Electronics Recycling

© Colin Fitzpatrick

Electronics Recycling

Ability to design products for recycling is enhanced by an understanding of the recycling process

Effectiveness is affected by the ability to collect the products, extract or liberate the target materials and return them to use

Electronics Recycling

Understanding of the materials being recovered. Primary targeted materials being high value precious metals, aluminium, copper etc… Must also concern themselves with recovery of hazardous material and low value materials such as plastics or ferrous metals

The second aspect is minimising costs. Cost of liberating the materials and cost of the logistics to acquire the products

Thoroughly developed DfR plans will address both costs involved in material liberation along with logistics and collection issues.

Recycling Technologies

Manual Disassembly– Use of hand tools and methodologies similar to product

assembly– More expensive– Valuable sub-assemblies saved

Destructive Disassembly– Grinding or shearing followed by a number of material

separation techniques– Minimises labour costs– Yields more contaminated materials – Valuable sub-assemblies are destroyed

Recycling Technologies

The technique employed defines the DfR priorities. Reduction of disassembly time not necessary for

product to be shredded If disassembly times are large and recyclable

material value is low, high probability of recycling by shredding

Especially true for products with little reuse potential such as mobile phones due to rapid product obsolesce

Manual disassembly requires hidden treasure within

DfR Considerations

Material Considerations– Relative Recyclability– Toxicity

Disassembly Considerations– Barriers during assembly to the liberation of clean

recyclable materials

Material Considerations

Recyclability is the ability and desirability of reprocessing the material

Ability to reprocess the material such that its physical characteristics closely reflect the characteristics of virgin material

Desirability of using recycled material as measured in its cost versus virgin material

Closed Loop Recycling

Potential for reuse of entire parts or subassemblies.

Reintroducing the recovered raw materials into the manufacturing stream for that specific product.

Examples include large office equipment and integrated circuits

Closed Loop Recycling

Closed Loop Recycling

Developing Closed Loop Recycling involves– Analyse the potential for testing and verification of

recovered assemblies– Reverse logistical system– Disassembly must allow recovery– Gauging potential impact on the customers

perception of the product

Commonly Recycled Materials in Information Technology Products

ELEMENTS COMPOUNDS COMPONENTS

Platinum ABS plastic Integrated Circuits

Gold ABS-FR plastic Motors

Palladium Stainless Steel Power Supplies

Silver PVC Displays

Nickel Polyethylene Lead Acid Batteries

Copper Steel NiCad Batteries

Zinc Cardboard

Aluminium Glass

Mercury

Materials Recycling

Recyclability is enhanced or restrained by the inclusion of materials that are inherently recyclable and have a significant value on the recycled material market

Reverse logistics are crucial to the Recyclability Eats into the potential value of the material

– Example PET bottles are eminently recyclable but of little value and rarely get recycled when the logistics add even small costs to the process

Materials Recycling

Recyclability of a material can be significantly decreased by how it is incorporated into the product

– Steel Inserts in Aluminium Chassis require additional processing steps for separation.

– Labels added on the surface of plastics have the same effect. Label is a contaminant and can degrade the properties of the recycled material

– Otherwise recyclable parts can otherwise be incinerated or sent to landfill due to such economic considerations

Materials Recycling

Toxic materials must be recovered and processed Recycler must be able to identify, segregate, and

aggregate the materials for the recovery process Risks include release of hazardous materials during

post disassembly processing. Plastics with brominated and chlorinated flame

retardants have the potential to produce dioxins and may be sent to landfill.

Disassembly Considerations

Goal is to liberate recoverable materials at a minimum cost (measured by disassembly time)

The recycler is subject to learning curve DfR Considerations such as visibility and

ease of access to fasteners can significantly reduce the learning curve

Disassembly Considerations

Optimum Disassembly Time

Affected by– Number of fasteners– Number of materials– Time necessary to separate dissimilar materials– Number of tools required

The Optimum Disassembly time is not necessarily equivalent to the time to completely disassemble the product but too disassemble to the point of maximum return which can be determined using the net revenue curve

Net Revenue Curve

Net Revenue Curve

Y axis represents the liberated material value minus the cost of disassembly

X axis is time to disassemble Economic Goal is to operate at the peak of the curve Hazardous materials can impede this Product design establishes the parameter for this

curve by determining the purity, Recyclability, and rate of recovery of materials

Design for Recycling Analysis

Goal is to understand the products Recyclability and generate a list of potential product improvements

Three broad categories– Increasing the value of the liberated material– Decreasing the time to liberate the material– Reducing or eliminating hazardous materials

Design for Recycling Analysis

Recovered Material Value– Improve the quality of the material– Contaminates decrease the value recovered in

recycling– Joining of dissimilar materials need special

attention including different plastics and metals– Should be joined with fasteners or clips for ease

of separation.– Adhesives and welds should be avoided

Design for Recycling Analysis

Recovered Material Value– Materials with low recycled value should be

avoided as high potential they will be not recycled due to economic considerations. This is particularly true of packaging materials

Design for Recycling Analysis

Disassembly Time Reduction– Fasteners

Number Consistency (Phillips head preferred) Clips over welds

– Modularity of Design Can be beneficial or detrimental Depends on manual or destructive disassembly

Design for Recycling Analysis

Hazardous Material Elimination– No Brainer………

Quantifying Results

At conceptual stage need qualitative techniques– Grading scheme using criteria such as material variations,

relative material toxicity, weight, size etc…– Best Employed for comparisons between design proposals

Net Revenue Curve– When design has matured