A little bit about the ink
10 April 2014
In this article I want to look at the main types of inkjet ink , which are used in home and office printing , amateur and professional photo printing .
There are two main types of ink for the above tasks - is:
1. The water-soluble ink . (Dye ink)
2 . Pigment ink .
There are other types of ink, for example, sublimation, solvent, food-ink, and the others; but within this article we will not consider them.
So, first let's look at what a ink general. This is a very complex multicomponent chemical substance. Main components of the ink is a solvent a colorant and various modifiers stabilizers and chemical and physical properties.
As the solvent deionized water is used (not to be confused with distilled water) - in which water is not contained impurity ions, fact she has a purity of almost 100%.
In the role of colorant may be used, synthetic organic dyes or pigments. Dye - is a chemical that dissolves completely in water. Pigment - a colored substance which is not soluble in water and in the ink is in the form of very small solid particles.
Further deionized water and colorants for inkjet inks can be up to 20 components, ensuring stable operation of the print head and the correct color. Such a large number of components due to the high complexity of physical and chemical processes that control the supply and application of ink and the need to manage them literally with a jeweler's precision. Characteristics of each individual ink manufacturer usually differ significantly.
The main criteria for the quality of the inkjet ink :
2 . Surface tension
3 . Acidity (pH)
4 . Conductivity
5 . Colour absorbance
So, in order :
Viscosity - fluid property to resist movement of the body parts relative to one another , and it depends on temperature. Make no mistake : not flowing thick and liquid spreads . For example : a verbatim phrase from the instruction manual brand printers Epson: « yields may vary from the images that the print settings , paper type , frequency of use of the device and temperature ». It can be concluded that at higher temperature , where the viscosity of ink is lowered, the more they are used , which affects the total number of prints. And their quality , because the same ink have somewhere to go .
Ink optimum viscosity is from 2.9 - 3.5 mm 2 /a .
surface tension - термодинамическая характеристика interface of the two in equilibrium phase , determined work izotermokineticheskogo reversible formation per unit area of the surface of this section , provided that the temperature and volume of the system chemical potentials all components in both phases remain constant ( material is taken http://ru.wikipedia.org ) .
To put it more simply - the ability of the liquid to moisten the surface. This is one of the most important parameters that affect the integrity of the drop, edge sharpness and clarity of the print image .
Acidity - the acid is an aqueous solution. Wrong level of acidity can cause a color shift in a particular environment ; it can also cause damage to the print mechanism of the printer ( or print head cartridge ).
conductivity ( conductivity ) - here meant the ability of the ink to pass through an electric current, in other words, the reciprocal of the resistance. This property is a very important factor in the quality indicator ink , because the larger figure deviates from the norm , the more different impurities included in the ink , and the lower the quality of the product. On the other hand , the required electrical conductivity can not guarantee absolute quality inkjet inks since some primesti not affect its conductivity or mutually compensate their influence .
Color absorption - ability to absorb ink differently rays of light in different directions. What affects the rate of color shade and intensity ; affects the tonal reproduction , halftone , black and white tones and gradation .
Now let us consider specifically the difference between dye-based inks and pigment .
So , inkjet ink - is ink, dye-based inks , which is completely dissolved in the solvent and the pigment ink contains a colored substance which is not soluble in water and in the ink is in the form of very fine solid particles (particle size about 0.1 microns).
Advantages of the water-soluble ink :
• In comparison with the pigment , " edema " has a wider color gamut . It is necessary to properly use the correct color profiles , but the company ColorWay, has long and successfully produces ink that work just fine without color profiles .
• Printhead printing device is much easier to recover after use " dropsy »
• Penetrate into the deeper layers of paper and more suitable for printing on various types of microporous paper and glossy .
• They are cheaper pigment .
Disadvantages soluble ink :
• They are more exposed to the environment and will lose their original color saturation .
• Printing on plain office paper is not characterized by high quality , due to the spreading of drops and excessive impregnation of the paper itself .
• Another little-known drawback is prolonged stabilization color print after print .
Pros pigment ink :
• More resistant to the environment. Namely to light, moisture , etc. . Fingerprints obtained with the serenity you can have open spaces .
• Pigmented ink is thoroughly impregnated paper. Pigment ink very good print double-sided documents .
• With pigment ink , you can print good quality images on plain office paper .
Disadvantages pigment ink :
• Smaller color gamut , compared with dye-ink »
• Pigmented inks are more often clog the nozzles of an inkjet printer .
• If the nozzles are clogged with pigment ink , then rinse them very difficult .
• Poor absorption in the low-cost glossy paper .
• Their cost is much higher than that of dye-ink».
Ways to distinguish pigment and dye-based inks :
method number 1 : Take a drop of the test ink and dissolve it in a glass of water , carefully observe the result - pigment ink dissolves give grayscale regardless of breeding, until clear water . Dye-based inks at a certain degree of dilution given dirty shades of purple or other colors .
method number 2 : dilute the ink drop investigated in 10 ml of water and add a few drops of bleach - discolored water-based ink , pigment or did not respond , or will fall into the sediment .