Marking systems

The term ‘marking systems’ encompasses all the technologies (both hardware and software) used for marking. These include, among other things:

• Marking devices such as label printers or label dispensers.
• The software that powers the marking devices.
• Label software, i.e. computer programs used to design labels.

Marking systems are not only suitable for marking products, but they are also able to mark primary and secondary packaging.

The primary task of a marking system is to label products or packaging with a wide variety of information such as barcodes, sequential numbers, best-before dates, graphics or text. This information enables:

• The automated reading of the respective content.
• The automation of logistics processes and product traceability along the entire supply chain.
• The end consumer to be informed at the point of sale about product content and recommendations for use. In the case of food, important information is added, such as a list of ingredients, allergen information, production and best-before dates, as well as recommendations for storage, preparation and consumption.

Although office printers can print complex codes and data, they are not suitable for industrial environments. There are many reasons for this:

• Office printers often only print on paper and are limited to the DIN A4 format.
• They print rather slowly and work with much smaller ink or toner volumes.
• They have limited RAM and can usually only be controlled by PCs.
• They are only suitable for office environments and not for production environments, where they may be exposed to moisture or dust.

In contrast to office printers, marking systems are robust machines suitable for industrial use across all sectors, including logistics, packaging and manufacturing. They offer several advantages, including the following:

• Marking systems can print at high speed. In addition to the conveyor belt speed, the required print speed and throughput of a marking system also depends on the distance between the products and the volume of the content to be printed. Standard or high-speed systems are available, depending on how many products or packages need to be marked per minute. The printing speed of industrial marking systems is therefore much faster than that of conventional printers. There are thermal inkjet printers that can apply up to 120 variable markings per second. This requires, among other things, a large main memory.
• Marking systems provide a superior print quality. These systems offer razor-sharp labeling with a resolution of up to 600 dpi. The markings adhere within milliseconds to a wide variety of substrates and are abrasion-resistant. They are precise, very easy to read, rich in contrast and (if desired) permanent.
• Industrial marking systems are capable of producing large-area print images up to 800 millimeters high and six meters long. They clearly exceed the capacities of conventional office printers many times over.
• Marking systems offer contactless printing, meaning they can print at variable distances from the product or packaging. This provides a high level of flexibility in production environments.
• Industrial marking systems can not only print on flat paper, but also on other surfaces like cardboard, plastic, glass or metal. The inks used in the printing system are based on the respective condition and color of the surface to be marked. They can be water-, oil- and solvent-based, but also pigmented, alcohol-, grease- and condensate-resistant. In addition to this, the structure of the surface to be marked does not necessarily have to be flat. For example, round products can be guided along the print head in a rotary motion. This ensures consistently good print quality, even on uneven surfaces.
• Industrial marking systems do not require an external computer for control, but are equipped with their own software. They can either be operated directly on the control unit or via a network connection or external PLC.
• Industrial marking systems are also equipped with high IP protection classes. IP protection classes 55 or 65 are required for production environments in which the technology used is exposed to moisture, dirt or dust. There are devices that lock themselves automatically during production breaks and do not have to be dismantled or covered during wet cleaning.
• Marking systems can be integrated into production environments. The print heads are mounted directly on conveyor belts in order to be able to mark products or cardboard boxes as they pass by. In cramped production environments, it is possible to set up the control unit belonging to the system a few meters away from the print head. Alternatively, there are marking systems that combine the printhead and controller in a single, tiny device. As a result, these devices can be accommodated in the smallest of spaces.

There are different types of marking systems. A rough distinction can be made between direct marking systems and labeling systems.

Direct marking methods include inkjet printing (which includes drop-on-demand inkjet printing and continuous inkjet printing), thermal transfer printing and laser marking.

Labeling systems, on the other hand, are an alternative to direct marking. They are suitable for applications where direct marking is out of the question or impractical. In addition, they use multi-colored pre-printed labels which offer more far-reaching possibilities than pure (single-color) printing or marking. Labeling systems can also apply information at variable positions and the units do not have to run across the belt at a fixed distance from the labeling machine.

The range of labeling systems available on the market ranges from entry-level devices for simpler labeling tasks to semi-automatic systems for bottle labeling or systems that can control complete logistics processes (including all peripheral devices).

Labeling systems are available as label dispensers (for pre-produced labels) or label printers and dispensers (with an additional print module for individual labeling). Label dispensers are extremely variable in terms of their configurations and equipment. Depending on the production environment and labeling task, they can be equipped with different pressure modules, dispensing strokes and applicators. It is worth noting that a combination of a label dispenser with a system for direct marking such as an inkjet printer or laser marker is also possible.

Finally, label printers are also a type of labeling system. Label printers can be divided into small and industrial printers. Small label printers the size of a pocket calculator are often understood as a marking system. In most cases, only letters, numbers and a few special characters can be printed on self-adhesive labels with a specified height. Industrial label printers, on the other hand, can mark large volumes of products in a short amount of time. They are not limited to letters, numbers or special characters, but can also print elements such as logos, barcodes or QR codes.

A particularly cheap marking system are the so-called marking embossing devices, which work entirely without electricity or batteries. The embossing tape is labeled using a turning and click mechanism. These devices are popular for home use, for example to label storage containers.

For business use in the office or for product marking, there are portable, battery-operated marking devices that offer more design options and an electronic display.

Nowadays, robots are used in combination with marking systems. In many cases, articulated robots (also known as universal robots and whose movements are freely programmable) are used.

The greatest advantage of using robots is that labeling can be designed more flexibly and efficiently. As an example, robots are extremely useful if labels have to be applied in variable positions or if larger distances have to be bridged.

Camera-controlled systems are also used in modern marking. The best example of this is quality control, where the legibility of the label is checked by scanners in order to eject faulty products before they are shipped.

Another advantage of modern marking systems is the possibility to connect all the marking devices to an intelligent network. This way, key production figures can be recorded and later evaluated. These figures can then provide answers to many questions, including how many units were produced, what the (average) line speed was, how many rejects there were, how long production was idle or which errors occurred and how often.

Determining which marking system is the most suitable for a particular usage depends on many factors, including what is being manufactured or what the production environment is like. Other parameters that may determine which marking system is the most appropriate include:

• The material to be marked (e.g. cardboard, plastic, wood, metal).
• The industrial sector. The food and the automotive industry, for example, have quite different requirements with regard to print quality.
• The rate at which the products are manufactured or packaged. If the rate is high, marking systems that can be directly integrated in the production line are often preferred.