MAKING A RUBBER TIRE

The original catalog description provided by the Ford Motor Company reads as follows: “The rubber tree grows in the wet tropical lands about the equator.” World map showing tropical regions. “The rubber producing region of the world.” Map, shaded areas rubber producing. “Wild rubber forests and cultivated rubber.” Map, wild and cultivated areas labeled. “The raw rubber goes largely to the United States.” Shipping routes marked on map. “Rubber is the latex or sap of a tree growing in the wet tropical region.” Forest - close-up of tapped tree - worker tapping tree, containers attached to tree to catch sap, sap dripping - worker empties container into bucket, replaces it on tree - workers in native costumes carry buckets, pour sap through screen into large vat. “There are many ways of coagulating or thickening the latex. Acetic acid is most commonly used for this purpose.” Coagulated rubber in vat. “Rubber when washed and rolled out into sheets of irregular surface is called crepe rubber. In drying, the maximum surface is exposed to the warm rays of the tropical sun.” Strips of crepe rubber hanging - workers sitting on ground fold crepe rubber. “The raw rubber comes to the factory in mats and biscuits.” Workers unpacking rubber from cartons. “These mats are of cultivated rubber from the Island of Ceylon.” Worker displays rubber. “The crude rubber is squeezed between rollers to force out the dirt and impurities.” Worker rolling rubber on spool - cuts it off. “After washing, it is dried in vats of high temperature.” Rubber on dolly is moved into dryer. “The raw rubber is mixed with zinc, sulphur and lamp black to give it color and strength.” Workers place ingredients in vat - worker places rubber on roller - cuts it off, puts it back on. Worker adds ingredients to rubber on roller, cuts it off. “To start an inner tube a thin sheet of rubber is rolled about a metal cylinder.” Workers tending machinery. “The tubes are vulcanized at a temperature of over 300°F.” Workers remove tubes from vulcanizer. “When removed from the vulcanizer the tubes are like rubber hose.” “The ends are joined.” “Each tube is air tested.” Tube is blown up. “The cotton for the casing is grown in Arizona.” Cotton field. “The cotton fiber is tested for flaws, thickness and durability.” Worker with cotton cloth on rollers. “The fabric is placed in a heavy press and the rubber forced into the cotton.” Press in operation. “The rubberized cotton is cut into strips by machine and hand.” Workers operating cutting machinery. “Building a casing by machinery.” Worker places rubberized fabric on turning wheel. “Each layer is pressed into place.” “Inside of the mold is the tread design.” Workers lowering casing into mold. “The casing is shaped in a metal mold.” “The upper half of the mold is placed over the casing.” “A hydraulic press stamps the molds together, forming the tread design.” Molds come off conveyor belt - molds in press - press in operation. “The casings in the mold go to a vulcanizer for heating.” “Removing the vulcanized casing.” “After final inspection and cleaning, the tire is ready for market.” Workers remove pieces of mold from inside tires - trucks on steep, rutted road. “End.” “Ford Educational Library.” [1921]