1443: "Carbon Fiber"

HistoryPodcastScience
Written By JC

Interesting Things with JC #1443: "Carbon Fiber" – Metal was strong but heavy. Plastic was light but weak. Carbon found the space between...threads thin as hair, strong enough to reshape flight. From Edison’s glow to hypersonic shells, the lightest answers carried the most force. Episode inspired by Dr. Igo.

Curriculum - Episode Anchor

Episode Title
Interesting Things with JC #1443: "Carbon Fiber"

Episode Number
1443

Host: JC
JC

Audience: Grades 9–12, college intro, homeschool, lifelong learners
Grades 9–12, introductory college, homeschool, and lifelong learners

Subject Area
Materials Science, Physics, Engineering History, Technology & Society

Lesson Overview

3–4 measurable learning objectives using action verbs:

  • Define carbon fiber, carbon-fiber-reinforced polymer (CFRP), and key production steps (e.g., PAN precursor, carbonization).

  • Compare the strength-to-weight tradeoffs of carbon fiber versus metals and plastics using episode examples.

  • Analyze the historical development from early carbon filaments (Swan/Edison) to modern aerospace composites (F/A-18, Space Shuttle, 787).

  • Explain why cost and manufacturing constraints limit carbon fiber’s use in everyday products today.

Key Vocabulary

  • Carbon fiber (KAR-bən FY-ber) — A material made of long, thin strands of carbon atoms bonded in aligned crystals; when used in a sentence: “Bonded with epoxy, carbon fiber forms CFRP that is light and strong.”

  • Polyacrylonitrile, PAN (pol-ee-uh-CRY-loh-NYE-tril) — A polymer precursor heated to remove non-carbon elements, leaving aligned carbon crystals; “RAE scientists heated PAN to create high-strength fibers.”

  • Tensile strength (TEN-sil STRAYNGTH) — The maximum pulling (tension) force a material can withstand before it breaks; “Carbon fiber’s tensile strength can surpass steel at a fraction of the weight.”

  • Epoxy (ih-POK-see) — A thermoset resin used as the binder (matrix) to hold fibers together in a composite; “Epoxy bonds carbon fibers into rigid CFRP laminates.”

  • Fatigue (fuh-TEEG) — Weakening of a material due to repeated stress cycles; “CFRP resists fatigue better than many metals in aerospace structures.”

  • Composite (kum-PAH-zit) — A material made by combining two or more constituents (e.g., carbon fibers + epoxy) to achieve superior properties; “The 787 uses a composite airframe to reduce weight.”

  • Reinforced carbon–carbon, RCC (AR-SEE-SEE) — A high-temperature composite used on spacecraft surfaces; “The Space Shuttle used RCC on wing leading edges.”

Narrative Core

  • Open
    Engineers faced a persistent problem: metals were strong but heavy, plastics were light but weak.

  • Info
    Early carbon filaments appeared in the 1860s (Swan) and were later improved by Edison with bamboo carbonized at high temperatures, but these filaments were brittle and the idea lay dormant.

  • Details
    In 1958, Roger Bacon discovered carbon whiskers, and RAE Farnborough refined PAN-based carbon fibers with extraordinary tensile strength. Bonded with epoxy, these fibers formed CFRP—light as plastic, strong as steel—transforming aerospace by the 1980s and beyond (F/A-18, Space Shuttle, Boeing 787 at ~half composite by weight, with notable fuel savings).

  • Reflection
    Costs still limit everyday use, but recycling, wood-based precursors, and nanostructured designs show progress. The same element that once glowed in bulbs now holds together hypersonic machines.

  • Closing
    These are interesting things, with JC.

A close-up image of woven black carbon fiber with a glossy, reflective surface, showing its diagonal weave pattern beneath bold white text that reads “Interesting Things with JC #1443: Carbon Fiber.”

Transcript

It began with a problem every engineer knew too well. Metals were strong but heavy. Plastics were light but weak. Somewhere between them had to be something better.

The answer came from the element at the center of all living things…carbon.

The story starts in 1860 with English physicist Joseph Swan, who burned cotton thread into one of the first carbon filaments for a light bulb. Thomas Edison later improved the idea with bamboo fibers heated to 2,700 degrees Fahrenheit (1,482 degrees Celsius). They worked, but they were brittle. The idea slept for almost eighty years.

