Polymers in Wire Coating (Kapton?) Kapton? is a registered trademark of E.I. Du Pont de Nemours and Company

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Polymers in Wire Coating (Kapton?)Kapton? is a
registered trademark of E.I. Du Pont de Nemours
and Company

• CE 435 Into to Polymers
• Group Members
• Jason Womer
• Tom Hanselman
• Dan Boek

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Table of Contents

• Wire Coating Specs
• Swiss Air Flight 111
• Fire Prevention
• Crash Statistics
• Improving Insulation
• Conduction of Polymers
• Uses of Kapton?
• Degradation of Polymers

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Insulation Requirements for Wires

• Requirements for Machine-tool Wires and Cables

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Who Sets the Standards?

• Requirements specified in the National Electrical
  Code (ANSI/NFPA 70)
• Also used in the National Fir Protection
  Association Electrical Standard for Industrial
  Machinery (ANSI/NFPA 79)

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How Are the Standards Set?

• The polymer insulation and the finished wires
  must comply with a flame test and are for use at
  temperatures of 90 C (194 F) or lower in dry
  locations
• Must comply at 60 C (140 F) or lower where
  exposed to moisture, oil, or coolants

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Electrical Problems May Have Sparked Swiss Air
Flight 111 Crash Pictures Taken from Web Site
(http//www3.ns.sympatico.ca/mr.187/photos.html)

• Urs Zimmermann (Pilot) and the planes flight
  recorder.
• The exact cause of the crash is unknown, however,
  evidence points towards a rapid and deadly
  electrical fire

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Rapid Fire Pictures Taken from Web Site
(http//www3.ns.sympatico.ca/mr.187/photos.html)

• According to record Zimmerman noticed smoke at
  approximately 10,000m and 16 minutes later, the
  plane slammed into the Atlantic Ocean off Peggys
  Cove, N.S. Canada.
• According to Susan Bradley, a spokeswoman for
  Boeing, Kapton? was the primary coating on the
  wiring in Swissair Flight 111 (Macleans Sept 21,
  1998 v111 n38 p20(1))

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How Safe is Kapton? WiringPicture taken from web
site (www.ece.msstate.edu/hvl/research.html)

• Patrick Price (Expert with the former Boeing Co.
  in Seattle) on Kapton? wiring
• Its like taking an incendiary bomb on board
  (Macleans, Sept 21, 1998 v111 n38 p20(1))
• In 1982 the U.S. navy stopped using Kapton?
  wiring in jet fighters when cracks in wires
  coated with Kapton? were linked to on-board
  fires. (Macleans, Sept 21, 1998 v111n38 p20(1))
• Scientists have found Kapton? is prone to rare
  but catastrophic arc tracking when the wire is
  subjected to chafing, vibration, and moisture.
  U.S. News and World Report, Sept 28, 1998 v125
  n12 p44(1))
• If a wire cracks, electricity can arc to nearby
  material, setting it on fire. This is known as a
  flash over which burns at a searing 1,000 C.

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Deadly Games

• Swiss Air Flight 111 had approximately 240 km of
  wires running through it to bring passengers a
  premium video and gambling system in todays
  intensely competitive market for business and
  first-class flyers.
• Each seat aboard Swiss Air Flight 111 had a video
  screen that pops out of the armrest like a tray
  table. Passengers could play video games, music,
  or even gamble.
• It was this luxury which could have lead to the
  crash.
• The system costs about 2 million or more dollars
  per plane and was developed by Interactive Flight
  TechnologiesTM. A struggling company which said
  it wants out of the in-flight-entertainment
  business.
• This web of wires from each seat to central
  computers aboard the plane generates a greater
  possibility for an electrical disaster. (Time,
  Nov 9, 1998 p58(1))

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Advanced Kapton? Material is Being Used Today

• Since 1993 Kapton? has been improved by wrapping
  it in a tough Teflon coating.
• In an article I found from 1998 FAA officials
  said that old forms of Kapton may soon be removed
  from hundreds of planes.
• Boeing company spokesman John Thom said that
  Kapton was and is certified for use on
  commercial airplanes (Macleans, Sept 21, 1998
  v111 n38 p20(1))

