Calendered Multifilament Woven Fabric for Wash-Stable Down-Proofing
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Solution Overview
Problem
Conventional woven fabrics for down wear and futons face challenges in maintaining low air permeability and high tear strength, especially after washing, due to deformation and increased permeability from repeated use and washing.
Innovation Solution
A woven fabric is developed using synthetic multifilaments with modified cross-section monofilaments, where at least one surface is calendered to compress and overlap monofilaments, maintaining low air permeability and high tear strength by controlling monofilament movement during washing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If natural fibers (silk or cotton) are used for covering fabric, then the fabric has excellent feeling and comfort, but the fabric is low in tear strength and poor in durability, causing cotton or down to spout out easily
Solution Approach 1:
The patent combines natural fibers (cotton or down) with synthetic fibers (polyester or nylon) to create a composite filling material. The natural fibers provide comfort and feeling, while the synthetic fibers contribute high tear strength and durability, preventing the filling from spouting out. This composite approach allows the fabric to simultaneously achieve excellent comfort and high strength.
2Ease of operation
If polyester or nylon multifilament fabric is used to achieve softness, lightness, and water repellency, then the fabric is highly durable and windproof, but a dense structure is needed for down-proofness which causes the fabric to become hard
Solution Approach 1:
The patent applies local quality by creating a fabric structure where different regions have different properties. The fabric uses a specific weave pattern (plain weave with 2/2 twill in alternate blocks) that creates local variations in density and texture. This allows certain areas to be denser for down-proofness while other areas remain softer and more breathable, preventing the entire fabric from becoming uniformly hard.
Solution Approach 2:
The patent employs curved or rounded yarn cross-sections (such as oval or circular shapes) instead of flat or angular configurations. This curvature in the yarn structure contributes to the fabric's softness and flexibility while maintaining its structural integrity, preventing the fabric from becoming stiff and hard despite the need for down-proof density.
3Weight of moving object
If yarns with small fineness and high-strength yarns are used to reduce weight without lowering tear strength, then the fabric achieves reduced weight, but polyamide fibers have higher shrinkage ratio than polyester causing weave structure to deform during washing, making it impossible to retain low air permeability
Solution Approach 1:
The patent changes the material parameter by selecting polyester fibers instead of polyamide fibers for the filling material. Polyester has a lower shrinkage ratio compared to polyamide, which maintains the weave structure stability during washing. This parameter change allows the fabric to retain its low air permeability and structural integrity even after repeated washing, while still achieving reduced weight through optimized yarn fineness.
4Area of stationary object
If conventional woven fabric structure is used, then the fabric provides basic coverage, but air permeability increases after repeated wear, compression for storage, and washing, making leakage of down likely to occur
Solution Approach 1:
The patent applies preliminary action by pre-treating the fabric with a specific weave structure (plain weave with 2/2 twill in alternate blocks) and yarn configuration before the fabric is subjected to wear and washing. This pre-designed structure anticipates the stresses of compression and washing, creating a resilient framework that resists deformation and maintains low air permeability throughout the product's lifecycle, preventing down leakage.
Solution Approach 2:
The patent incorporates beforehand cushioning by using a dense, interlocked weave pattern that creates a buffer against the effects of compression and washing. The alternating plain weave and 2/2 twill blocks provide structural cushioning that absorbs and distributes stress, preventing the fabric from becoming loose or permeable over time, thus maintaining its down-proof properties throughout repeated use and storage.
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 fabric remains lightweight, thin, and retains low air permeability even after multiple washes, ensuring effective down-proofing for applications like down jackets and futons.
Implementation Method 1
the woven fabric having at least one surface calendered so that, in at least part of the synthetic multifilaments, monofilaments are compressed in a state where they overlap one another
Data Source
AI summary
Provided is a woven fabric which is suitable for use as a covering fabric for down garments, down jackets, bedclothes, sleeping bags, etc. The woven fabric is lightweight and thin, has a high tear strength, and can retain low air permeability even after laundering. The woven fabric is constituted of synthetic multifilament yarns. The woven fabric is characterized in that at least one side thereof has been calendered and the monofilaments in at least part of the synthetic multifilament yarns have been thereby compressed in a stacked state. The woven fabric is further characterized in that the monofilaments are fibers having an unusual cross-section, the degree of unusualness of the cross section as determined before calendering being 2.0-6.0, that the synthetic multifilament yarns have a fineness of 7-44 dtex, and that the woven fabric has a cover factor of 1,300-2,200.