# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DdPH4HJA2pT
- **Gondola URL:** https://gondola.cc/posts/70577853-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/8d119a9e7b.jpg
- **Posted:** 2026-09-13T17:44:37.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

A passenger tyre looks like a single black object. It is closer to twenty-five separate components, drawn from roughly two hundred raw materials, assembled cold and then fused into one body under heat and pressure.

It begins in a Banbury internal mixer, patented by Fernley Banbury in 1916. Counter-rotating rotors fold polymer, carbon black, silica, oils and curatives together at 150 to 170 degrees Celsius, and the batch must be dumped before the accelerators wake up and cure the compound inside the machine.

From there the components diverge:
- Steel cord and textile fabric pass through a calender, which forces rubber into the gaps between filaments
- Tread and sidewall are co-extruded, often as four compounds through a single quadruplex head
- Bead wire, high-tensile steel near 2,000 MPa, is wound into hoops that clamp the tyre to the rim

Assembly happens on a building drum and yields a green tyre: right shape, no tread pattern, no strength. Curing supplies both. A bladder inflates inside the carcass and presses it into the mould at roughly 15 bar and 170 degrees Celsius. Sulphur bridges the polymer chains, zinc oxide and stearic acid activate the system, and accelerators such as CBS govern when the reaction starts. Cross-link density sets modulus. Meanwhile the brass plating on the steel cord grows copper sulphide at the interface, bonding metal to rubber chemically rather than mechanically.

Charles Goodyear stumbled into vulcanisation in 1839. John Boyd Dunlop revived the pneumatic tyre in 1888. Michelin filed the radial patent in 1946, splitting casing and tread into two independent structures and roughly doubling tread life.

Every tyre is a chemical reaction with a tread pattern printed on it.

#stemantics #materialsscience #manufacturing #engineering #polymerscience

## Stats

- **Views:** 16,128
- **Likes:** 165
- **Shares:** 0
- **Comments:** 1

## Tags

engineering, materialsscience, manufacturing, stemantics, polymerscience

---
Copyright (c) Gondola