Recycling Guidelines

1
Recycling Guidelines
2
Design for Recycling Guidelines

• Most recycling guidelines are divided into three
  categories
• Component design
• Material selection
• Fastener selection
• Most people agree that these issues, plus the
  choice of which processes are employed for
  recycling, have the largest impact on
  recyclability.
• Mechanical and manual separation techniques can
  be suggested for each of the above areas.
• Some also emphasize packaging.

3
Fundamental Lessons Learned

• As part of ongoing efforts in improving vehicle
  recyclability, a number of fundamental lessons
  have been learned from the disassembly of
  vehicles and studies by the Vehicle Recycling
  Partnership
• The limiting factor in economic recycling of
  complex, integrated assemblies (such as
  instrument panels) is the separation into pure
  material streams.
• Both manual and mechanical separation have their
  advantages and disadvantages.
• Significant value must be retained in a part for
  manual separation to be economically feasible.
• Different design techniques should be employed
  depending on whether one wants to facilitate
  manual separation or mechanical separation.
• These fundamental lessons should be kept in mind
  when generating design alternatives.

4
Process Selection Guidelines
5
Metric for Selecting Separation Technique

• How do you know which process to design for?
• The following flowchart provides a relatively
  simple metric for design decision support.

Material Removal Rate Material kg / time min
From Coulter, S. L., Bras, B. A., Winslow, G.
and Yester, S., 1996, Designing for Material
Separation Lessons from the Automotive
Recycling, 1996 ASME Design for Manufacturing
Symposium, ASME Design Engineering Technical
Conferences and Computers in Engineering
Conference, Irvine, California, August 18-22,
ASME, Paper no. 96-DETC/DFM-1270.
6
Detached Weight for Cost Neutral Recyling (g/min)

• The amount of material (in grams) that has to be
  detached per minute if recycling is to be cost
  neutral for manual disassembly
• Precious metals
• gold 0.05
• palladium 0.14
• sliver 5.1
• Metals
• copper 300
• aluminium 700
• iron 50,000
• Plastics
• PEE 250
• PC, PM 350
• ABS 800
• PS 1000
• PVC 4000
• Glass 6000

Based on West-European hourly rates and material
prices in Sept. 1995 (Philips Center for
Manufacturing Technology)
Estimated total industrial labor rate US0.6/min
7
End-of-Life Destination Flowchart (from TNO
Industry Delft, The Netherlands)

• General guidelines to determine end-of-life
  destinations

8
Material Selection Guidelines
9
Recycling Two or More Materials(from GE Plastics)
Rule of Thumb You want to take the shortest path
for material recycling
NOTE Ideally, you just want to have ONE material!
10
Material Compatibility

• Compatibility matrices (or tables) list whether
  two materials are compatible, that is, they can
  be processed together.
• Most tables are for plastics, but some also exist
  for metal alloys. Most use a (rough) scale of 1-4
  or 1-3.
• Typically, the information regarding
  compatibility (and especially detailed
  information) is buried in chemical handbooks.

In case of doubt, see your material expert.
Question Are regular and galvanized steel
compatible?
The table shown here is translated from VDI 2243.
11
Glass and Ceramics Compatibility

• good, 0 moderate, - poor/nil

The table shown here is from Ecodesign A
Promising Approach to Sustainable Production and
Consumption, UNEP/IE, United Nations.
12
Compatibility of Metals

• In general, metal parts are easily recycled, but
  the following rules and guidelines apply
• Unplated metals are more recyclable than plated
  ones.
• Low alloy metals are more recyclable than high
  alloy ones.
• Most cast irons are easily recycled.
• Aluminum alloys, steel, and magnesium alloys are
  readily separated and recycled from automotive
  shredder output.
• Contamination of iron or steel with copper, tin,
  zinc, lead, or aluminum reduces recyclability.
• Contamination of aluminum with iron, steel,
  chromium, zinc, lead, copper or magnesium reduces
  recyclability.
• Contamination of zinc with iron, steel, lead,
  tin, or cadmium reduces recyclability.

