The most obvious feature of a barcode label is the print quality. Is the barcode crisp and clear, even at tiny sizes? Will the printing last or will it succumb to extreme temperatures, moisture, chemicals, scratching, and smudging? When ordering custom labels, it’s essential to specify the right facestock to handle a particular application, but there are also many options for choosing an adhesive. If the label doesn’t stick when and where it’s supposed to, it doesn’t matter how clear the label is printed because it will end up on the floor somewhere. Or, at the other end of the spectrum, the label can’t be removed or leaves adhesive residue where it shouldn’t.
Remember that an adhesive is a chemical formulation. The “stickiness” is based on a physical reaction with a particular surface, so not all adhesives provide the same degree of adhesion. According to 3M (creators of the “sticky note”), adhesion occurs via a molecular attraction between two unlike surfaces. A higher surface energy creates a stronger molecular attraction, while low surface energy produces a weaker one.
Metals and some plastics (including PVC, polyester, fiberglass, and acrylic) have a high surface energy. Other plastics, like polystyrene, polypropylene, and Teflon, have a low surface energy. If you’ve ever tried to stick a label on a Styrofoam takeout container, you know how tricky this surface is!
Adhesives are made from various materials, including acrylics, butyl, natural or silicone rubbers, nitriles, a number of styrene based copolymers and vinyl ethers, and even some water-based formulations, which are best for dry environments. For example, if you plan to use your custom barcode labels for refrigerated or frozen products, a water-based adhesive will break down and the label will fall off.
Before you order custom barcode labels, consider these aspects for their use:
What type of surface will the label need to adhere to? Will the surface be clean, dirty, dusty or sooty; flat or curved; rough, textured or smooth; oily or greasy; frosty or frozen; dry or wet?
Will the label be exposed to harsh conditions? It’s not just the surface printing that needs to hold up to wear and tear. If your custom label needs to withstand tough environments like extreme heat or cold, liquids and chemicals, abrasion or exposure to ultraviolet light, you’ll need an adhesive that is formulated for those conditions.
How long should the label remain affixed to the surface? Some barcode labels are temporary, while others need to stay put for much longer, like documents, medical samples, shipping labels, and parts numbers. Still other barcode labels are required to be removed, like a shelf label or a gift item price label.
Do you need a security feature? Do you need to know if a label has been tampered with? Gift cards, for example, should have their barcode labels protected by a tamper-evident adhesive that leave a mark or the word “VOID” on the item when the adhesive is removed.
Here are the main types of adhesives and how they are most often used:
Removable: Stays positioned for months or years and can be removed without leaving an adhesive residue on the surface where it was applied or any damage to the label. For general uses where the label will need to be removed, like shelf labels, gift item price labels, or tote bin labels. Repositionable: Easily removed at initial application, but can then be removed and adhered again in a different location; becomes permanent over time. For products where the label might need to be temporarily removed because it’s covering some aspect, such as decorative home furnishings and artwork or it was applied in the wrong place and requires adjustment. High Tack: Adheres to rough surfaces. For labeling uneven surface areas, like tires, wood, and powder-coated metal. Permanent: Stays positioned permanently with the initial application and withstands general conditions. Designed for labeling any item that needs to retain the label for long periods; can withstand many conditions but may not be strong enough for extreme heat or cold. Freezer/Cold Temperature: Long-term adhesion in extreme cold. For products that will be refrigerated or frozen, either at the time of label application or during its life span.