The double-sided printing solutions for sheet-fed paper were only used as a supplement, but from the perspective of international trends in the last five years, double-sided printing of sheet-fed papers has been increasingly emphasized by publishing companies. Major printing equipment manufacturing groups are also paying more and more attention to the development of double-sided printing technology for sheet-fed paper.
The reason is that the requirements for publishing and printing are getting higher and higher, and the specifications of books, magazines and magazines are becoming more and more complex. The limitation of rotary printing equipment is that it is not economical to print on multiple specifications and short editions. When Nuley's company in China, also began using sheet-fed printing equipment in recent years to enhance its market competitiveness and ability to accept orders.
Here's a look at the classification of double-sided printing equipment choices:
Rotary double-sided printing solution
Rotary double-sided printing solutions are mainly divided into (1) press rotation equipment; (2) commercial rotation equipment.
Among them, the main requirements of the market for press rotation equipment (double-sided printing of rubber blankets on blankets) are:
Speed ​​> 30000 print/hr; 50-80GSM non-coated paper; Up to 150 lines/IN; Short ink path or splash ink supply;
The main requirements of the market for commercial rotation equipment are:
Speed ​​20000 printing / hour; 70-200GSM coated paper and non-coated paper; Network points up to 175 lines / IN; Uniform ink, with drying tunnel;
It should be noted that rotary printing basically takes the form of [BLANKET TO BLANKET] (B2B). Newspaper rotation mainly pursues high printing speed and high production efficiency. Commercial rotation is more demanding than press rotation in terms of printing accuracy, ink control, and drying. The biggest difference between the two lies in the design, speed, and drying system requirements of the ink path.
Sheet-fed double-sided printing equipment solution
After market analysis in recent years, we found that Japanese printing machinery manufacturers are more concerned with the practice and development of double-sided lithographic printing on sheetfed paper than Europe and the United States. There is a sentence that describes this phenomenon as very appropriate: "The United States is a revolutionism and Europe is a single-sided polychromaticism."
Europe and the United States have some difficulties with double-sided offset printing on sheetfed paper. The main reason is that the efficiency of double-sided printing is lower than that of rotary printing, and the control is also more complicated than single-sided printing. However, the prominent comprehensive efficiency and professional capabilities of double-sided printing make it more and more important in the current market.
Sheet-fed double-sided printing equipment can be divided into four types according to technology.
(I) Two-sided alternating printing equipment (based on Akiyama and Komori)
3-roll positive and negative alternate printing
The key technology is to solve the problem of non-stick ink and printing ink
Advantages in the same level of ink removal as single-sided printing presses
There are requirements for paper quality, suitable for double-sided printing on paper with small deformation
Komori adopted a solution with 9 double-diameter cylinders, which reduced the number of paper transfers (11 times) but also increased the manufacturing precision requirements, adjustment requirements, and operating requirements. The printing results (results) were often unsatisfactory.
Akiyama uses 18 equal-diameter roller arrangements, and the number of transfer processes in the printing process has reached 20 times. However, the printing results are easily controlled. From the comparative analysis of Japanese printing companies, the Akiyama plan is considered to have an advantage over Komori. Komori's current double-sided offset printing also turned to Hyde's flipping mechanism as the main program.
(b) Single-sided printing with reversed double-sided printing equipment
The use of flip roller on both sides of the teeth and the transfer of the opposite side of the printing
Multi-purpose equipment for single-sided multi-color or double-sided printing
Key Technology to Solve Imprinting Rollers
For paper and cutting, positive and negative overprints have operational requirements
The original roll-to-roll solution was used on two-color and four-color machines. The advantage is that it can be used as a single-sided multi-color or double-sided printing.
However, more and more devices that manufacture 8-color ribbon flipping are actually not the focus of their flexibility. They have become a professional two-sided 4-color printing solution.