Plastic Lumber Stiffness via PE-ABS Polymer Blend

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

High-density polyethylene (HDPE) plastic lumber lacks stiffness compared to wood and existing reinforcement methods are unpredictable and costly, with limited recycling options for electronic waste materials.

Innovation Solution

An immiscible polymer blend of polyethylene (PE) and acrylonitrile-butadiene-styrene (ABS) or polycarbonate (PC), or a mixture of ABS and PC, with specific melt flow rates, is used to create a composite material for plastic lumber, such as railroad ties, enhancing stiffness and utilizing recycled materials from electronic waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If HDPE is used to make plastic lumber, then it is available from curbside collection and can substitute for chemically treated wood, but it has reduced stiffness compared to wood

Engineering Contradiction:

Improvesubstitute for chemically treated woodVSAvoidstiffness

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The patent combines HDPE with recycled electronic waste materials (PC and ABS) to create a composite polymer blend. This composite approach allows the material to achieve wood-like stiffness while maintaining the availability and cost benefits of recycled HDPE, directly resolving the contradiction between versatility as a wood substitute and insufficient stiffness

Inventive Principle:

Principle #40Composite materials

2Strength

If stiffening agents are added to HDPE to increase stiffness, then the modulus improves, but it becomes unpredictable which materials are compatible and cost-effective

Engineering Contradiction:

ImprovemodulusVSAvoidcompatibility and cost-effectiveness

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The patent specifies precise parameter ranges for the polymer blend components: HDPE with melt flow index of 0.1-1.0, PC with melt flow index of 5-20, and ABS with melt flow index of 5-20. By controlling these parameters, the patent ensures predictable compatibility and processability while achieving the desired stiffness enhancement, resolving the uncertainty in material selection

Inventive Principle:

Principle #35Parameter changes

3Quantity of substance

If recycled materials from electronic waste are used, then supply is plentiful and cost is low, but there are limited recycling possibilities for these materials

Engineering Contradiction:

Improvesupply availabilityVSAvoidrecycling options

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent creates a multi-functional application for recycled electronic waste materials by incorporating them into structural plastic lumber products. The polymer blend technology enables these materials to serve both as filler content and as functional structural components, expanding recycling possibilities beyond traditional applications and creating new markets for e-waste recovery

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS8629221B2Compositions and methods of making plastic articles

Publication Date: 2014.01.14 RUTGERS THE STATE UNIV

AI summary

Disclosed are immiscible polymer blends, plastic articles containing the blends, and methods for making the plastic articles. One type of article is plastic lumber, which can be in the form of a railroad tie or a marine piling.