Heat transfer ink in heat transfer printing have a key position, ink various properties are very important to product production,among them ink viscosity is more important.
Viscosity refers to ink flow fluid in the process,fluid intermolecular interactions will produced hinder molecules relative movement ability measure.It reflects a property of fluid layers in the ink to stop each other flowing and ink itself resistance to flow ability,its essence is ink cohesion (intermolecular binding) strong and weak performance.High viscosity, ink has high cohesion, ink mobility is lower.
Affecting viscosity has many factors, including the amount of pigment, oil absorption and fineness, linkers viscosity, fillers. The following introduce the pigment amount, oil absorption and fineness degree to viscosity extent impact.
For the same type of binder, the greater proportion of pigment, the greater force between molecules,ink viscosity is large, but pigment in the ink amount is limited. Oil absorption refers to a certain amount of pigment wetting to form a slurry need to adsorption oil amount (g / 100g),is a description about pigments and greases binding ability. Under normal circumstances, the higher pigment dispersion, small particles, the pigment is larger than surface area,oil absorption is large, ink viscosity is small, fluidity increased. In addition, oil absorption is related to pigment moisture, oil acidity. Pigments containing more water, oil volume is low; oil acidity increased, pigment oil absorption will be reduced.
Ink have a good fineness, indicating that solid particles is very fine, evenly distributed in the ink. Ink fineness depends on bonding material for pigments ect solid particles wetting degree, ink agitation, grinding and other processes handle degree.Bonding material has a strong wetting properties, pigments and solid particles easily wetted, the solid particles easily dispersed, after rolling the ink has a good fineness.
Normally, pigments solid particles are present in fine particles flocculated state. Pigment particle size and dispersion state for ink viscosity, adhesion, fluidity and other rheological properties have a certain impact. Pigment particles should be controlled between 0.5-3um, however below 1um pigment particles should be accounted for 80-100%. In the same amount of pigment and filler circumstances, two kinds of solid powder particles are smaller, the higher dispersion, the more fully wetting in the ink binder, ink viscosity is relatively large, made of circular ink pigment particles compared with other shapes made of ink particles, its viscosity is smaller.
Qingyi heat transfer ink can choose a lot of pigments, such as fluorescent yellow, lemon yellow, ultramarine, dark blue, silver and so on.