Editorís note: Sometimes itís the seemingly simple and ubiquitous components that get overlooked or are taken for granted in an electronics or electrical design. This can prove disastrous in your design.
Stephen Earley, TE Connectivity's global product manager for wire and cable identification, explains why it's important to select the right type of identification marker for the job Ė and why the ink and printing techniques are just as important as the label or sleeve itself.
As a technician, if you're about to work on an electrical installation and are faced with an array of devices, terminations, cables and wires, how do you tell which is which? This is when identification markers come into play. Its job is to ensure that technicians and engineers can quickly identify devices and cables during inspections, refurbishment, repair or refit. However, choosing the wrong type of identification marker can result in hidden costs - if the mark is no longer visible or in place, it will cost time, money and frustration.
Which marker is the best?
Most installers and their customers have personal preferences of which type of identification marker they think is best. Markers range from pre-printed slide-on, snap markers and printable flat, self-laminating or flag-style pressure sensitive labels, to heat shrink sleeves used on cables in harsh environments. With so much variety available, installers often turn to well-known brands or make their choice based on recommendations from a colleague they trust.
However, it's worth learning more about choosing the right product for the application as the right marker can save time, money and frustration.
They can often be exposed to chemicals, moisture, mechanical wear and tear, extreme temperatures and strong sunlight, all of which can reduce their life. The printing can rub off or fade or the material itself may become brittle. Itís important to choose a marker that will remain in place and readable so that maintenance technicians will be able to find a cable or termination quickly and efficiently.
The material is selected based on the temperature and conditions it will need to face during its life, so for example, a polyvinylidene fluoride label can resist waters, oils and cleaning agents as well as UV light. Alternatively, a heat shrink sleeve based on an irradiated cross-linked polyolefin can be used to identify wire and cable in really tough environments. This includes aviation where the wire, cable, and printed marker will experience extreme and frequent heat cycles between hot and cold as an aircraft takes off, flies, and lands. A third example is polyimide, which can be used as an adhesive label on printed circuit boards, as it can withstand the heat of soldering.
As well as taking into consideration the material for adhesive labels, the actual adhesive needs to be matched to the type of surface that the label needs to adhere to. It is relatively straightforward to find an adhesive to stick to a surface like glass but powder coated surfaces such as electrical cabinets have a low surface tension and require special adhesives.
Design and testing
When creating an identification marker, the ink and printing techniques are just as important as the label or sleeve itself. Many years of materials science have gone into the development of identification markers. To achieve long-term performance, we use a system approach that includes the material, printer ink, printer settings and print software.
Extensive and ongoing laboratory testing proves that the performance of the markers reaches industry standards. This includes simulating the stress caused by a tough environment with exposure to a combination of different chemicals, high or low temperatures, UV light, mechanical wear or proximity on a printed circuit board to the short but extreme heat of soldering.
Control and traceability are also key during manufacturing. Although the same ingredients may be used in the same quantities, the quality of the end product can still vary because of variables in the production process such as temperatures and mixing rates. Even the grain size of a chemical additive during production can also affect the long-term performance. However, tight control and traceability of the product, raw materials and manufacturing will lead to consistently high-quality markers that are dependable, readable and will remain firmly attached.
Ultimately, itís important to check that the identification solution meets the standards and technical specifications of the application.
For more information visit TE Connectivity Identification & Labeling site.