Seamless Extensible Film Shoe Inserts for Waterproof Breathability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing waterproof, breathable footwear often results in poor fitting shoes due to mismatched shoe inserts, compromised flexibility, and reduced breathability, primarily because of the use of multiple laminate pieces and sealing processes that can lead to wrinkles and air gaps.
Innovation Solution
A seamless, extensible film-based bootie or shoe insert with a three-dimensional configuration, utilizing materials like polyurethane, polyethylene, or polyester, which can stretch and conform to shoe sizes, eliminating the need for seams and ensuring a snug, breathable fit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple laminate pieces are used to form the shoe insert, then waterproofness can be achieved through sealing, but flexibility and breathability are compromised
Solution Approach 1:
The patent merges multiple separate laminate pieces into a single seamless membrane structure. The shoe insert is formed from one continuous piece of waterproof breathable membrane that is stretched and molded to fit the shoe interior, eliminating the need for multiple sealed joints while maintaining waterproofness.
Solution Approach 2:
The patent employs a thin film waterproof breathable membrane as the core component of the shoe insert. This flexible membrane can be stretched over the shoe last and conforms to the interior shape, providing waterproof protection without compromising flexibility or breathability.
2Reliability
If seams are sealed with adhesive or welding, then waterproofness is improved, but breathability and flexibility are reduced
Solution Approach 1:
The patent extracts and eliminates the seams and sealing elements (adhesives, welding joints) from the shoe insert construction. By using a seamless membrane that is stretched and molded into place, the design removes the very elements that compromised breathability while maintaining waterproofness through the membrane's inherent properties.
3Strength
If the shoe insert is attached with adhesive over the entire surface, then attachment strength is improved, but the insert appears wrinkled and pulls away from the upper
Solution Approach 1:
The patent applies preliminary action by pre-stretching the membrane over the shoe last before the shoe upper is assembled. This ensures the membrane is already conforming to the desired shape and size, preventing wrinkles and pull-away issues that occur when adhesive is applied to a non-conformed insert.
4Adaptability or versatility
If the shoe insert is made to fit different shoe sizes, then adaptability is improved, but manufacturing complexity increases due to multiple sizes
Solution Approach 1:
The patent creates a universal shoe insert design where a single seamless membrane structure can be stretched and molded to fit multiple shoe sizes. The membrane's elastic properties allow it to conform to different last dimensions without requiring separate manufactured components for each size, simplifying production while maintaining adaptability.
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 solution provides a conformable, waterproof, and breathable shoe insert that closely fits the shoe interior, reducing air gaps and enhancing comfort while maintaining breathability and flexibility, as demonstrated by passing centrifuge waterproofness tests.
Implementation Method 1
the film has a minimum elongation at break of 200% or more in at least one direction. The bootie has a maximum of 25 N/cm force to stretch at 10% elongation in any direction. In addition, the bootie has an elastic recovery of at least 50% in any direction.
Implementation Method 2
the film may be a porous film and is selected from the group consisting of polyurethane (PU), polyethylene (PE), polyester (PES), polypropylene (PP), polyether (PE), polyacrylonitrile (PAN), polystyrene, and copolymers thereof
Data Source
Figure 1~2
Figure 3A
Figure 3B
AI summary
Waterproof, breathable socks, booties, shoe inserts, and footwear assemblies containing the shoe inserts are provided. The booties and shoe inserts may include a laminate comprising a seamless extensible film, such as a polyurethane film, and at least one textile. The bootie is suitable for a range of sizes and shoe shapes. The bootie may shrink to fit, or, alternatively, be stretched to fit, an asymmetrical last having a desired size to form a shoe insert. A bootie having a seamless extensible film eliminates the need to have multiple sizes of shoe inserts correlating to particular shoe sizes. In embodiments where the polyurethane film is seamless and continuous, the shoe insert eliminates the need for a waterproof seam tape, which is conventionally used to make shoe inserts waterproof. Methods of forming the socks, booties, and shoe inserts are also provided.