Coated paper is a high quality printing paper known for its high quality surface finish and printing effect. It is usually used for the printing of high-quality books, magazines, picture albums, greeting cards and other cultural publications, as well as high-end packaging, business cards and so on. In the manufacturing process of coated paper, a coating process is usually used to coat the surface of high whiteness paper with a layer of adhesive and white filler, so as to obtain a smooth surface and printing effect.

What is coated paper and what performance should be tested?

The detection of coated paper needs to pay attention to the following main properties:

Thickness and density: the thickness and density of coated paper will directly affect its stability and printing effect. The thickness and density can be measured by measuring paper thickness, density and base weight.

Smoothness: Coated paper needs to have a very smooth surface to ensure clarity and detail of text and images. The test of smoothness can be carried out by measuring the paper surface smoothness, feather height and plate crown and other indicators.

Whiteness: Coated paper needs to have a certain whiteness to ensure the color restoration and contrast of the printed text and image. The detection of whiteness can be carried out by measuring the color and color difference of the light reflected by the paper.

Gloss: Coated paper needs to have a certain gloss to enhance the visual effect of the print. The detection of gloss can be done by measuring the reflectivity of the paper surface.

Strength: Coated paper needs to be strong enough to withstand the tension and pressure in the printing process. The test of strength can be carried out by measuring the tensile strength, tearing strength and compression strength of the paper.

Printing performance: coated paper needs to have certain printing performance to ensure the printing quality of printed matter. The detection of printing performance can be carried out by measuring the paper’s water absorption, oil absorption, printing clarity, color reduction and resistance to printing pollution.

Environmental protection: coated paper needs to meet environmental standards, does not contain harmful substances, no pollution to the environment. Environmental protection can be tested by measuring paper volatile organic compounds, heavy metals, chloride ions and fluorescence

Light brightening agent and other indicators to carry out.

Bonding strength: The surface of coated paper is coated with a layer of adhesive and white filler, so its bonding strength also needs to be tested to ensure that the filler on the surface of the paper is not easy to fall off. The adhesion strength can be measured by measuring the peeling strength, cutting strength and ring compression strength of the paper.

Copper coating: copperplate paper is characterized by its surface through a layer of copper and polishing treatment, in order to obtain a good gloss and smoothness, so the quality and uniformity of copperplate paper coating also need to be tested. The detection methods include thickness measurement, surface quality detection and microstructure analysis.

The above performance indicators are the key content of coated paper testing. Different usage requirements and standards will also affect the testing standards and methods of paper.