Here is a concise summary of the provided text:
**Title:** How Tires are Made
**Overview:**
* Millions of vehicles consume over 250 million tires yearly, relying on natural rubber as the main raw material.
* Natural rubber is sourced from latex in rubber trees, extracted through careful bark tapping to avoid harming the tree.
**Manufacturing Process:**
1. **Raw Material Preparation:**
* Latex is collected, coagulated, and transformed into solid rubber sheets.
* Sheets are heated and dried for 3 days.
2. **Tire Assembly:**
* Rubber is mixed with various components (e.g., synthetic rubber, steel, sulfur) to enhance durability.
* Layers are built up using a tire forming machine, including:
+ Inner liner (tire casing)
+ Ply with steel threads
+ Rubber-coated steel belts
+ Tread with specific rubber formulations
3. **Final Shaping:**
* Vulcanization: Tire is molded under high temperature (180°C) and pressure to transfer tread pattern and strengthen rubber.
* Excess rubber is removed, and the tire undergoes final inspections before being rolled out.
**Key Stats:**
* Over 250 million tires produced annually
* 10-15 different components used in modern tire manufacturing
* India is one of the largest natural rubber producers worldwide
Here are the key facts extracted from the text, numbered and in short sentences:
**History and General Facts**
1. The wheel has been in use for thousands of years.
2. Rubber was first used to cover wooden/steel wheels in the 18th century.
3. Charles Goodyear (note: text incorrectly mentions "Charles Charles" and "Kutcher") discovered vulcanization in 1839.
4. Over 250 million tires are manufactured every year.
5. India is one of the largest producers of natural rubber in the world.
**Natural Rubber Production**
6. Natural rubber comes from the latex of rubber trees.
7. Latex is a milky liquid composed of rubber and water molecules.
8. Latex is extracted by careful cutting of the tree's bark to avoid damaging it.
9. Fresh latex is mixed with ammonia to prevent coagulation.
10. Latex is processed into solid rubber through a 10-hour pressing process.
**Tire Manufacturing**
11. Natural rubber is too elastic to be used alone in tire manufacturing; it must be hardened and mixed with other components.
12. A modern tire consists of 10-15 different components, including natural/synthetic rubber, chemicals, steel, and textiles.
13. These components are mixed under heat and pressure in giant mixers.
14. The tire manufacturing process involves multiple layers, including the inner liner, ply, steel belts, and rubber tread.
15. Vulcanization (heating under pressure) transforms the rubber into a stronger, more elastic material.
**Specific Manufacturing Steps**
16. Rubber sheets are heated for three days to dry out excess moisture.
17. The tire carcass is built using a rotating drum with multiple layers.
18. Steel cables are wound to create the bead (rim-attachment part).
19. Rubber tread is applied using a computerized system with graduated tension.
20. The final tire shape is achieved through a vulcanization process at 180°C.
**Quality Control and Completion**
21. Finished tires undergo final inspections to confirm uniform shape and geometry.
22. Tires are then ready for use, completing the journey from tree to wheel.