Textile printing is a very old business. This industry revolutionized with the passage of time, moving from hand printing to digital printing. There are two main types of printing techniques: analogue and digital.
Analogue techniques do not use computerized programs. They include flatbed and rotary screen printing. In analogue techniques, mesh screens are used to transfer the dye or pigment paste to the fabric.
Flatbed Screen Printing
Flatbed Screen PrintingFlatbed printing is a technique in which fabric is printed using 4 – 12 colours through mesh screens by squeeze method. It is an advanced version of hand screen printing.
In this method, for multi-colour printing, each dye has a screen to print on. For example, if you have to print a design that contains 06 colours, then you have to engrave 06 screens to print this multi-colour design.
The flatbed screen printing has a fabric feeding device and rubber blanket that is glued to stick the fabric to avoid distortion during printing.
The flatbed has a number of screens according to the required colours, a flatbed table with a system to lift and lower the screens, and a scrapper to squeeze the dye.
How Flatbed Printing Works?
The printing is started by ensuring straight feeding of the fabric to the machine by an infeed device. Fabric absorbency should be more than 04 centimeters. Low capillary fabric does not absorb the pigment paste uniformly, which causes faded printing.
Fabric Capillary before PrintingThe other issue with low capillary fabric is that there might be possible fabric distortion from its position, which will cause flushing. The fabric is glued on the blanket which carries it to the entire screen step by step.
The blanket is driven by an inside motor, which carries the specific length of the blanket to the forward direction. This specific length movement is based on the dimensions of the printed fabric and screen.
When the blanket moves forward, the screen is uplifted so that the blanket can move easily. After the blanket moves, the screen is pressed down on the blanket, and the scrapper moves from one side of the screen to the other side to squeeze the dye paste.
The screens are engraved with designs that have some portions open and some blocked, so when scrappers squeeze the paste, the fabric is printed according to the open mesh design.
Once the scrapper squeezes the paste, the screen is lifted upward, the scraper moves to its starting position, and the blanket carries the fabric to the next color screen. After reaching the next screen, the screen is again pressed down, and the scrapper squeezes the dye paste.
How Flatbed Printing Works?Similarly, this procedure continues until all colours are printed simultaneously. After the fabric is passed through all color screens, it is passed through a heating chamber to dry. The heating chamber helps to avoid flushing by quick drying.
Precaution
Cleaning the rubber blanket is very important for smooth printing. It is washed and dried after each design completion or a certain number of productions.
Advantages & Limitations of Flatbed Printing
Flatbed printing is a semi-continuous process because it works on a start/stop operation. The production speed varies from 15 to 25 yards per minute. Compared to rotary, flatbed has a low production capacity.
This printing method has limitations. Like digital printing, we cannot print every type of design through this machine. We have to be selective in design when choosing this printing method.
You have to limit your design according to the dimensions of the screen. This technique cannot print all-over designs due to the screen’s specific width and length dimensions, but it has many other advantages in terms of cost.
The flatbed is beneficial for small-scale production; it can produce 7,000 – 9,000 meters/day while working 24 hours. We can construct wider flatbed machines to print large-width fabrics, like carpets, sheets, flags, or plaster.
The other benefit of a flatbed is its ability to allow multiple passes or strokes, which forces the paste to penetrate heavy fabrics like piles, blankets, and towels.
When to use Flatbed Printing instead of Rotary?
When to use Flatbed Printing instead of Rotary?Flatbed or Buser is also called screen printing or block printing. If it does not fall in the latest advanced technology, like digital printing, then why do we use this printing technique instead of rotary printing?
Now we know the reason. Suppose an image or figure is up to 91 cm; we can easily make it on rotary screen printing because the rotary’s cylindrical circumference is up to 91 cm. So these images can be easily printed on rotary screen printing.
What do we do if the image size is greater than 91 centimeters?
We can solve this issue in three ways.
- Width for length printing
- Digital printing
- Flatbed printing
Width for length printing has an issue; we have to prepare fabric, especially on the loom, by changing the width, which is not a good choice because we will have to set a loom special for this purpose, which will affect the whole loom house production.
Digital printing is costly, so manufacturers or suppliers move to flatbed printing. On this machine, they can easily print their fabric through screen or block printing.
The basic purpose of using the flatbed is to print larger motives greater than 91 cm.
Colorfastness Testing
A good dyeing and printing process must ensure that the colors are not only vibrant but also have lasting color fastness. Color fastness testing is a crucial step in this process. Textile laboratories use standardized testing instruments, such as:
These instruments operate according to international standards (such as ISO, AATCC, and ASTM) to help manufacturers evaluate and improve the quality of printed products, ensuring they meet the strict performance requirements of customers and the market.
Conclusion
Flatbed printing is a technique in which fabric is printed using 4 – 12 colours through mesh screens by squeeze method. It is an advanced version of hand screen printing.
The flatbed is beneficial for small-scale production; it can produce 7,000 – 9,000 meters/day while working 24 hours. We can construct wider flatbed machines to print large-width fabrics, like carpets, sheets, flags, or plaster.
FAQs
How many types of printing techniques are used?
There are two main printing techniques: analogue and digital.
What is the analogue printing technique?
The analogue technique does not use computerized programs; it includes flatbed and rotary screen printing.
What is flatbed screen printing?
Flatbed printing is an advanced version of hand screen printing in which fabric is printed using 4 – 12 colours through mesh screens by squeeze method.
What are the main parts of screen printing?
The flatbed screen printing has a fabric feeding device, a rubber blanket that is glued to stick the fabric to avoid distortion during printing, a scrapper to squeeze, and a flatbed printing table.
What is the limitation of flatbed screen printing?
You cannot print all-over designs using this technique due to the screen’s specific width and length dimensions.