The table shown here is from Ecodesign A
Promising Approach to Sustainable Production and
Consumption, UNEP/IE, United Nations.
13
A Well Known Laminate Example

• Look around and you will see a lot of room for
  improvement.

From Green Products by Design Choices for a
Cleaner Environment, Office of Technology
Assessment, US Congress, Oct. 1992.
14
Material Selection

• At the onset of a new program, the Design
  Office, Platform Engineering, Purchasing and
  Supply, and the component supplier should discuss
  recycling issues associated with a concept and
  determine the best fit materials and processes
  for specific applications.
• Suppliers should be encouraged to demonstrate
  recyclability and to take materials back for
  recycling at the end of the vehicles useful life
  to be recycled in automotive and other
  applications.
• The use of materials which have been recycled,
  including from old vehicles, is desirable where
  it is economically viable.
• (from Chrysler Vehicle Recycling Design
  Guidelines)

15
Diversity of Plastics

• There is an incredible variety of plastics in
  modern vehicles.
• However, the top 7 used plastics are (in
  N-America)
• Urethane 1990 - 454 mill. lbs, 1995 - 493
  mill. lbs.
• Polypropylene (PP) 1990 - 437 mill. lbs, 1995 -
  522 mill. lbs.
• Acrylonitrile/Butadiene/Styrene (ABS) 1990 - 281
  mill, 1995 - 289 mill. lbs.
• Polyvinylchloride (PVC) 1990 - 264 mill. lbs,
  1995 - 288 mill. lbs.
• Nylon 1990 - 208 mill. lbs, 1995 - 246 mill.
  lbs.
• Polyethylene (PE) 1990 - 191 mill. lbs, 1995 -
  248 mill. lbs.
• Polyester composite (SMC) 1990 - 173 mill. lbs,
  1995 - 261 mill. lbs.
• Thus, if you have to choose a plastic, try
  picking one which is widely used.
• Minimizing material diversity is beneficial for
  acquisition, storage, manufacturing, recycling,
  etc.

16
Main Material Concerns

• Meet environment, health, and occupational safety
  requirements for regulated or restricted
  substances or processes of concern.
• Do not, or limit, the use of materials which pose
  human or environmental risk.
• Mark materials according to standards.
• Generate minimal home and pre-consumer scrap
  during manufacturing.
• Make components of different recyclable materials
  easily separable, or use materials which can be
  recycled as a mixture.
• Standardize material types.
• Reduce painting.

17
Cathode Ray Tubes - Problem

• Cathode ray tubes (CRTs) pose a major difficulty
  for recycling.
• The phosphor-based coating used to provide the
  necessary luminescence contains heavy metals and
  other toxins, while the glass itself is loaded
  with lead and barium.
• Recycling a specific design of CRT with known
  constituents is relatively straightforward, but
  finding a process that will handle very large
  quantities of CRTs of varying age and
  specification is not so easy.

18
Marking of Plastics

• SAE J1344 April 1993 contains the standards on
  marking of plastic parts.
• Based on standard symbols as published by ISO
  1043.
• Allows for expansion and inclusion of new symbols
  for new material. (complete appropriate forms).
• See SAE J1344 for examples and specifics.
• European legislation will require the marking of
  all plastic parts with a weight greater than 100
  grams.

19
Positions and Life of Markings

• No position of marking is prescribed, but
• Field service people should be informed regarding
  the material.
• If practicable, marking should be located where
  it may be observed while it is in use. May
  consider multiple markings.
• Marking on the outside is preferred for field
  service people.
• Also, markings should last
• Markings applied with inks, dyes, paints should
  not bleed, run, smudge, or stain materials in
  contact with the marking.
• Markings should be designed to remain legible
  during the entire life of the part.
• Markings which are molded into the part are
  preferred since they are permanent and do not
  require additional manufacturing operations.
  BUT, molded parts should not create a stress
  concentration.

