Roofing Shingle Coating Asphalt Production from Commodity Feedstock
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Solution Overview
Problem
The asphalt roofing industry faces a shortage of special-grade asphalts needed for roofing shingle coating, making it costly and challenging to produce high-quality coating asphalts, as existing methods fail to consistently meet specifications using non-coating grade asphalts like commodity paving asphalts.
Innovation Solution
A method involving partial air blowing of non-coating grade asphalts to adjust their penetration and softening point, followed by the addition of a wax to achieve the desired properties for roofing shingle coating asphalts, providing independent control over softening point, penetration, and melt viscosity while ensuring excellent stain index and storage stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If special-grade asphalt feedstocks are used to produce coating asphalts, then the desired properties (softening point, penetration, viscosity) can be achieved, but the cost increases and supply becomes limited
Solution Approach 1:
The invention changes the chemical parameters of non-coating grade asphalt through controlled oxidation (air blowing) to transform it into coating grade asphalt. By adjusting oxidation time, temperature, and catalyst usage, the softening point, penetration, and viscosity are modified to meet coating asphalt specifications, enabling the use of abundant, low-cost feedstocks instead of limited special-grade asphalts
Solution Approach 2:
The invention employs air blowing (oxidation) as a chemical treatment process to modify the non-coating grade asphalt. The oxidation process introduces oxygen functional groups that increase the softening point and adjust the penetration characteristics, effectively converting low-grade asphalt into high-grade coating asphalt that meets ASTM specifications
2Ease of manufacture
If non-coating grade asphalts are used to produce coating asphalts, then cost and availability improve, but the ability to consistently meet specifications deteriorates
Solution Approach 1:
The invention implements a controlled oxidation process with monitoring and adjustment mechanisms. By measuring parameters such as softening point, penetration, and viscosity during the air blowing process, the oxidation can be adjusted to achieve consistent target properties, ensuring that non-coating grade asphalt is reliably converted to coating grade asphalt meeting ASTM specifications
Solution Approach 2:
The invention performs preliminary characterization of the non-coating grade asphalt feedstock to determine its oxidation potential and required processing parameters. This preliminary assessment allows for optimization of the oxidation process conditions (temperature, time, catalyst) before full-scale production, ensuring consistent results and reducing variability in the final coating asphalt product
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 effectively produces coating asphalts that meet ASTM and manufacturer specifications, offering improved weatherability and reduced energy and emissions, while utilizing widely available and cost-effective commodity paving asphalts, thus addressing the shortage of special-grade asphalts.
Implementation Method 1
asphalt feedstocks used to produce coating asphalts for roofing shingles are usually chosen so that they can be air-blown to: 1) raise their softening point
Implementation Method 2
a wax is added to the partially blown non-coating grade asphalt to further raise its softening point to a second softening point that is within the target softening point range
Data Source
AI summary
A method of producing a roofing shingle coating asphalt from a non-coating grade asphalt feedstock includes the following steps. The non-coating grade asphalt feedstock is partially blown to lower its penetration to a first penetration that is within or close to a target penetration range of the coating asphalt, and to raise its softening point to a first softening point that is lower than a target softening point range of the coating asphalt. Then a wax is added to the partially blown non-coating grade asphalt to further raise its softening point to a second softening point that is within the target softening point range to produce the coating asphalt.