History Of Printing Technology

The development of textile printing technology has been developing for a long time.

In the first millennium of the human era, our ancestors made outstanding contributions to the development of fabric printing technology. Nowadays, various printing processes, such as direct printing and dyeing prevention, are common.

Development of printing machine

flat screen printing machine

Although rotary screen printing shows absolute advantages and has improved greatly in fineness, flat screen printing will not be eliminated.

In fact, flat screen printing technology is being paid attention again because the trend of small batch printing is increasing day by day. From the economic point of view, it is advantageous to use flat screen printing under such circumstances.

With the introduction of automation technology of digital network and shortening the time of network switching, the convenience of flat screen printing has become a printing technology that can not be overlooked.

There are two new models. The printing band can be heated to 50 degrees centigrade, and the same bright and fine effect can be obtained.

A multifunctional KOMBIPRINT printing machine combines the characteristics of flat screen and circular net, equipped with a robot for changing nets and scraping printing devices, realizing complete automation.

Rotary screen printing machine

The printing machine manufacturers have been concentrating their interest on rotary screen printing machines, especially in researching and developing an effective system to reduce the waste of fabric and color paste in printing process.

De MontFort University in Leicester, England, analysed the printing defects information collected from 8 printing factories, and showed that the most common defects were incorrect flowers and incorrect alignment.

In old-fashioned equipment, flowers and calibration are done through naked eye observation and manual adjustment.

In the past 10 years, many improvements have been made in this area. For example, the arrangement of screens can be calibrated by laser beams, and the location of each screen can also be corrected.

In order to eliminate the error caused by the gear gap or the torque distortion of the driving shaft, the AC servo motor was adopted on the Zimmer printing machine, while the Stork printing machine adopted a grading or stepless ring motor driven by direct screen.

One of the other improvement measures that Stork provides to improve accuracy is to detect metal sheets fixed on the conduction band by sensors mounted on each printing head, and accurately control the drive of single screen with the help of pulses to ensure synchronization between the conduction band and the screen. This technology is a patent of STORK company, or BPMS.

For example, the latest RD-DD and Dong Gus type rotary screen printing machines have installed separate pmission systems on each printing head, each equipped with a ring motor, which can be directly connected to the motor rotor, thus avoiding the gear pmission which is prone to error. Depending on the combination of the pulse generator and the electrode measuring device, the speed and the angle position of the rotary net can be precisely controlled. The pmission of the conduction belt equipped with the BPMS positioning measuring system is separated from the head, and the two can be accurately controlled by electronic control.

This kind of separate drive rotary screen printing machine can achieve 0.06mm accuracy between opposite two nets.

De Montfort university research shows that if the above advanced system is installed, it can save about 90% of the fabric used in the beginning of printing.

The ultimate goal of the study is to provide an intelligent video surveillance and defect identification system for printing machines. At present, EVS camera system has been applied to detect printed fabrics and report defects.

The key to improve the printing efficiency of small batch products is screen replacement time.

The way to improve is to improve the degree of mechanization and install the electronic control system.

Most of the printing machines use open grid and open bearing to facilitate the replacement of scrapers and rotary nets.

Buser claims that the proper time required for a 7 color printing machine is only 15 minutes.

If you change the net 25 times a day, the efficiency of the machine can reach 70%.

Now there is an online washing system. For example, each machine head of Stork's Print@Change printing machine is equipped with telescopic curtain gates, which can span the machine platform and extend under the screen to prevent the color drops falling onto the fabric when changing / washing the net.

If a 16 color printing machine has to continuously print two patterns of 8 colors, the system can ensure the minimum time delay caused by changing the net.

According to Reggiani and Ichinose, with the on-line cleaning, the cleaning of 15 colored circular nets can be completed in about 10 minutes.

Different scraping systems have been studied, and a series of theoretical studies on the shear behavior of scrapers and scrapers have been reported.

Research shows that compared with the scraper, the magnetic roller has no special advantages.

The hydraulic slit pulping and scraping device developed by Zimmer can use hydraulic slit through the slit pulp feeder of the net, which has good penetration effect on the fabric, but there is also the problem of friction between the outer edge of the slit and the screen.

The device is suitable for carpet printing or foam printing.

In addition to traditional horizontal printing, Japan's Ichinose has introduced an oblique round screen printing method.

The color paste is input from top to bottom, and keeps uniform supply of the quantitative fresh color paste. It reduces the scar marks caused by the impurity of the knife rack in the color paste and the uneven prints of the printing paste, and improves the printing quality of the products.

Equipment manufacturers also try to reduce the waste of printing paste by limiting the amount of waste slurry and reusing the remaining color paste.

