Inkjet Printers
The typical printing process over the centuries included using castings of letters that were organized as words to be printed on paper or cloth. The process required years of training, was highly complicated, and involved the use of large equipment and machines. Over the years, through the introduction of various technological advancements, the ancient laborious printing process has been replaced by a wide variety of processes that enable anyone to print images, words, logos, and other printed matter on all types of materials and surfaces.
One of the methods that has arisen from the technical advancements is inkjet printing, a method of printing that sprays ink in tiny droplets on a surface to create images, designs, words, and other types of printed material. The inkjet method of printing is used by residential printers and large industrial printers. It is a quick and efficient method for various applications, from students printing book reports to manufacturers labeling identification codes on products.
Quick links to Inkjet Printers Information
The Inkjet Printing Method
In simplest terms, the inkjet process of printing involves forcing ink through a nozzle in minute droplets to create text, images, numbers, and other printed material. The creation of colors for inkjet printers involves the use of the four basic colors that are used by various types of printers, which are magenta, yellow, black, and cyan. Through study and research, it has been found that blending these colors in different percentages can create any color on the color wheel.
Although the most common form of inkjet printer is residential, the more advanced and reliable versions of inkjet printers are used by various industries. Industrial inkjet printing is a form of digital printing that uses heavy duty industrial grade inkjet printers to print on the substrate of products. Industrial inkjet printing is high volume printing that involves placing data and information on thousands of products as they pass on an assembly line. The printable substrates include plastics, paper, metals, and glass.
The wide use of inkjet printing for industrial purposes is due to the process's low cost, ability to print on nearly any type of substrate, the high quality of the printing, quick drying, ability to endure high volume printing, and the versatility to print on large and small products. Unlike other printing methods that have to make contact with the substrate, inkjet printing can print on any substrate whether the surfaces are uneven, lumpy, curved, or angled.
Types of Inkjet Printers
Inkjet printers for industrial use fall into two general categories, which are continuous (CIJ) and drop on demand (DOD), each of which operates without the need for an operator. Continuous inkjet printers are used for high volume and high-speed industrial printing that have a response time and must be completed immediately. Drop on demand printers are a practical form of industrial printer in that ink is dispensed when needed in variable drop sizes.
Continuous Inkjet Printers
Continuous inkjet printers are used to place labels and product markings. The material that is printed by continuous printers includes numbers, symbols, barcodes, and other forms of identifying marks that can be used to locate a product or its origin. As items pass by a continuous inkjet printer, ink is dispensed and discharged at the target item to leave a crisp, clear, clean, and flawless image without making contact with the substrate of the item having the ink applied.
Ink for a continuous inkjet printer is supplied to the print head from a controller that feeds ink into the nozzle of the printer. The small droplets of ink are released by the printer in the proper proportion to print the predetermined design. In preparation for the delivery of the ink through the nozzle, the ink is given a negative electrostatic charge. It then forms an ink column and is saturated with a negative charge that transforms the ink into small minute particles that are separated from the ink column.
The create ink particles pass electrodes that create a high voltage electrical field where a bending force acts on the particles that is in accordance with the ink’s electrostatic charge and changes the direction that the ink particles move. In the midst of this process, the print head of the printer prints the programmed image onto the substrate of the target item using the created droplets.
A required feature of inkjet printing, and especially continuous inkjet printing, is breaking down the ink into tiny droplets to be ejected by the print head. The fragmentation of the ink, using high frequency vibrations, produces the droplets that are charged and ensures a steady flow of ink in droplet form.
Continuous inkjet printers fit easily into product assembly operations and are able to keep up with the speed of assembly processes. Modern industrial manufacturing requires rapid movement, accuracy, and efficiency, which is why continuous inkjet printers are ideally suited for today’s manufacturing processes.
Drop on Demand Inkjet Printers
The process for drop on demand inkjet printers is distinctly different from that of continuous inkjet printers. Drop on demand inkjet printers still use the inkjet process but approach the process using different technology. With drop on demand inkjet printing, the small droplets of ink are dispensed in variable drop sizes, which are created by heating the ink such that it turns into a vapor that is created by electric voltage.
The heating of the ink for a drop on demand inkjet printer turns the ink into a vapor that forms ink bubbles that expand and are ejected onto the substrate through a controlled printing nozzle. The key to the drop on demand process is that it only uses enough ink to create the desired image. This factor makes drop on demand printing less expensive than continuous inkjet printing but with the same efficiency.
Other Inkjet Printing Methods
Of the various industrial printing methods, continuous inkjet printing and drop on demand printing are the most common but are not the only methods. Variations of the drop on demand process are piezo drop on demand and thermal drop on demand, which are variations of the initial drop on demand process that have altered the method for creating the ink vapor and how ink droplets are delivered to the substrate.
Other forms of inkjet printing are flatbed inkjet printing and single pass inkjet printing that have improved the inkjet printing process such that it can be used for a wider variety of products. Flatbed inkjet printing is not restricted to a particular size of printing surface. The process has been developed such that inkjet printing can be used for large format printing on any type of surface. Part of flatbed inkjet printing includes the use of ultraviolet light that instantly cures the inked image.
Single pass inkjet printing involves the use of over 300 nozzles being used for a single project with capabilities of placing over 300 dots per inch with exceptional resolution. The process for single inkjet printing is fast due to the multiple nozzles. The efficiency and effectiveness of the process is due to various technological advancements that have improved the inkjet printing.
Conclusion
The inkjet printing process is a non-contact form of printing that is capable of applying an image to any type of surface regardless of the texture of the surface. It is a highly efficient and effective process that is completed quickly and prints sharp clear text and images. The drawbacks to inkjet printing, in any form, is its expense and the need to constantly be replenishing the source of ink, which has to be closely monitored. Several technological advances have improved the inkjet printing process with some of providing cost effective methods.