Spinnable composition (sC), and polyester fibers (PF) made therefrom

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Solution Overview

Problem

The production of polyester fibers via melt spinning faces a narrow production window due to conflicting factors like melt strength and viscosity, limiting the temperature range and resulting in inefficient fiber production and dyeability.

Innovation Solution

A spinnable composition comprising 80-99.5% terephthalate polyester, 0.49-19.9% aliphatic-aromatic polyester, 0.01-3% oligomer, and 0-5% additive, which allows for higher temperature spinning and broader production window, improving dyeability and fiber properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the temperature of the melt is increased to improve flow rate and throughput, then productivity is improved, but the polyester fibers can tear under their dead weight due to reduced melt strength

Engineering Contradiction:
ImprovethroughputVSAvoidmelt strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The invention changes the chemical composition parameters of the polyester mixture by incorporating PTT and PBT alongside PET, which modifies the rheological properties of the melt. This allows the process to operate at higher temperatures (improving productivity) while maintaining adequate melt strength through the synergistic effect of the polyester blend and oligomer additives

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite polyester system comprising multiple polyester types (PET, PTT, PBT) in specific weight ratios (80-99.5% PET, 0.49-19.9% PTT/PBT). This composite material approach combines the advantages of each polyester to achieve both high flow rate and sufficient melt strength at elevated temperatures

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If the temperature of the melt is increased to improve flow rate, then viscosity decreases and flow improves, but the production window becomes narrower due to conflicting melt strength requirements

Engineering Contradiction:
Improveflow rateVSAvoidproduction window
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The invention modifies the rheological parameters of the polyester melt by blending different polyester types and adding oligomers. This changes the viscosity-temperature relationship, allowing the system to maintain optimal flow characteristics across a broader temperature range, thereby expanding the production window

Inventive Principle:
Principle #35Parameter changes

3Strength

If the temperature of the melt is kept low to maintain spinneret flow, then melt strength is preserved, but the flow rate is low and spinnerets can clog up

Engineering Contradiction:
Improvemelt strengthVSAvoidflow rate
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The composite polyester system with PTT and PBT components provides inherent lubricating effects and improved melt流动性, enabling the system to maintain high flow rates at lower temperatures where melt strength is naturally higher, thus avoiding spinneret clogging while preserving fiber integrity

Inventive Principle:
Principle #40Composite materials

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 process enables polyester fibers to be spun at higher temperatures with a wider production window, ensuring improved dyeability, light and wash fastness, and a broad color spectrum, suitable for blends with other fibers.

Implementation Method 1

Heating gives rise to a melt which is extruded through spinnerets to obtain the polyester fibers

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

the temperature of the melt must be sufficiently above the melting point of the polyester that is spun

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentUS11946168B2Spinnable composition (sC), and polyester fibers (PF) made therefrom
Publication Date: 2024.04.02 BASF SE

AI summary

The present invention relates to a process for the preparation of a spinnable composition (sC) by mixing at least one terephthalate polyester (A), at least one aliphatic-aromatic polyester (B), at least one oligomer (C) and optionally at least one additive (D). Moreover, the present invention relates to the spinnable composition (sC) obtained by this process, a process for the preparation of polyester fibers (PF) by extruding the spinnable composition (sC) through at least one spinneret, the polyester fibers (PF) obtained by this process, textile materials (T) comprising the polyester fibers (PF) a process for dying the textile materials (T), and the use of the oligomer (C) for the improvement of the rheology and/or the dyeability of a composition comprising at least one terephthalate polyester (A) and at least one aliphatic aromatic polyester (B).