Loose tube is a fiber optic cable construction in which the fiber is placed inside a plastic tube of much larger diameter, often gel-filled, to isolate it from mechanical stress.
In a loose tube construction, optical fibers rest loosely within a plastic tube whose diameter greatly exceeds that of the fibers. The extra space isolates the fragile fibers from exterior mechanical forces acting on the cable, allowing the cable to bend, expand, and contract without transferring stress to the glass. This isolation is key to protecting fibers in environments where the cable itself is subject to movement and temperature change.
The space inside the tube is frequently filled with a gel that cushions the fibers and blocks moisture. In commercial and industrial fiber optic systems, this construction protects fibers in demanding environments and over long runs, helping maintain signal integrity where the cable is exposed to physical and environmental stress. The combination of free movement and gel filling makes loose tube cable a robust choice for challenging conditions.
This resilience is why loose tube cable is a common choice wherever fiber must remain dependable under demanding physical conditions, including long runs where temperature swings and handling forces would otherwise threaten the delicate strands inside.
At Windy City Wire, the focus on fiber optic cable for commercial communication includes constructions like loose tube that protect fibers in demanding settings. Supplying cable engineered to isolate fibers from stress helps ensure that optical links maintain their performance across the conditions a facility may present.
Also called buffer tube construction