Method of producing a chemical pulp from a textile material which comprises cellulose and a molded body from the chemical pulp

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Solution Overview

Problem

Current methods for manufacturing cellulose-based molded bodies from textile materials are inefficient and unsustainable, as they often require high-purity cellulose and cannot effectively process mixed textile waste containing non-cellulosic fibers and foreign materials.

Innovation Solution

A method involving the comminution, mechanical separation, and chemical separation of textile materials to isolate cellulosic fibers, followed by processing into chemical pulp for regenerating cellulose-based molded bodies using the lyocell or viscose method, allowing for the reuse of recycled textile materials like old clothes and waste fibers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If textile materials with high content of non-fiber constituents and non-cellulosic fibers are used as raw material, then the availability and sustainability of the process is improved, but the manufacturing precision and quality of the chemical pulp deteriorates

Engineering Contradiction:

Improveavailability of raw materialVSAvoidpurity of chemical pulp

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The separation process is divided into multiple sequential stages: preliminary separation of non-fiber constituents, mechanical separation of non-cellulosic fibers, and chemical separation of remaining non-cellulosic fibers. Each stage targets specific impurities, progressively purifying the cellulosic fibers to achieve high-quality chemical pulp from mixed textile waste

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Chemical separation utilizes changes in chemical parameters (solubility differences) to distinguish between cellulosic and non-cellulosic fibers. The process exploits the fact that non-cellulosic fibers dissolve or react differently under specific chemical conditions, enabling their removal while preserving the cellulose structure

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If multiple separation steps (mechanical and chemical) are applied to purify cellulosic fibers, then the purity of chemical pulp is improved, but the device complexity and process steps increase

Engineering Contradiction:

Improvepurity of chemical pulpVSAvoidnumber of separation steps

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Mechanical and chemical separation methods are combined in a sequential integrated process. The mechanical separation (using hydrocyclones or screens) removes bulk non-cellulosic fibers, while chemical separation (using dissolving or cooking processes) eliminates remaining impurities. This combination achieves high purity that neither method could accomplish alone

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If conventional methods are used to process mixed textile waste, then the process simplicity is maintained, but the productivity and efficiency of chemical pulp production deteriorates

Engineering Contradiction:

Improveprocess simplicityVSAvoidefficiency of chemical pulp production

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

Non-fiber constituents (buttons, zippers, labels) are removed before the main separation process begins. This preliminary action prevents these impurities from interfering with subsequent mechanical and chemical separation steps, ensuring smoother operation and higher overall efficiency of the chemical pulp production process

Inventive Principle:

Principle #10Preliminary action

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 method enables the efficient and sustainable production of cellulose-based molded bodies from recycled textiles, achieving high purity and quality comparable to conventional wood-based pulp, while reducing waste and resource consumption.

Implementation Method 1

the textile material is comminuted, at least a part of non-fiber-constituents of the comminuted textile material is separated from fiber-constituents

Methodology Applied

Scientific EffectMechanical comminution:

Implementation Method 2

at least a part of non-cellulosic fibers of the fiber-constituents is mechanically separated from cellulosic fibers of the fiber-constituents

Methodology Applied

Scientific EffectMechanical separation:

Implementation Method 3

at least a further part of the non-cellulosic fibers is chemically separated from the cellulosic fibers

Methodology Applied

Scientific EffectChemical separation:

Implementation Method 4

the molded bodies are generated from the chemical pulp based on the cellulosic fibers after mechanically separating and chemically separating

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentUS11828005B2Method of producing a chemical pulp from a textile material which comprises cellulose and a molded body from the chemical pulp

Publication Date: 2023.11.28 LENZING AG

AI summary

A method of producing a chemical pulp from a textile material which comprises cellulose for manufacturing regenerated cellulosic molded bodies, wherein in the method the textile material is comminuted, at least a part of non-fiber-constituents of the comminuted textile material is separated from fiber-constituents of the comminuted textile material, at least a part of non-cellulosic fibers of the fiber-constituents is mechanically separated from cellulosic fibers of the fiber-constituents, at least a further part of the non-cellulosic fibers is chemically separated from the cellulosic fibers, and producing regenerated molded bodies from the chemical pulp based on the cellulosic fibers after mechanically separating and chemically separating.