im refearing to EU military practices, and possibly american special forces,
due to limited amounts of troops with in eu nations , and a stronger concentration in peace keeping rather then agressive conflict, i think is the reasoning behind their exsistance.
afaik they come standred on Leopard 2A6 tanks
A smoke screen is a release of smoke in order to mask the movement or location of military units such as infantry, tanks or ships.
It is most commonly deployed in a canister, usually as a grenade. The grenade releases a very dense cloud of smoke designed to fill the surrounding area even in light wind. They have also been used by ships.
Whereas smoke screens would originally have been used to hide movement from enemies' line of sight, modern technology means that they are now also available in new forms; they can screen in the infrared as well as visible spectrum of light to prevent detection by infrared sensors or viewers, and also available for vehicles is a superdense form used to prevent laser beams of enemy target designators or range finders on vehicles.
Infrared smokes
The proliferation of thermal imaging FLIR systems on the battlefields necessitates the use of obscurant smokes that are effectively opaque in the infrared part of electromagnetic spectrum. To achieve this, the particle size and composition of the smokes has to be adjusted. One of the approaches is using an aerosol of burning red phosphorus particles and aluminium coated glass fibres; the infrared emissions of such smoke curtains hides the weaker emissions of colder objects behind it, but the effect is only short-lived. Carbon (most often graphite) particles present in the smokes can also serve to absorb the beams of laser designators. Yet another possibility is a water fog sprayed around the vehicle; the presence of large droplets absorbs in infrared band and additionally serves as a countermeasure against radars in 94 GHz band. Other materials used as visible/infrared obscurants are micropulverized flakes of brass or graphite, particles of titanium dioxide, or terephthalic acid.
Older systems for production of infrared smoke work as generators of aerosol of dust with controlled particle size. Most contemporary vehicle-mounted systems use this approach. However the aerosol stays airborne only for a short time.
The brass particles used in some infrared smoke grenades are typically composed of 70% copper and 30% zinc. They are shaped as irregular flakes with a diameter of about 1.7 µm and thickness of 80-320 nm.
A reportedly good improvised system for production of aerosol effective even in far infrared is said to be a dry powder fire extinguisher.
Some experimental obscurants work in both infrared and millimetre wave region. They include carbon fibres, metal coated fibres or glass particles, metal microwires, particles of iron and of suitable polymers.
but im sure as a US army vet you are extermly well versed in the construction and components of smoke grenades from all over the world?