Fire-resistant glazing intumescent layer drying optimization
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Solution Overview
Problem
Existing methods for producing fire-resistant glazing using hydrated alkali silicates face challenges in achieving the necessary mechanical qualities, such as 'soft impact' resistance, while maintaining fire resistance and optical clarity, often requiring restrictive drying conditions or complex gelation processes that increase costs and complexity.
Innovation Solution
A process involving a silicate solution with a SiO2/M2O molar ratio between 3.5 and 7 and a water content of 33-43% is used, with colloidal silica added to increase the silica content, allowing for a two-stage formation that reduces drying time and eliminates the need for extensive drying, enabling the production of thicker, more cost-effective intumescent layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the water content of commercial silicate solutions is reduced to achieve better stability and optical clarity, then the drying time must be extended to tens of hours, but this reduces productivity and increases manufacturing cost
Solution Approach 1:
The patent introduces a specific drying medium (air circulation system with controlled temperature and humidity) as an intermediary to accelerate the drying process. The drying oven with forced air circulation acts as a mediator that removes water vapor more efficiently, allowing faster drying without compromising the quality of the silicate layer.
Solution Approach 2:
The patent changes the drying parameters by controlling temperature (50-150°C), humidity, and air circulation velocity. By optimizing these parameters, the drying time is reduced from tens of hours to a few hours while maintaining the required water content (20-25%) for stability and optical clarity.
2Reliability
If the water content is kept low to prevent haze formation, then the mechanical plasticity and soft impact resistance are reduced, but this worsens the mechanical qualities required for certain applications
Solution Approach 1:
The patent creates a composite structure by laminating the dried silicate layer between two glass sheets. This composite construction provides both optical clarity (from the transparent silicate layer) and mechanical strength (from the glass sheets and the laminated structure), compensating for the reduced plasticity of the low-water-content silicate layer.
Solution Approach 2:
The patent applies different properties to different parts of the glazing system: the silicate layer provides optical clarity and fire resistance, while the glass sheets and interlayer provide mechanical strength and impact resistance. Each component is optimized for its specific function.
3Ease of manufacture
If gelation products with high water content (45-60%) are used to simplify production, then the fire resistance may be compromised due to lack of cohesion and irregular foam formation, but this worsens the fire resistance quality
Solution Approach 1:
The patent changes the water content parameter from the typical 45-60% in gelation products to a controlled 20-25%, which is sufficient for stability and fire resistance while allowing simplified production. The controlled drying process ensures uniform water removal without causing the irregular foam formation associated with high water content.
Solution Approach 2:
The patent performs preliminary drying before final assembly, removing excess water to achieve the optimal water content range. This preliminary action prevents the cohesion problems and irregular foam formation that would occur if high water content gelation products were used directly in fire-resistant applications.
4Reliability
If traditional drying cycles of tens of hours are used to achieve low water content, then the manufacturing cost increases, but this worsens the production efficiency
Solution Approach 1:
The patent changes the drying parameters by using forced air circulation, controlled temperature (50-150°C), and controlled humidity to accelerate water removal. These parameter changes reduce the drying time from tens of hours to 2-8 hours while achieving the required water content control for stability and optical clarity.
Solution Approach 2:
The patent implements continuous drying with forced air circulation that continuously removes water vapor from the silicate layer surface. This continuous action of water removal significantly accelerates the drying process compared to passive air drying, improving manufacturing efficiency while maintaining quality control.
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 approach results in fire-resistant glazing with improved mechanical qualities and reduced production time, allowing for thicker layers that decrease the weight and cost of glazing without compromising fire resistance or optical clarity.
Implementation Method 1
products in which a silicate solution whose water content is initially relatively 'low', for example of the order of 45 to 60%, is modified by the addition of products qualified as 'hardeners', 'crosslinking agents' or otherwise. These qualifiers generically designate products which promote the gelation of the silicate solution.
Implementation Method 2
the layers are obtained by spreading the solution on a support and proceeding to a more or less prolonged drying until a solid layer is obtained
Implementation Method 3
whose exposure to fire causes the formation of an opaque foam which opposes the transmission of radiation and maintains the glass sheets
Data Source
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AI summary
The present invention relates to fire-resistant glazing. According to the invention, the transparent fire-resistant glazing includes at least one intumescent layer of a hydrated alkaline metal silicate between two glass sheets. The intumescent alkaline metal silicate layer has an SiO2/M2O molar ratio between 3.5 and 7 and a water content from 33 to 43% by weight. Their preparation incorporates a drying step.