Sintered Roofing Granules with Penetrating Coating
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Solution Overview
Problem
Roofing materials often absorb substantial solar heat due to low near-infrared radiation reflection and low emissivity, leading to increased energy demand for HVAC systems, contributing to the Urban Heat Island effect and reducing the lifetime of these materials.
Innovation Solution
Sintered roofing granules with a coating that penetrates into the surface of base particles, providing high solar reflectance and UV opacity, which are used to form roofing membranes and shingles with enhanced durability and fire resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional roofing materials are used, then they provide basic roofing coverage, but they absorb substantial solar heat due to low near-infrared radiation reflection
Solution Approach 1:
The patent applies a coating containing pigments that specifically reflect near-infrared radiation while maintaining visible color. This allows the roofing granules to change their optical properties by reflecting harmful NIR radiation rather than absorbing it, thereby reducing solar heat gain without compromising aesthetic appearance.
Solution Approach 2:
The patent creates a composite structure with a ceramic base particle coated with a glassy matrix containing pigments. This composite material combines the structural integrity of ceramic with the optical properties of the glassy coating, achieving both durability and high near-infrared reflectance.
2Duration of action of stationary object
If conventional roofing materials are used, then they provide basic protection, but they have reduced lifetime due to heat absorption
Solution Approach 1:
The coating with specific pigment composition reflects near-infrared radiation, preventing temperature increase in the roofing materials. This thermal management through optical property modification extends the service life of the roofing by preventing heat-related degradation.
Solution Approach 2:
The glassy matrix coating protects the ceramic base particles from thermal stress and environmental degradation, while the pigment-containing coating reflects harmful radiation. This multi-layer composite structure enhances overall durability and lifetime.
3Object-affected harmful factors
If a coating is applied to base particles, then solar reflectance is improved, but the coating may not adequately penetrate or bond with the base particle surface
Solution Approach 1:
The sintering process parameters (temperature, time, atmosphere) are optimized to create a base particle surface with appropriate porosity and chemical composition. This enables the subsequent coating to penetrate to a controlled depth (at least 0.5% of base particle radius) and form strong chemical bonds, ensuring reliable adhesion.
Solution Approach 2:
The interface between the ceramic base particle and glassy matrix coating is engineered to create a gradient composition that ensures strong bonding. The coating formulation includes components that chemically bond to the ceramic surface, creating a reliable composite 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 solar heat absorption, improving energy efficiency, extending the lifespan of roofing materials, and providing excellent durability and fire resistance.
Implementation Method 1
the base particles are sintered
Implementation Method 2
Some roofing materials may reflect little near-infrared ('NIR') radiation and consequently absorb substantial solar heat
Implementation Method 3
the coating has a depth of penetration into an outside surface of at least about 0.5% of an average radius of the base particles
Data Source
AI summary
A roofing product can include roofing granules, wherein the roofing granules include base particles and a coating covering the base particles. The base particles are sintered. The coating has a depth of penetration into an outside surface of at least about 0.5% of an average radius of the base particles. In an embodiment, the coating has a depth of penetration into an outside surface of at least about 2.5 microns into the base particles. Further included is a process of forming the roofing granules.