Industrial Thermal Inkjet Printers

A Brief Overview of Inkjet Printers

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There are two main categories of inkjet printing technology:

1. Piezoelectric printing: Uses vibrations and electricity to propel ink onto the substrate.
2. Thermal inkjet printing: Propels ink using a series of small chambers and heating elements. 

Printers like the DuraCode continuous inkjet (CIJ) printer use the piezoelectric approach to enable high-speed, continuous operation. However, to bring the ink toward the piezo printhead, CIJ printers need to use a system of ink pumps, multiple fluid sources, and pressure regulators. Consequently, CIJ printers are large, stationary machines that generally weigh around 60 to 100 pounds. Thermal inkjet printers are much smaller, weighing only a couple of pounds.

Below, we will take a closer look at the construction layout of a TIJ printer, using the schematic of an Anser U2 Smart as an example. Following this examination, we will delve into the thermal inkjet principle to explain how these different parts enable “drop ejection” printing.

TIJ Construction Layout

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The specific part layout of each TIJ printer will vary based on the model. However, all TIJ printers share the same basic elements to facilitate the thermal inkjet technical principle.

The diagram shown above numbers the different parts of an Anser U2 Smart thermal inkjet printer. Corresponding titles and functional descriptions of the parts are provided below:

1. Dust Cover: Protects the ink cartridge from the possibility of dust damage, allowing for operation in harsh environments.
2. Printhead: Uses the ink supplied in the cartridge to print the text/graphic onto the substrate.
3. Built-in Photocell: Senses the presence of an object, triggering the printing function.
4. Alarm LED: Lights up if there is an issue with the ink cartridge, if there is no cartridge inserted, or if the cartridge is out of ink.
5. Ink Low LED: Lights up when ink is low.
6. Print LED: Lights up when the machine is in printing mode.
7. Run LED: Lights up when the power is connected.
8. Display Screen: Allows the user to access printer options or view printing content. The Anser U2 utilizes an LCD screen for this function, but newer models like the Anser X1 offer touchscreens for more intuitive operation.
9. Infrared Receiver: Enables remote operation by receiving an infrared signal emitted from a remote control.
10. Infrared Receiver Light: Lights up when the machine is receiving an infrared signal.
11. Power Port: Connects the printer to its power supply.
12. Ink Cartridge: Contains the ink that is propelled toward the substrate. While most TIJ printers can only use cartridges containing water-based inks (the ideal ink type for porous substrates), certain models like the Anser U2 Pro-S can use water-based and solvent-based inks, allowing them to print on both porous and non-porous materials.
13. USB Port: Connects the printer to either a computer or USB drive to receive data or software updates.
14. Infrared On-Off Switch: Turns infrared receiver on or off.
15. Cartridge Latch: Secures the cartridge in place.
16. RS485 Port: Connects the printer to any external devices.

The Thermal Inkjet Principle

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While continuous inkjet printers use large refillable bottles as an ink source, thermal inkjet printers use smaller, disposable cartridges instead. TIJ machines propel the cartridge-stored ink toward a substrate through a process called  “drop ejection.” Drop ejection is accomplished through the following four steps:

• A Heater Heats the Ink: The ink is sent from the cartridge toward a chamber where electronic resistors heat it at a rate of 1,800,032° F / 1,000,000° C per second.
• Ink Vaporization Generates a Bubble: After the ink has reached a temperature of 644°F / 340°C, the effect of vaporization generates a bubble.
• The Bubble Forces Ink Out of the Nozzle: The ink is propelled from the chamber and out the nozzle as the bubble expands.
• The Bubble Collapses: As the ink droplet breaks away from the nozzle and lands on the substrate, the bubble collapses and creates a vacuum effect. The vacuum pulls more ink into the chamber, repeating the process. 

Zero-Maintenance Operation

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Thermal inkjet printers are simple, modular systems that use removable cartridges as ink supplies. These cartridges are designed to act as both ink reservoirs and printheads. Consequently, when an old cartridge is replaced, it provides the printer with a new printhead. In a piezoelectric system, the printheads are separate from the ink supply and require routine cleanings to maintain top performance.

The effortless printhead replacement enabled by TIJ construction allows the printers to successfully operate for years without maintenance. Further, if there is any damage to the printhead, repair costs are limited to simply replacing the cartridge altogether. When compared to other printing systems, this zero-maintenance operation allows for a much lower total cost of ownership.

