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THE IMPORTANCE OF PRE-TREATMENT IN QUANTITY DIGITAL PIGMENT PRINTING ON COTTON FABRIC

There are five main types of ink used to digitally print textiles. Reactive, Acid, Direct Disperse, Sublimation and  Pigment  inks. Each ink has a printing, drying and fixing method associated with it. All of the above, with the exception of the pigment, are fixed by chemical bonding with fabric fibers.

The purpose of this article  is to understand how Digital Textile Pigment Ink works with fabric and what effect all variables have on this process. Before we start, let's start with the quality criteria of printed fabrics.

The performance of the printed fabric (by any method) is evaluated by several important criteria such as Color Fastness, Wash Fastness, Wet and Dry Rubbing Fastness, Perspiration Fastness, Hand Touch Feel and Safety considerations regarding Colorants and ink formulations. Let's understand how Digital Textile Pigment Inks in general  evaluate each of these aspects. Thanks to highly fade resistant pigments, these inks have excellent Color Fastness against fading. The latest advances in ink formulations offer highly reliable performance for Wet and Dry Rubbing Fastness as well as Wash Fastness. Pigment inks also offer very good sweat fastness. The only disadvantage of pigment-printed fabrics is that they have a slight tactile feel in the printed area.

Pigment inks are fixed by allowing the pigment to adhere to the fabric. Pigment inks typically contain binder, which is a polymer-based compound. During the fixation process, this polymer is heated to a temperature where it becomes plastic (transformed into a semi-solid state) and then forms a bond between the fibers of the fabric and the pigment particles in the ink. In a way, this creates a physical bond between the pigment particle and the fabric. This binder plays a critical role in the performance of pigment inks. It's a variety of things depending on the binder, from the stability of the ink, the nozzle spraying performance, preventing the print head from clogging, ensuring the fastness of the ink on the fabric, minimal feel. Managing all this is a challenge, and so finding a good pigment ink becomes difficult.Interestingly, this bonding process gives pigment inks some unique advantages. Most importantly, the fixation process can be done by exposing the printed fabric to heat. All you need to fix the ink to the fabric is the right temperature for enough time. This saves the enormous amount of water required for other printing techniques. In addition, you can use pigment inks for printing on various fabrics, even with compositions in cotton blends. This opens up possibilities for digital printing on cotton blend fabrics. In addition, pigment inks are used intensively in some applications where it is not desired to process the fabrics after printing.

From the printing process perspective, PFP fabrics need to start. "PFP" or "Ready to Print" fabrics usually contain various oils, waxes, sizing agents, etc., used in various production stages. processed to extract. These chemicals interact and prevent the inks from setting properly. A significant part of the industry pre-coats the fabric before printing. Here is a graph of an ideal print flow.It is possible for digital textile pigment inks to print directly on fabrics without any pretreatment. This is an absolute fact, but it would be interesting to understand the role of Pretreatment in improving print results. As you know, pigment inks are primarily used for printing on natural fiber-based fabrics. When pressed directly onto the fabric, the pigment particles are absorbed by the porous fibers of the fabric. Therefore, although the results look good during printing, they look pale as the print dries. This is where the role of preprocessing comes into play.

Depending on the chemical base, pretreatment chemicals perform various functions. First of all, they all help the ink stay on the surface of the fabrics. This prevents ink from being absorbed into the fibers. Retaining more ink on the fibers helps the inks produce bright colors. Some pretreatments go further and help improve the fixation of inks to fabrics. Thus, it improves the washing, wet rubbing and dry rubbing fastness properties of inks. You can also use less ink and fewer print passes if the fabric is already coated. This helps increase productivity and lower ink costs.

NEW INDUSTRIAL PRINT HEAD IN UV PRINTING MACHINES RICOH GH2220

The most popular printing system based on Epson DX5 is obsolete, it has many disadvantages and high price in the market. In addition, EPSON does not sell or service heads directly to the user. In the digital printing market, all DX5 heads are "extracted" from office printers.

Ricoh company introduced new printhead on the market: with the speed and quality in Ricoh GEN4, longer life and lower price for color than EPSON. Ricoh GH2220.

A GH2220 head has 2 independent ink channels and each can be used for a separate color.

As a result, the 2 printheads GH2220 make it purely CMYK. If white is added to another head, the total amount of the full color system will be $1200.

PRINT QUALITY

GH2220 is small droplet system with 2.5 pl ink drop size. It is two times smaller than the DX5 droplet and 5 times smaller than the standard system. The working frequency of the print head is 30 kHz, and a variable point system is also available. You can print new, higher resolution images without any artifacts, but with better halftone rendering.

UP TO 5 YEARS WORKING LIFE

The print head Epson DX5 is not built for abrasive UV inks, which wear the head from the inside over time. This reduces the service life of the head by 2-3 years. If you print a lot, use poor quality inks, and wash the print head with solvent too often, the Epson DX5 will not last more than a year.

The printing system on the Ricoh GH2220 is more resistant to solvent and UV inks, is technically better mounted and has an extended service life of up to 5 years (confirmed by developer testing). This is the print head for the industrial market.

Also, two separate ink channels allow repairing the system by replacing just one head ($500) instead of buying the entire system (starting at $1500) as with the Epson DX5.

INDUSTRIAL SPEED

The high operating frequency of the GH2220 printhead (30 kHz) allows printing 1.5 times faster than Epson DX5-based systems at average production settings.

Thanks to the small droplet size of the GH 2220 (2.5 pl), you can complete some orders in one pass but with the highest quality. In this case, the Ricoh printhead is above its competitor.

