If it’s glass, then it definitely breaks fast, isn’t it? Well, that is not exactly how things go with fiber optic. We can understand why some people might be concerned about the durability of the cables; in the end, fiber optic IS made out of glass. But truth be told, they last considerably longer than what you would expect. When handled correctly, fiber optic cables stand the test of time. And here’s why.
When we hear the word ’glass’ we automatically think about drinking glasses that break in tens of small pieces the second you drop them, or we envision the window that cracks as soon as a kid’s football touches it. So why on earth do people say that fiber optic is so flexible and incredibly strong?
Well, everything can be traced back to the manufacturing process. The common glasses are made by melting silica (which is basically sand), pouring everything in a mould and cooling it very fast, to avoid crystallization. Simple, isn’t it? The glass obtained through this process is not pure and therefore its strength and ability to transmit light is limited.
The process of making fiber optic is completely different. The pure silica rod and the rest of the materials must be stored at high temperatures; ultra-pure glasses are used to create a preform. Once the preform is solidified, it is placed in a drawing tower where the fiber is pulled into long strands.
This whole complex process makes the fibreglass transparent and strong. The theoretical maximum strength of fiber optic is around 2 million pounds per square inch, but practically it is 10 to 20 % of that.
Fiber is also very flexible. You can take a cable a tie it in a knot without damaging it in the end. O course, the tight bends can cause a loss in fiber strength, but the soft jacket of the cable will prevent it from breaking. Once you untie the knot, the patch cord will return to its initial condition.