Spunbonded Nonwoven Fabric Embossing for Filter Rigidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods fail to produce a nonwoven fabric with high rigidity suitable for filters that maintains pleat retention and durability, especially in heating environments, while also ensuring effective filtration performance.
Innovation Solution
A spunbonded nonwoven fabric with a basis weight of 150 to 400 g/m², featuring single-component polyester-based fibers thermocompression bonded using an embossing roll and a flat metal roll, comprising 98.0 to 99.95 wt % polyester-based resin with a glass transition temperature of 60° C or higher and 0.05 to 2.0 wt % incompatible thermoplastic resin, providing longitudinal bending repulsion of 20 to 60 mN and tensile strength of 400 N/5 cm or more.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the thickness of the nonwoven fabric is increased to achieve high rigidity, then rigidity is improved, but the network structure becomes coarse and fiber fusion is insufficient, deteriorating shape retention property
Solution Approach 1:
The invention changes the crystallization state parameter of the polyester fibers from oriented crystallization to non-oriented crystallization. By using fibers in a non-oriented crystallization state and controlling the embossing conditions, the patent achieves sufficient fiber fusion without requiring excessive thickness, thereby maintaining both rigidity and shape retention property.
Solution Approach 2:
The invention utilizes the phase transition of polyester fibers during embossing by controlling crystallization. By adjusting the embossing temperature and pressure to induce controlled crystallization of non-oriented fibers, the patent achieves adequate fiber fusion and bonding without increasing thickness excessively, resolving the contradiction between rigidity and shape retention.
2Strength
If undrawn yarns with low orientation degree are used as thermobonding component to improve fiber fusion, then fiber fusion property is improved, but crystallization is promoted by embossing making fibers brittle and deteriorating shape retention property and durability
Solution Approach 1:
The invention changes the crystallization state parameter from oriented to non-oriented, and controls the degree of crystallization during embossing. By using non-oriented crystalline polyester fibers and controlling embossing conditions, the patent achieves adequate fiber fusion while preventing excessive crystallization that would make fibers brittle, thus maintaining both fiber fusion property and durability.
3Strength
If high basis weight is used to increase thickness and rigidity, then rigidity is improved, but fiber fusion by embossing becomes insufficient and moldability deteriorates
Solution Approach 1:
The invention changes the crystallization state parameter of the fibers and controls the embossing parameters (temperature, pressure, dwell time). By using non-oriented crystalline polyester fibers with controlled basis weight and optimizing embossing conditions, the patent achieves sufficient fiber fusion and rigidity without compromising moldability, as the fibers remain sufficiently plastic during forming but crystallize adequately during embossing.
4Strength
If low melting point component is used as sheath component for thermobonding to improve rigidity and pleat retention, then rigidity is improved, but relaxation occurs due to glass transition temperature causing deterioration in durability
Solution Approach 1:
The invention extracts and eliminates the low melting point component from the fiber structure. By using pure polyester fibers in a non-oriented crystallization state without low melting point additives or sheath-core structures, the patent avoids the glass transition and associated relaxation that would compromise durability, while still achieving rigidity through controlled crystallization and embossing.
Solution Approach 2:
The invention changes the thermal properties parameter by eliminating low melting point components and using polyester with a defined glass transition temperature of 60°C or higher. This ensures the fibers maintain structural integrity and do not undergo harmful relaxation during filter operation, preserving durability while achieving required rigidity through embossing.
5Strength
If needle punching is used to interlace fibers and improve rigidity, then rigidity is improved, but pores are created lowering filtration performance and binder resin drops during pleating
Solution Approach 1:
The invention replaces the mechanical needle punching system with a thermocompression bonding system. By using heat and pressure to fuse fibers at embossing points instead of mechanically interlacing them with needles, the patent achieves rigidity without creating through-pores that would compromise filtration performance, and without requiring binder resin that would drop during pleating.
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 fabric offers excellent pleatability, bending durability, and pleat retention properties, along with high filtration efficiency for particles between 0.3 μm and 0.5 μm, and maintains shape stability even under load, making it suitable for filters with improved durability and performance.
Implementation Method 1
subjecting a deposited fiber assembly that comprises single-component polyester-based fibers to thermocompression bonding using an embossing roll and a flat metal roll
Implementation Method 2
subjecting a deposited fiber assembly that comprises single-component polyester-based fibers to thermocompression bonding using an embossing roll and a flat metal roll
Data Source
AI summary
The purpose of the present invention is to obtain a spunbonded nonwoven fabric, which comprises a single-component polyester-based fibers, having a high basis weight and a high rigidity by embossing, which is difficult to attain in the conventional art. Further, the present invention provides a filter base material having excellent pleatability, pleat retention property and durability, and a filter using thereof. The present spunbonded nonwoven fabric is obtained by subjecting a deposited fiber assembly to a thermocompression bonding by embossing with a pair of an embossing roll and a flat metal roll, and has a basis weight of 150 to 400 g/m2, a longitudinal bending repulsion of 20 to 60 mN and a longitudinal tensile strength of 400 N/5 cm or more.