Enzymatic Polyurethane Degradation in Multilayer Packaging
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Solution Overview
Problem
Current recycling technologies for multilayer plastic packaging are inefficient, requiring harsh chemicals and conditions, and result in low recycling rates and downgraded materials, making it difficult to recycle polyurethane (PU) layers used in food packaging without prior separation and leading to environmental waste.
Innovation Solution
A method involving an enzyme cocktail comprising at least one lipase and one cutinase, such as Thc_Cut2 and RoL, is used to selectively degrade PU layers in multilayer packaging, allowing for the recovery of PU monomers and liberation of the PE backbone for recycling, without the need for harsh processing conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mechanical recycling is used for multilayer packaging, then recycling rate is improved, but material quality is downgraded and prior separation is required
Solution Approach 1:
The patent extracts and removes the PU adhesive layer from the multilayer packaging structure using enzymatic degradation. This allows the PE barrier layer to be recovered in high quality without requiring manual separation, resolving the contradiction between recycling rate and material quality
Solution Approach 2:
The patent replaces mechanical separation and thermo-mechanical recycling processes with enzymatic degradation. This biological approach selectively degrades PU while preserving PE, achieving both high recycling rates and maintained material quality without mechanical intervention
2Productivity
If chemical recycling is used for polyurethane degradation, then complete degradation is achieved, but harsh chemicals and extreme conditions are required
Solution Approach 1:
The patent introduces enzymes (cutinase and lipase) as biological intermediaries to mediate the degradation of PU. These enzymes catalyze the breakdown of PU under mild conditions, replacing harsh chemicals while maintaining complete degradation efficiency
Solution Approach 2:
The patent changes the degradation parameters from extreme chemical conditions to mild physiological conditions (neutral pH, moderate temperature). The enzymatic system operates under these gentle parameters while achieving complete PU degradation, eliminating the need for harsh chemicals
3Device complexity
If single enzyme treatment is used for PU degradation, then process simplicity is maintained, but degradation efficiency is insufficient
Solution Approach 1:
The patent merges two different enzymes (cutinase and lipase) into a combined treatment system. Cutinase targets the polyester segments while lipase targets the urethane bonds, creating a synergistic effect that achieves complete degradation more efficiently than either enzyme alone
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 enables efficient and cost-effective degradation of PU layers, allowing for high-quality recycling of polyethylene (PE) and potentially other components, reducing waste and environmental impact by using mild conditions and enzyme synergies.
Implementation Method 1
The PU may be a PU-based layer in a multilayer packaging structure comprised in a packaging. Remarkably, the subject matter of the present invention allows the efficient selective degradation of PU containing layers in multi-layer packaging materials.
Implementation Method 2
a method of degrading polyurethane (PU) comprising the step of subjecting the PU to at least one cutinase in combination with at least one lipase
Data Source
AI summary
The present invention relates generally to the field of degrading polyurethane (PU), for example PU layers in multi-layer packaging. For example, the present invention relates to a method of degrading polyurethane (PU) comprising the step of subjecting the PU to an enzyme cocktail comprising at least one lipase and at least one cutinase. The PU may be a PU-based layer in a multilayer packaging structure comprised in a packaging. Remarkably, the subject matter of the present invention allows the efficient selective degradation of PU containing layers in multi-layer packaging materials.