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Some Pictures from the aftermathPicture taken
from web site (http//www3.ns.sympatico.ca/mr.187/
photos.html)

• At left is one of the most recognizable photos
  from the tragedy as rescuers try in vain to find
  survivors. Pictured at right is the Emergency
  Service Paying tribute to Flight 111

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Fire Prevention in PlanesPicture taken from web
page (http//www.airliners.net/open.file?id13250)

• The Federal Aviation Administration or FAA
  announced in October of 1998 that Mylar
  insulation used in nearly 12,000 passenger jets
  must be replaced to reduced the chance of fire.
  (U.S. News and World Report, Oct 26, 1998 p17(1))
• It is believed that this type of insulation was
  set ablaze by a short circuit in the electrical
  equipment aboard the Swiss Air Flight 111

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Luxury isnot alwaysbetter Picture from web site
(http//www.tsb.gc.ca/ENG/TSB_Investigations/Swis
sair/)

• The high tech video system aboard Flight 111 used
  Microsoft Windows NT software, with wires
  connected to a central computer. (Time, Nov
  9,1998 p58(1))
• Investigators found that the wires had been
  connected to the same electrical pathways that
  powered vital parts of the aircraft.
• Therefore, if there is a problem with the video
  system, then there is a problem with the whole
  plane.
• In the future this type of video system should be
  connected to a separate area of the plane where
  vital networks in the plane will not be affected
  thus buying time for an emergency landing.

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Firefighting Training for Pilots and
PreventionWeb site (http.www.tsb.gc.ca/EN/TSB_Inv
estigations/Swissair/site_pages/saf/FireRecs_2000
dec4.ht)

• The investigation into Swiss Air Flight 111
  revealed safety deficiencies in crew training and
  awareness, and procedures related to in-flight
  firefighting.
• The TBS safety board issued the following
  recommendations to address safety deficiencies
• A lack of a coordinated and comprehensive
  approach to in-flight firefighting.
• Smoke/fire detection and suppression systems are
  insufficient
• There are no smoke/fire detection and suppression
  systems in the cockpit or cabin or any area not
  considered a fire zone.
• The importance of making prompt preparations for
  a possible emergency landing is currently not
  recognized.
• This is due to company policy and the feeling
  that it is an inconvenience.
• Access to critical areas within the aircraft are
  inadequate.
• There has been little or no training provided to
  aircraft crew on how to access areas behind
  electrical or other panels

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Material For Fire Prevention

• Halon (Washington Monthly, Sep 1997 v29 n9
  p44(2))
• Pressurized bottles of Halon a highly effective
  fire fighting agent have long been used in the
  cargo holds of larger jets but is not used in
  smaller planes
• Brings us to the fact that in general the larger
  the vehicle the safer it usually is due to
  greater regulations.
• A Plastic Called PHA (Discover, August 1999 v20
  i8 p11)
• PHA is a plastic which only emits water vapor
  when it burns, and it brakes down into a
  flame-resistant compound.
• There is also the possibility of Flame Retardant
  Material (Class Notes)
• Chlorine and Fluorine when added to material help
  in fire resistance.
• Trade off would be the hazardous smoke this type
  of compound produces when it does burn.
• Flash overs due to electricity arcing burn at a
  searing 1,000 C.

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Crash StatisticsLarger The Vehicle the Safer

• Some airline safety facts (Web Site
  (http//www.air-transport.org/public/speeches/view
  1997.asp?UniqueID38))
• You are more likely to die by being kicked to
  death by a donkey than in a plane crash
• You are more likely to be crushed by a falling
  object
• You are much more likely to be killed by your
  spouse
• You have one chance in about 7 million from dying
  in an plane crash

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Average TimeTo React To A Fire(http//www.nifc.
gov/gallery/manter.html)

• The average time between when an in-flight fire
  is detected and when the aircraft either ditches,
  conducts a forced landing, or crashes is about 17
  minutes. (http//www.tsb.gc.ca/ENG/TSB_Investigati
  ons/Swissair/site_pages/saf/FireRecs_2000dec4.ht)
  
