Permabond CPP621 – Fingerprinting : when blooming becomes an advantage

Blooming is a well-known effect for cyanoacrylate adhesives users : it relates to these whitish marks that can be observed on surfaces (close to the area where the glue has been deposited). When dispensed, the cyanoacrylate vapors react with the humidity of the air and the humidity naturally present on the surface of the materials. This chemical reaction forms a white deposit, particularly visible on black materials and some transparent plastics (i.g. polycarbonate).

For years, users and manufacturers of cyanoacrylate adhesives have tried to suppress blooming, in order to improve the aesthetic aspect of their bonded assemblies. For example, Permabond has developed a full range of alkoxy-ethyl cyanoacrylate adhesives (Permabond 940, 941, 943 and 947), that have been specially designed to limit the generation of vapors, and thus prevent the formation of white streaks due to blooming.

However, there is one major application for which we seek to maximize the blooming effect : the revelation of fingerprints at crime scenes or on exhibits.

In particular, Permabond CPP621 is used by the Forensic Police Department of several countries. This product is specially formulated to generate a large amount of vapor when heated. When used in a place with a high air humidity level, the vapors naturally deposit on fingerprints, react with the humidity, and generate enough blooming to make fingerprints appear in a few minutes.

The easy to use, reliable process of Permabond CPP621 is one of the cheapest methods for revealing fingerprints on crime scene investigations