Multi-roll Granule Application for Shingle Manufacturing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing granule delivery systems in shingle manufacturing struggle to maintain precision and control at higher production speeds above 800 feet per minute, leading to indistinct and distorted granule patches on asphalt-coated sheets, limiting production speed due to the limitations of servo motor control and gravity-driven granule fall.
Innovation Solution
The use of multiple granule applicators spaced apart, each applying a partial charge of granules and synchronized to drop at the same location, allowing for slower operation and finer control, enabling precise application of granule patches even at high speeds by sharing the task of creating complete patches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single granule applicator is used to maintain precision at lower speeds, then manufacturing precision is improved, but productivity deteriorates due to the inability to operate at higher speeds
Solution Approach 1:
The single granule applicator is divided into multiple granule applicators (first, second, and third applicators) that are spaced apart along the direction of sheet movement. Each applicator applies a portion of the granules to the same target area, collectively forming a complete granule patch. This segmentation allows each applicator to operate at a reduced cycling rate while maintaining the overall production speed, thereby preserving manufacturing precision at high productivity levels.
2Productivity
If servo motor speed is increased to match higher production speeds, then productivity is improved, but manufacturing precision deteriorates due to reduced control accuracy
Solution Approach 1:
The granule application task is segmented across multiple applicators, each operating at a slower, more controllable cycling rate. This allows servo motors to maintain high positional accuracy and control precision at lower speeds, while the combined output of multiple applicators achieves the required high production speed.
Solution Approach 2:
Each granule applicator applies only a portion (partial charge) of the total granules needed for a complete patch, rather than applying the full charge in a single action. This partial action approach reduces the speed and acceleration demands on each applicator, enabling more precise control while still achieving the required overall application rate through the combined effort of multiple applicators.
3Productivity
If granule application frequency is increased to match production speed, then productivity is improved, but manufacturing precision deteriorates due to smeared edges and distorted patterns
Solution Approach 1:
The granule application process is segmented into multiple discrete application events by different applicators. Each applicator makes fewer, more controlled application passes, reducing the smearing effect that occurs at high frequencies. The segmented approach from multiple applicators collectively achieves the required granule application rate while maintaining sharp patch edges and clear patterns.
Solution Approach 2:
Multiple granule applicators are operated in a coordinated periodic sequence, where each applicator cycles at a lower frequency but in synchronization with the others. This periodic action from multiple sources achieves the equivalent of high-frequency application from a single source while avoiding the smearing and distortion problems, as each applicator has sufficient time to complete its granule discharge before the next application cycle begins.
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
This method allows for the creation of well-defined granule patches at production speeds exceeding 800 feet per minute, maintaining precision and control by reducing the cycling demands on servo motors and improving granule distribution, thus accommodating higher production rates without compromising patch quality.
Implementation Method 1
When a fluted roll is rotated and stopped by its servo motor, a metered charge of granules is drawn from the granule hopper and dropped onto the moving asphalt coated sheet below
Implementation Method 2
The gate assemblies also may be controlled by the controller. When a fluted roll is rotated and stopped by its servo motor, a metered charge of granules is drawn from the granule hopper
Data Source
AI summary
A method and apparatus for applying or dropping granules onto the asphalt coated surface of a moving sheet in shingle manufacturing is disclosed. The method includes sharing each drop between two or more blend rolls with a subsequent blend roll or rolls applying a partial drop directly on top of partial drops already applied by a first blend roll or rolls. High production speeds can be accommodated since each roll can be operated at slower rotation rates and with slower acceleration and deceleration requirements than would be required if the full granule drop were applied during the same time interval with a single blend roll.