Flexible printing systems replace pre-fabricated labels

Professional labelling is essential for clear assignment of components and cables in electrical systems for building installations.

Efficient and flexible printing systems are now replacing pre-fabricated labels or manually applied labelling. 

In the building installations sector, time is a crucial factor, just like in any other branch of industry. Industrial buildings, office complexes and other functional buildings are being built faster and faster.

This trend is also affecting the electrical installation industry: Whoever can make control cabinets the fastest will win the contract.

Every customer-specific building system design requires custom labelling. In the past, manufacturers would often order pre-labelled materials, but nowadays there is no longer time for this.

With flexible printing systems, components can be custom-labelled in the factory or directly at the customer's site prior to operation. Labeling volume is the key factor in choosing a printing system, and two different systems are used:

• Individual labelling materials are inserted manually
• Labeling materials are automatically inserted in roll form or in cartridges

Traditionally, labelling plotters have been a popular choice for marking terminals and equipment used for small-to medium-sized jobs. Plotters use solvent-based ink, which hardens when the solvent evaporates. This simple method has a disadvantage: The labelling pens can easily dry out.

This problem is prevalent in all ink-based printing systems. Either the pens dry out, or the printers must be thoroughly cleaned before they can deliver good results again.

The medium itself is problematic. Ink-based systems contain solvents that give the ink the necessary viscosity. Solvents such alcohol, oil or water evaporate into the air, leaving behind just the ink, which becomes a permanent part of the substrate. This process is difficult to control because evaporation depends on many different factors.

Ambient temperature, humidity and long intervals between operating times can also cause problems. Continual monitoring of the printing process is time-consuming and makes ongoing operations expensive. In addition, printer cartridges and dried-out pens pollute the environment.

One alternative to solvent-based labelling systems is thermal transfer printing, a method in which the ink is directly applied to the labelling material.

The thermal printer head is a key element of these systems and is comparable to a pin-style printer head. The distance between the pins, which serve as heating elements, determine the print resolution.

The current standard is 300 dpi (dots per inch), which allows for font sizes up to 0.5 mm. The ink is applied to the print medium wherever the heated elements contact the ribbon.

The printed result is smudge-proof, resistant to alkalis and acids and can withstand temperatures up to 150°C.

This fixed-ink printing system has several advantages:

• Low procurement costs
• Compact, enabling mobile applications
• Always available, even during downtimes

UV-based printing produces a scratch-resistant, solvent-resistant typeface on a range of materials, from terminals to wires to equipment.Thanks to these advantages, thermal transfer printing is now widely used for printing labels and heat-shrink tubing in industrial environments.

Flat roll-form materials are typically used as they are easy to feed through the printer, and their flat shape makes them excellent for thermal transfer printing.

Contact-free printing methods such as inkjet printing have many advantages for these applications.

Phoenix Contact's Bluemark printing system uses a special solvent-free fluid designed specifically for this application.

It contains no solvents and is hardened using short-wave UV light. No heat is needed, and there are no emissions.

This UV-based, contact-free printing method has the following advantages:

• No drying times
• Highly smudge-proof and resistant to abrasion
• Highly resistant to chemicals
• Solvent-free and environmentally friendly

UV-based printing is no longer a new technology for labelling plastics or paper and has been used in offset printing since the 1950s. These special printing systems were predominantly used for large format prints such as wall posters.

After printing, the large printed area is illuminated by several UV lamps, and the fluid on the labelling material is hardened by this high-energy but short-wave UV light (typically between 200-380 nanometres).

This process is called polymerisation. This method is also used in medical technology applications such as hardening of dental fillings.

The unique feature of this method is that no heat is needed for drying. After the UV exposure, the surface of the labelling material is cool enough to touch. The material can be immediately processed after printing and is not placed under any thermal stress. If any part is missed, the material can be reinserted and printed.

Less energy

Modern UV LEDs are used for the UV exposure. In the Bluemark CLED printing system, these LEDs are integrated using compact chip-on-board technology. This LED version is up to 90 percent more energy-efficient than other systems on the market. The UV LED unit is designed to last the entire lifetime of the printer.

Because it generates minimal heat, the Bluemark CLED has no fan, which means it runs quietly. The printer offers high output despite its low power consumption of 70 watts.

Designed for continuous operation, the printer can easily produce 10,000 labels per hour. A wide array of materials is available for labelling terminals, wires and equipment, and the cartridge can hold up to 40 strips. Exchangeable cartridges allow for better preparation of print jobs.

The printer comes ready-to-use and can also process individual print jobs without delay. As soon as the printer is powered up, it can be used at full capacity thanks to semiconductor technology.

The warm-up time associated with other types of lamps, such as infrared LEDs, is eliminated. Even single cards can be inserted without using the cartridge. This makes the system extremely flexible even when processing large volumes.

A new smart card solution gives this industrial printer even more flexibility. With this card, print jobs can be purchased on a time and volume basis, and the printer is made available free of charge. In this way, peaks in demand can be easily managed without the need for additional investments.

The ideal printing system for labelling components in industrial electrical engineering environments is chosen based on workflows and print volume.

Requirements regarding materials and the durability of the print result are determined by the application. Generally speaking, however, both ink-based and thermal transfer systems are designed to meet the requirements of the building engineering industry.