Ink printing is one of the most common processes in the printing industry, which is widely used in books, packaging, advertising and other fields. In order to ensure printing quality, improve production efficiency and reduce material waste, operators should pay attention to the following key matters:
Different printing materials and processes need to use different types of inks. For example:
1. Offset printing ink: suitable for paper printing, fast drying and bright colors.
2.UV ink: It is suitable for non-absorbent materials such as plastics and metals, and needs UV curing.
3. Water-based ink: environmental protection and non-toxic, commonly used in food packaging and printing.
Choosing the wrong ink may lead to poor adhesion, poor drying or color deviation.
Controlling ink viscosity
Ink viscosity directly affects printing quality. Too high viscosity will lead to uneven ink transfer, wire drawing or ink accumulation; Too low viscosity may cause dot diffusion and color fading. The ink viscosity should be adjusted according to the speed of the printing machine and the ambient temperature and humidity, and thinner or thickener should be added if necessary.
Ensure a stable printing environment
The change of temperature and humidity will affect the drying speed and fluidity of ink. The ideal printing environment should maintain:
1.Temperature: 20-25℃
2.Humidity: 50-60%
3.Too high humidity may lead to moisture absorption and deformation of paper, while too low humidity will easily generate static electricity, which will affect printing accuracy.
Correctly adjust the printing pressure
Excessive printing pressure may lead to dot enlargement and paper deformation; If the pressure is too small, the ink transfer will be insufficient, which will affect the color saturation. The printing pressure should be adjusted according to the thickness and hardness of the substrate to ensure uniform ink layer.
Pay attention to the ink drying method
Different inks have different drying methods:
1. Oxidation drying: It is suitable for offset printing ink, and it needs a certain period of natural drying.
2. Volatilization drying: for example, solvent-based inks are dried by solvent volatilization.
3.UV curing: UV lamp irradiation is needed for rapid curing.
Appropriate drying method should be selected according to the characteristics of ink to avoid rubbing or adhesion caused by incomplete drying.
Regular maintenance of printing equipment
The cleaning and maintenance of printing machines directly affect the printing quality. On a regular basis:
1. Clean the ink roller and blanket to prevent residual ink from affecting color reproduction.
2. Check the scraper and anilox roller to ensure uniform ink transfer.
3. Calibrate the printing machine to avoid misregister or color difference.
Safety and environmental protection
The solvent in the ink may contain volatile organic compounds (VOCs), and the operation should be:
1. Ensure that the workplace is well ventilated.
2. Wear protective gloves and masks to avoid direct contact with ink.
3. Waste ink and cleaning agent should be treated according to environmental protection requirements to avoid environmental pollution.
Conclusion
The quality of ink printing is affected by many factors, from ink selection to equipment maintenance, every link needs to be strictly controlled. Following the above precautions can effectively improve the quality of printed matter, reduce waste and ensure production safety.
