A summary of natural rubber production:
You will notice in the picture that they only cut the bark for 1/2 the circumference of the tree. When they are done with one half (~5 years), they start tapping the other half while the first regrows. The actual tapping is done over something like a meter high section of the tree, always at an incline (it looks like 30 degrees). They send workers to collect the sap every day, and cut a new strip every two days, for the entire lifetime of the tree (apparently like 20 years). Rubber trees live exclusively in the tropics so it is year-round. Also the tapping panel (the missing bark) is always a certain height above ground, a little more than one meter, and the depth of the cut is also constant (if you cut too deep the bark will not regrow). The actual latex is not exactly extracted, but it is pushed out by internal pressure as a liquid which drips down that slant into the collection cup.
The liquid latex is transported to a nearby processing facility before coagulating, where it is poured into molds and treated with formic acid. The resulting block of solid latex is rolled out into rubber sheets, which are then piled into cubes, boxed, and shipped to whoever wants it.
A lot of rubber we are familiar with is further processed by vulcanization, which is what Goodyear (as in Goodyear tires) is famous for. It is just charring rubber which is treated with sulfur, resulting in hard rubber such as the rubber on electric plugs or tires.
Learn more:
http://ecoport.org/ep?SearchType=…&earticleId=644
https://en.wikipedia.org/wiki/Rubber_tapping