Microducts are a growing part of the last mile infrastructure. Their bundles, distribution nodes, junction boxes, and connection points compose a no-nonsense network of pathways that are relatively easy to install and maintain.
Individual microducts are small diameter tubes destined to receive fiber optic cable that begin at relatively low fiber counts, starting from one to well into the hundreds. Microducts are found in sizes ranging from 3 to 16 mm OD, 20 mm, and sometimes more. They are usually assembled and jacketed into bundles containing from 1 to 24+ microducts or multi-ways.
A typical microduct construction is composed of high-density polyethylene, a marking feature, and a low-friction characteristic. It can be extruded as a single, double, or triple layer tube. In a triple layer configuration, the inner layer is silicon based or ribbed for low friction, while the outer layer is either a color skin or a stripe.
Jacketed bundles can be single layer or double layer with an overlapped aluminum strip. A microduct network starts with a service point in a neighborhood and spreads out in a tree structure towards several access points.
Microduct pathways are extended end-on end by using duct connectors. Connectors are also used to switch from one bundle to the next, for example at a junction box. The goal is to create uniform uninterrupted routes which will result in little or no fiber splices between the service point and the user destination.
A popular installation method is air-jetting (i.e. blowing) the fiber through the microduct. The microduct network may first be empty. As users come on-line, fiber is blown to destination. Fiber is easily replaceable by pulling or blowing out existing capacity and blowing in new one, as demand changes.
The effort needed to modify the network is drastically reduced (i.e. limits digging up the road). The advantage of a microduct network is its ability to evolve. It is extremely flexible to install and operate.
Fiber service to the home and the ability to extend / upgrade the network over time are increasing the demand for flexible infrastructures. Our portfolio includes the entire manufacturing package from single microduct extrusion to large bundle jacketing. Productivity and minimum scrap are achieved thanks to solutions like triple layer co-extrusion, aluminum taping, and long-length conditioning.
We respond to microduct manufacturer’s interest in making long lengths. The limiting factor is the reel or barrel containing the individual microducts extruded during the first step. Consequently, the determinant length of a jacketed bundle would be the shortest of its assembled microducts. Maillefer proposes conditioning systems for realizing optimum lengths between extrusion and assembly.
We have been responding with microduct manufacturing solutions for more than three decades. The top names in the field, starting with the industry’s pioneers, are on our reference list and remain partners with us to this day.
Maillefer is helps producers of microduct find their place along the expanding last miles.
Philippe Giovangrandi
Technical Director, Pipe & Tube Business
philippe.giovangrandi@maillefer.net