Abstract: In one embodiment, an air-blown optical fiber unit includes one or more optical fibers, an inner layer substantially completely embedding the one or more optical fibers, and an outer layer radially external to the inner layer. The inner layer has a tensile strength of from 0.1 MPa to 1 MPa, and an elongation at break of from 10% to 80%.

Abstract: In one embodiment, an air-blown optical fiber unit includes one or more optical fibers, an inner layer substantially completely embedding the one or more optical fibers, and an outer layer radially external to the inner layer. The inner layer has a tensile strength of from 0.1 MPa to 1 MPa, and an elongation at break of from 10% to 80%.

Abstract: A process for manufacturing an optical fibre unit for air-blown installations includes: providing a deposition chamber for applying particulate material, the deposition chamber having an inlet end and an outlet end and a longitudinal axis; passing through the deposition chamber an optical fibre assembly including at least one optical fibre embedded in an inner layer of cured resin material, and having an outer layer around the inner layer, the outer layer including uncured resin material; injecting a flow of fluid and particle material in the chamber in a direction substantially parallel to the chamber longitudinal axis, at an injection speed of 5 m/s at most; perturbing the flow when in the chamber, thus causing the particle material to impact and partially embed into the outer layer of the optical fibre assembly; and curing the outer layer.

Abstract: An optical fiber unit for air-blown installations includes a number of optical conductors, a first layer of resin material, a second layer of resin material radially outer to the first layer of resin material and a sheath of a thermoplastic material, wherein the second layer of resin material has a secant modulus higher than a secant modulus of the first layer of resin material and wherein the sheath of thermoplastic material is over and in close contact with the second layer of resin material.

Abstract: An optical fiber unit for air-blown installations includes a plurality of optical fiber sub-units and a central member, wherein the optical fiber sub-units are stranded around the central member; wherein each of the optical fiber sub-units includes a number of optical fibers, an inner layer which is radially outer to the optical fibers, and an outer layer which is radially outer to the inner layer, wherein the outer layer includes particulate material which is partially embedded into the outer layer; and wherein the optical fiber unit further includes a binder for keeping the stranded optical fiber sub-units in a proper arrangement.

Abstract: An optical fiber unit for air-blown installations includes a number of optical conductors, a first layer of resin material, a second layer of resin material radially outer to the first layer of resin material and a sheath of a thermoplastic material, wherein the second layer of resin material has a secant modulus higher than a secant modulus of the first layer of resin material and wherein the sheath of thermoplastic material is over and in close contact with the second layer of resin material.

Abstract: An optical fiber unit for air-blown installations includes a plurality of optical fiber sub-units and a central member, wherein the optical fiber sub-units are stranded around the central member; wherein each of the optical fiber sub-units includes a number of optical fibers, an inner layer which is radially outer to the optical fibers, and an outer layer which is radially outer to the inner layer, wherein the outer layer includes particulate material which is partially embedded into the outer layer; and wherein the optical fiber unit further includes a binder for keeping the stranded optical fiber sub-units in a proper arrangement.

Abstract: A process for manufacturing an optical fibre unit for air-blown installations includes: providing a deposition chamber for applying particulate material, the deposition chamber having an inlet end and an outlet end and a longitudinal axis; passing through the deposition chamber an optical fibre assembly including at least one optical fibre embedded in an inner layer of cured resin material, and having an outer layer around the inner layer, the outer layer including uncured resin material; injecting a flow of fluid and particle material in the chamber in a direction substantially parallel to the chamber longitudinal axis, at an injection speed of 5 m/s at most; perturbing the flow when in the chamber, thus causing the particle material to impact and partially embed into the outer layer of the optical fibre assembly; and curing the outer layer.