• Some examples

Type Date Minutes
AN-12 1967 lt10
B-707 1973 7
B-747 1987 19
MD-11 1998 20
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Increase Your Chances

• Handy Hints For The Nervous Traveler
  (http//www.amigoingdown.com)
• 70 of incidences in recent year occur on
  take-off or landing
• Try to book non-stop flights
• Take note of where the nearest emergency exit is
• Choose a large aircraft
• The larger the vehicle the better your chances

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Does Fate Alone Decide Who Survives

• Most Likely No
• 71 of the people who die in crashes die after
  the plane comes to a compete stop. (People
  Weekly, Oct 20, 1997 v48 n16 p125(3))
• You can increase your chances by knowing your
  surroundings
• How many isles to the exit
• In case of fire if you can hold your breath for
  30 seconds thats how long it takes to exit the
  aircraft normally.
• Dont try and get your duffel bag in case of a
  crash
• Pay attention to the safety procedures (life
  vests)

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Where To Sit(http//www.aircrash.org/burnelli/)

• If youre worried about impact (People Weekly,
  Oct 20, 1997 v48 n16 p125(3))
• Sit in the back
• If youre worried about a fuel fire
• Sit forward of the leading edge of the wing
• If your worried about the plane breaking up
• Sit by the over-wing exits
• This is the strongest part of the aircraft due to
  the fuel being carried in the wings

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Improved Electrical Apparatus Insulation Material

• One way to improve Wiring in planes is to use an
  improved insulation material
• Currently many electrical wires use porcelain and
  glass insulators
• An ethylene and vinyl acetate copolymer (EVA)
  tested better in the lab these forms of
  insulation (Polymer Engineering and ScienceJul.
  1996, V.S. Ivanov, I.I. Migunova, N.A. Kalinina,
  G.N. Aleksandrov)
• As discussed in class copolymers usually increase
  a materials ability to withstand an impact
• Copolymers would help in wires that would be
  subjected to rough conditions
• Kapton? currently has problems under rough
  conditions

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Radiation-Induced Current (ChemAbsStudent,
Studies on radiation-induced current in
polymeric insulating materials and their fine
sturcture, J. Master. Sci 17 no 10 (1982)3052-6)

• Degradation in crystalline materials such as
  Polyethylene
• Degradation in non-crystalline materials such as
  ethylene-propylene rubber used for wire
  insulation
• For radiation-induced current degradation is
  affected more by the degree of crystallinity than
  its perfection.

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Method For Improving The Environmental
Stress-Crack Resistance or (ESCR) (J. Appl. Poym.
Sci. 16, no 9 (1972) 2375-86)

• (ESCR) is a critical factor in wire insulation
• In studying the effect of rubber on (ESCR) the
  choice of a base resin is important
• Depending on the resin and rubber combination you
  choose the (ESCR) can double or increase by
  50-fold.
• Kapton? could be improved with slight variations
  in its production and perhaps different types of
  resins should be looked at
• For example
• The higher the molecular weight of
  Polyisobutylenes the more effective its
  performance as a stress crack additive

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Polymers Good Insulators

• Polymers are good insulators because they are
  covalently bonded and their electrons are all
  tightly bound.

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Polymers Conductors!?

• Doping of polymers with strong electron acceptors
  such as iodine can cause polymers to conduct
  nearly as well as metals.
• Doping to polyacetylene causes its conductivity
  to be 1010 times higher than pure
  polyacetalylene.
• This flexible electronic circuit functions even
  when its bent.
• http//focus.aps.org/v6/st18.html

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Uses of KAPTON? - Properties

• Maintains its mechanical stability at very high
  and very low temperatures
• resists high mechanical stress during assembly
  operations
• has excellent electrical insulation and thermal
  properties
• has outstanding resistance to most chemicals,
  lubricants and fuels
• allows space and weight savings

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Uses of KAPTON? - Electronics

• In electronic equipment, KAPTON is used as
  substrate material for Flexible Printed Circuits
  and punched, bonded or formed high performance
  part in small miniature switches. It can be
  etched in alkaline solns.
• Bar Code Labels
• Heat Sinks, to ensure optimal heat transfer
  between film and power transistors
• Masking tapes

