I was very fortunate to have worked in an industry which produced products of rubber. I doubt that very many folks are aware of the amazing aspects surrounding obtaining, or synthetically producing, rubber to turn into useful product. In the first video, look for the guy pulling freshly-mixed rubber compound out of the Banbury Mixer, where the weird-shaped lobed mixer parts are revolving. Exceedingly strongly-built, such mixing of raw rubber (not yet vulcanized) requires unimaginably great force. Below, the light-brown rubber being formed into sheet is actually natural rubber, obtained from rubber trees! It is good for general use, but not things like tires, or applications experiencing presence of oils or lubricants; modern, synthetic rubbers of various kinds have for such applications replaced it. A short take on the final work done to produce truck tires. Clearly, products as large as tires require huge, powerful, energy-guzzling machines to make them. Think tires are too costly? Small parts are of course commonplace, too. It should be mentioned that the final part of almost any rubber part-making involves vulcanization, a process which "fixes" the rubber mechanically and chemically, leaving it with the desired usable properties. Vulcanization is done typically at pretty high temperatures, perhaps 350 degrees F or more. It is HOT in rubber factories! Chemical additives add dusts to the air, adding environmental control concerns, and some of the needed stuff in rubber is fairly toxic. As my old supervisor at Victor sealing Products said, "Rubber is MAGIC. You can make it move in a mold to conform, often it will refuse leaving unfilled crevices, "cure" sometimes fails, color is off, the true "troubleshooters" in the industry command top dollar." Frank
Thanks, @Frank Sanoica. My father worked in a tire factory from 1944-1974, building what they called giant tires, like those used for road-building equipment. I think he said his job was "applying treads." Wish I could find a video of someone doing that before all the modern machinery. Most videos are of passenger tires. I remember him talking about when they went to steel belted radials, but not for the larger tires. There was one test mile of rubber road in my home town in front of the Goodyear Factory. I don't think it ever got potholes.