Talking About The Influence Of Ink Performance On Printing Quality

Ink is a colored colloidal dispersion system. The main components are colored substances (pigments) and binders. The colored substances play a role in color development. By contrasting with the color of the substrate, the image is displayed on the substrate. The binder is a fluid with a certain viscosity and viscosity, which can mix and connect solid particles such as powdered pigments, and make the cohesive pigments finally adhere to the printed product. Only by correctly understanding and understanding the properties of the ink and adjusting the proportions of the various components of the ink can the ink's proper printing suitability and use performance be achieved, and the printing ink can be well matched with the printing plate, printing machine and printing material. Make the printing process go smoothly.

Viscosity

When a liquid is stirred, the speed of its flow is proportional to the applied force. In the printing process, the viscosity of the ink is closely related to the transfer of the ink. Generally, the higher the machine speed, the faster the ink separation speed, and the lower the viscosity of the ink is required, otherwise the transfer effect is not ideal. In addition, the lower the surface strength of the paper, the lower the viscosity of the ink is also required, otherwise it is prone to pull the paper. Therefore, in the gravure production process, the viscosity of the ink must be strictly controlled to ensure the printing effect. The ink viscosity also affects the color difference value of the printed matter, and the hue of the printed matter can be well controlled by controlling the color difference value.

Fluidity

Fluidity means that the ink flows like a liquid under its own gravity, which is determined by the viscosity, yield value and thixotropy of the ink, and is also closely related to temperature. The fluidity of the ink affects the transfer of the ink between the ink tank, the printing plate and the substrate, thereby affecting the printing effect. Ink with high viscosity has poor fluidity; ink with low viscosity has good fluidity. In winter, if the temperature is low, the fluidity of the ink will be reduced. For products with higher quality requirements, the ink can be heated during printing. Usually a barrel is added outside the ink barrel, and the built-in electric heating tube heats the water in the barrel. Keep the ink at a certain temperature to maintain the fluidity of the ink to stabilize the printing effect.

Dryness

The ink should have good drying performance. Too fast or too slow drying of the ink will affect the control of the printing process and the printing quality. If the ink drying is too slow, the wet ink film on the surface of the printed product will easily be transferred to the back of the next printed sheet. During the stacking of the printed product, it will easily cause the back side to be dirty. In severe cases, adhesion will occur and "roller pulling" will occur. "Phenomena, the ink will stick to the paper roller, and the printed matter will be "pulled out". If the ink dries too fast, it will be difficult to control the fluidity of the ink during the printing process, resulting in difficulty in ink transfer, poor ink transfer, and inconsistency of ink color.

Fineness

The fineness of the ink refers to the size of the pigment and filler particles in the ink and the uniformity of the pigment particles distributed in the binder. Ink with poor fineness is prone to uneven ink distribution, strips, fly bars, and ink paste during the printing process. In severe cases, it will also cause quality problems such as worn printing plates and poor color rendering. The fineness of the ink is good, its concentration is relatively large, the color saturation is high, the ink transfer is good, and the printing is clearer. In addition, during the production process of paper, less paper dust will be produced on its surface. During the printing process, the paper dust will fall into the ink tank and affect the fineness of the ink. It will also cause strips and flying ink. Therefore, it can be added in the ink circulation loop. Install a filter to filter out the impurities in the ink.

Tinting strength

The color strength of the ink determines the intensity of the ink hue. When the coloring power of the ink is large, the printing hue will be darker; on the contrary, the printing hue will be lighter. Ink with high tinting strength consumes relatively less ink in printing, and the quality of ink color is also better; on the contrary, ink with low tinting strength uses more ink in printing, and the ink color is relatively lighter, which has a difference in color. The value has a greater impact. For inks with low tinting strength, the viscosity of the ink can be appropriately increased or the engraving depth of the printing plate can be increased appropriately.