Optical Fiber Preform Joint Annealing to Prevent Pipe Cracking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The separation and cracking of cladding pipes and glass pipes at the connecting parts in the rod-in-collapse method of manufacturing optical fiber preforms is a significant issue in existing manufacturing processes.
Innovation Solution
A method involving melting and connecting glass pipes to cladding pipes, heating the connecting parts below the melting temperature, and slowly cooling them to relieve glass strain and repair microcracks, with specific heating and cooling parameters to prevent separation and cracking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the cladding pipe and glass pipe are connected by melting at high temperature, then the connection is achieved, but glass strain is introduced and microcracks occur causing separation and cracking
Solution Approach 1:
The patent applies parameter changes by controlling the cooling rate after melting connection. Specifically, the connecting part is cooled at a controlled rate of 1-100°C per minute to relieve glass strain and prevent microcrack formation, thereby maintaining both connection strength and reliability without requiring additional reinforcement measures.
Solution Approach 2:
The patent utilizes phase transitions of glass material during the heating and cooling process. The glass is heated to melting point for connection, then controlled cooling through the glass transition region allows strain relief and microcrack repair, transforming the material state to achieve reliable connection without separation.
2Productivity
If rapid cooling is applied after heating, then production efficiency is improved, but glass strain causes separation and cracking at the connecting part
Solution Approach 1:
The patent optimizes the cooling rate parameter within the range of 1-100°C per minute to balance production efficiency and connection integrity. This controlled cooling rate prevents glass strain-induced separation while maintaining reasonable production throughput, eliminating the need for overly slow cooling that would reduce productivity.
Solution Approach 2:
The patent establishes a standardized cooling process protocol that can be replicated for each connection operation. By defining specific cooling rate parameters and heating temperature ranges, the process becomes repeatable and controllable, achieving both efficiency and precision through consistent parameter application.
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 method effectively suppresses the separation and cracking of connecting parts by relieving glass strain and repairing microcracks, ensuring the integrity of the optical fiber preform manufacturing process.
Implementation Method 1
heating a connecting part between the cladding pipe and the glass pipe at a heating temperature below a melting temperature of the connecting part
Implementation Method 2
slowly cooling the connecting part from the heating temperature after the heating
Data Source
AI summary
The optic fiber base material production method includes melting and connecting glass pipes to both ends of a clad pipe, in which holes are provided, so as to surround the holes, heating the connections of the clad pipe and glass pipes at a heating temperature below the melting temperature of the connections, and slowly cooling the connections from the heating temperature after heating.