Thermal transfer technology can basically solve the problem of chemical fiber materials. For digital printing of pure cotton fabrics, there are basically only two types of direct injection and thermal transfer paper. This section mainly introduces the development of direct injection technology.

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The direct injection of pure cotton fabrics has basically started to appear some prototypes since the appearance of pigment ink. At the beginning, mainly in Europe, it was realized by converting EPSON printers into flatbed printers, which was probably from 1999 to 2001. The real commercialization was probably around 2003-2004, and some cotton T-shirt flatbed printers modified with EPSON2200 and 4800 began to appear at the exhibition. At that time, there were about 2-3 companies, namely USScreenPrint Company in the United States, DTG Company in Europe and Sawgrass Company in the United States, but due to the poor stability of ink and color saturation, they did not achieve great success.

It was Kornit in Europe and Brother in Japan that really pushed the digital printing of pure cotton fabrics to the industrialization. They selected industrial print heads developed by Spectra and Kycera, and developed specialized pure cotton pigment inks to achieve reliable high-volume printing of pure cotton fabrics. At present, the main personalized T-shirt printing companies are basically equipped with Kornit931DS printers (about 70,000-100,000 US dollars a set) and brother GT541 printers (about 15,000-20,000 US dollars a set). These machines were all launched in 2005.

Because these professional machines are too expensive, there is still a certain market for flatbed direct injection machines modified with epson4800, especially in China. Due to the low technical threshold for this modification, there are many companies in China, South Korea and Taiwan that manufacture and sell such machines. The price of machines has also fallen rapidly. From 100,000 yuan per unit 3-4 years ago, it has fallen to 40,000-50,000 yuan. This is still a relatively complete function, and there is a modified machine with its own RIP software. If you just change it to a tablet, it will only cost about 30,000 yuan. At present, the more reliable conversion machines on the market include FAST-T from USscreenprinting, Directadvantage from sawgrass, flexi-jet, DGjet from Singapore, Nanojet from Europe, and some machines from South Korea. There seem to be several in China. I tried a machine from a company in Zhongguancun, Beijing last year. It feels that the function is relatively simple, and their RIP software is also problematic, and the color of the pattern is somewhat distorted. They seem to be using Rohm and Haas ink.

After talking about the machine, it's time to talk about the ink. At present, the best quality inks on the market for conversion machines mainly include pure cotton inks produced by DuPont, Rohm and Haas (ROHM&HASS), American sawgrass, and British nanojet. Most of the machines use ink from the above companies. These inks are acceptable in terms of color gamut, washability, and stability. Of course, they are quite different from Kornit and brother's professional machines. But the price is also much cheaper than brother ink (brother ink retails for about $900/liter, and the cheapest Rohm and Haas ink is about $30-50/liter). But I heard that since 2008, Rohm and Haas stopped producing their pure cotton ink, maybe the profit is too low to make money. A lot of pure cotton ink in Korea is very cheap, but I haven't tried it, and the quality is not very clear.

There is also white ink that cannot be avoided in pure cotton printing. Since 1997, many companies have regarded the development of white ink as their main scientific research project. By 2005, they had basically given up. Only DuPont white ink is currently on the market. DuPont's white ink was introduced at the ISA trade fair in Atlanta in September 2005. It was used in USscreenprinting's Fast-T cotton printer. At that time, T-shirts were pretreated and printed three times with white ink and then colored ink. Nevertheless, it still attracted the attention of all exhibitors. USscreenprinting has sold thousands of printers with white ink. Can be described as a moment of beauty. But white ink is a very immature product. Because the machine plugs are too frequent, USscreenprinting has to spend a lot of energy to deal with quality problems and even court lawsuits. At one time, funds were very tight and they operated by borrowing. It is really "success is also Xiao He, defeat is also Xiao He". In 2007, DuPont launched the second generation of white ink, which is said to have improved stability. According to the author's test, the new ink has improved in whiteness and washability, but the stability is still very poor, and the plugs are frequently blocked.

Cotton T-shirt printing is basically a thing of the past. With relatively expensive investments, unstable equipment and ink, it has proven to be very difficult to achieve stable profitability. If you have a large customer base, you might as well invest in professional printers from Kornit and brother. However, the formulation process and development of pure cotton ink provide valuable experience for the wide-format and digital printing production of pure cotton fabrics. Since 2012, the digital printing process of wide-width pure cotton fabrics has appeared in various exhibitions, and various digital printing equipment manufacturers, software manufacturers, and ink manufacturers have begun to integrate and provide reliable printing processes. This will be hot in the next 2-3 years.