20
Material Selection  Summarizing

• General
• Avoid regulated and/or restricted materials
• These often MUST be recycled, whatever the
  monetary cost of removal is.
• Use recyclable materials
• Both technically as well as economically
• Use recycled materials, where possible
• This increases recycled content
• Standardize material types
• May involve corporate decision
• Reduce number of material types
• Can be done at engineering level
• Use compatible materials, if different materials
  are needed.
• Single material is preferred, however.
• Eliminate incompatible laminated/non-separable
  materials.
• These are a major hassle.

21
Material Selection (cont.)

• Manual Separation
• Avoid painting parts with incompatible paint
• Especially plastics can be contaminated by paint.
• Eliminate incompatible laminated/non-separable
  materials
• Mechanical Separation
• Reduce number of materials as much as possible
• Probably two materials can be economically
  recovered
• Choose materials with different properties (e.g.,
  magnetic vs non-magnetic heavy vs light), thus
  enabling easy separation.
• Allow for density separation
• Maintain at least 0.03 specific gravity
  difference between polymers
• Isolate polymers with largest mass by density
• Eliminate incompatible laminated/non-separable
  materials

22
Component Design Guidelines
23
Component Design

• Apply Design for Manufacturing and Assembly
  (DFMA) and Serviceability Guidelines as
  appropriate in component design.
• Facilitate ease of assembly removal and material
  separation.
• (There is a close correspondence between DFA,
  DFD, and Design for Service)
• Route wiring to facilitate removal.

Pay attention to detail and reduce the amount of
frustration and special equipment. Label
dangerous operations.
24
Minimize Part and Material Count

• To facilitate separation and collection
• Minimize the number of components within an
  assembly.
• Minimize material types within an assembly.
• Build in planes of easy separation where this
  does not affect part function.
• Look under a hood for good and bad examples.
• (By the way, think also about modularity)
• Question What other (non-DFR) reasons exist for
  minimizing part and material count?

25
Classical Component Integration Example

• Springs and their support systems are always
  classical examples of component integration.
• Note the reduction in part and material count.

26
Laminates and Paints

• Avoid laminates which require separation prior to
  reuse.
• Even though unique separation techniques exists,
  it increases the cost of the recyclable material.
• When laminates are used, design them from
  compatible materials and adhesives.
• Examples
• Dashboard cover
• Old design PVC top foil, PUR foam core, steel
  support plate
• New design PP top foil, PP foam core, support
  layer of PP
• Bumper
• Old design PC skin, PUR foam core, steel
  support
• New design Integral foam of PC, PP, support
  frame of PC, PP
• Avoid painting parts wherever possible.

27
Problems with Paints

• In general, paints contaminate plastics to be
  recycled.
• Compatible paints exists, but the majority is
  non-compatible.
• One percent (!) of contamination can be enough to
  ruin a plastic batch for recycling.
• Many painting processes are subject to
  regulations.
• For example, in case a city-wide smog alarm goes
  off, certain painting processes (or other
  processes with volatile compounds) need to be
  stopped.
• Stripping paint is also a very nasty process.
• Environmentally benign stripping processes
  exists, but the paint chips still have to be
  disposed off.

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Component Design - Summarizing

• General
• Integrate parts
• Reduce disassembly time
• Minimize scrap during production
• Mechanical separation
• Avoid using incompatible materials
• E.g., stiffen sections rather than adding foam
  for noise-vibration-heat areas
• Manual
• Use Design for Manufacturability/Assembly and
  Serviceability guidelines
• Reduce number of steps to remove a recyclable
  part
• Reduce chance of contamination
• Route wiring to facilitate removal
• Separate at bulkheads/interface areas

29
FastenersGuidelines
30
What about fasteners ?

• In VDI 2243, an example is given on the
  remanufacture of a four cylinder internal
  combustion engine.
• About 32.5 of all activities in the disassembly
  process consist of the loosening of screws.
  These activities consume 54 of the entire
  disassembly process time.
• According to VDI 2243, this is a typical example.
  
