How your Rubber Boots are Made
The production of vulcanised rubber boots started in the mid nineteenth century and many of the production steps are unchanged since that time....and its all a bit like making pastry!
The natural rubber comes from the plantations in Vietnam where it is tapped straight from the tree. It arrives at the factory in its raw state in big brown blocks, it looks like crepe rubber at this stage.
The raw rubber is put through a series of "milling" machines that work the rubber to remove all the lumps and disperse the other materials that amongst other things add colour and flexibility.... and then, just like making pastry, the rubber is rolled out into thin sheets ready for cutting. If the boot is made up of more than one colour then the factory has to first of all produce sheets of all the different colours....and so manufacturing for Poddy & Black has the added complexity of getting all our colours right!
The sheets are cut by hand using a metal cutting tool ( imagine a giant pastry cutter) that has the shape of the boot or style being made . Every single piece is inspected before it is used and all off-cuts or rejects go back to the start of the process to be re-used - almost nothing is wasted!
To assemble the boot first of all the cotton lining is sewn into a boot shaped sock and this is pulled onto the metal last. Poddy & Black is unusual in choosing cotton for the lining as there are cheaper options, but we wanted both the softness and comfort of cotton and also decided that using a recycled natural material was better for the environment than using an oil based textile.
Then the pre-cut raw rubber pieces are laid by hand onto the covered last. It is highly skilled work and care must be taken to position the pieces in exactly the right spot, make sure there are no unwanted bumps as the layers are built up, and above all else ensure there are no gaps between the pieces or at the joins as this would cause a leak in the finished product.
Meanwhile in another part of the factory the soles are being made. Carefully weighed pieces of raw rubber are laid into metal moulds that are made according to the design of the sole, the mould is then slipped into a heated press allowing the rubber to melt and take shape. These partially cooked soles are attached to the upper which has been made on the foot shaped last.
After checking everything is ok the boots on the metal lasts are loaded onto a metal trolley and rolled into the oven ( known as an autoclave) where they are "cooked" for about 35 mins reaching 170 degrees Celcius. This is ofcourse the reason why the lasts and the racks are all metal.
Finally the boots are cleaned, trimmed of any surplus rubber, slipped off the metal last and checked for quality - this includes immersion in a watertank to see if any air escapes as they must ofcourse be waterproof!
And now the boots are ready waiting to be packed into our lovely recycled cardboard shoe boxes and sent by ship to the UK!