Hemp Fiber Recycled HDPE Composite Structural Strength

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Solution Overview

Problem

There is a growing need for new uses of recycled high density polyethylene (HDPE) and for building materials with increased strength and resistance to water and insect damage, as the global HDPE market expands and existing materials like PVC and steel pose safety risks due to shattering hazards.

Innovation Solution

Development of hemp fiber composites with a recycled HDPE matrix, where hemp fibers are treated with NaOH to enhance fiber-matrix adhesion, resulting in improved mechanical properties and resistance to moisture and insects, using processes like extrusion, pultrusion, and vacuum-assisted infusion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If PVC or steel is used for building materials, then structural strength is achieved, but safety risks arise due to shattering hazards

Engineering Contradiction:

Improvestructural strengthVSAvoidshattering hazards

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent creates a composite material combining hemp fibers with recycled HDPE polymer matrix. This composite achieves structural strength comparable to steel and PVC while eliminating shattering hazards, as the material is flexible and tear-resistant rather than brittle.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameters by using recycled HDPE instead of virgin plastic and incorporating natural hemp fibers. This transforms the material properties to achieve both strength and safety, creating a non-shattering alternative to traditional materials.

Inventive Principle:

Principle #35Parameter changes

2Strength

If conventional building materials are used, then structural integrity is maintained, but environmental harm increases

Engineering Contradiction:

Improvestructural integrityVSAvoidenvironmental harm

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent recovers and reuses recycled HDPE plastic that would otherwise be waste material. By incorporating this recovered polymer into composite structures with hemp fibers, the patent creates environmentally friendly building materials that maintain structural integrity while reducing environmental harm from plastic waste.

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The composite structure combines natural hemp fibers with recycled polymer, creating a material that is both structurally sound and environmentally sustainable. The hemp provides reinforcement while the recycled HDPE provides matrix binding, reducing reliance on virgin materials.

Inventive Principle:

Principle #40Composite materials

3Ease of manufacture

If fiber-matrix adhesion is poor, then manufacturing is simpler, but mechanical strength decreases

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidmechanical strength

Core Design Contradiction:

Ease of manufactureVSStrength

Solution Approach 1:

The patent applies preliminary treatment to the hemp fibers before composite fabrication. The fibers undergo alkali treatment and surface modification to enhance their adhesion properties with the HDPE matrix, ensuring strong mechanical bonding while maintaining manufacturing feasibility through standardized pre-treatment processes.

Inventive Principle:

Principle #10Preliminary 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 hemp fiber-rHDPE composites demonstrate superior tensile and flexural strengths, moisture resistance, and durability, making them suitable for structural applications such as bridges and hurricane-proof panels, while also being environmentally friendly and cost-effective.

Implementation Method 1

the natural hemp fibers were treated with a NaOH solution. The effect of alkali treatment was investigated by FTIR and SEM. Pectin, wax and lignin were completely removed from hemp fiber surface

Methodology Applied

Scientific EffectAlkali treatment:

Implementation Method 2

FTIR results indicated that there is an increase in the percentage of —OH groups, which may provide more reaction sites for fiber-matrix adhesion

Methodology Applied

Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentUS9187624B2Hemp fiber reinforced composite with recycled high density polyethylene and production thereof

Publication Date: 2015.11.17 JUNIVERSITI OF NORT KAROLINA EHT SHARLOTT

AI summary

Novel structural materials composed of industrial hemp fiber with recycled high density polyethylene (HDPE) as well as methods for the production of the same are disclosed. The material's mechanical strength outperforms that of conventional lumber and could compete with glass fiber reinforced composites, particularly in tensile strength. In addition, this material offers many other significant advantages including insect free, high moisture resistance, no harmful chemical treatments, and no rapid corrosion in water environments.