Then, in 1958, Dr. Roger Bacon at Union Carbide discovered carbon whiskers — microscopic crystals formed between graphite electrodes. Each was thinner than a human hair yet five times stronger than steel. Across the Atlantic, scientists at the Royal Aircraft Establishment in Farnborough (FAHR-nuh-bur-uh) built on the same idea, heating a polymer called polyacrylonitrile, or PAN, through stages that burned away everything but carbon. What remained were long, perfectly aligned crystals with extraordinary tensile strength.

Bonded together with epoxy, those threads became something entirely new: carbon-fiber-reinforced polymer…light as plastic, strong as steel.

By the early 1980s, aircraft like the McDonnell Douglas F-18 Hornet and NASA’s Space Shuttle used it in their structures. Today, more than half the Boeing 787 Dreamliner’s frame — about 52 percent by weight — is carbon fiber. That shift cut more than 20,000 pounds (9,072 kilograms) from the aircraft and improved fuel efficiency by nearly 20 percent.

But carbon fiber still carries a cost. Industrial grades sell for about five to eight dollars a pound ($11 to $18 per kilogram), while aerospace-grade fiber can reach twenty-five dollars a pound ($55 per kilogram). Aluminum, by contrast, is closer to a dollar per pound ($2.20 per kilogram). That’s why carbon fiber fills airplanes, race cars, and satellites — not everyday cars or bridges, at least not yet.

A single ribbon of the material, no thicker than sewing thread, can support the weight of a grown man. It resists fatigue, holds its shape, and survives stresses that make metals fail.

Even now, scientists are finding ways to recycle and improve it — using wood-based precursors and nanostructured designs. The same carbon that once glowed in Edison’s bulb now holds together machines that travel five times the speed of sound.

From soot to spacecraft, carbon fiber is proof that the lightest answers often come from what’s been with us all along.

These are interesting things, with JC.

Student Worksheet

  1. Define CFRP and identify its two main components.

  2. Summarize how PAN becomes carbon fiber in two to three steps.

  3. Compare carbon fiber to aluminum using two properties from the episode (e.g., weight and fatigue resistance).

  4. Identify two aerospace applications mentioned and explain why CFRP was advantageous for each.

  5. Creative prompt: Sketch (or outline) a non-aerospace product that could benefit from CFRP; label the properties that make CFRP suitable and note one barrier to adoption.

Teacher Guide

  • Estimated Time
    45–60 minutes (15 min direct instruction, 15 min guided analysis, 15–30 min discussion/worksheet).

  • Pre-Teaching Vocabulary Strategy
    Frayer models for “composite,” “tensile strength,” and “PAN”; quick demo with two rulers (wood vs. metal) discussing stiffness vs. weight before introducing CFRP.

  • Anticipated Misconceptions

    • “Carbon fiber is always better” — clarify tradeoffs: cost, repairability, manufacturing complexity.

    • “Carbon fiber is a plastic” — clarify: carbon fibers + polymer matrix (epoxy) = composite.

    • “Early carbon filaments = modern carbon fiber” — distinguish incandescent filaments from structural fibers.

  • Discussion Prompts

    • What engineering constraints drove the shift from metals to composites?

    • How did historical discoveries (Swan/Edison/Bacon/RAE) stack to enable modern CFRP?

    • Where might lifecycle benefits (fuel savings, durability) offset high upfront material costs?

  • Differentiation Strategies: ESL, IEP, gifted

    • ESL: Provide a bilingual glossary; use images of fiber, weave, layup; sentence starters for compare/contrast.

    • IEP: Chunk the timeline; allow oral responses; guided notes with icons for “material,” “process,” “application.”

    • Gifted: Mini-research on lignin/wood-based precursors or RCC on spacecraft; propose a cost model variable that most affects adoption.

  • Extension Activities

    • Hands-on: Test strips of different materials (paper, plastic, aluminum foil, cardboard) for mass and breaking load using a simple setup; discuss specific strength qualitatively.

    • Design challenge: Create a laminate schedule for a hypothetical UAV wing (qualitative), justifying fiber orientation and matrix choice.

    • Research: Explore recycling routes (pyrolysis, solvolysis) and present pros/cons.

  • Cross-Curricular Connections

    • Physics: Stress/strain, modulus, specific strength.

    • Chemistry: Polymer chemistry, carbonization/graphitization.

    • History of Technology: Invention timelines, research institutions (Union Carbide, RAE).

    • Economics/CTE: Cost curves, manufacturing yield, qualification/certification in aerospace.

