All rubber is black right?

By DKL Rubber
schedule28th Jan 20

Rubber is naturally black right??

Wrong! People are under the impression that rubber is naturally black when in fact it starts life white and comes from a tree called Heava Brasiliensis ( Ficus elastica )

To ensure the trees grow it requires

250cm of rain evenly spread throughout the year without any dry spells.

Temperatures of 20 to 34 degrees (68 to 93 Fahrenheit)

Humidity of 80%

2000 hrs of sunshine per year

No strong winds.

The trees are normally grown in the south and southeast Asia. It reproduces by the fruit on the tree bursting open and spreading it seeds up to 100 feet from the tree.

The tappers come first thing in the morning when the tree pressure is at its highest, they gently tap the tree. The tree then realises a milky white substance called Latex, which the tree will only start producing when its around 6 years old. A good tapper can tap a tree every 20 secs and can do 450-650 trees a day!

Coconuts are tied to the tree supported by a wire which grows with the tree to catch the latex in. Each tree drips latex for up to 4 hours a day. In order to prevent the sap from solidifying, ammonia is added. Acid is then added to the mix to extract the rubber, in a process called coagulation. This can take about 12 hours.

The mixture is then passed through rollers to remove excess water. Once this is complete, the layers of rubber are hung over racks in smokehouses or are left to air dry. Several days later they will then be folded into bales ready for processing.

So how does it become Black?

Once the natural rubber is formed it is then shipped all over the world to compounders which then add various chemicals such as carbon black. This isn’t just for cosmetic reasons, but because adding chemicals like carbon black to the rubber drastically increases desirable qualities of the rubber.

There are various colours of rubber, you could get any colour you want if there is a pigment to add to the natural rubber then the colour is yours. It doesn’t just have to be black.