Laminating Process Testing with IFTH

Context

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Since adsorption regulation is a surface phenomenon, the product performs better when its surface is fully exposed. The goal of these tests was to determine the optimal method for laminating our solids onto flat supports.

So Sponge collaborated with the French Institute of Textile and Clothing (IFTH) to compare different powder laminating techniques.

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Study Objectives

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The main objectives of this study were:

• Identify the most reliable method for depositing mesoporous powder between two nonwoven (NW) layers.
• Evaluate different welding methods to ensure an effective bond between NW layers.
• Optimize deposition and bonding parameters to maintain the product’s hygroscopic properties.

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Methodology & Test Results

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The process was divided into three stages: product deposition, support bonding, and edge welding. The tests followed this structure, with improvements made at each step.

Initial Tests:

• Method: Uniform distribution of powder over the entire NW surface, followed by exposure to a 165°C oven under pressure.
• Results: The NW layers did not bond properly due to excessive powder quantity.

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Spot Deposition Method:

• Method: Powder deposited in small spots, allowing NW layers to bond in powder-free areas.
• Results: Although more promising, the fine powder and porosity of the existing NW prevented the pressing system from applying sufficient pressure, hindering bonding.

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Pressure & Temperature Optimization:

• Method: Passing between two rollers (upper roller at 130°C) with 2-bar pressure.
• Results: Uniform pressure prevented effective welding in powder-free areas.

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Edge Welding:

• Method: Manual welding of NW edges without powder.
• Results: Method validated, but requires a more practical welding system, such as a die-cut press.

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Conclusion

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The tests conducted by IFTH provided valuable insights into the technical challenges of integrating So Sponge’s mesoporous materials into nonwoven structures. The next steps will focus on refining these methods and optimizing manufacturing parameters to enhance product performance and viability.

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