Problems Demanding Prompt Solution In The Field Of Digital Printing Technology

Undoubtedly, it is a hot spot in the field of printing and dyeing in China. But why is the industrialization process not satisfactory? What are the problems found in the process of the use of the enterprise? What are the impacts of these problems on the production of the enterprises? What aspects should be improved and improved? How can we solve these problems? Reporters recently interviewed Guo Wendeng, chief engineer of Zhejiang Huatai silk Co., Ltd., which has been tracking the development of digital printing for more than a decade.

Technological problems

Lack of scientific color matching methods

Sizing process lag

Positive and negative chromatic aberration

Reporter: what problems do you find in digital printing technology? What are the effects of these problems on products?

Guo Wendeng: it should be said that the research of digital printing technology in China has not officially started yet.

The main reason is that there are not many enterprises that have large scale digital printing machines at present. Most of the manufacturers of digital printing machines have only 3~5 equipment or even less.

So few digital printing machines can't be industrialized at all.

Because the output is very small, the general technology can be satisfied.

However, if the digital printing industry is really industrialized, the output will be large and the varieties of production will be more.

From the perspective of industrialization in recent years, the technology of digital printing is too superficial to adapt to the development of digital printing.

The problems existing in digital printing technology mainly include the following aspects.

Color matching is done by artificial experience without a scientific color matching method.

Digital printing is controlled by computer output color, and the color displayed on the computer screen is different from that of the jet printing mode (the color of the display is RGB mode, and the inkjet printing is CMYK mode), which requires a color matching process.

In the process of color matching, different processing parameters should be set according to the characteristics of dyes, the accuracy of inkjet printing and the type of fabrics.

If the parameter settings are not good, the color of jet printing will be different from that of the manuscript.

In addition, because the digital printing uses four color separation principle to print, any change of parameters will cause great changes in color.

In particular, four color combinations of grey, coffee, olive and other color systems, any change in parameters will seriously affect the color effect of printing.

And toning can not be directly pferred on the computer. It needs to rely on the experience of the operator, set several parameters, and adjust it step by step.

Such a color matching method is still mainly based on human experience.

If you encounter unskilled operators or hard to adjust colors, you may not be able to get a pattern of colors for several days.

The color matching technology of digital printing is related not only to the accuracy of color, but also to the speed of delivery.

If there is no scientific color matching method, color matching with artificial experience is not symmetrical with advanced digital printing equipment.

But this key technology has not yet been reported.

Sizing equipment and technology are lagging behind.

Before printing, all fabrics must be starched to prevent ink from seeping.

This involves two big problems: first, what auxiliaries are used, and what is the sizing of the two.

If there are "weft", "wrinkle print", "uneven" and "uneven" in sizing, there will be problems such as "seepage", "escape cloth" and "uneven color" when printing. The rate of defective products is very high. Silk like digital printing is currently used as the main sizing agent for most of the manufacturers because of the reactive dye ink jet printing.

The alginate nano pulp is very easy to absorb moisture in the air. Therefore, when the weather changes and dry humidity of the fabric are different, the moisture content of the fabric will be inconsistent, which will cause great changes in the color of the digital printing.

In addition, so far, there is no special equipment suitable for digital printing and sizing.

Most manufacturers use the existing continuous printing machine, Taiwan version and the stretching machine for sizing, but the sizing quality and speed of these equipment all have such and such problems, which can not be satisfactory.

If the sizing is done on a continuous printing machine, although the speed is very fast and the uniformity of sizing is good, it will cause uneven sizing after drying in the drying chamber. Sizing, sizing speed and evenness of the sizing machine can reach the effect of the continuous printing machine, and it can also be rolled after drying.

Ping Ting is helpful, but the weft deviation is serious. The size of the plate is made by hand. If the special roll machine is equipped with it, it can make the sizing skew control relatively small, but the speed is slow and the uniformity is poor.

At present, there are one or two special sizing machines on the market, but the design is not in place, and the speed is fast.

The color is serious and the pattern is not bright enough.

Digital printing is carried out by the four color separation principle of paper printing. It shows the colors of all kinds of natural light through the cross reflection of four colors in three-dimensional space.

However, we found that the fabric after digital printing is often not bright enough.

In particular, where the color is mixed, the higher the grayscale, the better the fabric's surface is covered with mist.

Through observation, it is found that the main reason is the ink ejected from the nozzle, which is caused by color leakage on the surface of the fabric.

Because the four colors are red, yellow, blue and black. The four colors are independent of dots. If they can not mix with each other, the color will be more vivid.

But if these colors are mixed together after printing, the reflected color will turn black or gray.

The process of digital printing is, first of all, the fabric itself absorbs moisture in the air. After printing, it is steamed, and the sizing agent and the fabric absorb moisture at the same time. This causes the ink droplets to be printed onto the fabric to produce osmotic, and the multicolor cross color of the ink causes the dull color.

Although digital printing has rich color expressive power, it has a good pition to the color level of moire, landscape and portrait.

However, the brightness is not as good as traditional printing, and some very bright colors can not be made.

