Irregular Granular Infill for Artificial Grass Stability

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Solution Overview

Problem

Current granular infill materials for artificial grass surfaces, particularly those of thermoplastic origin, face issues with performance, volumetric efficiency, moisture retention, cost, drainage, and environmental impact, as well as stability and durability problems due to their uniform size and shape, and challenges in sourcing and processing vegetable-based materials.

Innovation Solution

A granular infill material composed of a thermoplastic polymeric matrix with a cellulose-based vegetable load, sourced from offcuts and waste materials like wallpaper, offering irregular prismatic shapes and high porosity, which enhances water absorption and volumetric performance, and can be recycled, allowing for customizable characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If uniform shaped granules are used, then manufacturing is simplified, but volumetric performance and stability deteriorate

Engineering Contradiction:
Improvegranule manufacturing simplicityVSAvoidinfill stability and volumetric performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies asymmetry by using granules with irregular prismatic shapes rather than uniform geometric forms. This irregularity allows the granules to interlock more effectively, improving stability and volumetric performance while still being manufacturable through extrusion processes that can accommodate varied cross-sectional geometries.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent applies local quality by varying the cross-sectional geometry of granules at different locations along their length. The granules feature different cross-sectional shapes at different positions, creating local variations that enhance interlocking and stability without requiring complete redesign of the entire granule structure.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If vegetable-based loads are used, then environmental impact improves, but processing difficulty and material availability worsen

Engineering Contradiction:
Improveenvironmental impactVSAvoidproduction process difficulty
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by carefully controlling the moisture content and thermal parameters during extrusion. By adjusting these parameters, the vegetable-based loads (cellulose, starch, or protein) can be processed without burning or degrading, maintaining their environmental benefits while making the production process feasible.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies composite materials by combining thermoplastic polymeric matrices with vegetable-based loads (cellulose, starch, or protein) in a single extrusion process. This creates composite granules that leverage the environmental advantages of vegetable materials while using the processing capabilities of thermoplastics to ensure manufacturability.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If mineral loads are used in thermoplastic granules, then cost reduces, but performance and moisture retention deteriorate

Engineering Contradiction:
Improvepolymer quantity and costVSAvoidperformance and moisture retention
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies parameter changes by replacing mineral loads with vegetable-based loads and adjusting the moisture content parameters of the granules. This allows the granules to retain moisture effectively while reducing polymer quantity, achieving both cost reduction and improved performance through the natural hygroscopic properties of vegetable materials.

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 granular infill material provides improved stability, moisture retention, and cost-effectiveness while maintaining surface freshness and performance, overcoming the limitations of traditional materials by leveraging the abundance and versatility of cellulose as a raw material.

Implementation Method 1

The granular material has an appreciable granular porosity; the porosity enables obtaining a water absorption that is particularly appreciated

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP3722504B1Infill material for artificial grass surfaces and method for producing such
Publication Date: 2021.12.01 POLYGREEN SRL
  • EP3722504B1 patent drawingFigure 1

AI summary

An artificial grass surface structure (1), in particular for sports fields, comprises a mat (2) with filaments (4) which simulate a grass surface, and at least a filling layer (5) comprising a granular infill material (6) arranged between the filaments (4). The granular infill material for synthetic grass surfaces comprises a plurality of granules (8) comprising a thermoplastic polymeric matrix and a load dispersed in the matrix, where the load includes at least a cellulose-based vegetable component wherein the cellulose is present in a measure of between 20% and 40% in weight.