Thermoplastic Railway Sleeper With Structured Rod Reinforcement

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Solution Overview

Problem

Existing railway sleepers face challenges in achieving sufficient flexural rigidity and strength, particularly due to the use of glass fibers which lead to wear and the complexity of multi-part designs, and the need for geometric adaptations in reinforcement and housing shells.

Innovation Solution

A railway sleeper design featuring a rod-shaped reinforcement element with a toothed or corrugated structure made of plastic or glass fiber reinforced plastic (GRP), enclosed by thermoplastic material in a form-fitting manner, which eliminates the need for glass fibers and simplifies the base body structure, ensuring desired strength and rigidity through partial melting of thermoplastic particles and thermokinetic mixing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If glass fibers are used to provide strength to the railway sleeper, then the desired strength and rigidity are achieved, but heavy wear occurs during compounding and the material cannot be recycled

Engineering Contradiction:
Improveflexural strengthVSAvoidwear during compounding
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent changes the reinforcement material from glass fibers to rod-shaped elements made of plastic or GRP with structured surfaces. This parameter change eliminates the wear problem during compounding while maintaining the necessary flexural strength through the structured surface geometry that enables form-fitting enclosure by thermoplastic material.

Inventive Principle:
Principle #35Parameter changes

2Strength

If a two-shell design with reinforcement is used to achieve sufficient strength, then the flexural rigidity is improved, but the design and production complexity increases due to geometric adaptations

Engineering Contradiction:
Improveflexural rigidityVSAvoiddesign and production complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent merges the reinforcement element and housing into a single-form design where the rod-shaped reinforcement with structured surface is directly enclosed by thermoplastic material in a form-fitting manner. This eliminates the need for separate shell components and complex geometric adaptations, simplifying both design and production while maintaining structural integrity.

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If rod-shaped reinforcement elements with structured surface are used, then the form-fitting enclosure by thermoplastic material is achieved, but the manufacturing process complexity increases

Engineering Contradiction:
Improveform-fitting enclosureVSAvoidmanufacturing process simplicity
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent uses rod-shaped reinforcement elements with specific structured surfaces (corrugated, ribbed, or threaded) that enable form-fitting enclosure. The structured surface geometry is optimized to work with thermoplastic material properties, allowing the thermoplastic to naturally conform to the reinforcement shape during molding, thereby achieving stable composition without excessive manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

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 enhanced flexural rigidity and strength, reduces wear, and allows for cost-effective production with recyclable materials, while avoiding the destruction of long-chain polymer molecules and ensuring no longitudinal movement of the reinforcement element within the base body.

Implementation Method 1

The particles are subjected to a heat treatment in such a way that preferably not all of the particles melt completely, but at least some of the particles are only melted on the surface

Methodology Applied
Scientific EffectPartial melting: Melting

Implementation Method 2

This is preferably done by means of thermokinetic mixing

Methodology Applied
Scientific EffectThermokinetic mixing:

Implementation Method 3

the reinforcement element is rod-shaped and is a solid or hollow rod made of plastic or an existing tubular element and has a toothed structure, such as a corrugated structure, on the outside

Methodology Applied
Scientific EffectForm-fitting enclosure:

Data Source

PatentEP3263767B1Railway sleeper and method for manufacturing the same
Publication Date: 2018.12.05 INTEGRICO EURO GMBH
  • EP3263767B1 patent drawingFigure 1
  • EP3263767B1 patent drawingFigure 2
  • EP3263767B1 patent drawingFigure 3a

AI summary

A shaped body (10, 100) and a method for producing such a body, wherein the shaped body (10, 100) comprises a base body (12) made of or containing thermoplastic material with reinforcement (14, 16, 18, 20, 114, 116, 118, 120) extending in its longitudinal direction. The reinforcement (14, 16, 18, 20, 114, 116, 118, 120) is provided to be at least one rod-shaped reinforcement element having a surface structure, wherein the structure is completely enclosed by the thermoplastic material in a form-fitting manner.