What are the features of ink and what are its precautions?
densityDensity is the weight of a unit volume of ink at 20 degrees centigrade. Expressed in g/cm3. The density of the ink depends on the kind and proportion of the raw material used in the ink, and is affected by the outside temperature. The density of printing ink has certain relation with printing process. The density of the ink is related to the amount of ink used in the printing process. Under the same printing conditions, the density of the ink is greater than the density of small ink.The density of the ink is too large, mainly due to the large density of pigment in the ink. In the printing process, the binders cannot drive the large density of pigment particles transferred together, so that the pigment and other solid particles deposited on the roller and plate, or blanket surface, forming a blocking version of the phenomenon. Especially in high speed printing or ink dilution, the use of density ink is more prone to this phenomenon. At the same time, the density of ink mixed with the ink density is small when using, if the two gap is too large, easy to produce ink layer phenomenon. Small density ink floating, density of the sinking, so that the color of the ink surface bias in the small density of ink, the bottom of the ink color is biased towards the density of ink. In general, the density of the printing ink is between 1g/cm3 and 2.25g/cm3.
Characteristics of inks:The physical and chemical properties of ink mainly refer to its density, fineness, transparency, gloss, light resistance, heat resistance, and acid, alkali, water, solvent (alcohol).
finenessFineness is the degree of dispersion of the solid powder, such as pigments and fillers, in the binder, also known as dispersion. It shows the size of the solid particles in the ink and the extent and extent of the particle distribution in the binder. The fineness of the ink is good, indicating the fine particles of the solid, the ink in the distribution of solid particles. The fineness of the ink depends on the degree of wetting of the solid, such as pigment and ink, and the fineness of the ink after the ink is agitated and rolled.The fineness of the ink is related to the printability, fluidity and stability of the printing ink. It is an important quality index. Ink fineness difference, coarse particles, printing will cause blocking. In offset lithography and gravure printing, it can cause damage to printing plates and scrapers. And because of the uneven dispersion of pigment, the intensity of the ink color can not be fully brought into play, affecting the colouring power of ink and the brightness of the ink film after drying.
glossThe fingerprint brush ink surface gloss after drying in the light, the ability to the same concentration of reflected light. Ink with high gloss shows great brightness on printed matter. The glossiness mainly depends on the kind and property of the ink in the ink, the treatment of the refining process in ink making and the smoothness of the ink film after drying. In addition, the ink gloss by nature pigment ink composition, particle size and shape effect of dispersion; ink penetration, leveling, drying properties of the substrate material and so on.
transparencyTransparency refers to the degree of refraction (transmittance) of the incident light by the ink. In printing, transparency refers to the extent to which an object's surface is exposed when it is uniformly coated in a film. Ink transparency is low, can not make the background appear, will be covered in a certain extent background, so the performance of ink is also called zhegaili. The opacity of the ink is inversely related to the covering power. The transparency is indicated by the thickness of the ink layer when the ink is completely covered with a certain base color. The greater the thickness, the better the transparency of the ink and the lower the hiding power.Transparency depends on the difference between the refractive index of the pigment and the binder in the ink, and is related to the degree of dispersion of the pigment. The smaller the refractive index difference between the pigment and the binder, the better the dispersion of the pigment in the binder, the higher the transparency of the ink.
