Wood Plastic Composite Fiber Alignment Method

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Solution Overview

Problem

Existing methods fail to uniformly distribute high tenacity fibers within wood plastic composite matrices, affecting the material's strength and toughness.

Innovation Solution

A method involving combining high tenacity fibers with a polymer and natural fibers, melting the polymer to form a mixture, cooling and forming pellets, and then extruding the mixture through a fiber alignment plate to achieve a composite with aligned fibers, ensuring at least 70% of the fibers are aligned in the flow direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high tenacity fibers are incorporated into natural fiber polymeric composites by adding an aramid-containing resin layer between the layers of a natural fiber laminate structure, then the toughness and strength of the matrix are increased, but the ability to uniformly distribute these aramid fibers within the wood plastic composite is poor

Engineering Contradiction:
Improvetoughness and strength of the matrixVSAvoiduniform distribution of aramid fibers
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The incorporation process is divided into two distinct stages: first, natural fibers are mixed with molten polymer and extruded to form a base composite; second, aramid-containing resin layers are applied to the surface of the extruded composite. This segmentation allows each fiber type to be optimally distributed in its own process step, preventing the aggregation problems that occur when both fiber types are mixed simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The natural fiber-polymer composite is fully formed and extruded before the aramid fibers are introduced. This preliminary action ensures that the natural fibers are already uniformly distributed within the polymer matrix, creating a stable base structure that receives the aramid reinforcement layer without disrupting the existing fiber distribution.

Inventive Principle:
Principle #10Preliminary action

2Strength

If high tenacity fibers are added to increase material strength, then the mechanical properties are improved, but the complexity of achieving uniform fiber distribution increases

Engineering Contradiction:
Improvemechanical propertiesVSAvoidprocess complexity for fiber distribution
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The manufacturing process is segmented into separate operations for natural fiber incorporation and aramid fiber incorporation. Natural fibers are mixed with polymer in the extruder, while aramid fibers are applied in a subsequent coating or lamination step. This segmentation simplifies each individual step while achieving the cumulative effect of enhanced mechanical properties with uniform fiber distribution.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The extrusion process continues uninterrupted while natural fibers are being incorporated, and the aramid fiber application follows immediately as a continuous secondary operation. This continuity eliminates batch processing interruptions and ensures consistent fiber distribution throughout the product, maintaining both simplicity and effectiveness.

Inventive Principle:
Principle #20Continuity of useful action

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 method results in a dimensionally stable, water-resistant composite material with improved mechanical properties, such as increased rupture strength and uniform fiber dispersion, enhancing the material's structural integrity.

Implementation Method 1

mixing the fibers and polymer at a temperature sufficient to melt the polymer thus forming a mixture comprising a discontinuous phase of fibers dispersed in a polymeric continuous phase

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

cooling and cutting to length the extruded panel

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentUS9120251B2Composite material and method for making
Publication Date: 2015.09.01 DUPONT SAFETY & CONSTRUCTION INC

AI summary

This invention relates to an improved method for making composite structures by dispersing a high tenacity fiber such as aramid in a polymeric matrix to form a premix, combining the premix with a natural fiber such as wood flour and extruding the resulting mixture through a fiber alignment plate and die such that the fibers are substantially aligned in the flow direction of the extrudate.