Flexographic Printing and Environmentally Friendly Packaging (Part 2)

【Summary Description】 1. Flexible plate materials and their matching with the latest ink can achieve optimal results in smaller dot enlargement, smoother printing output, fewer plate washes, and better ink transfer performance when used in combination. The resin plate used for corrugated printing adopts new, higher purity, and the best surface performance raw materials, and the manufacturing process has been improved. This new type of printing plate can achieve uniform and thick ink transfer under the set minimum printing pressure. The amount of ink transfer and its impact on ink release performance are the determining factors affecting ink color and ink coverage performance.

4、 Key Technologies for Making Environmentally Friendly Flexographic Cartons

 

1. Flexible plate materials and their matching with the latest ink can achieve optimal results in smaller dot enlargement, smoother printing output, fewer plate washes, and better ink transfer performance when used in combination. The resin plate used for corrugated printing adopts new, higher purity, and the best surface performance raw materials, and the manufacturing process has been improved. This new type of printing plate can achieve uniform and thick ink transfer under the set minimum printing pressure. The amount of ink transfer and its impact on ink release performance are the determining factors affecting ink color and ink coverage performance.

 

2. The influence of box surface printing on the compressive strength of corrugated cardboard boxes

 

Compressive strength is an important indicator for testing and evaluating the performance of corrugated cardboard boxes. If the compressive strength of the cardboard box does not meet the requirements for use, it will not play a protective role in the circulation of goods, causing damage to the goods and economic losses. The factors that affect the compressive strength of corrugated cardboard boxes mainly include raw material factors (edge compression strength, moisture content, adhesive, etc.), circulation environment factors (temperature, humidity, storage time, etc.), and cardboard box design factors (box opening circumference, aspect ratio, printing design, etc.). Printing design is one of the important factors affecting the compressive strength of corrugated cardboard boxes. Therefore, when designing cardboard box printing, printing pressure should be minimized as much as possible. If the pressure is too high, it is easy to crush the corrugated board; Avoid full plate and strip printing. Generally, when corrugated cardboard boxes are fully printed, their compressive strength decreases by about 40%; Try to reduce the number of overprinting as much as possible. Experiments have shown that after monochrome printing, the compressive strength of corrugated boxes decreases by 6% -12%, while after three color overprinting, it will decrease by 17-20%.

 

3. Production of flexible printing plates

 

For printing plates, the most basic requirement is to be able to produce uniform and thick ink transfer with low dot expansion. Other common requirements include precision and smooth printing of fine images and lines such as barcodes; The reduction of pasting phenomenon and the exquisite printing of high difficulty levels. The maximum resolution of the photosensitive resin has exceeded 250 lines/inch, the dot reproduction power has reached 95%, and the minimum independent point can reach 100 μ m. The flatness of the plate can reach ± 0.013mm, and the printing resistance can reach several million times. From an international perspective, the plate making process of flexo has matured and standardized and scaled up the plate making process.

 

With the development of digital technology and laser technology, the direct plate making system of flexographic printing has entered the practical stage. The digital printing plate made using direct plate making technology has advantages such as complete dot patterns, high light points that are not easily lost, low dot enlargement rate, step length adjustment, and large dots that are not sticky. At present, the direct plate making system mainly uses digital transmission technology. After color separation and plate assembly, images are directly formed on the resin plate, and then the photosensitive resin plate is washed to produce the printing plate required for printing.

5、 New Technologies for Improving Flexographic Printing

 

The development of cutting marks in corrugated cardboard production has brought possibilities for the use of preprint paper.

 

2. Vacuum adsorption paper feeding and paper delivery servo drive technology is replacing gear transmission machinery, bringing precise paper feeding control, faster setting, improved die-cutting quality and printing ability.

 

3. Flexible offline printing, changing the ink transfer roller system for high-quality graphic printing.

 

4. The introduction of laser cutting ceramic mesh rollers for flexographic printing machines has improved the quality of ink application. The introduction of a closed scraper ink system has greatly improved the quality of ink transmission.

 

5. The improvement in the quality of photosensitive printing plates provides better accuracy, and flexible plates are directly printed for standard color applications.

 

6. Using a dryer in printing reduces issues related to ink and coating deviation, resulting in faster production speed. Due to the high speed capability of computer settings, the output can reach a higher output of 6000 sheets per hour.

 

7. The application of automatic die cutting, complete vacuum cleaning, and automatic stacking to achieve clean production.

 

In recent years, the multifunctional functions of unit type inline flexographic printing machines and combination printing processes, such as UV production lines, wire screen printing, and hot stamping, have been highly valued both domestically and internationally, improving the practicality of flexographic printing machines.

 

Many new technologies used in flexographic printing machines, such as shaftless transmission technology, sleeve rolling technology, computer automatic control technology, and on machine automatic cleaning technology, are all used in the new generation of flexographic printing machines. These new technologies have promoted the development of high-quality flexographic printing and opened up new fields for the environmental protection performance of flexographic printing technology.

 

6、 Green Manufacturing and Clean Production Law

 

Green manufacturing, also known as environmentally conscious manufacturing or clean manufacturing. Green manufacturing is a modern manufacturing model that comprehensively considers environmental impact and resource optimization utilization. Its goal is to minimize the impact on the environment, maximize resource utilization, and optimize the economic and social benefits of enterprises throughout the entire product lifecycle from design, manufacturing, packaging, transportation, use to disposal. Its architecture includes green design, environmental and material selection, green process planning, green packaging recycling and remanufacturing technology, eco-industrial technology for environment and resources, and decision analysis for full lifecycle assessment

 

In the printing process, flexographic printing is closest to green manufacturing and belongs to the environmentally friendly manufacturing industry.

 

For this reason, flexographic printing, also known as "environmentally friendly printing", is gradually replacing the printing of packaging paper and boxes in the domestic food industry with flexographic printing. The packaging paper for hamburgers, McDonald's packaging boxes, Yili ice cream boxes, and rooftop packages such as Mengniu, Guangming, San, and Wanda Mountain are mostly printed using flexographic printing.

 

As an important transportation and sales packaging, corrugated cardboard boxes with exquisite printed patterns, trademarks, relevant explanatory texts, and storage and transportation signs on their surface will form a huge pattern when stacked, forming a strong visual impact and becoming a "scenic line" in the process of commercial circulation, providing consumers with the enjoyment of "environmental beauty".

 

Due to the minimal impact of green manufacturing on the environment, it is becoming increasingly important to address environmental issues