Woven Polyester Fabric Crystallinity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for manufacturing PET tapes for weaving applications result in tapes that are prone to splitting and fibrillation due to high tensile loads and deformation, leading to interruptions and pollution in the weaving process, and the use of additives to improve splitting resistance complicates the manufacturing process and affects transparency.
Innovation Solution
The method involves preparing uniaxially oriented PET tapes with moderate crystallinity, weaving them into a fabric, and then heat-setting the fabric to increase crystallinity, thereby achieving dimensional stability and mechanical properties without the need for additives, which allows for the production of a transparent and durable woven fabric.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If PET tapes are stretched and heat-set using conventional methods to achieve dimensional stability, then the tapes gain crystallinity and resistance to shrinkage, but they become prone to splitting and fibrillation under tensile loads during weaving
Solution Approach 1:
The patent changes the crystallinity parameter from high (conventional) to moderate (40-60%), and adjusts the heat-set temperature to a specific range (180-220°C) to achieve the optimal balance between dimensional stability and splitting resistance. This parameter optimization resolves the contradiction by finding the sweet spot where the material is stable enough to resist shrinkage but flexible enough to withstand weaving stresses without splitting.
2Reliability
If additives are incorporated into PET tapes to improve splitting resistance, then the tapes become more resistant to fibrillation, but the manufacturing process becomes more complex and transparency is affected
Solution Approach 1:
The patent extracts the additives from the system entirely, achieving splitting resistance through pure PET with optimized processing parameters (moderate crystallinity of 40-60% and controlled heat-set temperature). This eliminates the need for complex additive incorporation processes and maintains the transparency of the final product, resolving the contradiction between reliability improvement and process complexity.
3Strength
If high draw ratios are applied to PET tapes to achieve high tensile strength, then the tapes resist shrinkage better, but they become more susceptible to splitting and fibrillation
Solution Approach 1:
The patent modifies the draw ratio parameter from high (conventional) to moderate levels, combined with a specific heat-set temperature range (180-220°C) and controlled crystallinity (40-60%). This parameter adjustment reduces the internal stresses and structural defects that lead to splitting, while maintaining sufficient tensile strength through the optimized crystalline structure formed during heat-setting.
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 prevents tape splitting during weaving, ensures dimensional stability, and maintains transparency, resulting in a fabric with high tensile strength and resistance to hot shrinkage, suitable for applications like sacks and carpet backing.
Implementation Method 1
The heat setting increases the crystallinity to about 30%, and the hot shrinkage, i.e. shrinkage at high temperature, is significantly reduced
Implementation Method 2
The amorphous precursor article is stretched uniaxially or biaxially above the glass transition temperature (Tg) at about 85-105 °C
Data Source
Figure 1
AI summary
The present invention relates to a method for the manufacture of a woven article comprising the steps of i) preparing a plurality of uniaxially oriented tapes of a polyethylene terephthalate composition, optionally comprising a step of heat setting said tapes, to obtain tapes having a first crystallinity, ii) weaving at least two of said tapes into a woven article, iii) heat setting the woven article to obtain tapes having a second crystallinity higher than the first crystallinity.