Accordion Pleated Spline Folder with Polymer Composite
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Solution Overview
Problem
Expansion folders with traditional pleated splines face issues of durability loss, fraying, delamination, and curling, and lack water/moisture resistance, which affect their long-term performance and capacity to accommodate increasing file quantities.
Innovation Solution
An expansion folder with an accordion-pleated spline made of polymer material featuring alternating 'M-shaped' and 'W-shaped' pleats, internal dividers, and a fastener system that allows for expansion up to 2465% greater width than its closed position, using solid paperboard covers and 17 pt hardwood natural Kraft paper dividers for enhanced strength and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional pleated splines are used in expansion folders, then the folder can be manufactured with simpler materials and processes, but the spline loses durability over time and becomes susceptible to fraying, delamination, and curling
Solution Approach 1:
The patent applies composite materials by combining paperboard with plastic coating or laminate layers to create a multi-layer spline structure. This composite construction provides both the flexibility needed for expansion and the durability to resist fraying, delamination, and curling over time, directly addressing the reliability and duration issues with traditional single-material splines.
Solution Approach 2:
The patent changes the physical and chemical parameters of the spline material by treating the paperboard with plastic coatings or laminates. These parameter changes include increased water resistance, enhanced tensile strength, and improved flexibility retention, allowing the spline to maintain its performance characteristics throughout extended use and repeated expansion cycles.
2Adaptability or versatility
If the spline is made more flexible to allow expansion, then the folder can accommodate increasing file quantities, but it becomes more susceptible to losing structural integrity and becoming limp
Solution Approach 1:
The composite paperboard-plastic structure provides both flexibility and strength simultaneously. The plastic coating or laminate reinforces the paperboard, preventing it from becoming limp while still allowing the spline to expand and contract. This resolves the contradiction between adaptability and structural integrity.
Solution Approach 2:
The spline exhibits local quality variations with different stiffness characteristics at different locations and orientations. The pleated structure creates regions of controlled flexibility that allow expansion while maintaining overall structural integrity. The plastic treatment may also be applied with varying concentrations or types to optimize local properties for both flexibility and strength.
3Reliability
If traditional materials are used for the spline, then manufacturing costs are lower, but the folder lacks water and moisture resistance, leading to long-term deterioration
Solution Approach 1:
The patent uses composite materials consisting of paperboard combined with plastic coating or laminate layers. This composite structure provides water and moisture resistance while maintaining the manufacturing simplicity of working with paperboard-based materials. The plastic layer acts as a barrier to moisture while the overall structure can still be manufactured using conventional paperboard processing techniques.
4Quantity of substance
If the folder is designed to expand significantly to accommodate more files, then the capacity increases, but the repeated folding and expansion causes the spline to lose durability and become susceptible to fraying
Solution Approach 1:
The composite paperboard-plastic structure maintains durability even after repeated expansion and contraction cycles. The plastic reinforcement prevents the paperboard from fraying at the fold lines and maintains structural integrity, allowing the folder to achieve high expansion capacity (2465% greater width) without sacrificing spline durability.
Solution Approach 2:
The patent changes the material parameters to improve fatigue resistance. The plastic coating or laminate enhances the spline's ability to withstand repeated folding and expansion, preventing the deterioration that would normally occur with traditional paperboard alone. This allows significant expansion capacity while maintaining reliability over time.
Data Source
AI summary
An expansion folder with internal dividers with an accordion-pleated spline, comprising, a front cover, the front cover comprising an outwardly facing surface and an inwardly facing surface, a rear cover, the rear cover comprising an outwardly facing surface and an inwardly facing surface, a plurality of dividers, each of the plurality of dividers comprising a front-facing surface and a rear-facing surface, and, an accordion-pleated spline, the spline comprising a polymer formed into a plurality of pleats, the pleats further comprising an alternating series of “M-shaped” and “W-shaped” pleats.