Recycled Polyolefin 3D Printing with Olefin Block Copolymers

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Solution Overview

Problem

Additive manufacturing of thermoplastic polymers, particularly using post-consumer recycled polyolefins, faces challenges such as warping and inadequate printing due to crystalline formation and composition variations, especially when forming larger parts or parts with complex geometries, and is hindered by the presence of contaminants in the material streams.

Innovation Solution

A method involving the use of a thermoplastic material comprising 5 to 75 weight percent post-consumer recycled polyolefin and 25 to 95 weight percent olefin block copolymer, heated and extruded through a nozzle to form layers adhered together, allowing for the creation of additive manufactured parts with improved adhesion and reduced warping, using a combination of horizontal displacement and CAD/CAM methodologies for pattern formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If post-consumer recycled polyolefin is used in additive manufacturing, then material sustainability is improved, but warping and printing quality deteriorate due to crystalline formation

Engineering Contradiction:
Improvematerial sustainabilityVSAvoidprinting quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent creates a composite material system combining post-consumer recycled polyolefin (PCRPO) with olefin block copolymer (OBC). This composite approach allows the recycled polyolefin to provide sustainability benefits while the OBC component suppresses crystalline formation and warping, enabling both environmental and manufacturing quality goals to be achieved simultaneously

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the material composition parameters by specifying that the PCRPO content ranges from 5 to 75 weight percent and OBC content ranges from 25 to 95 weight percent. This parameter optimization allows control over both the sustainability aspect (higher PCRPO content) and manufacturing quality (higher OBC content to prevent warping), finding an optimal balance between the two competing requirements

Inventive Principle:
Principle #35Parameter changes

2Strength

If high density polyethylene or polypropylene is used, then material strength is improved, but warping increases due to crystalline formation in particular orientations

Engineering Contradiction:
Improvematerial strengthVSAvoidwarping control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The olefin block copolymer acts as an intermediary component that modifies the behavior of the polyolefin matrix. The OBC interferes with the crystalline formation process of HDPE or PP, preventing the development of particular crystal orientations that cause warping, while allowing the base polyolefin to maintain its strength properties

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent introduces local quality changes by having the OBC distributed throughout the polyolefin matrix, creating localized regions where crystalline formation is suppressed. This allows the material to maintain overall strength from the polyolefin while having localized anti-warping effects where the OBC is present

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If larger parts are manufactured, then part utility is improved, but warping becomes more severe

Engineering Contradiction:
Improvepart utilityVSAvoidwarping control
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The olefin block copolymer performs a preliminary action by preventing crystalline formation and warping tendencies before they can develop during the printing process. This preemptive effect is particularly important for larger parts where warping would otherwise become more severe, allowing successful manufacturing of bigger components

Inventive Principle:
Principle #10Preliminary action

4Reliability

If recycled polyolefin streams are used, then environmental benefit is improved, but composition variation and contaminants increase

Engineering Contradiction:
Improveenvironmental benefitVSAvoidcomposition consistency
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The olefin block copolymer serves as a unifying component that creates a homogeneous material system despite the inherent heterogeneity of recycled polyolefin streams. The OBC blends well with various polyolefin types (HDPE, LLDPE, LDPE, PP) and contaminants, creating a consistent composite material that prints reliably regardless of the specific composition of the recycled feedstock

Inventive Principle:
Principle #33Homogeneity

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

This method enables the successful additive manufacturing of parts with reduced warping and improved adhesion, utilizing post-consumer recycled materials effectively, and allows for the creation of complex geometries by using olefin block copolymers to stabilize the polyolefin layers, enhancing the utility of recycled polyolefins in 3D printing.

Implementation Method 1

heating and dispensing said thermoplastic material through a nozzle

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

thermoplastic material... softened by heating (e.g. melted)

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 3

The extruded filaments fuse together upon cooling

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 4

The extruded filaments fuse together upon cooling

Methodology Applied
Scientific EffectFusion: Welding

Data Source

PatentEP4041822B1Additive manufacturing using recycled polyolefins with olefin block copolymers and articles made therefrom
Publication Date: 2023.12.06 DOW GLOBAL TECHNOLOGIES LLC
  • EP4041822B1 patent drawingFigure 1~3
  • EP4041822B1 patent drawingFigure 4~6

AI summary

A method comprising, (i) providing a thermoplastic material comprising 5-75 wt% of a post-consumer recycled polyolefin composition and 25-95 wt% of an olefin block copolymer composition based on total weight of the thermoplastic material, wherein the post-consumer recycled polyolefin composition comprises at least 50 wt%, of a polyolefin and at least 0.1 wt% of a contaminant; (ii) heating and dispensing said thermoplastic material through a nozzle to form an extrudate deposited on a base, (iii) moving the base, nozzle or combination thereof while dispensing the thermoplastic material so that there is horizontal displacement between the base and nozzle in a predetermined pattern to form an initial layer of the material on the base, and (iv) repeating steps (ii) and (iii) to form a subsequent layer of the material adhered on the initial layer, and (v) optionally repeating step steps (ii) and (iii) to form additional subsequent layers.