RELIABLE VERSATILITY

Ricoh GH2220 is compatible with UV, solvent, water-based and dye sublimation inks. You can change the ink type immediately after cleaning the system and this option definitely makes the GH2220 based equipment multifunctional.

Source: https://www.linkedin.com/in/edward-mirchev

As POWERJET, we offer an integrated unit that will be used for Pre-Treatment and post-dryer, and even for fixation after digital printing. POWERJET TX 1800S

LET US GUIDE YOU IN SELECTING PRINTHEADS….

AGE IS THE AGE OF ACHIEVING QUALITY AND SPEED TOGETHER.

The Use of Ricoh Printheads Has Become Inevitable!

A) Ricoh Gen 5 and GEN 6

1. As an industrial print head, the Ricoh GEN5 head is currently widely used. Overall, it is the best and most cost-effective printhead.
2. The Ricoh GEN5 head has a total of 1280 nozzles. Each head prints 2 colors.
3. The Ricoh GEN5 head consists of the independent plate, the connecting cables and the hub head. It prints 54mm wide and is made of steel with strong corrosion resistance.
4. The Ricoh GEN5 printhead can operate continuously 24 hours a day. Ricoh GEN5 head can be used for 3 - 5 years, 3 times more than other heads.
5. Ricoh GEN5 head offers the smallest inkdot as 7PL. UV printing effect is excellent and realistic, which can print words clearly in 2pt font with variable inkdot printing.
6. The Ricoh GEN5 is not affected by ink temperature and viscosity by the operating environment. Suitable for a variety of inks to ensure high resolution printing and smooth prints
7. Ricoh Gen6 heads are the 2019 version and are 30% faster than Gen5 heads.

B ) Ricoh GH 2220

1. The Ricoh GH2220 printhead is a low-cost, all-steel-bodied economical type of industrial head. With its steel structure, it offers 4 gray levels variable inkdot printing.
2. It is the only head among industry heads that can achieve 3pl inkdot printing, with higher resolution than EPSON offering 3.5pl inkdot. Moreover, the Ricoh GH2220 controls variable inkdot printing more flexibly.
3. Ricoh GH2220's speed is higher than EPSON head. (Ricoh GH2220 can write 8-12㎡/h, EPSON head can write 5㎡/h).
4. The lifetime of the GH2220 head is 1.5 times longer than the EPSON head.
5. Moreover, the price of a Ricoh GH2220 head is much cheaper than an EPSON DX5 head.

CONCLUSION

1. The Ricoh printhead combines the precision of the Epson printhead and the speed of the Seiko printhead.
2. Variable 7~35pl ink droplets, the head is not easily clogged.
3. Longevity is an important advantage, its lifespan is 5 years with regular maintenance.
4. Rich ink compatibility makes it compatible with most ink types available on the market.

INNOVATIONS IN POWERJET DIGITAL T-SHIRT PRINTING MACHINES

PRINTING WHITE AND COLOR DYES TOGETHER

1. PRINTING ON BLACK AND DARK COLOR T-SHIRTS; THE LATEST INNOVATION TO REDUCE PRINT TIME AND REDUCE PRINT HARDNESS / TOUCH; PRINTING WHITE AND COLOR PAINT TOGETHER…
2. PLEASE WATCH THE VIDEO:  https://youtu.be/b4arzZyRxk0
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CONTINUOUS, CONSEQUENTIAL PRINT

1. POWERJET MACHINES PROVIDE CONTINUOUS, CONSEQUENTIAL PRINTING WITH ITS SINGLE TABLE SYSTEM. YOU DO NOT NEED TO STOP THE MACHINE TO LEAVE AND LIFT FABRIC. THE TRIPLE TABLE OF THE POWERJET 1S GIVES YOU THIS OPPORTUNITY. INCREASES EFFICIENCY. YOU ALSO HAVE INDIVIDUAL AND ONE-PIECE PRINT AREA WITH BETWEEN-TABLE ADAPTERS.
2. PLEASE WATCH THE VIDEO:  https://youtu.be/b4arzZyRxk0
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REPEAT BUTTON

1. AVAILABLE ONLY ON POWERJET PRINTING MACHINES, THIS FEATURE ENABLES THE OPERATOR TO CONTINUE PRINTING WHILE THE MACHINE IS AT THE MACHINE. IT DOESN'T NEED TO GO TO THE COMPUTER AGAIN AND GIVE COMMANDS. IT IS A HUGE TIME SAVING IN MASS PRODUCTION.
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CIRCULATION SYSTEM

1. IT SHOULD ALSO BE PREVENTED TO DOWNLOAD THE WHITE COLOR IN THE CONTAINER IN THE MACHINE.

AUTOMATIC HEAD CLEANING SYSTEM

1. WHITE PAINT MAKES PRINTING POSSIBLE ON DARK FLOORS; MADE WITH TITAN DIOXIDE RAW MATERIAL. WITH ITS STRUCTURE LIKE TITAN DIOSIDE POWDER; DOWNLOAD IN THE PAINT, EVEN CAUSES FROSTING AND Clogging in the PRINT HEAD.
2. THERE IS A RISK OF WHITE DYE CLOGGING THE HAIR THICKNESS NOZZLES ON THE PRINT HEAD, EVEN FREEZING THERE. FROM 2013, POWERJET MACHINES HAVE "AUTOMATIC HEAD CLEANING SYSTEM (AHCS)". THANKS TO THIS SYSTEM AVAILABLE IN POWERJET MACHINES, THE HEAD OF THE MACHINE GOES TO THE "AUTOMATIC HEAD CLEANING" MODE WHEN NO PRINTING IS MADE. SPRAYING OF PAINT FROM NOZZLES ON THE HEAD; PREVENTS WHITE PAINT DRYING AND CLOGGING THE HEAD