Two properties that decide it
Weight
For any given threat rating, a polycarbonate build weighs a fraction of the equivalent laminated glass panel.
That single fact changes what is possible:
- Opening panels. A rated door or window in laminated glass may simply be too heavy for any reasonable hardware. In polycarbonate it becomes practical.
- Upper floors and lightweight structures. Where the slab or the partition cannot take the load.
- Retrofit. Where an existing frame or opening cannot be strengthened.
- Installation. A panel that can be carried and handled rather than craned.
No spall
When a ballistic panel is struck, fragments can be thrown from the protected face even if the round does not penetrate. Polycarbonate does not do this — it deforms and absorbs energy rather than fracturing.
For anyone standing directly behind the glass, that is the difference between protected and injured. At a teller window, a cash counter or a reception position, it is the property that decides the material.
What you give up
Surface hardness. Polycarbonate is soft compared with glass. It marks during routine cleaning, especially with an abrasive cloth or with grit on the surface — and in Mumbai there is always grit on the surface. Hard-coated grades help substantially, but not to the level of glass.
UV stability. Untreated polycarbonate yellows under prolonged sunlight. UV-stabilised grades slow this considerably, but on a west-facing elevation over a twenty-year life it remains a consideration.
Appearance. It does not look quite like glass, and people notice on a shopfront.
The hybrid answer
If the weight and no-spall benefits are what you need but the surface durability is unacceptable, glass-clad polycarbonate puts a glass face on a polycarbonate core. You get the glass surface and most of the weight advantage, at higher cost.
That is often the right specification for a customer-facing position that also needs to look good for years.
Blunt-force performance
Worth noting separately. Polycarbonate is exceptionally tough against blunt impact — considerably more so than glass of any kind. Where the realistic threat is a smash-and-grab with a hammer rather than a firearm, this is a strong argument for it regardless of the ballistic rating.
Specifying it
As with every build in the bullet-resistant range, the frame has to be rated to match. A polycarbonate panel in an unrated frame relocates the weak point rather than removing it.
For the wider decision about whether ballistic glazing is the right answer at all, see bulletproof windows in Mumbai.