Dark-colored garment inkjet printing involves many difficult movements, and white ink printing is always a lingering problem. This paper systematically introduces the history and current status of white ink printing of ready-to-wear inkjet printing machines, challenges and solutions, and related pretreatment systems.
Over the past four years, a lot of news about ready-to-wear inkjet printers has revolved around the reliability of white ink printing technology. This technology has undoubtedly developed during this time. As a distributor of ready-to-wear inkjet printers, we often hear potential customers talk about the daunting story – white ink and the processes associated with white ink printing. However, in many cases, these experiences are not no longer correct, or they have not been right from the beginning.The history of white ink
In order to understand which markets of white ink printing are suitable for direct inkjet printing of garments, we must be aware of its roots. In September 2005, Mr. Scott Fresener, then CEO of screen printing and Inkjet Technology, USA, first publicly demonstrated the white ink printing process on the Epson-based ready-to-wear inkjet printer T-Jet2, which marked the white ink. Printing has taken the first step in the ready-to-wear inkjet printing market.
As with all new technologies, the early white ink printing on ready-to-wear inkjet printers was mixed with success and failure. The ink does not remain suspended for a long period of time. Proper pretreatment sometimes requires some "magic" to be applied, and the original setting must not be intuitive. However, when things are handled properly, the results will be very good. For most people, the white ink printing process is too tricky, and it does only show reproducibility for companies that use a ready-to-wear inkjet printer to do a lot of white ink printing.
One year passed away. In October 2007, DuPont released its first official white ink upgrade product - often referred to as the second generation of white ink, referred to as Gen2. Since the company has supplied its all-inkjet printer manufacturers with its white ink products, more companies are working to introduce software and hardware solutions to improve the white ink printing process, while at the same time increasing people. Understanding of the white ink printing process.
When left for a long time, the Gen2 white ink is less prone to solid deposits and exhibits a consistently smooth feel when printed at the higher resolution required for white background. In addition, the printed ink is more flexible and less prone to cracking, which is beneficial for long-term washability. But it also introduces new maintenance issues that were not previously available. The Gen2 white ink dries quickly, causing ink build-up on the sponge pad, pump assembly, and printhead to become a new problem. Suppliers of ready-to-wear inkjet printers were immediately aware of the consequences of this accident and began to address it during routine day maintenance and weekly maintenance procedures.
In October 2008, DuPont announced the first major change in pre-treatment since the introduction of white ink three years ago. The new pretreatment is more tolerant, resulting in less wasted garments and more consistent output. Gen2 white ink only occurs "soft precipitation" - it can be restored to a suspension after agitation. Many suppliers also realize that it is better to store white ink in a 0.5 liter bottle than to use a more common 1 liter bottle. The industry as a whole is more familiar with the white ink printing process. Today, more users are using high-quality dark-printed garments using the white ink printing technology of ready-to-wear inkjet printers.
White ink challenges and solutions
The biggest challenge facing white ink comes from its chemical composition. The whitest pigment is generally considered to be titanium dioxide (TiO2). Rutile titanium dioxide is a pigment used to make white ink. Unlike the pigments used in the four primary colors of yellow, yellow, black and black, titanium dioxide is a mineral. It is heavier than other pigments and tends to be out of suspension if left to stand for a long time.
The new white ink will "soft precipitate", which means that the white ink can be easily restored to a suspension by stirring or shaking. The process of returning the pigment to suspension can create other problems. Excessive shaking causes bubbles to enter the ink and causes dry ink particles from the edges and sides of the ink bottle to move; the former can cause printing problems - note that these problems are more common in open systems. Generally, it is preferred to return the ink to suspension by "spinning" rather than shaking. Innovative users use balls and pinballs in their white ink bottles to help the white ink return to suspension.
Many equipment manufacturers have developed solutions that can help solve the inherent challenges of white ink printing. DTGDigital is a manufacturer of DTG ready-to-wear inkjet printers that use the so-called White Ink Management System (WIMS). The white ink management system varies from printer to printer, from the automatic print head cleaning of some low-end models to the white ink circulation, filtration and agitation systems on medium and high-end equipment. Anajet and Belquette (the manufacturer of MOD printing machines) have implemented a closed ink delivery system that eliminates air in the ink delivery system and is said to reduce the more common precipitation and clogging problems in open ink delivery systems. .
In many cases, the latest ready-to-wear inkjet printers are based on the new Epson printer, which has a specially coated printhead that reduces clogging. Routine maintenance procedures recommended by all large garment inkjet printer dealers are now focused on proper maintenance of the foam pad and wiper assembly. These parts are the location of many white ink printing problems, and can be avoided after a lot of maintenance.
Pretreatment system
Another factor contributing to the improvement of the white ink printing process is the emergence of various pretreatment equipment on the market. The pretreatment system has two functions related to the performance of dark garment white ink printing. First, the porosity of dark garments results in an inability to provide the desired printed surface. The pretreatment system saturates the dark garments and closes the pores, providing a better printed surface for the ink. Second, the pretreatment solution acts as a medium to accept the ink. The price of the pretreatment system varies from approximately $4,000 to $8,000. All devices have their own advantages and disadvantages, but the most important thing is that they all achieve good, consistent pre-processing capabilities, which is a key to the success of white ink printing. As the operator's learning process has also become shorter, they are more willing to promote and use white ink printing technology.
In general, white ink printing is now in the direct inkjet printing industry. Many of the horror stories about white ink printing that appear on the forums are old things. Specifically, if properly maintained, using good pre-treatment techniques and doing a little bit of practical work, achieving consistent, high-quality dark garment printing on ready-to-wear inkjet printers will not be difficult.
Your training experience should cover every area mentioned above. Don't be fooled into thinking that dark ready-to-wear printing is a task that can be easily done on your own. The enlightenment that a good training class brings to you will reduce your time to frustration and the piles of destroyed clothes. Now, the key is to try to ensure that your dark garments have an appropriate price to keep profitable, but this is another topic.