Tight-buffered Optical Fiber Unit with Aliphatic Amide Slip Agent

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Tightly buffered optical fibers face challenges in accessibility due to the difficulty in removing the protective buffer tube without causing friction or water ingress, which can lead to attenuation and bending issues.

Innovation Solution

Incorporating an aliphatic amide slip agent into the polymeric buffering layer to facilitate easy stripping of the buffering layer, allowing for the removal of significant lengths of the buffering layer with minimal force while maintaining low attenuation and preventing water ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lubricant layer is used to reduce friction between the optical fiber and buffer tube, then accessibility is improved, but manufacturing complexity increases due to additional tooling and high precision requirements

Engineering Contradiction:
ImproveaccessibilityVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces a slip agent as an intermediary substance between the optical fiber and buffer tube. This slip agent migrates to the interface during operation, providing the necessary lubrication effect without requiring complex manufacturing processes. The slip agent acts as a mediator that reduces friction and improves accessibility while avoiding the manufacturing complexity associated with applying lubricant layers during production.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The buffer tube is designed to self-regulate friction by incorporating the slip agent within its structure. As the buffer tube is installed and used, the slip agent automatically migrates to the fiber-buffer interface through diffusion and mechanical movement, providing lubrication on-demand without external intervention. This self-service mechanism eliminates the need for complex external lubrication systems or precise application tooling.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If an air-filled gap is employed between the buffer tube and optical fiber, then accessibility is improved, but water ingress susceptibility increases leading to fiber attenuation

Engineering Contradiction:
ImproveaccessibilityVSAvoidwater ingress
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The slip agent serves as an intermediary that eliminates the need for air gaps while preventing water ingress. By migrating to the fiber-buffer interface, it creates a hydrophobic barrier that repels water molecules, preventing them from penetrating along the interface. This allows the buffer tube to be tightly fitted to the fiber for mechanical protection while still enabling easy stripping through reduced friction, without creating pathways for water contamination.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If an air-filled gap is used between the buffer tube and optical fiber, then accessibility is improved, but fiber buckling and bending increase causing attenuation

Engineering Contradiction:
ImproveaccessibilityVSAvoidfiber attenuation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The slip agent acts as a mediator that enables tight buffering without compromising accessibility. By reducing friction at the fiber-buffer interface, it allows the buffer tube to be stripped easily even when tightly fitted to the fiber, eliminating the need for air gaps. This maintains close mechanical coupling that prevents fiber buckling and bending, ensuring signal reliability while still enabling easy installation and maintenance.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Strength

If the buffer tube is tightly fitted to the optical fiber, then protection is improved, but accessibility deteriorates due to high friction making stripping difficult

Engineering Contradiction:
ImproveprotectionVSAvoidaccessibility
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The slip agent serves as a temporary intermediary that reduces friction between the buffer tube and optical fiber during installation and maintenance. It allows the buffer tube to be tightly fitted for mechanical protection while enabling easy stripping when needed. The slip agent's low friction properties at the interface reduce the force required to remove the buffer tube, reconciling the conflict between tight fitting for protection and ease of removal for accessibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes changes in the friction parameter at the fiber-buffer interface through the slip agent. The slip agent alters the coefficient of friction between the buffer tube material and optical fiber coating, transforming the interface from a high-friction state (difficult to strip) to a low-friction state (easy to strip). This parameter change enables the buffer tube to maintain tight mechanical coupling for protection while allowing easy removal when accessibility is required.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables improved accessibility of the optical fiber with reduced friction and minimal attenuation, allowing for efficient stripping of the buffering layer without compromising the fiber's performance, even under varying temperature conditions.

Implementation Method 1

the polymeric buffering layer including an aliphatic amide slip agent in an amount sufficient for at least some of the aliphatic amide slip agent to migrate to the inner surface of the polymeric buffering layer

Methodology Applied
Scientific EffectMigration: Diffusion

Implementation Method 2

This gap is often filled with a lubricant to reduce friction between the optical fiber and the surrounding buffer tube

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP2284587B1Tight-buffered optical fiber unit having improved accessibility
Publication Date: 2018.03.21 DRAKA COMTEQ BV
  • EP2284587B1 patent drawingFigure 1~2

AI summary

Disclosed are tight-buffered and semi-tight-buffered optical fiber units. The optical fiber unit includes an optical fiber that is surrounded by a polymeric buffering layer to define a fiber-buffer interface. The buffering layer includes an aliphatic amide slip agent in an amount sufficient for at least some of the aliphatic amide slip agent to migrate to the buffer-fiber interface to thereby promote easy stripping of the buffering layer. For example, at least about 15 centimeters of the polymeric buffering layer can be removed from the optical fiber in a single operation using a strip force of less than about 10 N.