Gummi is a collective name for rubber (caoutchouc in French) and related elastic fabrics.
Tube is perfectly usable as elastic, luggage strap or seal.

rubberboomIt is made of latex, the sap of e.g. the Brazilian rubber tree (Hevea brasiliensis), Indian rubber tree (Ficus elastica), Russian dandelion (Taraxacum kok - saghyz).
The milky sap is recovered by half spiral grooves (at an angle of 25 to 30° in the smooth bark of the rubber tree. Every 1 or 2 days, the coagulated latex is removed and a new incisions above or below the old are made​​.
After tapping full recovering for the bark takes 7 to 8 years and then can be tapped again.
The harvest is with some water and (formic) acid cooked to clump the rubber, turned in carpets and hung to dry.

Rubber is a polymer which occurs in latex. Approximately 33% of the juice is made of rubber.
The name comes from the English word for rubbing (with a (pencil) eraser), to rub.

With dandelions foresaw Russia in 1930-1940 to 30 percent in the demand for rubber.
Mining and small-scale production is not economical, maybe not possible? The content and quality of the rubber does not match that of the rubber tree (yet).

Vulcanization is the process whereby people, usually with latex – make more linkages between different monomer chains.
By the addition of oxygen and sulfur, both of which have two electrons deficit, one can create bridges between two chains of latex monomer which have a double bond -free.

These cross- links make liquid latex stiffer and more brittle. Different concentrations of sulfur give different types of rubber: very elastic (low sulfur), to car tires by 3 to 5% sulfur, and hard rubber (bats, etc.) with about 40% sulfur.

In the same way oxygen causes the aging process of (car) tire it causes that tires wear. This process is accelerated by UV - radiation.

(One way or another, it must be able to make textile waterproof with the juice of dandelions??)

The Fraunhofer Institute for Molecular Biology and Applied Ecology (Germany) has launched since 10/2013 an optimized cultivation in collaboration with Continental to produce dandelion rubber for tires in Europe. http://www.sciencedaily.com/releases/2013/10/131028114547.htm

 

If we made enough condoms for Africa there were insufficient tires for Europe. (to Peter Cook)
Elastic: that with which Rudolf Hess hanged himself, and died of a skull fracture. (Tom Lanoye)