What are the properties of ink in the printing of packaging boxesfonmoo
In order to print high quality boxes, we need to be familiar with and understand the ink required for printing, and master the different characteristics and functions of different inks, so that we can choose different inks for printing in different printing requirements. What are the general functions of the inks used by our packaging box printing factory?
A, the optical function of the ink
- What are the objectives of the optical function of the ink
We often say that the optical function of the ink refers to the ink film dried gloss, lucidity and color state. The essence of the resolution of the optical function lies in the film layer on the irradiation of the exterior light reflection, transmission and absorption capacity, the combined effect of the three capabilities on the performance of the ink film gloss, lucidity and color state.
We laminate our boxes, UV varnish and plastic coating process is to improve the gloss of our boxes, gloss is also an important goal of our printing quality.
Brightness refers to the fact that when light shines on the surface of the film layer, a part of the light will enter the film layer through refraction, and part of this refracted light will be absorbed by the film layer and part will penetrate the film layer. The more absorption, the stronger the covering power of the film layer; the more transmission, the higher the brightness of the film layer.
The color of the packaging box, the color is because the yellow, magenta and cyan pigments used in the ink are very different from the color of the natural spectrum, so that each ink will occur chromatic errors and grayscale, resulting in the color of the print does not reach the expected hue and density. Generally will require us to adjust and compensate in the image processing, and the condition of compensation is to understand the color characteristics of the three primary colors of ink.
- Elements affecting the optical function
① ink leveling, is the function of the ink in the substrate leveling evenly present enough luster and no pinholes.
② When our paper laxity can not make the connection material is too thin, the amount of penetration is large, the ink layer has a tendency to chalking, ink film without light.
③ paper itself smoothness is not good, paper smoothness is not good packaging box will attack diffuse emission, which sha light reflection will present errors, and then affect the ink layer luster.
What are the factors that affect the brightness of the packaging box?
- The crystalline shape of the pigment, the size, and the refractive index of the connecting material
- the size of the pigment particles, the amount of the amount, the resolution of the laxity of the magnitude, the resolution of the reflection of light, the amount of absorption, light absorption capacity rise, lucidity decline.
③The shape, composition and purity of pigment particles. Impure material will constitute harmful absorption, so that the color is not pure.
Second, the ink resistance
Resistance resistance refers to the ink constitutes a solid film layer, the film layer is affected by external factors, adhere to the film color and other quality of the function of the same. Ink resistance resistance generally includes the ink light resistance (sunlight resistance), heat resistance, acid and alkali resistance, resistance to organic solvents, water resistance, etc..
Generally affect the film resistance of the elements of two points: 1. film layer of information erosion, chemical structure changes, and then lead to color change. 2. film layer of information eroded and destroyed, the pigment free from the film layer.
Third, the fineness of the ink
Packaging printing plant in the printing ink fineness is also an important goal in the function of the ink. The fineness of the ink refers to the size of the pigment, filler and other solid particles in the ink and the degree of dispersion. Ink particles coarse will cause printing problems: lithographic printing may occur in the pile plate, paste plate or even destroy the plate; solvent-based ink will cause destruction of the plate, ink sink, etc.. In particular, printing plus the number of lines of higher printing, the ink fineness requirements are higher.
Fourth, the ink viscoelasticity
We know that viscoelasticity is the unique properties of polymers, both viscous and elastic. Ink is a mixed viscous system, especially where the dissolved polymer resin, also has the same characteristics.
Ink viscoelasticity is in the high-speed operation of the printing press under the alternating stress, the most prominent performance is the two ink rollers after the pressure and then parted, the sticky ink is pulled into the ink filament, thus cracking, constituting a “flying ink” process.
Viscoelasticity occurs because of the internal structure of the system and the structure of the molecules themselves. Most of the molecules in the ink have polarity, the number of alternative groups, the dissolution of the resin into the system viscosity increases, coupled with the high degree of dispersion of the pigment particles and filler particles, so that the system movement damping is very large, all the material between the molecules of the various interactions constitute a huge attraction to the system as a whole bound together to form a “net frame “. Therefore, the ink in shear or tensile force under the action of the phenomenon of viscoelasticity.
The above is our general printing ink has the function and influence the function of the ink some of the influencing factors, these issues need us to continue to find and improve in the printing work, and then ensure the quality of our printed products, to understand these is to ensure the quality of the conditions.