Forming Roll Cooling for Non-Uniform Glass Ribbon Thickness
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Solution Overview
Problem
Manufacturing glass sheets of non-uniform thickness using forming rolls with grooves or pockets results in significant temperature differences between thick and thin portions, leading to high stresses and warp, requiring complex and costly equipment solutions.
Innovation Solution
A glass manufacturing apparatus with forming rolls having recesses to create protrusions, combined with localized cooling methods such as air or aerosol directed at thick portions and hollow forming rolls with cooling fluids, to reduce temperature gradients between thick and thin portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If forming rolls with grooves or pockets are used to create non-uniform thickness, then material utilization improves, but temperature difference between thick and thin portions increases
Solution Approach 1:
The patent applies local quality by providing different surface characteristics (e.g., roughness, thermal conductivity, or wall thickness) at different locations on the forming roll. Specifically, the region corresponding to the thick portion has enhanced cooling capability compared to regions corresponding to thin portions, allowing localized temperature control that compensates for the temperature differences caused by non-uniform thickness formation.
Solution Approach 2:
The patent changes physical parameters of the forming roll, such as surface roughness, thermal conductivity, or wall thickness, in different regions. By modifying these parameters locally, the cooling rate is adjusted to compensate for the temperature differences arising from variable thickness, thereby reducing thermal stress and warpage.
2Ease of manufacture
If forming rolls with grooves or pockets are used to create non-uniform thickness, then finishing costs reduce, but equipment complexity increases
Solution Approach 1:
Instead of adding complex external cooling systems or multiple processing stages, the patent incorporates localized cooling capabilities directly into the forming roll structure. This integrated approach simplifies the overall equipment by eliminating the need for separate cooling apparatus while still achieving the desired temperature control.
3Loss of substance
If forming rolls with grooves or pockets are used to create non-uniform thickness, then material utilization improves, but ribbon deformation increases
Solution Approach 1:
The patent applies local quality by providing different surface characteristics (e.g., roughness, thermal conductivity, or wall thickness) at different locations on the forming roll. Specifically, the region corresponding to the thick portion has enhanced cooling capability compared to regions corresponding to thin portions, allowing localized temperature control that compensates for the temperature differences caused by non-uniform thickness formation.
Solution Approach 2:
The patent changes physical parameters of the forming roll, such as surface roughness, thermal conductivity, or wall thickness, in different regions. By modifying these parameters locally, the cooling rate is adjusted to compensate for the temperature differences arising from variable thickness, thereby reducing thermal stress and warpage.
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
Reduces temperature differences and minimizes defects like back-protrusion, deformation, and stress in the ribbon, simplifying equipment complexity and cost.
Implementation Method 1
a forming roll can be hollow and filled with a cooling fluid, such that the forming roll can extract a greater amount of heat from the thick portion than the thin portion
Implementation Method 2
local cooling can be applied to the thick portion by air or an aerosol directed toward the thick portion
Data Source
AI summary
A glass manufacturing apparatus includes a delivery apparatus defining an upstream portion of a ribbon travel path extending in a first travel direction. The glass manufacturing apparatus includes a forming roll extending along an axis parallel to the travel path and perpendicular to the first travel direction. The forming roll includes a recess that imparts a protrusion to a ribbon traveling along the ribbon travel path in the first travel direction. The forming roll includes a first surface defining the recess and a first surface characteristic. The forming roll includes a second surface defining an area surrounding the recess and including a second surface characteristic. The first surface characteristic is different than the second surface characteristic. During a cooling period of time, the first surface cools at a faster rate than the second surface. Methods of manufacturing a ribbon are provided.