• The separation of staple, glue, press joints or
  joints made by deformation not only require more
  specialized equipment, but also embody a higher
  risk of damaging the component, if it is to be
  reused.
• Additional problems occur when contaminations
  such as oil, dirt and corrosion are present.

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Assembly and Disassembly

• Adhere to Design for Assembly guidelines
• Good designs take ease of assembly as well as
  service and recycling into account.
• Facilitate disassembly (Design for Disassembly)
• Select fasteners which facilitate disassembly by
  any method including destruction (by shredding)
  after a vehicles useful life.

32
Reduce and Commonize Fasteners

• Reduce the number and types of fasteners used.
• Select fasteners that do not require
  post-dismantling material separation for
  recycling.
• When practical, use fasteners of the same (or
  compatible) material as the attaching part.
• If this is not possible for plastic fasteners,
  use ferrous fasteners or inserts to allow for
  magnetic separation after shredding.
• Commonize fasteners
• Try to design with minimum screw head types and
  sizes. (remember the Volkswagen Bugs 13 mm
  wrench standardization)
• DO NOT JEOPARDIZE STRUCTURAL INTEGRITY OR
  FUNCTION !!

33
Select Proper Coatings

• Corroded fasteners cause severe problems for fast
  removal of parts
• Select coatings which minimize corrosion.
• This may drive up the cost.
• Phospate oil coatings have low corrosion
  resistance
• Better (but more costly) coatings may be
  warranted for recyclability (and servicability).
• Cadmium coatings should not be used because of
  potential health and environmental hazard.

34
Snap fits

• Use snap fits wherever possible to reduce the use
  of additional fasteners.
• Molded clips should be removable without breaking
  off.
• IMPORTANT
• Do not jeopardize product integrity.
• Also, consider long term effects (hardening of
  plastic, fatigue failure, frustration of broken
  snaps).

35
Adhesives

• Joining or bonding materials of the same type
  with compatible adhesives enhances recycling.
• But, non-compatible adhesives may cause
  contaminants to enter the material waste stream.
• Therefore, adhesive selection and the effect on
  part recyclability should be discussed with
  Materials Engineering as part of the development
  process at the onset of a program.

36
VDI 2243s Fastener Selection Table

• This table gives an overview of a German rating
  of fasteners.
• It will give you an idea of how different
  fasteners compare against each other.
• Caution By no means is this a definite table!

37
Fastener Selection Summarizing

• Clear distinction between manual vs mechanical
  separation guidelines
• Manual Separation
• Reduce number of fasteners
• Commonize fastener types
• Use fasteners made of compatible materials
• Consider snap-fits (two-way, if necessary)
• Consider destructive fastener removal
• Possible inclusion of break points in material

38
Fastener Selection Mechanical Separation

• IMPORTANT Fasteners will not be unfastened!
• Disassembly time is irrelevant!
• Material properties are (again) key issue
• In order of preference, use
• 1) Molded-in fasteners (same material)
• 2) Separate fasteners of same or compatible
  material
• 3) Ferrous metal fasteners (easy to remove due to
  magnetic properties)
• 4) Non-ferrous metal fasteners (can be removed
  using, e.g., Eddy-current)

39
Trade-offs

• Design for Recycling can negatively affect
  performance and cost issues.
• For example, required material substitution is
  not always possible or will cost more.
• However, in most cases, the trade-offs can be
  resolved and often converted in win-win
  situations.
• Often cited and studied and questioned are the
  trade-offs between design for disassembly and
  design for assembly.
• Take a look at the DFA guidelines and compare
  them not just with DFD, but also with DFR in
  general.
• Remember, a shredder does not care much about
  geometry and fasteners

40
Product Design for Assembly Guidelines

• Product Design for Assembly
• 1) Overall Component count should be minimized.
• 2) Minimum use of fasteners.
• 3) Design the product with a base for locating
  other components.
• 4) Do not require the base to be repositioned
  during assembly.
• 5) Design components to mate through
  straight-line assembly, all from the same
  direction.
• 6) Maximize component accessibility.
• 7) Make the assembly sequence efficient.
• - Assembly with the fewest steps.
• - Avoids risks of damaging components.
• - Avoids awkward and unstable component,
  equipment, and personnel positions.
• - Avoid creating many disconnected subassemblies
  to be joined later.