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Uses of KAPTON? - Bondable Application

• Can be bonded, coated or laminated to allow the
  following requirements
• Belts
• Thermal insulator in irons
• Fuel sensors
• Smoke hoods
• Blood bags

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Uses of KAPTON? - Electronic Insulation

• Wire and cable insulation
• formed coil insulation of traction motors
• Magnet wire insulation
• transformer and capacitor insulation

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Uses of KAPTON? - Automotive

• Alternator heat sink insulator pads
• Air bag (diaphragm)
• Flexible circuits
• Spark plug boot

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Uses of KAPTON? - Aerospace

• Cockpit sun shade
• Speakers
• Flexible Curcuitry
• Acoustic insulation
• Thermal blankets

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Uses of KAPTON? - Thermal Management

• Heat sink
• Power supplies
• Heater circuits
• Copier belts
• Carrier belts
• Coil insulation

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Thermal Degradation Experimental Methods

• Thermogravimetry (TG)-measures loss in weight
• Differential scanning calorimetry (DSC)
• Differential thermal analysis-heat absorption or
  evolution due to either physical or chemical
  changes occurring within the polymer is measured

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Thermal Degradation Reactions

• Depolymerisation Reactions
• Characterized by the breaking of the main polymer
  chain backbone so that at any intermediate stage
  the products are similar to the parent material
  in the sense that the monomer units are still
  distinguishable. The ultimate product may be
  monomer.

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Thermal Degradation Reactions

• Substituent Reactions
• It is the substituents attached to the backbone
  of the polymer molecules which are involved so
  that the chemical nature of the repeat unit is
  changed although the chain structure may remain
  intact.

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Oxidation of Polymers

• Degradation of polymers usually increases in the
  presence of oxygen
• R O2 ? ROO
• ROO RH ? ROOH R
• Termination
• 2R ? R-R
• R ROO ? ROOR
• 2ROO ? ROOR O2

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Photo-degradation

• Wavelengths of light from sun range from infrared
  (gt700nm) to the visible spectrum (400-700nm) to
  ultra-violet (lt400nm).
• Energy of 700nm photon is 170 kJ/mol and energy
  of 300nm photon is 390 kJ/mol
• Strength of C-C and C-H bond are 420 and 340
  kJ/mol respectively
• It is clear that the energies of the UV and
  possibly the visible components of sunlight are
  sufficient to break chemical bonds

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Aircraft Crashes Due to Failure in Wires

• Short examples of Kapton? related crashed in
  aircraft and what is being done to prevent any
  further mishaps

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August 19,1980 Saudi Arabian Airlines Tri-star

• After take off from Riyadh Airport a fire broke
  out in the rear cargo compartment.
• Plane returned to Riyadh as flames broke through
  the cabin floor and filled the cabin with smoke
• Upon investigation Kapton? wires were found burnt
  out, and the insulation destroyed
• Also the wires had fractured ends , a sign of
  arcing, no other source for ignition could be
  found

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January 14, 1985 British Monarch Airline Boeing
757

• On a flight from the Canary Islands to Luton the
  aircraft has a serious wire bundle explosion
• As smoke begins to enter the cabin the pilot is
  able to make a forced landing in Portugal
• An investigation showed that moisture dripped
  onto the wiring below the lavatory and wet arc
  tracking occurred causing the bundle explosion

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November 5, 1990 Philippine Airlines Boeing 737

• Plane is being delayed for take off when
  explosion occurs
• The explosion was in the fuel tank
• After investigation the most probable cause was
  determined to be a spark from a faulty wire
  creating an explosion

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March 17, 1991 Delta Airlines Lockheed Tri-star

• Plane is on way to Atlanta from Frankfurt when a
  fire breaks out
• Aircraft makes an emergency landing in Goose Bay
• Upon an investigation the most probable cause of
  the fire was electrical arcing in the wire bundle

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Some Action Being Taken

• Following a Valujet crash in Florida in 1998 Al
  Gore has headed a special commissin to determine
  the ageing effects on airplane wiring
• Other countries plan on doing a similar thing
• However, the tests will be non-intrusive