PPS Nonwoven Fabric Crystallinity Multilayer Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Poly(phenylene sulfide) (PPS) fiber nonwoven fabrics face challenges with poor dimensional stability against heat due to significant thermal shrinkage, low tensile strength, and complex production processes, which hinder their practical application in harsh environments.
Innovation Solution
A heat-resistant nonwoven fabric is developed using PPS fibers with crystallinity in the range of 25-50% by weight, forming a multilayer structure with high crystallinity layers and a low crystallinity intermediate layer, which reduces thermal shrinkage and maintains heat resistance, chemical resistance, and flame retardancy without the need for post-treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If PPS fiber nonwoven fabric is prepared by melt blowing with thin fibers to achieve excellent filtering performance, then filtering performance is improved, but tensile strength becomes low and dimensional stability against heat becomes poor
Solution Approach 1:
The patent applies local quality by creating a multilayer structure where different layers have different crystallinity levels. The first and third layers have high crystallinity (40-50%) to provide strength and heat resistance, while the second layer has low crystallinity (10-30%) to maintain filtering performance. This spatial differentiation of material properties resolves the contradiction between strength and filtering performance.
Solution Approach 2:
The patent uses composite materials by combining PPS fibers with different crystallinity levels in a multilayer configuration. The high-crystallinity layers provide mechanical strength and dimensional stability, while the low-crystallinity layer provides filtering performance, creating a composite structure that achieves both requirements simultaneously.
2Measurement precision
If PPS fiber nonwoven fabric is prepared by melt blowing with thin fibers to achieve excellent filtering performance, then filtering performance is improved, but dimensional stability against heat becomes poor
Solution Approach 1:
The patent applies local quality by creating a multilayer structure where different layers have different crystallinity levels. The first and third layers have high crystallinity (40-50%) to provide strength and heat resistance, while the second layer has low crystallinity (10-30%) to maintain filtering performance. This spatial differentiation of material properties resolves the contradiction between strength and filtering performance.
Solution Approach 2:
The patent uses composite materials by combining PPS fibers with different crystallinity levels in a multilayer configuration. The high-crystallinity layers provide mechanical strength and dimensional stability, while the low-crystallinity layer provides filtering performance, creating a composite structure that achieves both requirements simultaneously.
3Stability of the object's composition
If post-treatment for dimensional stabilization against heat is applied to PPS fiber nonwoven fabric, then dimensional stability is improved, but production process becomes complicated and production efficiency is lowered
Solution Approach 1:
The patent applies preliminary action by incorporating dimensional stability into the fiber production process itself rather than applying post-treatment. The PPS fiber is spun with controlled crystallinity (40-50%) that inherently provides heat resistance, eliminating the need for subsequent heat treatment steps and maintaining high production efficiency.
Solution Approach 2:
The patent uses parameter changes by controlling the crystallinity of PPS fiber during the spinning process. By adjusting spinning parameters to achieve 40-50% crystallinity, the fiber gains inherent dimensional stability against heat, eliminating the need for post-treatment and maintaining production efficiency.
4Temperature
If oxidation treatment is applied to PPS polymer to make it nonmelting, then heat resistance is improved, but the fiber becomes very brittle and production process becomes complicated
Solution Approach 1:
The patent uses parameter changes by controlling the crystallinity of PPS fiber during the spinning process. By adjusting spinning parameters to achieve 40-50% crystallinity, the fiber gains inherent dimensional stability against heat, eliminating the need for post-treatment and maintaining production efficiency.
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 resulting nonwoven fabric exhibits excellent dimensional stability, heat resistance, and chemical resistance, with reduced thermal shrinkage and improved filtering and barrier performance, while simplifying the production process and reducing costs.
Implementation Method 1
30% by weight or more of the PPS fiber forming the nonwoven fabric has a crystallinity of 25 to 50%
Data Source
Figure 1
AI summary
The present invention provides a heat-resistant nonwoven fabric wherein the nonwoven fabric is formed from a poly(phenylene sulfide) fiber, and 30% by weight or more of the poly(phenylene sulfide) fiber has a crystallinity of 25 to 50%. Moreover, the properties of the heat-resistant nonwoven fabric can be further improved by making the nonwoven fabric have a multilayer structure in which layers composed of a poly(phenylene sulfide) filamentary fiber and layers composed of a poly(phenylene sulfide) fine fiber are stacked and integrated.