High Mobility and Easy Line Integration

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The simplicity of the thermal inkjet principle eliminates many traditional inkjet printer components (e.g. pumps, filters, pressure regulators, etc.). As a result, TIJ printers are compact machines that often weigh two to five pounds. For instance, the Anser U2 Pro-S sports dimensions of 114 (L) x 76 (W) x 60 (H) mm.

Since TIJ machines are small, they can easily be installed and moved along assembly lines. They can also function as handheld devices when designed accordingly.

Clearly Legible Codes

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TIJ printers are widely used to place batch numbers, lot codes, and expiration dates on product packaging. These codes help prevent material counterfeiting, aid inventory counts, and enable traceability. Distribution channels often require their presence as a result. Failure to apply the required codes legibly can lead to large fines from retailers, and even place manufacturers in violation of federal and state laws.

Companies avoid these issues by properly marking their products in correspondence with retailer requirements and governmental regulations. TIJ printers accomplish this by applying ink at a high resolution. Anser series printers are capable of printing at a DPI resolution of 600 x 300. 

High resolution not only ensures that the codes are legible to human eyes, but it also allows barcodes or QR codes to be successfully scanned by a Barcode/QR Code Reader. Given how essential barcodes are to directing shipments, many companies also utilize TIJ printers to mark their shipping cartons with the appropriate labels. 

Versatile, High-Power Application

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Today’s TIJ printers can code a wide variety of substrates with industrial strength. When TIJ printers were first introduced to the market in the early 1980s, their applications were limited to only certain substrates such as paper and cardboard. Speed was generally capped to around 30 m/minute.

Now, thermal inkjet technology has evolved to the point where certain models have industrial capabilities. Machines like the Anser U2 Pro-S can use both solvent-based ink and water-based ink, allowing a single printer to print:

• Non-Porous Substrates: including metals, varnished woods, plastics.
• Semi-Porous Substrates: including concrete, plaster, coated paper, waxed surfaces.
• Porous Substrates: including cardboard, paper, untreated woods, sponge.

Operating speed has also evolved. The average TIJ printer can operate at a speed of around 100 m/minute, meeting many of the line needs for small and medium-sized businesses. Additionally, industry-leading models like the Anser X1 are now achieving speeds as high as 300m/min—a printing speed that was previously only possible with a CIJ printer.

The versatile nature and industrial-strength capabilities of TIJ printers have made them useful for a wide range of industries, including:

• Food Packaging
• Beverage Bottling 
• Personal Care Product/Cosmetic Packaging
• Chemical Packaging
• Pharmaceutical Packaging

The Anser X1: The Future of Thermal Inkjet Technology

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Ever since TIJ printers first entered the market in the 1980s, manufacturers have continuously improved the technology by increasing print speed, the resiliency of printer enclosures, and by delivering higher-DPI codes. Today, the Anser X1 is at the forefront of TIJ technology advancements. Featuring both industry-leading speed and unrivaled protection due to the IP66 enclosure, the Anser X1 also offers the following benefits:

• One Printer for Two Production Lines: The X1 can control two different production lines simultaneously, providing operations with a way to save costs and boost productivity.
• High-Speed Coding: The X1 offers a maximum printing speed of 300m/min—a speed that rivals many flagship printers.
• Large-Image Coding: As a single printhead, the X1 is capable of creating 1-inch codes. As a stitch printhead, the X1 can make 2-inch codes.
• High-Resolution Coding: The X1’s maximum printing resolution is 600 x 600 DPI, a level that alternative TIJ printers simply can’t match.
• IP66 Construction: The X1 is built with an IP66 enclosure, meaning that it offers the greatest possible protection against dust particles and a high degree of water protection, including from powerful jets.
• Wide Operating Temperature Range and High Humidity Resistance: The X1 can successfully operate in temperatures ranging from 0°- 40° Celsius (32°-104° Fahrenheit), as well as relative humidities ranging from 0% - 90% (non-condensing).
• Robust Screen Protection: The X1’s touch panel is built with industrial-grade strength, protecting it against many accidental work site impacts.

The X1 is a tough, high-performance printer that can handle almost anything you can throw at it.