कला
सुन्दरता र कल्याण
हस्तकला
संस्कृति र इतिहास
मनोरञ्जन
वातावरण
खाना र पेय
रिभर्स इन्जिनियरिङ
विज्ञान
खेलकुद
प्रविधि
पहिर्न मिल्ने
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.
शुरुआती
3 hours
निर्देशनहरू
1
1
The rig
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.
2
2
Cut base and ramp
Cut base and ramp
From 18 mm plywood saw two boards 400 x 120 mm. Sand the edges.
यस चरणका सामग्री:
प्लाइउडको पाता1 टुक्राचाहिने औजार:
हाते आरा
फलामे रुल
सी-आकारको क्ल्याम्प3
3
Hinge them
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.
यस चरणका सामग्री:
ढोकाको कब्जा1 टुक्रा
काठका पेच4 टुक्राचाहिने औजार:
तारविनाको ड्रिल
बाकसमा ड्रिल बिटको सेट
स्क्रुड्राइभर सेट4
4
Fit the steel counterface
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.
यस चरणका सामग्री:
नरम इस्पातको पाता1 टुक्रा
दोहोरो टेप1 रोल
आइसोप्रोपाइल अल्कोहल ९९ %10 मिलिचाहिने औजार:
सफा सुरक्षा चस्मा5
5
Make four sleds
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.
यस चरणका सामग्री:
PTFE पाता1 टुक्रा
नाइलन पाता (6/6)1 टुक्रा
एक्रिलिक पाता1 टुक्रानरम इस्पातको पाता1 टुक्रादोहोरो टेप1 रोलचाहिने औजार:
हाते आरा
काम चलाउने चक्कु6
6
Tilt until it goes
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.
चाहिने औजार:
कोणमापकफलामे रुल7
7
Load it
Load it
Repeat the PTFE sled with a weight taped on top. The angle should not change.
चाहिने औजार:
बोझकोणमापक8
8
Angles into friction
Angles into friction
Jupyter नोटबुक लोड हुँदैछ…
9
9
History & Context
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.
सामग्री
9- 1 टुक्राप्लेसहोल्डर
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- 10 मिलिप्लेसहोल्डर
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आवश्यक उपकरणहरू
10- प्लेसहोल्डर
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- 1 vendor sell this, none ship to you yetप्लेसहोल्डर
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डिजाइन फाइलहरू
1सम्बन्धित ब्लुप्रिन्ट
यी ब्लुप्रिन्टहरूले ज्ञान साझा गर्छन् — प्रविधि, सामग्री वा सिद्धान्त
CC0 सार्वजनिक डोमेन
यो ब्लुप्रिन्ट CC0 अन्तर्गत जारी गरिएको छ। तपाईं अनुमति नसोधी प्रतिलिपि, परिमार्जन, वितरण र प्रयोग गर्न सक्नुहुन्छ।
ब्लुप्रिन्ट मार्फत उत्पादनहरू किनेर सिर्जनाकर्तालाई सहयोग गर्नुहोस् सिर्जनाकर्ता कमिसन विक्रेताले तोकेको, वा यो ब्लुप्रिन्टको नयाँ संस्करण बनाउनुहोस् र आम्दानी बाँड्न आफ्नो ब्लुप्रिन्टमा जडानको रूपमा समावेश गर्नुहोस्।