Sealed Fastener Cap Structure to Block Moisture Wicking

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Solution Overview

Problem

Existing fastener caps allow moisture infiltration, leading to issues such as rot, mold, mildew, fungus growth, and fastener corrosion, and existing sealing solutions either trap moisture or create installation messes.

Innovation Solution

A fastener cap system with a rigid cap and sealing member forming a liquid barrier around the cap, including a central seal disc and secondary seal ring to prevent moisture ingress, and a method of manufacturing these caps and sealing members using co-molding or co-extrusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a flat rubber washer is placed under the fastener head to seal, then moisture infiltration is reduced, but moisture is trapped under the cap and the rubber washer acts as a wick to draw moisture toward the substrate

Engineering Contradiction:

Improvemoisture infiltrationVSAvoidmoisture wicking

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The sealing member is divided into multiple functional zones: an outer sealing portion that contacts the substrate to prevent moisture entry under the cap, and an inner sealing portion that contacts the fastener head to prevent moisture entry at the fastener interface. The deliberate gap between these portions prevents continuous moisture pathways, eliminating the wicking effect while maintaining sealing effectiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner sealing portion acts as an intermediary barrier at the fastener head interface, preventing moisture from reaching the fastener shaft. By positioning this seal at the interface rather than allowing direct contact between the rubber washer and substrate, the patent interrupts the capillary action pathway that would otherwise enable wicking.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If a rupture-able receptacle filled with liquid sealant is placed under the cap, then sealing is achieved when the nail pierces the receptacle, but the receptacles can break before installation creating a mess

Engineering Contradiction:

Improvemoisture infiltrationVSAvoidinstallation reliability

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The sealing members are pre-installed onto the fastener caps during manufacturing through co-molding or co-extrusion processes, creating a unified assembly. This preliminary action eliminates the risk of sealant leakage during handling and installation, as the seal is already in place and cannot break or create messes during the installation process.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sealing member is merged with the fastener cap into a single integrated component through co-molding or co-extrusion. This combination ensures the seal remains securely attached during handling, transport, and installation, eliminating the reliability issues associated with separate sealant receptacles that can break before installation.

Inventive Principle:

Principle #5Merging (Combining)

3Object-affected harmful factors

If a seal extends under the cap to the fastener shaft, then moisture infiltration is prevented, but the seal acts as a wick to draw moisture toward the fastener

Engineering Contradiction:

Improvemoisture infiltrationVSAvoidmoisture wicking to fastener

Core Design Contradiction:

Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The sealing member is segmented into distinct portions with a deliberate gap between them. The inner sealing portion contacts the fastener head to prevent moisture entry at the interface, while the outer sealing portion contacts the substrate to prevent moisture entry under the cap. The gap between portions interrupts continuous moisture pathways, preventing capillary action and wicking toward the fastener shaft.

Inventive Principle:

Principle #1Segmentation

4Ease of operation

If traditional fastener caps are used without sealing, then installation is simple and efficient, but moisture infiltration occurs leading to rot, mold, mildew, fungus growth, and fastener corrosion

Engineering Contradiction:

Improveinstallation simplicityVSAvoidmoisture infiltration

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The sealing member is combined with the fastener cap into a single integrated component through co-molding or co-extrusion processes. This merging ensures the seal is always present and properly positioned during installation, eliminating moisture infiltration issues without requiring separate sealing steps or complex installation procedures, thus maintaining installation simplicity while providing comprehensive protection.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS12546359B2Sealed fastener cap and related method of manufacture

Publication Date: 2026.02.10 NAT NAIL CORP

AI summary

A fastener cap system can include a rigid cap and a sealing member which forms a liquid barrier so moisture is impaired from entering a space under the rigid cap and/or around a fastener installed through it. The sealing member can include a central seal disposed on an upper surface of the cap, the seal extending beyond a head of a fastener, which extends through the cap and sealing member, so that moisture is impaired from entering the cap under the head. The sealing member can be above and below respective lowermost and uppermost cap surfaces so the cap system can be fed cleanly and efficiently through a cap feeder during installation via a tool. The sealing member, which can have a higher coefficient of friction than the rigid cap, thereby does not drag along a cap feeder and cause feeding issues. Related methods are provided.