How it Works: Engineering Labels for the Laboratory Environment

Problem: Labeling of tubes, vials, plates, slides and other labware by hand using a “permanent” marker or a laser-printed paper label has significant drawbacks when used on labware in a laboratory environment. Exposure to chemicals, including solvents, caustics, and even water, can remove ink from surfaces, leaving an unintelligible mark. Paper labels are susceptible to physical damage, stain easily, and will become saturated when exposed to water and other liquids, leading to image distortion and adhesive failure. Adhesives used in most paper labels are not strong enough and ‘winging’ of labels is common. Traditional labels become brittle and fail when applied to labware exposed to cryogenic conditions. Also, most ink printed labels are incompatible with barcoding technology.

Solution: Engineered labels are specifically designed for the laboratory environment. Each label component— material, image and adhesive—is customized for the specific application and the label is then tested in that environment to ensure performance. Although there is no one universal laboratory label construction, certain labels perform successfully for a wide range of laboratory applications.

Polymer label material is commonly selected for the laboratory because of its chemical resistance as well as performance in hot, cold and wet environments. Polymer resists tearing and other physical damage. Material flexibility and thickness are important factors for labels applied to curved or irregular surfaces. Label thickness is also an important consideration for labware placed in holders or racks; sometimes containers like microtubes will not fit in their holders after labeling.

Thermal transfer imaging, using a heat-activated ribbon material in the label printer, is the best choice for engineered labels for several reasons. Thermal transfer ribbons allow users to select the image durability most suitable for their application. Images are transferred from the ribbon to the label using heat to ensure the image is durable and cannot smear after printing. Thermal transfer printing also offers up to a 600 dpi image, making the image suitable for barcode and other high-density data storage methods. In some cases, over-laminates are designed into the label to protect the image from even the strongest chemicals after printing.

The third critical label component for laboratory use is adhesives, which are designed for different surfaces, materials and environments. The rough finish often found on extruded plastics requires a thicker layer of stronger adhesive to overcome the lower surface area and sufficiently penetrate into surface irregularities. Adhesives used for plastics are often different than those used for glass, and many adhesive types exist for different types of plastics. Molded plastic can have residual chemicals used in the molding process on the surface, which is a challenge for most label adhesives. In cryogenic applications, most labels will fail when exposed to temperatures at or below -20° C, and will not stick when applied to cold or frosted surfaces, so it’s important to choose a label specifically designed for cryogenic conditions.

In considering each label component, from material to image to adhesive, engineered labels are the best choice for use on labware within the laboratory environment.

For more information, visit www.computype.com/laboratory.