Along with the development of the printing industry, the quality of printing society continuously put forward more and more high demand, from printing equipment, printing materials, printing consumables, to operating personnel operational skills have higher requirements. This paper from the water to offset the quality evaluation, this paper discusses the effect of water quality of the printing and the improvement of water.
1. The quality of the water hardness
When the hardness of calcium, more than 200 PPM can lead to it and printing ink of resin contact form, and in the saponification calcium with acid solution phase at contact, will produce like citric acid calcium and calcium phosphate, of salt.
Saponification calcium has the lipophilic, will lead to ink deposition in the don't need area, such as the water roller, plastic cloth with soft nap, surface water calcium salt have very good hydrophilic, would block the ink transfer and lead to ink roll deinking.
In addition the water calcium if to exceed bid, so will directly affect the service life of the rubber roller, will lead to plastic roller surface crystal.
Conclusion one: excellent water will aggravate the ink emulsifying process, will lead to ink on waterways in the deposition, will aggravate the roller surface crystal) (aging.
2. When the water conductivity fluctuations
Education version fluid dynamic surface tension depends on which education version of the original concentration, the higher the concentration, the bottom surface tension.
Some of the commercialization of automatic conveyer device can control education version of the original concentration, to achieve a predetermined conductivity. When the water conductivity too big when, will cause the concentration of original education version changes, the result is that oil and water imbalance, the trigger fault offset printing.
If the proportion of the original education version, as the other as quantitative and accurate control unit, the problem may not quite, but when the water supply of conductivity change is very big, can still cause of the imbalance between oil and water each role.
Conclusion two: when the water conductivity have volatility, printing process of education version of automation control and testing liquid influence.
3. For many of the factory large companies
Some companies in several cities are factory, needed in order to achieve standardization management is unified quality. To use the same water quality put forward higher request. For example, several cities the hardness of the water itself, a few cities of how water impurity rate how. This is all to have to consider the question.
Conclusion: when three different parts of the water quality at the same time, will not for printed matter of quality standardization produce certain effect.
Through the above analysis, we found that the quality of the water itself, the printing process in a certain range is an influence, so the water and not to deal with the insignificant things, the ability of the enterprise to printing water treatment is necessary, on water quality in bad water treatment is a must.
Water processing methods:
The treatment of water can be said to be DuoZhong channel can be carried out, for example: distillation, softening water treatment, activated carbon filter, micro filter, utrasmall filtering, reverse osmosis filtration and so on.
1. The softening water treatment:
Use sodium chloride gradually after the resin filter to water, when combined with resin has been the sodium ions to meet the water of calcium, magnesium, manganese ions in will be the ion replaced, that is the ion in the water, and at the same time, to calcium, magnesium plasma adsorption to resin.
This treatment can effectively reduce the water hardness (which reduce the water content of calcium magnesium ions), but it is worth bearing in mind is because the water is of the concentration of the ions and did not change, so the water itself of conductivity and not change.
2. Ion to divide
This method is to use cationic resin exchange agent and anion exchange resin agent respectively, the water exchange way ion of Yin and Yang. When the pressure of water through the exchange system, the water of the ion will be resin absorption of hydrogen ions, resin or hydroxyl ions into the water displacement, and also be the resin with charge to consumption. When the resin after failure, can use acid and alkali for reduction of resin.
Using this way water treatment equipment to basically have two kinds:
(1) double bed type resin exchange equipment. This equipment general has two resin containers (Yin and Yang).
(2) mixed. Use the resin using non-ionic Yin and Yang according to certain mixing ratio, use at the same time, if mixed, then deal with proper proportion of the water quality is to get very good.
3. The method:
In normal circumstances, the spread of water from the low concentration to direction of the high concentration of place, the diffusion method is to use certain materials and a means to this process, in reverse pressure to water from the direction of high concentration to low areas of concentration spread. The method is a more thorough impurity removal techniques, be in usually able to remove our drinking water in 90 to 95% of the impurities. More commonly used filter materials: cellulose acetate membrane, polyamide membrane and composite membrane.