Eight Key Points for Saving and Controlling in Gravure Printing Production
1. Layout Design
During the layout design process, strive for the highest quality printing results with the simplest and most rational design.
(1) For color marks, cutting marks, bag making marks, dot signal bars, and other indicators, use smaller sizes and reasonable colors to reduce the process loss of the substrate.
(2) Reduce the use of spot color plates and spot color inks, use primary colors for overlay instead of spot colors to save plates and ink.
(3) Reduce the number of colors, optimize layout design, and minimize the overlap of printing areas.
2. Plate Making and Usage
In the plate making process, preferentially use non-film electronic engraving technology to reduce the use of etching processes. In plate storage and usage, pay attention to protecting the plates and improving their durability. Plate durability not only depends on the quality of chromium plating but is also greatly influenced by operational practices. Good operational habits can significantly enhance plate durability. When plates show signs of wear after a certain print volume, promptly re-chrome and re-plate them to avoid them becoming unusable. Discarded plates should be returned to the plate-making factory for recycling.
3. Ink Viscosity Control and Usage
Ink viscosity directly affects the color consistency of printed products. Improper control can result in a large amount of waste and material loss. Therefore, ink viscosity should be reasonably controlled during the gravure printing process. Automatic viscosity control devices can be used to control ink viscosity, or solvents can be added to the ink supply system, and measures such as covering ink pans, ink barrels, and solvent barrels can compensate for the effects of solvent evaporation on ink viscosity. For spot color inks, energy-cured inks, and expensive specialty inks, smaller ink troughs should be used to reduce residual ink volume. Waste film should wrap ink troughs to reduce the workload of cleaning ink pans and solvent consumption. Used ink barrels should be thoroughly cleaned to minimize ink residue.
4. Mixing of Spot Color Inks
When mixing spot color inks, in addition to recording the proportions of each ink color, a sufficient amount of ink samples should be retained. When reprinting, ink can be mixed according to the proportions, and ink samples can be compared repeatedly until there is no visual difference in color appearance before printing. This approach addresses the impact of ink color differences between different batches on color consistency. Advanced gravure printing companies can also use computer color matching and allocation systems to improve ink color accuracy and minimize the amount of old ink remaining in the ink inventory.
5. Selection and Usage of Doctor Blades
Doctor blades are essential components of gravure printing equipment. During high-speed operation, they inevitably experience wear and tear. Therefore, after completing a certain print volume or replacing plates, doctor blades need to be replaced. To reduce the frequency of blade replacement and save costs, measures such as reducing blade angles and pressure, increasing the thickness, smoothness, and hardness of chromium plating on plates, thoroughly filtering ink, and keeping substrates and printing units clean should be implemented. Additionally, used doctor blades can be refurbished for reuse or used for full-area printing in white versions, among other measures.
6. Usage of Material Rolls
To reduce material waste during the printing startup phase caused by registration adjustments, printing plates should be adjusted to the correct position to minimize initial plate errors. Alternatively, waste or lower-grade materials can be used for setup. Control printing tension and other parameters to achieve high-precision registration of substrates. When automatically feeding new material rolls, prepare the new roll in advance. In cases of significant registration errors, manually adjust before switching to automatic registration systems to avoid producing a large amount of waste due to registration errors. Additionally, proper labeling of defective prints reduces the intensity of reinspection work and minimizes material waste in post-printing processes. Keeping detailed process records facilitates quick registration for subsequent printing, improving production efficiency and yield.
7. Environmental Control in the Gravure Workshop
Gravure workshop environmental factors include temperature, humidity, cleanliness, etc. Improving the workshop environment significantly contributes to enhancing print quality and reducing printing failures. For instance, under conditions of high temperature or dryness, slow-drying solvents may need to be added to ensure satisfactory results for fine-line printing, increasing drying loads and the risk of solvent residue. In such cases, humidification systems should be used during dry seasons to reduce static electricity, improving fine-line printing results. Additionally, a clean production environment prevents dust from adhering to films, aiding in reducing printing faults such as blade lines.
8. Waste Recycling and Reutilization
(1) After opening containers and when ink remains in ink pans, promptly seal them for storage. Discarded ink can be reformulated into black ink or other spot color inks for reuse, and solvents from unusable leftover ink can be recovered.
(2) Discarded plastic films can be used for setup or, after cutting, can be used for protective packaging of plastic pipes, doors, and windows, and other building materials.
(3) Rag usage should be graded, minimizing the use of discarded rags for cleaning printing plates, impression rolls, guide rollers, ink barrels, and ink pans.
(4) Various waste generated during printing should be sorted and collected. Films, papers, aluminum foils, cardboard boxes, paper tubes, baffles, ink barrels, etc., can be recycled. Waste cloth, sand screens, sandpaper, etc., should be collected by waste collection stations and subjected to resource recovery or sanitary landfilling.