Standards for Material Selection in Single-Color Offset Printing
As the name suggests, a single-color offset printer prints only one color at a time.
When it comes to selecting printing consumables for a single-color offset printer, there are some differences compared to multi-color offset printers. Multi-color printers generally have higher requirements for consumables, while single-color printers are relatively more flexible.
In fact, the selection of printing materials should be made carefully, considering factors such as cost, quality, and cost-effectiveness. Here, I will briefly discuss the selection of consumables for a single-color offset printer.
1. Suction Cup Liners (Suction Rollers)
The only consumable that needs frequent replacement at the feeder section is the suction cup liner. There are generally three thickness options: thick, standard, and thin.
In most cases, all three thicknesses can accommodate various paper types. Even with the thinnest suction cup liner, it can handle thick paper without issue. However, in the paper feeding process, if the paper is not being sucked up properly, adjustments to the suction height and airflow can help compensate.
Recommendation: Standard suction cup liners have a wider application range. Prices range from 0.3 to 1 yuan per piece.
2. Paper Transport Brushes and Belts
The choice of paper transport brushes and belts should be made according to the specific situation. For brushes, it's recommended to use smaller ones, as smaller brushes tend to have less deformation, resulting in better paper transport stability.
3. Ink Selection
Ink choice is crucial. Many single-color printers use "Peony" ink, which is known for its excellent cost-performance ratio and stable quality. It is one of the most reliable inks on the market. Additionally, "Peony" ink has many suppliers, which creates healthy price competition and keeps profit margins lower. This is one reason why many print shops have been loyal to Peony ink for years. Other recommended inks include Tianjin Tian Shi, Shanghai Huaxing, and Hangzhou Hanghua.
Ink additives include ink thinners, anti-tack agents, and ink adjusting oils.
In most cases, ink adjusting oil is preferred for its good cost-effectiveness. Anti-tack agents and ink additives tend to be more expensive, and in situations where necessary, ink additives can be used instead of anti-tack agents as their effects are similar.
4. Wetting Powder
Wetting powder is important. Many printers believe that the more wetting powder used, the better the printing quality. However, this is not the case. Excessive wetting powder can damage the printing plate. While wetting powder does have a certain ability to prevent dirt transfer, its main function is to ensure the water quality is fine and stable, helping control surface tension and preventing water splashing.
5. Plate Repair Materials
Plate repair materials such as plate repair paste, plate repair liquids, and repair pens should be selected according to the specific situation. It is recommended to use plate repair paste in the plate-making room and plate repair pens on the printing press.
6. Plate Cleaners and Plates
The price gap between plate cleaners and plate cleaning liquids can be significant. To save on these materials, consider using sponges instead of cloth when cleaning the plates. Sponges have strong water absorption capabilities, and you can keep a bucket of water near the printing press to soak the sponge. Over time, the residual plate cleaner will dissolve into the water. I've seen one printing shop where a single machine only used two boxes of plate cleaner a month, as they reused the water daily. The water was disposed of only when it started to smell.
While this is an economical approach, from a hygiene perspective, it’s best to use it moderately.
As for plate selection, it depends on the specific requirements. Some companies can work with recycled plates, while others may only use premium brands like Huaguang plates. For large-volume printing, high-quality plates are necessary, but for smaller runs (e.g., a few thousand sheets), recycled plates are also suitable. Since single-color printing machines generally have lower print quality requirements, recycled plates can be a good option. As for rubber blankets, it is recommended to use high-quality ones, such as Dico (USA) or FireGod (Italy). With proper use, these can last several months before needing replacement, which is quite cost-effective. However, if a company prints thick paper regularly, which can easily damage the rubber blanket, domestic rubber blankets may be more appropriate.
7. Restorative Agents for Rubber Blankets
There are two types of restorative agents: one is a cleaning-type restorative agent (which is not very effective and costs around 10 yuan per bottle), and the other is a stronger restorative agent (which comes in a paste form and is much more effective, priced between 60 and 80 yuan). The choice depends on the price of the rubber blanket. Sometimes, the cost of one strong restorative agent can equal the price of a new rubber blanket.
8. Other Auxiliary Materials
Other auxiliary materials include anti-drying agents, calcium removers, anti-skinning agents, and wash water. Calcium removers are used to clean the surface of rollers, and they work effectively to remove most contaminants. If roller contamination is severe, they may need to be disassembled and cleaned with toluene. Anti-skinning agents can help reduce the waste of wash water, although I don’t recommend using them if the machine has been idle for more than 4 hours. In such cases, it’s better to wash the rollers.
9. Spray Powder
The choice of spray powder depends on the printing job. For finer powder, choose larger particles; the choice should be based on ink coverage, paper thickness, and the smoothness of the paper surface. For printing on materials like dinner plates, eco-friendly and non-toxic spray powder should be used.
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