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PTFE (Polytetrafluoroethylene)
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Martin

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Martin

22. september 2026NO
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PTFE (Polytetrafluoroethylene)

On 6. April 1938 Roy Plunkett at DuPont opened the valve on a cylinder of tetrafluoroethylene gas, a candidate refrigerant, and nothing came out - though the cylinder still weighed full. Sawn open, it held a white waxy powder: the gas had polymerised by itself. The powder resisted every solvent and acid tried on it, did not melt like other plastics, and almost nothing would stick to it. **US 2,230,654**, "Tetrafluoroethylene polymers", Plunkett, assigned to Kinetic Chemicals, granted 4. February 1941. Its first claim is two words: "Polymerized tetrafluoroethylene." **Tetrafluoroethylene is explosive and is never handled outside a plant.** You build what the material is for: a hinged tilting ramp that measures the coefficient of friction of PTFE against steel, beside nylon, acrylic and steel itself.
Byrjandi
3 hours

Leiðbeiningar

1

The rig

The whole rig: a 400 mm base, a hinged ramp with a steel strip on top, a prop under the raised end, and a faced sled.
HönnunarskráBLENDCC0 - Free
Sækja líkan
2

Cut base and ramp

From 18 mm plywood saw two boards 400 x 120 mm. Sand the edges.

Efni fyrir þetta skref:

KrossviðarplataKrossviðarplata1 stykki

Nauðsynleg verkfæri:

HandsögHandsög
StálreglustikaStálreglustika
C-þvingaC-þvinga
3

Hinge them

Lay the boards end to end and fit the butt hinge across one short joint with 4 wood screws, pilot-drilled 2 mm. The ramp must lift from flat to 45° without rocking.

Efni fyrir þetta skref:

HurðarlömHurðarlöm1 stykki
TréskrúfurTréskrúfur4 stykki

Nauðsynleg verkfæri:

HleðsluborHleðslubor
Borasett í kassaBorasett í kassa
SkrúfjárnasettSkrúfjárnasett
4

Fit the steel counterface

Stick a 360 x 100 mm strip of mild steel sheet to the ramp's top face with double-sided tape. Wipe it with isopropyl alcohol - grease halves any reading.

Efni fyrir þetta skref:

Plata úr mjúku stáliPlata úr mjúku stáli1 stykki
Tvöfalt límbandTvöfalt límband1 rúlla
Ísóprópanól 99 %Ísóprópanól 99 %10 ml

Nauðsynleg verkfæri:

Tær öryggisglerauguTær öryggisgleraugu
5

Make four sleds

Saw four 60 x 60 mm plywood blocks. Face one each with PTFE, nylon, acrylic and steel cut to 60 x 60 mm, fixed with double-sided tape. Clean every face with alcohol.

Efni fyrir þetta skref:

PTFE-plataPTFE-plata1 stykki
Nælonplata (6/6)Nælonplata (6/6)1 stykki
AkrýlplataAkrýlplata1 stykki
Plata úr mjúku stáliPlata úr mjúku stáli1 stykki
Tvöfalt límbandTvöfalt límband1 rúlla

Nauðsynleg verkfæri:

HandsögHandsög
DúkahnífurDúkahnífur
6

Tilt until it goes

Set a sled 100 mm from the top. Raise the ramp slowly, about 1° per second. Stop the instant it slides and read the angle finder on the ramp. Five tries per sled.

Nauðsynleg verkfæri:

Gráðubogi / hornmælirGráðubogi / hornmælir
StálreglustikaStálreglustika
7

Load it

Repeat the PTFE sled with a weight taped on top. The angle should not change.

Nauðsynleg verkfæri:

LóðLóð
Gráðubogi / hornmælirGráðubogi / hornmælir
8

Angles into friction

Hleð Jupyter-vinnubók…
9

History & Context

**What the patent specifies:** the polymer of tetrafluoroethylene itself, a solid insoluble in ordinary solvents. **Modern build (derived):** machined PTFE sheet against clean mild steel on a tilting plane. Its first large use was seals and gaskets for the Manhattan Project's uranium hexafluoride plant, a gas that attacked everything else. DuPont registered Teflon in 1945; non-stick pans followed in the 1950s, and stretched PTFE became Gore-Tex. Its limits: it creeps under steady load, wears quickly without fillers, cannot be glued without etching, and above about 260 °C in use it begins to give off harmful fumes.

Efni

9

Nauðsynleg verkfæri

10

Hönnunarskrár

1

Tengd Blueprint

Þessi blueprint deila þekkingu — tækni, efni eða meginreglur

High-Pressure Polyethylene

High-Pressure Polyethylene

eftir KarenSE

Plastgerð

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Nylon — The First Fully Synthetic Fiber from Coal, Air, and Water

Nylon — The First Fully Synthetic Fiber from Coal, Air, and Water

eftir TexFO

Textíll og leður

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CC0 opinbert ríki

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Studdu smiðinn með því að kaupa vörur í gegnum teikningu hans þar sem hann fær þóknun smiða sem seljendur ákvarða, eða búðu til nýja endurskoðun á þessari teikningu og tengdu hana sem tengingu í þinni eigin teikningu til að deila tekjum.

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