The quality of the ink used in pigment characteristics and evaluation
2014.07.09 13:26The quality of the ink used in pigment characteristics and evaluation
Accurate evaluation of pigment in the ink quality, for paint and ink workers is a very important work.
With organic pigment ink application performance evaluation due to the way of printing, printing materials, varieties and many types of ink, its may have a quite different link types, etc, therefore, evaluate whether a paint quality conforms to the requirement of printing ink, first of all, from the point of view of practical application to determine the application of the paint system types, according to different links of system to select the corresponding performance evaluation methods, so as to more accurately grasp the application of the paint performance.
Four-color offset printing ink pigment application performance evaluation
Currently, four-color offset printing ink in the main use of rosin modified phenolic resin, in the process of production of the resin has been given, such as water resistance, film strength and adhesion, and paint the wettability of various problems, so the application performance of such pigments will be around the gel ink correct evaluation on the physical and chemical performance of the link, that is to choose the corresponding test methods. For dry powder paint, for example, can be made from three roll grinding methods to test the quality indexes of pigment ink, and can accurately evaluate the dispersion.
For some special filter cake, you can directly made ink commutation method squeeze water base ink to evaluation.
Solvent ink pigment application performance evaluation
Because the links made of resin and solvent feeding system of the physical and chemical performance difference is bigger, pigment for solvent printing inks evaluation need more targeted. Due to the links of different solvent ink material has different properties, so the links should be based on different material system to select different application performance of the paint.
Water-based ink quality requirements of pigment in is much more strict than other types of solvent-based inks, mainly reflected the influence of the pigments on water-based ink rheological properties. At present, water-based ink generally use acrylic resin emulsion system, due to the particularity of the system, some applications in other systems performance good pigment varieties in water-based ink links in the material system may not be able to use. Such as the widespread use of azo lake red PR57:1 pigment, often cause when common varieties used in water-based ink viscosity is too high, and the longer the storage time, ink is thick, the serious influence its printing eligibility. To solve this problem, should be the necessary surface treatment technology and mix color lake method to improve them.
In addition, the solvent resistance transference of ink on the substrate, the boiling resistance requirements also have to pay attention to, the chemical structure of organic pigment, molecular weight, crystal particle size, polarity of hair and type of surface treatment agent used in the manufacturing process, etc., are likely to impact on it.
Pigment ink with physical and chemical properties analysis
Data from the application of performance evaluation is printing inks paint quality characteristics of a form. But decided to the manifestation of the intrinsic factor is its physical and chemical properties. The fact that the physical and chemical properties of organic pigments analysis and application of performance assessment, can act as both alone cannot achieve the effect of the evaluation.
Using the instrument analysis evaluation of physical and chemical characteristics of organic pigment is a kind of efficient and fast method. Organic pigments of instrument analysis mainly includes the following two aspects, one is the determination to the chemical molecular structure and form elements. Among them, the latter of organic pigment in the ink is more important to evaluate the performance of practical application. Among them, the latter of organic pigments used in printing ink performance more that strong. Commonly used organic pigment chemical analysis instrument meter has the following kinds: (1) particle size distribution. Size distribution apparatus (PSDA) can be used to measure the particle size and distribution of pigment particles dispersed state region. Ideally, the more concentrated the particle size distribution, the better, to maximize the chance that clear of pigment, transparency and tinting strength, light fastness and dispersion stability, etc.