Coding & Marking
A Complete Guide to Coding and Marking Equipment in Packaging
May 17, 2023
1 min read
Welcome to Package This 201 — your guide to packaging machinery and materials, produced by the Emerging Brands Alliance in conjunction with Packaging World and PMMI, the Association for Packaging and Processing Technologies.
In this episode, we focus on a type of equipment found in nearly every packaging facility: coding and marking. These machines print or mark variable data like expiration dates, product codes, bar codes, and batch numbers on materials including paper, plastic, metal, and glass.
Coding systems play a crucial role for brands in areas such as inventory management, safety, and traceability throughout the supply. For example, batch codes on packages help brands isolate a specific batch of products if there is a problem. Consumers also rely on product codes daily, in the form of expiration dates printed on food packaging to ensure that a product is consumed before it spoils.
Marking and coding technology is also used to produce packaging security features as well as special decorations.
First, let’s dive into inkjet systems. In this non-contact method, machines propel droplets of ink onto the surface material – called the substrate – to mark lot codes, expiration dates, and other information directly on a package at high rates.
Inkjet coders can be grouped into two main types: small- and large-character systems.
Small-character inkjet coders can print in areas as small as 1- to 2-milimeters in height. They code variable data on a wide range of substrates, including on products with irregular, uneven and curved surfaces, such as bottles and cans. Small-character inkjet printers are used across many market segments, including in the beverage industry, as we see in this clip.
Here, Squid Ink’s JetStream system is coding expiration dates on the rounded bottom end of aluminum cans. This technology, called continuous inkjet or CIJ, applies a steady stream of electrically charged ink droplets onto the surface material. This Squid Ink model prints up to five lines of code and can run at line speeds of up to 1,000 feet per minute. Squid Ink supplies the JetStream with automatic start-up and shut-down features to further maximize uptime for busy facilities.
Large-character inkjet systems are often used to produce barcodes, logos, and product descriptions when legibility and machine scan-ability of the code are top requirements, such as during shipping and palletizing.
Let’s look at Squid Ink’s CoPilot Max inkjet system in action. Using up to two, 2.8-inch printheads from a single controller, this large-character inkjet printer produces high-resolution characters, text, logos and scannable bar codes for cases at a 360-dpi resolution. The CoPilot Max Turbo will run oil-based, solvent-based, or UV curable inks for sharp printing on a wide range of porous and non-porous substrates. This model also features a 4.3-inch, full-color touchscreen, providing operators with easy access to the system’s internal messages and print functions.
Large character inkjet systems can also be solutions in palletizing and bulk applications, such as printing SKU information on pallets or creating labels with weight and product information for bulk bags.
Laser coding systems are another distinct type of marking and coding technology. This non-contact technology uses focused beams of energy to engrave, etch, and ablate surfaces, producing precise and durable markings. Laser coders are used in similar applications as inkjet technology, for coding directly onto glass, metal, and other materials. Some laser systems can also apply codes to flexible packaging materials such as labels.
Laser might be a good option to consider when graphic presentation and code durability throughout the supply chain are top priorities.
Shown here is Domino’s U510 UV laser system applying a code onto a white HDPE plastic pill bottle. Designed to keep the protective barrier intact, this laser coder creates a photochemical reaction on the very top layer of the packaging material without causing any damage. Its laser pulse has an extremely short wavelength and high absorption rate, minimizing thermal stress and soot particle buildup.
Domino’s system can even safely code very thin, sensitive packaging films, making it a solution for hard-to-mark plastics including sustainable packaging materials like recyclable mono-material films.
There are also specialized laser technologies used to create security features on packaging materials, such as systems that produce microtext codes on packages or products for counterfeit prevention.
Thermal transfer coding, also called thermal transfer overprint or TTO, is a direct contact method used in coding flexible packaging materials like plastic film, foil, and paper. Applying heat, TTO machines transfer an image from a ribbon to the packaging material to create high-quality barcodes, labels, and reliable variable data while keeping up with high-speed flexible packaging lines.
TTO technology is often highly versatile, sometimes blurring the lines between traditional coding and labeling.
The EasyPrint MLP from BELL-MARK prints up to 800 millimeters per second in an area of up to 8.3 inches. With such a wide print area, it handles logos and nutritional information, making this TTO a great solution to replace entire labels.
BELL-MARK offers a washdown version of this model with hygienic features like a sealed electrical bay and watertight connections, giving it an IP-67 rating for operation in harsh environments common in the meat, poultry and dairy industries. Its HMI touchscreen features label creation software and allows multiple users to manage and edit print files and monitor systems with full data logging.
Embossing and debossing equipment is typically used for raising or recessing brand logos, product names, or package components on boxes, aluminum cans, and some bags. Embossing and debossing helps brands add aesthetic appeal to packages while reinforcing brand recognition and promoting customer loyalty.
Finally, hot and cold stamping machines are used for marking and decorating as well as for security applications. Hot stamping technology uses a heated die to transfer a thin layer of foil onto the material, creating a metallic foil imprint used on specialty boxes and cartons for high-end products. Cold stamping machines apply pressure to transfer a pre-printed image or hologram onto the material as a graphic enhancement or tamper-evident feature.
There are even more types of specialty coding equipment, such as reciprocating coders used in bread bagging and other applications, that we won’t have time to cover here. But one thing is for sure: coding and marking equipment are vital tools for brands. They help maintain product data throughout the supply chain, ensure package and product security, and enhance package design through decoration.
We hope this video has given you a good overview of the main types of this technology as well as some typical applications.
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