Stork company adopts a unique color recovery system, and uses a special pump to pass a glue ball to the slurry hydraulic reflux drum remaining in the pulp pipe.

In order to minimize the waste of color paste, it is of great value to predict the amount of color paste needed for a color printing.

The equipment parameters affecting the pulp volume in the actual production of rotary screen printing were studied. The results showed that the error of the predicted pigment dosage can be controlled within 15% for the determined printing speed, fabric structure, mesh number and size of the scraper.

The development and manufacture of printing machines in China has also made some progress. Hubei Huangshi, Shanghai, Zhejiang Xinchang and other manufacturers have developed advanced flat screen or rotary screen printing equipment through cooperation with foreign countries and the introduction of technology.

But compared with foreign equipment, there is still a certain gap in function, performance and stability.

Digital printing system

Digital printing can not only save plate making process, reduce costs, but also store printed patterns in digital format, which makes the printing method more attractive. This research is in the ascendant.

At present, the most promising textile inkjet printing uses the "engine" of the paper printer. Its injection system is more than DOD (on demand) or continuous charged droplet flow.

Although it has been reported that piezoelectric inkjet is more reliable than bubbling, the printing machines based on these two principles have all entered the market and are mainly used for cotton fabrics.

These inkjet printing machines are equipped with a scanning printing head similar to the inkjet printer, and the output speed is between 1m/h and 1m/min.

Stork's TruColor4000 inkjet printing machine (charged droplet flow mode) has been used as an integral part of a design / sample evaluation / production formula and has been well applied.

The company has introduced Amber and Amefhyst printing machines for natural fibers as well as Zircon printing machines for polyester fibers.

Swiss Perfecta AG launched the Print Master2200R digital printing machine at the 1999 French textile machinery exhibition at a speed of up to 100m2/h.

In addition, Zimmer recently launched their Chromotex inkjet printing machine with printing speed up to 1.5m/min.

The machine uses a multilevel charged droplet printing method developed by Jemtex, which only uses dot color. Its droplet size is larger than that of other printing machines, but its resolution can reach 100-125dpi.

Most of the digital printing machines use green, magenta, yellow and black (CMYK) four kinds of color ink, according to the digital control signal to the fabric spray ink, in dot matrix combination form a variety of colors.

Although more and more devices and software have increased the number of primary colors to 8, this group color method still has limitations in terms of color quantity and chromatographic width.

For printing machine manufacturers, it is necessary to provide reliable software to ensure that the colors selected in the pattern design stage can be accurately reproduced on the printing machine.

Digital printing is a systematic project. Success depends not only on printing equipment, but also on the control of software and color ink.

In the research and development of jet printing technology, foreign enterprises attach importance to the expertise of companies with leading technology in different fields. For example, Encad Nova Jet Pr060 and TexPrint2000 integrated inkjet printing system are jointly developed by the American Encad company, Iris company and Japanese Innotech company to manufacture hardware, Belgium Sophis system design software and Ciba refined company provide special color ink.

Ciba has long experience in fabric printing, and has made great achievements in the development of jet printing ink.

A series of high-performance ink jet printing ink which can be used for different fibers, such as Cibacron MI reactive dyestuff with high fastness to cellulose, Terasi DI disperse dye for polyester, and acid dye dye for Lanaprint AI acid for silk, have been developed.

Xerox (Shi Le) has adopted different ways to develop textile digital printing.

The company has introduced an electrostatic printing machine which can print disperse dyes on paper carrier and pfer printing on polyester fabric with hot roller.

This method does not seem to be efficient, but the digital printing of pfer paper needs no monitoring. It can be done on the night shift. The pfer of fabric is arranged in the day shift, and also has a higher output.

The printing technology has been well received, but the applicable toners are few.

The technical and economic problems of digital printing are being solved one by one, and it is expected to increase the market share by 5% annually.

Theoretical research on the droplet ejection phenomenon of inkjet printing machine shows that whether the piezoelectric device, bubble jet device or solenoid valve device, the results observed for DOD printing machine are very similar.

Digital fabric printing technology is the representative of the most advanced technology in the textile processing field at the turn of the century. It has attracted wide attention in the domestic industry.

This is the representative of Hangzhou Honghua Computer Technology Co., Ltd.

Since 1999, the company has initiated the concept of "digital textile" and made progress in the research and implementation of digital textile integration solution based on digital jet printing and computer network.

The current digital printing proofing system and digital printing production system have two series and four varieties: Print Master2200R and 2200B (production system), A 'tex print Tex-1300 and 1600 (proofing system).

These devices are made of micro piezoelectric nozzle, the highest resolution 1440dpi, the maximum effective printing range 2200mm, the resolution 360dpi, the printing speed can reach 100m2/h.