Rubber is not a native tree to Thailand and it was after a visit to Malaysia that Phraya Ratsadanuprdit first thought of introducing the tree to Thailand. In 1901 Phra Sathon Sathanphitak went to Indonesia returning with 4 wooden boxes of seedlings that were planted in front of his house in Trang. Phraya Ratsadanupradit sent Government Officials to study the process of growing rubber assigning them to teach and support the growth of rubber in Thailand. The rubber industry was soon to become one of Thailand's most significant crops, and Phraya Ratsadanupradit become known as 'The Father of Rubber'
Read more: http://www.rubber.co.th/web/history_en.php
Para rubber trees (Hevea Brasiliensis) originated from the Amazon Rainforest in Brasil, the name Para derives from Brazil's second largest state. The Royal Botanical Gardens in Kew, England managed to cultivate some seedlings which were sent to Ceylon and Singapore in 1876. Over the following years rubber plantations spread over Southeast Asia.
Thanks to http://en.wikipedia.org/wiki/Hevea_brasiliensis
Despite the growth of tourism and the development of commercial Phuket there are still many plantations, especially in the Thalang area. Seedlings are planted together with pineapple to provide an income over the first few years before rubber latex can be collected.
Liquid rubber is tapped from the trees be cutting a groove in the bark, the latex rubber drips into a small coconut shell and these 'cups' of rubber are then processed into rubber sheets before being sold. If you want to see how rubber is processed try visiting a rubber plantation, they usually tap the rubber very early in the morning, or book up on a tour that offers this as part of their schedule.