Carbon Foam Panel Foaming Under Inert Atmosphere
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Solution Overview
Problem
Existing methods for producing carbon foam panels from starch powder face challenges in achieving uniform foaming without additional steam and ensuring reliable foaming conditions, often resulting in incomplete foaming or charred remains due to unsuitable temperatures and ambient conditions.
Innovation Solution
A method involving the application of a thin layer of foamable starch powder on a temperature-resistant substrate, followed by heating in an oven under an argon or nitrogen atmosphere, with controlled pressure and temperature conditions to achieve uniform foaming, and subsequent carbonization or graphitization to produce fine-pored carbon foam sheets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the temperature is increased to promote foaming, then the foaming reaction is enhanced, but the starch may decompose completely and no foam will form
Solution Approach 1:
The patent applies parameter changes by precisely controlling the foaming temperature within a specific range (180-450°C) and adjusting the ambient pressure (vacuum or inert gas atmosphere) to optimize the foaming process. These parameter modifications enable reliable foam formation while preventing complete starch decomposition.
Solution Approach 2:
The patent uses an inert atmosphere (vacuum or inert gas such as nitrogen or argon) to prevent oxidation and unwanted side reactions during heating. This creates a controlled environment that allows the starch to foam reliably at elevated temperatures without decomposing completely or reacting with oxygen.
2Length of stationary object
If a thicker layer of starch powder is applied, then thicker foam sheets can be produced, but uniform foaming becomes difficult to achieve
Solution Approach 1:
The patent applies segmentation by dividing the foam sheet production into multiple layers. Thin layers of starch powder (0.5-2 mm) are sprinkled sequentially onto the substrate, with each layer being foamed separately. This segmented approach ensures uniform foaming throughout the thickness while achieving the desired overall thickness through multiple layers.
Solution Approach 2:
The patent applies preliminary action by pre-sprinkling thin, uniform layers of starch powder onto the substrate before the foaming process begins. This preliminary preparation ensures that each layer has optimal thickness and distribution for uniform foaming, preventing the problems associated with applying thick layers all at once.
3Temperature
If the foaming temperature is lowered to prevent decomposition, then the starch remains stable, but the foaming process takes longer and may not achieve desired foam structure
Solution Approach 1:
The patent applies parameter changes by simultaneously adjusting both temperature and pressure parameters. By conducting foaming in a vacuum or inert gas atmosphere at optimized temperatures (180-450°C), the process achieves rapid and uniform foaming within minutes, preventing both decomposition and excessive processing time.
4Reliability
If additional steam is used to facilitate foaming, then the foaming process is enhanced, but the process complexity and equipment requirements increase
Solution Approach 1:
The patent applies self-service by enabling the starch powder to foam using only its own inherent properties when heated. The foamable starch powder contains built-in foaming agents or gas-generating components that release gas internally when heated, eliminating the need for external steam injection or complex humidification equipment.
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 method ensures uniform foaming and production of high-quality, fine-pored carbon foam sheets with a homogeneous structure, eliminating the need for additional steam and ensuring reliable foaming, while allowing for efficient production of thicker sheets through layered application.
Implementation Method 1
when heated to a higher temperature... another portion of this or a different polymer decomposes, forming a gas that is essentially trapped within the molten polymer, creating the desired foam
Implementation Method 2
During this process, some of the polymer melts, while simultaneously another portion of this or a different polymer decomposes
Implementation Method 3
place the starch-coated substrate in an oven... Heating to the foaming temperature is preferably carried out with a heating ramp
Data Source
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AI summary
The invention relates to a method for producing carbon foam panels from starch for use as an insulating material or filter. The aim of the invention is to provide a method for producing fine-pore carbon foam panels with a mainly homogeneous structure. This is achieved by sprinkling at least one maximally thin layer of foamable starch powder onto a temperature-resistant panel-type support, inserting the support coated with starch powder into a furnace, introducing air, argon or nitrogen into the furnace until an internal pressure of ᷉720 mbar to ᷉1000 mbar is established, heating the furnace to a foaming temperature of 180°C to 450°C to foam the starch powder, and maintaining the temperature over an extended period of up to 10 hours to stabilise the foamed starch to form a foam panel.