Textile Product Lamination Using Hot Melt Adhesive for Recyclability
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Solution Overview
Problem
Current textile products for floor coverings, such as carpets, face challenges with mechanical durability, water resistance, and recyclability due to the use of latex-based adhesives, which lead to issues like mildew, high VOC emissions, and difficulty in separating components for recycling.
Innovation Solution
A method involving a hot melt adhesive is used to anchor yarns to a backing material by melting the yarns on a heated surface and applying a dimensionally stable carrier sheet with the adhesive, creating a strong and recyclable textile product without the need for latex-based adhesives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If latex-based adhesives are used to anchor yarns and bind layers, then strong bonding and mechanical stability are achieved, but the product becomes difficult to recycle due to chemical cross-linking and component integration
Solution Approach 1:
The patent changes the bonding mechanism from chemical cross-linking (latex) to physical bonding (heat fusion). The yarns are thermally fused to the backing material by melting, and the carrier sheet is bonded through hot melt adhesive, both of which allow for thermal reversibility during recycling
Solution Approach 2:
The patent utilizes phase transitions of thermoplastics to achieve bonding. The yarns are melted and fused to the backing, and hot melt adhesive undergoes phase transition from solid to liquid and back, enabling strong bonding that can be reversed by heating for recycling purposes
2Ease of manufacture
If water-based latex polymer is used as adhesive, then ease of application and initial bonding are improved, but water resistance and moisture protection deteriorate leading to mildew and mould formation
Solution Approach 1:
The patent replaces water-based latex with thermoplastic materials and hot melt adhesives that are inherently water-resistant. The bonding mechanism changes from water-based chemical adhesion to thermal fusion and hot melt adhesive bonding, eliminating moisture susceptibility while maintaining ease of application through melting processes
Solution Approach 2:
The patent uses hot melt adhesive that can be applied readily and provides sufficient bonding for the product lifecycle, while being easily removable through heating for recycling, effectively replacing the need for water-based latex that requires drying and curing time
3Adaptability or versatility
If latex polymer with surfactants is used to achieve water-based bonding, then application flexibility is improved, but sensitivity to moisture and VOC emissions increase
Solution Approach 1:
The patent extracts and removes the harmful components (surfactants and volatile compounds) by replacing latex-based adhesives with thermoplastic hot melt adhesives. These adhesives are applied in molten state and solidify without requiring surfactants or emitting VOCs, while maintaining application flexibility through thermal processing
Solution Approach 2:
The patent changes the adhesive system from water-based latex requiring surfactants to thermoplastic hot melt adhesive that relies on thermal energy for application. This parameter change eliminates moisture sensitivity and VOC emissions while preserving application versatility through controlled melting and bonding processes
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 results in a textile product with improved mechanical stability, reduced VOC emissions, and enhanced recyclability, as the hot melt adhesive provides a strong bond while allowing for easy separation of components, addressing the limitations of latex-based systems.
Implementation Method 1
yarns stitched into the backing, the yarns extending from the front surface of the backing material, feeding the first intermediate product along a body having a heated surface, the back surface being pressed against the said heated surface, to at least partly melt the yarns present in the intermediate product to bond the yarns to the backing
Implementation Method 2
connecting the second intermediate product to the carrier sheet by providing a hot melt adhesive between the calendered surface and the sheet, and pressing the sheet to the second intermediate product to form the textile product
Data Source
AI summary
The present invention pertains to a method for manufacturing a laminated textile product comprising providing a first intermediate product comprising a primary backing having a front surface and a back surface, and yarns stitched into the primary backing, the yarns extending from the front surface of the backing material, feeding the intermediate product along a body having a heated surface, the back surface being pressed against the said heated surface, to at least partly melt the yarns present in the intermediate product to bond the yarns to the backing, wherein the part of the back surface that is pressed against the heated surface has a relative speed with respect to the heated surface, so as to provide a second intermediate product having a calendered back surface, providing a dimensionally stable carrier sheet or secondary backing, and connecting the second intermediate product to the carrier sheet by providing a hot melt adhesive between the calendered surface and the sheet, and pressing the sheet to the second intermediate product to form the textile product.