Aluminum Alloy Composition for High-Recycled Content Bottle Production

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Solution Overview

Problem

Current aluminum alloys for bottle production fail to balance formability, strength, and cost-effectiveness, with high formability alloys lacking strength and strong alloys having poor formability, and existing methods using prime aluminum are expensive and unsustainable.

Innovation Solution

Development of new aluminum alloys with optimized chemical composition and manufacturing processes that incorporate high recycled aluminum content, achieving strength, formability, and sustainability through thermomechanical processing including direct chill casting, homogenization, hot rolling, and cold rolling, allowing for high-speed production of bottles with complex shapes and variable strength requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If current aluminum alloys are used for bottle production, then formability or strength can be achieved, but the other property deteriorates (high formability alloys have low strength, strong alloys have poor formability)

Engineering Contradiction:
Improvebottle strengthVSAvoidformability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by optimizing the chemical composition parameters of the aluminum alloy, specifically controlling the content ranges of Mn (0.9-1.4 wt.%), Mg (0.65-1.2 wt.%), Cu (0.45-0.9 wt.%), Fe (0.35-0.55 wt.%), and Si (0.2-0.45 wt.%). This compositional parameter optimization enables the alloy to simultaneously achieve high strength and excellent formability, resolving the trade-off between these two properties.

Inventive Principle:
Principle #35Parameter changes

2Strength

If prime aluminum is used in casting, then alloy strength can be ensured, but production cost increases and sustainability decreases

Engineering Contradiction:
Improvealloy strengthVSAvoidrecycled aluminum content
Core Design Contradiction:
StrengthVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by setting the recycled aluminum content parameter to at least 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, 82 wt.%, 85 wt.%, 90 wt.%, or 95 wt.%. This parameter optimization demonstrates that high recycled content can be achieved while maintaining alloy strength through controlled composition and processing parameters.

Inventive Principle:
Principle #35Parameter changes

3Weight of moving object

If bottle wall thickness is reduced to achieve lower weight, then weight target is met, but mechanical performance requirements become more challenging to meet

Engineering Contradiction:
Improvebottle weightVSAvoidmechanical performance
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent applies parameter changes by optimizing the alloy composition parameters (Mn: 0.9-1.4 wt.%, Mg: 0.65-1.2 wt.%, Cu: 0.45-0.9 wt.%, Fe: 0.35-0.55 wt.%, Si: 0.2-0.45 wt.%) and processing parameters to achieve superior strength properties. This enables the use of thinner wall thickness while still meeting mechanical performance targets for column strength, rigidity, and bottom dome reversal pressure.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If high speed production is implemented, then throughput increases, but the shaping process must be completed in very short time

Engineering Contradiction:
ImprovethroughputVSAvoidshaping time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by optimizing the alloy composition and processing parameters during the manufacturing stage to pre-establish the material properties needed for high-speed forming. The controlled composition (Mn: 0.9-1.4 wt.%, Mg: 0.65-1.2 wt.%, Cu: 0.45-0.9 wt.%, Fe: 0.35-0.55 wt.%, Si: 0.2-0.45 wt.%) and processing create an alloy that requires minimal shaping time, enabling throughput of 1000 bottles per minute.

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 new alloys achieve high deformation capabilities, strength, and cost-effectiveness by using high recycled aluminum content, enabling efficient production of bottles with complex shapes and meeting mechanical performance targets while reducing production costs and environmental impact.

Implementation Method 1

Although alloys described herein are heat treatable, the precipitation hardening is achieved concurrently with coat/paint curing

Methodology Applied
Scientific EffectPrecipitation hardening: Precipitation Hardening

Implementation Method 2

Both the chemistry and manufacturing processes of the alloy have been optimized for the high speed production of aluminum bottles

Methodology Applied
Scientific EffectHomogenization: Heat Treatment

Implementation Method 3

The resulting cylinder is then formed into a bottle shape using, for example, a sequence of full-body necking steps or other mechanical shaping

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP3268503B1Aluminum alloys for highly shaped packaging products and methods of making the same
Publication Date: 2019.06.19 NOVELIS INC(US)
  • EP3268503B1 patent drawingFigure 1
  • EP3268503B1 patent drawingFigure 2
  • EP3268503B1 patent drawingFigure 3

AI summary

The disclosure is related to new, formable and strong aluminum alloys for making packaging products such as bottles and cans.