41
Component Design for Assembly Guidelines

• Component Design for Assembly
• 8) Avoid component characteristics that
  complicate retrieval
• (Tangling, nesting, and flexibility)
• 9) Design components for a specific type of
  retrieval, handling, and insertion.
• 10) Design components for end-to-end symmetry
  when possible.
• 11) Design components for symmetry about their
  axes of insertion.
• 12) Design components that are not symmetric
  about their axes of insertion to be clearly
  asymmetric.
• 13) Make use of chamfers, leads, and compliance
  to facilitate insertion.

42
DFR Special Issues
43
Limiting Factors

• Identify the limiting factors and address these
  first!
• Look at a combination of the following component
  aspects
• Weight If recyclability and recycled content
  are defined by weight, it makes sense to look at
  the heaviest components first. Improving a 10
  pound components recyclability rating from 4 to
  3 has a larger impact on the overall system
  recyclability than improving a 1 pound component.
  
• Distance from target ratings Components with
  recyclability ratings of 4 and lower should be
  improved. Pay special attention to components
  with a recyclability rating of 4 because they can
  often relatively easily be changed to obtain a
  (good) rating of 3. The same applies for
  material separation ratings, i.e., first focus on
  those components with a separability rating of 4.
  
• Risk Those components with a high risk are also
  prime candidates for improvement.
• Violation of Design for Recycling guidelines A
  component which clearly violates some of the
  Design for Recycling guidelines may also be a
  limiting factor and a prime candidate for
  improvement. Pay special attention to WHY one or
  more guidelines have been violated it may have
  been done intentionally to, say, increase
  functionality or manufacturability.
• Often, upon careful inspection, the material or
  combination of materials is the limiting factor
  in most parts.

44
Risk Assessments

• Some basic simple risk assessments with respect
  to achieving targets can be done

45
Management Issue Recyclability Target Setting

• Goal of designer Improve vehicle recyclability
• 85 (by weight) required recyclability in 15
  years
• Current recyclability (first revision) 75
• Four (yearly) revisions of vehicle expected
• Data available on
• expected production for each year
• estimated reliability of vehicles
• Aim Aid designer in setting appropriate targets
  for the recyclability of each revision of the
  vehicle

46
Target Setting Parameters

• Production Uncertainty Normal, ?? 5,000
• Recyclability Triangular, 3
• Reliability, Weibull distribution
• Monte Carlo simulation used to explore effects of
  a given set of targets

47
Target Setting Constant Improvement
48
Target Setting Achieving 85 Recyclability
49
Inclusion of Uncertainty

• How will changes in technology and legislation
  affect the target definition and prioritization
  of limiting factors?

50
Computer-Based Tools
51
Computer-Aided Design for the Life Cycle System
Architecture
52
Automotive Center Console

• Given are the geometric (solid) and assembly
  models of a center console design generated using
  a modern CAD package.

Assembly Model
Solid Model
53
Virtual Disassembly

• Disassembly in a Virtual Reality environment
  facilitates design for recycling as well as
  design for serviceability.
• Other assessments are also being added (e.g.,
  demanufacture process cost assessments)
• The key is to use the existing product models and
  add functionality in existing and (for a
  designer) familiar software systems.

• NSF grants
• Virtual Design Studio for Servicing and
  Demanufacture (Rosen, Bras, Mistree, Goel,
  Baker) DMI9420405
• CAD for De- and Remanufacturing (Bras and Rosen)
  DMI9414715
• Enhancing Reusability by Design (Bras)
  DMI9410005
• Integrated Product and De- and Remanufacture
  Process Design (Bras) DMI9624787

54
Kodak Funsaver Virtual Disassmbly

• Virtual disassembly allows tracking of basic
  disassembly path based on user/designer
  experience.
• This path can be fine-tuned using other tools.

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IGRIP Robotic Disassembly Simulation