In almost all cases, an antimicrobial plastic will be visually indiscernible from the same material without the antimicrobial. This can lead to confusion, particularly if a product is available in both antimicrobial and non-antimicrobial versions. In these instances, it can be useful to further modify the antimicrobial plastic with a means of visual detection.
While it isn’t possible to easily detect the antimicrobial additive itself, by blending the additive with a detectable material or taggant, it is possible to create a material that can be identified easily with relatively inexpensive equipment.
The most economical approach is to blend the antimicrobial with an optical brightener, which enables identification with a cheap UV light. This usually works best with light coloured plastics, but we have a particularly powerful brightener formulation that allows even black antimicrobial plastics to be easily differentiated from a non-antimicrobial.
While an optical brightener is a cheap and effective option, some customers prefer a laser detectable additive, such as “anti-stokes” or “up-conversion” phosphor taggants. These are inorganic phosphor compounds that convert lower energy light (e.g. infrared) into higher energy, visible light. The ‘detector’ would typically be a low cost laser pen with a wavelength of 950-980nm.
Both optical brighteners and anti-stokes phosphor additives provide a quick and easy visual confirmation, but it’s important to note that it is purely qualitative (i.e. yes/no). Quantitative detection is theoretically possible but in most practical applications our experience suggest that the accuracy is inadequate for a meaningful result.
