Ceramic Bushing Supports Resist Sagging
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Solution Overview
Problem
Fiberglass bushings sag under the load of molten glass, leading to deformation of the bottom plate holes and breakage of filaments, requiring costly reworking and downtime, especially as manufacturers use larger bushings to increase production rates.
Innovation Solution
A bushing system with elongated supports made of yttria-doped alumina-based ceramic that minimally expands and contracts, reducing sagging and deformation, and is supported by a frame to maintain hole geometry and prevent filament breakage, allowing for larger bushing sizes or reduced metal usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If larger bushings are used to increase production rates, then productivity increases, but the bottom plate sags more under the increased load
Solution Approach 1:
The patent applies ceramic supports at specific critical locations beneath the bottom plate where sagging occurs, rather than changing the entire bushing structure. These localized ceramic supports provide targeted reinforcement to prevent deformation while maintaining the overall larger bushing size needed for high production rates.
Solution Approach 2:
The patent uses a composite structure combining metal bushing components with ceramic support elements. The ceramic material (such as alumina or zirconia) is integrated into the metal bushing assembly to provide high-temperature stability and load-bearing support, preventing bottom plate sagging while enabling larger bushing dimensions for increased productivity.
2Temperature
If the bushing operates at high temperatures to maintain molten glass, then the glass remains fluid for fiber drawing, but thermal expansion and contraction cause deformation
Solution Approach 1:
The patent changes the material parameter of the supports from metal to ceramic, which has fundamentally different thermal expansion characteristics. The ceramic supports exhibit lower and more stable thermal expansion coefficients at high temperatures, maintaining the geometric stability of the bottom plate holes during thermal cycling while allowing the glass to remain molten.
Solution Approach 2:
The patent addresses thermal expansion by selecting ceramic materials with appropriate thermal expansion coefficients that match or complement the metal bushing components. This minimizes differential expansion and contraction during heating and cooling cycles, preventing deformation of the bottom plate and maintaining precise hole geometry for consistent fiber production.
3Device complexity
If metal supports are used in the bushing, then the bushing structure is simple, but the metal sags and deforms under heat and load
Solution Approach 1:
The patent transitions from purely metal supports to a composite system incorporating ceramic support elements. The ceramic material provides superior high-temperature strength and dimensional stability, preventing sagging and deformation under load while maintaining structural integrity. This composite approach enhances reliability without significantly complicating the overall bushing structure.
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 significantly reduces deformation, extends bushing life, and increases production volumes while lowering costs by minimizing material usage and preventing costly reworking.
Implementation Method 1
the support comprises an yttria doped alumina-based ceramic that generally resists sagging or excessive expansion and contraction during heating and cooling
Implementation Method 2
the force caused by the molten material above the bottom plate may cause the bottom plate to sag over time
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A bushing system includes a bushing having a bottom plate with a plurality of holes from which filaments are drawn. At least one elongated support extends through the bushing generally along a longitudinal axis to hold and stabilize the bushing. To handle the harsh conditions under which the bushing is subjected, the support comprises an alumina-based ceramic that generally resists sagging or excessive expansion and contraction during heating and cooling.