The quality of paper is good or bad, in fact depends on the pros and cons of raw materials, good copper must also have a thorough understanding of the characteristics of paper operators, in order to make good paper.

First, the division of coated paper

The varieties of coated paper are divided according to the different fillers and calendering processes, which are generally divided into single-sided and double-sided light.

From the properties of the coating and sub-casein coating.

So coated paper is also known as coating paper.

Improper operation of printing coated paper also tends to produce stickiness (over the bottom), powderization, slow drying, lack of star brightness, etc., so attention should be paid to the following problems.

1, for each batch of coated paper, before put into use, to cope with the smoothness of paper, ph, absorption, drying, scalability, and surface bonding strength and a series of problems involving printing, test analysis, and then according to the characteristics of the paper, adopts the corresponding process improvement, adjust the ink viscosity, liquidity, dryness and anti-sticking measures, prevent printing bad happens;

2, we should pay attention to the pad technology and printing pressure debugging these two very important links, to ensure that the printing ink layer is uniform and bright.

Coated paper printing pressure should be uniform and appropriate, excessive pressure is easy to produce bad powder, and easy to cause the defects such as dot imprinting is not clear, and may increase the plate wear.

On the contrary, it is easy to cause the dot imprinting is not strong, and blindly increase the ink layer to make up for the lack of pressure caused by the layout flower, as it is easy to produce sticky, slow drying, overprinting is not good, so the pressure of printing copperplate paper should be uniform and appropriate.

The packaging is made of neutral and hard materials.

3. Printing trademarks and packaging products on copperplate paper, often with light color as the background color, and overprinting by overlapping color.

This printing right process is improper, also easy to produce some problems and affect the quality, so, in the deployment of background ink, should try to choose heat and light resistant ink, and the diluent is best to use light paste deployment, so that the background color in the final printing effect is better, in order to prevent the first printing of background color easy friction damage ink layer.

4. Because the surface of coated paper is smooth and the ink absorption ability is poor, the "deep ink thin printing" should be done as far as possible when printing the field version of large plates.

That is, the ink phase is appropriately darkened, so that the ink layer corresponding or thinner, which can meet the requirements of printing hue, and can reduce the chance of imprinting over the bottom, and can prevent the overlap of color printing.

5. Due to the large amount of coating on coated paper, the phenomenon of depowdering and black shadow on the printing page is often encountered in the printing process.

In this case, we should pay attention to check whether the plate loading process operation, such as the printing plate has a heavy pad, because the pressure on the paper is too large, it is easy to crush the powder of the coating on the surface of the coated paper, resulting in powder removal and black spots.

In addition, should also check whether the ink viscosity is appropriate, if the printing ink layer is too thick, too sticky, is also one of the reasons for the paper powder and the accumulation of layout, in this case, should consider the application of auxiliary materials to adjust the quality of ink, the above quality problems can be better overcome.

6. We should pay attention to the production steps such as the anti-adhesion technology of coated paper printing.

Coated paper absorbency is weak, and the back is smooth, so that the printing ink is very layout or multi-color overprint, prone to stick dirty problem, so the anti-sticking measures should be taken to overcome them, such as to take right amount in the light oil is the first of anti-sticking agent, stirring evenly, make it into a liquid after join again beaten in the printing ink, printing when good anti-sticking effect can be received.

But the amount of anti-sticking agent should pay attention to reasonable control, can not exceed 4%, so as not to make the ink emulsification, printing ink layer flower and ink layer gloss decline and other undesirable defects.

Summarized the above six main points, as long as the characteristics of coated paper, in the printing process operation, to ensure the printing effect and printing quality.