the propanol concentration. 

There are several limitations on the physical properties of UV curable inkjet inks for piezoelectric DOD print heads. The viscosity needs to be fairly low — 8-12 cps at the jetting temperature (most print heads have on-board heaters, capable of reaching up to 70°C in many instances). The surface tension of the inks is also important, and depends on the print head technology being utilized. Some print heads are equipped with a non-wetting faceplate, while others work best with fairly high surface tension fluids (mid 20s to upper 30s, dynes/cm)... 

Banks (1) in a paper on litho fountain solutions, observed thaT most abnormal litho behavior such as scumming is accompanied by the spread of an oily film over the fountain solution. He also claims that if the fountain solution is adjusted to a surface tension in the range of 36-30 dynes/cm, the spreading of this sensitizing film from the ink will be inhibited. He feels that the prevention of spreading is not dependent on the particular composition of the fountain solution but only on its surface tension. 

Hansen (6) has observed that the interfacial tension of an offset ink with fountain solution should be neither too high, which would prevent sufficient emulsification, nor too low which would cause scumming. He states that the normal range for a good ink should be between 15-25 dynes/cm. 

The prevalent explanation for isopropanol s role in this kind of dampening system is that its surface tension, about 29 dynes/cm, sufficiently lowers the aqueous fountain solution surface tension to allow wetting of the inked form-roller by that solution, as illustrated in Figure 1. That is, the fountain solution wets and spreads onto, and is carried by the ink film on the form-roller to the printing plate, as a relatively thin, uniform film. 

Uses Solvent for coatings, cleaners, inks, textile lubricants, urethane prod. plasticizer for flexible thermoset polyester polymer intermediate for polyesfer polyols for urefhanes, wef-sfr. paper resins, polyester resins specialty chemical intermediate Regulatory DOT nonregulated SARA nonreportable Properties Clear colorless liq., mild sweet odor sol. in alcohols, ketones, ethers, most hydrocarbons si. sol. in water and higher paraffinic hydrocarbons m.w. 159 sp.gr. 1.092 (20 C) dens. 9.09 Ib/gal vise. 2.4 cSt vapor pressure 0.2 mm Hg (20 C) f.p. -20 C b.p. 196-225 C acid no. 0.3 max. flash pf. (TCC) 100 C surf. fens. 35.6 dynes/cm 99% min. esfers... 

Mazeen DBA-1 [BASF/Perf. Chems.j Chem. Descrip. Polyalkoxylated amine Uses Surfactant, wetting agent for paints, inks Properties Gardner 2 llq. sol. in min. oil, min. spirits, toluene, IPA m.w. 172 sp.gr. 0.860 flash pt. (PMCC) > 350 F surf. tens. 41 dynes/cm (0.1%) cationic 100% cone. 

Chem. Descrip. PEG 400 USP CAS 25322-68-3 EINECS/ELINCS 225-856-4 Uses Emulsifier, antistat for textiles rubber inks cosmetics paper film pesticide solubilizer/carrier intermediate for PEG esters, PU foams plasticizer, solvent for cork metalworking lubricants paints/resins pharmaceutical liq. preps., ointment bases, suppository bases binder for capsules/pills preservative for pathological specimens Properties APHA 25 color sol. in water and most polar org. soivs. m.w. 380-420 sp.gr. 1.130 vise. 7.3 cst (99 C) pour pt. 6 C flash pt. (OC) > 215 C ref. index 1.465 pH 4.5-7.5 surf. tens. 44.6 dynes/cm nonionic 99% act. 

Properties Water-wh. clear liq. m.w. 342 dens. 8.5 Ib/gal vise. 15-25 mPa S acid no. 0.1 max. flash pt. > 200 F ref. index 1.46 (20 C) surf, tens. 34.4 dynes/cm 0.5% max. moisture Storage Store in a cool, shaded, well-ventilated area away from direct sources of heat and sunlight may crystallize if subjected to cold Photomer 4399 [Cognis/Coatings Inks]... 

Uses Detergent, wetting agent, solubilizer, dispersant, micro-emulsifier for laundry prods., hard surf, cleaners, industrial specialties, solid air fresheners, toilet blocks, pesticides/herbicides agric. adjuvant for water disp. systems dispersant for aq. coatings and inks Properties Clear liq. oil-sol. pH 2.5 (10% aq.) surf. tens. 34.5 dynes/cm (0.01%) Ross-Miles foam 105 mm (0.1%, 40 C, initial) anionic 90 3% solids... 

Uses Solvent in coil, container, and automotive coatings, printing inks, acrylic lacquers, enamels, surf, primers for epoxies and polyesters, paint strippers, foundry core binders, resin cleanup, intermediates, industrial cleaners, wire enamel resins Features Offers VOC compliance, noncorrosive Regulatory DOT nonregulated SARA 302, 313 nonreportable Properties APHA 50 max. sweet odor sol. in alcohols, esters, glycol ethers, halogenated soivs., ketones, hydrocarbons sol. 5.5% in water m.w. 160 sp.gr. 1.086 dens. 9.06 Ib/gal vise. 3.88 cps f.p. -40.2 C b.p. 200-220 C acid no. 0.1 flash pt. (PMCC) 102 C surf. tens. 35.4 dynes/ cm 0.1% max. water content... 

Keywords Surface free energy, test inks, dyne pens, plasma treatment, adhesion, contact angle... 

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