Regenerated Cellulose Threads From Recycled Textile Waste
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Solution Overview
Problem
Current processes for recycling cellulose waste are complex, costly, and environmentally harmful, making it difficult to produce threads or felted cloth from post-consumer cotton waste, which often ends up in landfills or is incinerated.
Innovation Solution
A method involving depolymerization, dissolution, and polymerization of cellulose-based textile materials in controlled acidic and alkaline conditions, followed by extrusion and mesh dispersion to create contiguous threads and felted cloth from recycled cellulose waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If current recycling processes are used for cellulose waste, then some recycling is achieved, but the processes become complex, costly, and cause pollution
Solution Approach 1:
The patent changes the chemical parameters by using acidic solutions (pH 1-4) for depolymerization and coagulation, and alkali solutions (pH 10-13) for dissolving cellulose. These specific pH ranges enable efficient recycling while avoiding complex multi-step processes and reducing pollution compared to conventional methods
Solution Approach 2:
The patent utilizes phase transitions of cellulose between solid fiber form and dissolved state through controlled acid-base treatment. The cellulose transitions from solid textiles to dissolved cellulose solution through acid depolymerization, then reprecipitates as continuous fibers through controlled cooling and coagulation, enabling simple yet effective recycling
2Productivity
If post-consumer cotton waste is recycled using existing techniques, then some recovery is achieved, but the waste remains difficult to recycle due to impurities and wear
Solution Approach 1:
The patent uses extreme pH conditions (acidic pH 1-4 for depolymerization, alkali pH 10-13 for dissolving) to break down and reconstruct cellulose bonds. This aggressive chemical treatment effectively removes impurities and wear damage from post-consumer cotton, transforming it into clean, usable cellulose solution that can be reformulated into high-quality continuous fibers
Solution Approach 2:
The patent replaces mechanical recycling methods (which physically process and blend fibers, preserving impurities and wear) with chemical recycling through acid-base treatment. This chemical approach completely dissolves and reprecipitates cellulose, effectively removing contaminants and restoring fiber integrity for high-quality recycled products
3Object-affected harmful factors
If cellulose waste is not recycled, then existing products can be maintained, but environmental resources are not saved and greenhouse gases are produced
Solution Approach 1:
The patent enables cellulose waste to self-transform through acid-base treatment into usable continuous fibers. The process uses readily available acids and bases to dissolve and reprecipitate cellulose, converting waste materials into valuable recycling feedstock without requiring complex external intervention or specialized equipment
Solution Approach 2:
The patent leverages reversible phase transitions of cellulose between dissolved and solid states through controlled acid-base treatment. This allows complete conversion of cellulose waste into continuous fibers, maximizing utilization rate while avoiding environmental harm through a clean, efficient process
4Quantity of substance
If conventional recycling methods are used, then some fiber recovery is achieved, but the process requires multiple steps and generates toxic chemicals
Solution Approach 1:
The patent merges multiple conventional recycling steps into a single integrated acid-base treatment process. The acidic depolymerization and alkali dissolving steps are combined with controlled cooling and coagulation in one continuous operation, recovering maximum fiber quantity while eliminating the need for separate treatment stages and reducing toxic chemical generation
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
Produces high-quality, dyeable, and durable cellulose-based threads and felted cloth without the need for re-dyeing, utilizing a cost-effective and environmentally friendly process that reduces waste and conserves resources.
Implementation Method 1
depolymerizing the first fibers in an acidic solution of pH 1-4 in a pressurized and heated chamber at 50-150° C. and 10-20 psi
Implementation Method 2
dissolving the dried and depolymerized fibers of (c) into an aqueous alkali solution containing 6-20% by weight of an alkali through mechanical agitation, at temperature between −8 to −30° C. to make a gelled cellulose solution
Implementation Method 3
extruding the gelled cellulose solution 0.25-1 mm pore size into an acidic solution of pH 1-4 to polymerize the cellulose into second fibers and connecting the second fibers into a contiguous thread
Data Source
AI summary
The present invention is directed to efficient methods for producing contiguous threads or felted cloths from recycled cellulose-based waste. The contiguous thread produced is suitable to be sowed on a cloth; it is small enough to go through the pore of a needle, it is strong enough to hold together, and it is bendable and not disintegrated into fragments. The contiguous thread and felted cloth made by the present invention maintain their original dye color of the recycled cellulose waste, and they do not need to be re-dyed.