Quiz

Q1. Which early inventor first demonstrated a carbon filament light bulb in the 1860s?
A. Humphry Davy
B. Joseph Swan
C. Nikola Tesla
D. Michael Faraday
Answer: B

Q2. What polymer precursor did RAE scientists heat to create high-strength carbon fibers?
A. PVC
B. PET
C. PAN (polyacrylonitrile)
D. PTFE
Answer: C

Q3. In CFRP, carbon fibers primarily provide:
A. Toughness only
B. Aesthetic texture
C. Strength and stiffness
D. Electrical insulation
Answer: C

Q4. Approximately what fraction of the Boeing 787’s structure is carbon fiber/composites by weight (as cited in the episode)?
A. ~10%
B. ~25%
C. ~50%+
D. ~75%
Answer: C

Q5. Which factor most limits everyday use of carbon fiber today?
A. Lack of strength
B. High material and processing costs
C. Inability to bond with resins
D. Safety regulations banning composites
Answer: B

Assessment

  • Open-Ended Questions

    1. Trace the pathway from Edison’s carbonized bamboo filaments to Bacon’s carbon whiskers and RAE’s PAN fibers. How did each step solve a different engineering problem?

    2. Make an argument for or against using CFRP in mass-market automobiles. Use at least three evidence points (properties, cost, manufacturing, lifecycle).

  • 3–2–1 Rubric

    • 3 = Accurate, complete, thoughtful — Uses precise vocabulary; evidence from episode; clear reasoning with tradeoffs.

    • 2 = Partial or missing detail — Some correct facts and terms; limited evidence; reasoning needs support.

    • 1 = Inaccurate or vague — Misuses terms; lacks evidence; does not address tradeoffs.

Standards Alignment

  • NGSS (High School) – Physical Science/Engineering

    • HS-PS2-1 — Use mathematical and conceptual models of forces to compare material responses (specific strength of CFRP vs. metals).

    • HS-PS3-3 — Design strategies to minimize energy transfer (connect to aircraft fuel efficiency and lightweighting).

    • HS-ETS1-2 — Design problem-solving with criteria/constraints (optimize weight, strength, cost in material choice).

    • HS-PS1-3 — Plan an investigation to gather evidence of chemical processes (oxidation/carbonization of PAN into carbon fiber).

  • Common Core ELA/Literacy in Science & Technical Subjects (Grades 9–12)

    • CCSS.ELA-LITERACY.RST.11-12.1 — Cite specific textual evidence from the episode to support analysis of historical/technical developments.

    • CCSS.ELA-LITERACY.RST.11-12.7 — Integrate multiple sources (episode + references) to evaluate technological claims (weight savings, fuel efficiency).

    • CCSS.ELA-LITERACY.WHST.9-12.2 — Write explanatory texts about processes (PAN to carbon fiber).

  • C3 Framework (Social Studies – Technology & Society)

    • D2.Eco.1.9-12 — Analyze how scarcity and incentives (material cost, certification) influence choices.

    • D2.His.14.9-12 — Analyze multiple factors that influenced perspectives (inventors, labs, agencies in carbon fiber history).

  • ISTE Standards for Students

    • 1.3 Knowledge Constructor — Curate sources to deepen understanding of CFRP’s benefits and limits.

    • 1.4 Innovative Designer — Generate solutions considering constraints (design prompt on CFRP applications).

  • CTE (STEM/Manufacturing)

    • Manufacturing Production Process Development (MPPD) 4.0 — Apply materials/process knowledge to optimize production (fiber yield, curing).

    • STEM 11 — Apply engineering design to develop and test solutions under constraints (materials selection).

  • International Equivalents (for reference)

    • UK GCSE Physics (AQA 4.2.2/4.2.4, Properties of materials & Forces) — Relates to stress/strain and material choices in engineering.

    • IB DP Physics (Topic 10/Materials) — Mechanical properties and composite materials in applied contexts.

    • Cambridge IGCSE Physics (0625, Section 3: General physics – forces and material properties) — Elasticity, stress/strain, and material performance.

Show Notes

Carbon fiber’s story links 19th-century incandescent filaments to 20th-century breakthroughs in carbon whiskers and PAN-based fibers, culminating in modern aerospace composites that trade mass for performance. In class, this episode anchors discussions of specific strength, fatigue resistance, and how manufacturing cost and certification shape real-world adoption. Historical milestones (Swan, Edison, Bacon, RAE) pair with current aerospace examples (F/A-18, Space Shuttle RCC, Boeing 787) to illustrate why CFRP matters today: it enables lighter structures and fuel savings, yet still faces cost and scale challenges.

References

JC https://jimconnors.org
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