In-mold labeling is widely used for decorating and providing information on a variety of consumer products sold in plastic containers, including food, cosmetics, and even flowers. In-mold labels are specially designed for embedding into molded plastic parts (blow molding, injection molding or thermoforming) during the molding process and UL’s in-mold label (IML) program is specially designed to support IML manufacturers and their customers who use IMLs to display safety-related information on UL certified products.
In this portion of the Marking & Labeling Systems Recognition program, samples of IMLs are evaluated in accordance with the same safety standards used to evaluate pressure-sensitive labels, including UL 969, Marking & Labeling Systems; CSA, C22.2 No. 0.15; and many IEC-based UL end-product standards that require a marking durability rub test. UL evaluates IMLs in combination with generic plastic surfaces (e.g. ABS, polycarbonate or polypropylene) and one or more molding processes.
To provide label manufacturers and their customers with the broadest Recognition based on the tests conducted, labels found suitable for being molded into a particular generic plastic are considered suitable for being molded into any filled or reinforced plastic of the same generic type. Additionally, IMLs found suitable with two or more generic types of plastic can be considered suitable for being molded into blends of those plastics without additional testing.
While some end-product manufacturers may produce molded parts in-house, the molding of plastic parts is more commonly accomplished at a separate molding facility. To provide flexibility to end-product manufacturers, UL also established guidelines allowing end-product manufacturers to obtain IML parts from the molder of their choice. To do so, the parts must be molded within the prescribed molding process parameters and the molder must provide required traceability documentation.