Lignocellulosic Nail Head Recess for Pull-Through Strength

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Solution Overview

Problem

Metal nails tend to rust and cause discoloration in acidic wood materials, and traditional wooden nails can split the substrate during installation, while their production and recycling are costly.

Innovation Solution

A nail made from lignocellulosic material with a conical round point and a head area featuring a slot-shaped recess that allows for axial wedging to increase pull-through strength, reducing the risk of substrate splitting and enhancing production efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conical round point with small point angle is used to facilitate direct driving into wood, then the nail can be driven without pre-drilling, but the substrate material splits during installation

Engineering Contradiction:
Improvedirect driving capabilityVSAvoidsubstrate integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent changes the geometric parameter of the nail tip from a traditional small point angle to a flattened tip with a point angle of 30° to 60°. This parameter modification reduces the concentration of stress at the tip, allowing the nail to be driven directly into wood without pre-drilling while minimizing substrate splitting.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The flattened tip design acts as a cushioning element that distributes the driving force over a larger area before the nail enters the substrate. This beforehand cushioning prevents the sudden stress concentration that causes splitting, enabling direct driving while protecting substrate integrity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Strength

If metal nails are used to achieve high strength and durability, then the nails provide strong fastening, but they rust and cause discoloration in acidic wood materials

Engineering Contradiction:
Improvefastening strengthVSAvoidrust and discoloration
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent uses nails made from predominantly lignocellulosic material (wood-based) as a disposable alternative to metal nails. These nails are designed to be installed directly and left in the substrate without requiring removal or replacement, providing a cost-effective solution that avoids rust and discoloration issues while maintaining adequate fastening strength for the application.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The nail comprises a composite structure with a lignocellulosic core material and a polymer coating layer. This composite material combination provides the benefits of wood (non-corrosive, cost-effective) while the polymer coating enhances durability, moisture resistance, and surface properties, eliminating the rust and discoloration problems associated with metal nails.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If wooden nails are used to avoid rust and discoloration, then the nails are compatible with acidic wood materials, but their production cost is high and recycling is expensive

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidproduction cost
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent positions the nail as a disposable fastening element made from cost-effective lignocellulosic material with a relatively simple polymer coating. The nail is designed for single-use installation without removal or recycling, eliminating the need for expensive recycling infrastructure while maintaining corrosion resistance. The production process uses readily available materials and straightforward coating techniques, reducing manufacturing costs compared to traditional wooden nails.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 nail design significantly reduces substrate splitting and increases pull-through strength, while maintaining cost-effective production and recyclability, using materials like synthetic resin-bonded laminated wood with phenolic resin for enhanced durability.

Implementation Method 1

a wedge can be driven axially into it in order to push the material webs of the head area (1c) adjacent to the recess outwards

Methodology Applied
Scientific EffectWedge: Wedge

Data Source

PatentEP3397869B1Nail, in particular in a nail driver
Publication Date: 2023.08.23 RAIMUND BECK NAGELTECHNIK GMBH

AI summary

The present invention relates to a nail, in particular for use in a nail driver, which consists of a predominantly lignocellulosic material and has a nail shank (1a), at the front end of which a nail tip (1b) in the form of a conical round tip is provided, and in the rear end region of which a head region (1c) is formed, the tip angle of the nail tip being > 40°. Furthermore, the invention relates to a nail strip comprising a plurality of nails which have been inserted into corresponding openings in a perforated tape.