The color difference between the positive and negative sides of the fabric is relatively large, and its permeability is better than that of flat screen and circular screen printing.

Digital printing is based on ink demand, which consumes less ink. It can save water and energy when washing.

However, ink can only stay on the fabric surface due to the small amount of ink sprayed on the fabric.

In this way, there are two problems. One is the serious color difference between the reverse and the reverse. It is impossible to meet the requirements like a scarf or to make osmotic printing. Two, because of the serious negative coloring and loosely woven fabrics, as long as they are rubbed or sewn, they will produce negative, uncolored silk (or yarn) turned to the front, commonly known as "anti silk".

This result greatly affects the appearance of the fabric and can not be accepted by consumers.

If the amount of ink is increased, the reverse osmosis is improved. Although the "reverse silk" situation has improved, the pattern clarity of the printing is greatly reduced, the stalks are thicker, and the shapes are blurred, which can not satisfy the customers' requirements.

Ink equipment problem

Ink quality is unstable.

Less equipment manufacturers

Reporter: what are the key problems in the key R & D of ink? What are the prices?

Guo Wendeng: the research and development of ink is backward and the quality is unstable.

At present, digital printing ink has four major problems. First, the price is high. Although the price of digital ink has dropped to 300 yuan / kg, the price is still very high compared with that of powdered dyes.

According to estimates, the cost of ink per meter of fabric is about 8~10 yuan; two, there are many manufacturers of digital printing equipment, each equipment factory has its own set of ink, but it can not be used to each other; three, ink storage stability is poor, easy to coagulate and plug nozzle; four, the ink color rate is inconsistent, resulting in color difference easily.

The first two problems are the reasons leading to the high cost of digital printing. The last two problems are the important factors causing the poor quality of digital printing products.

Reporter: what are the main problems in the research and development of equipment?

Guo Wendeng: the number of manufacturers of digital equipment is small, and the R & D capability is quite different.

At present, there are not many manufacturers producing digital printing machines in China, most of them have only been in the ranks of digital printing machines in the past two or three years, and small units and weak economic strength have no ability to carry out independent research and innovation.

The production of digital printing machines are also mainly imitation, and the marketing of the market is mainly based on price war.

Such a way of operation will definitely affect the market and profit of the research and development of digital printing factories, and their enthusiasm for further research and development.

So that users can not get a more beautiful appearance, cost-effective printing machine.

Because of these problems, the quality problems of digital printing, such as color inconsistency, sizing times and nozzle blockage, have not been well solved.

Therefore, the quality of digital printing products is not high.

If and

The comparison is at least 20% lower.

There is also the problem of production price of digital printing products. Although the cost of digital printing has been greatly reduced, the price of producing one metre fabric is still more than 20 yuan, which is much higher than that of some silk fabrics. Therefore, many manufacturers and manufacturers are afraid of using digital printing equipment.

Solution

Joint tackling

Specialization division

Reporter: the development of digital printing is indeed in the ascendant, and there are many problems. How do you think about solving these problems?

Guo Wendeng: after more than ten years of rapid development of digital printing equipment, including the improvement of the speed of digital printing and the dramatic decline in the price of digital ink, digital printing is not like the technology that people first believed in the early days. It is just a small interlude in the textile printing project and a pitional printing technology.

Now it seems that the development of textile digital printing is indeed in the ascendant. It is a very important development trend of textile printing in the future.

China's printing production accounts for about 1/3 of the total printing output of the world. The annual printing output is about 12 billion ~130 billion meters.

If we want to realize the vision of China's textile power in 2020, it is imperative to narrow the gap with the advanced countries in digital printing as soon as possible.

The relevant government departments should launch the planning of the industrialization of textile digital printing as soon as possible.

Based on the full investigation of digital printing at home and abroad, the status and development trend of digital printing are understood and mastered. Based on the actual situation in China, a guiding plan for the development of digital printing in China is put forward to guide the healthy development of digital printing in China.

Organize effective research.

We should organize domestic experts and scholars to solve the main problems in digital printing equipment and technology, so as to promote the industrialization of digital printing in China.

In particular, through tackling key problems, we should establish a successful model of industrialization in cotton, linen, silk, wool, chemical fiber and other industries.

Through the drive of successful enterprises, we will promote the comprehensive development of China's textile industry's digital printing industry.

Refining professional division of labor and making bigger and stronger industries related to digital printing.

It is necessary to overcome the current situation that digital equipment enterprises are doing both printing machine and ink, and printing equipment and technology before and after printing.

Make the equipment concentrate on the core technology and standardization of the equipment, ensure that our digital printing machine can keep up with the world's advanced trend; do ink's wholeheartedly study the performance of digital ink, improve the quality and stability of digital ink, and constantly reduce the cost of ink; the application manufacturers strive to do well in the digital application process to ensure the stability and improvement of the quality of digital printing.

In the process of application, we have accumulated experience, and constantly put forward new requirements for the production equipment and ink manufacturers, in order to constantly promote the improvement of equipment and ink.

Only in this way can China's digital printing industry develop faster and larger in order to keep up with the trend of digital printing in the world.