Article#200920: Making of “Rubber” Shoes, Part 3: Water Transfer
This is the part 3 of Making of Rubber Shoes articles. In part 1 of Making of Rubber Shoes: Moulds and part 2 of Making of Rubber Shoes: Injection I explain toolings and process of making rubber alike shoes. One of the most interesting, fun and practical part of utilizing injection method of making shoes is the various of color options provided through injection. However, sometime brands just need to add a layer of additional design interest onto various of color options. Here, I am introducing the next step of styling rubber alike shoes with graphic applications.
This process of applying graphic sheets onto a rubber alike shoe is very much like applying temporary tattoos onto a surface of a body. Once The tattoo art is positioned, then layer of paper is peeled off.
There are 2 methods applying graphics onto a “rubber” shoe. Graphic applications are either transferred in a tank of water or in a vacuum thermal machine.
Water Based Transfer
Water transferring graphics from films to shoes is the least high tech or I should say, the most analog old school fashioned solution. Nevertheless water transferring method is cheap and efficient. It is also the most fun to watch process. Once you watch the process you will be amazed how ingenious humans are to utilize the power of nature.
In most case water transferring is used to apply graphics to an entire area of a surface (see below two shoe samples), in this case an entire shoe upper body. Meaning a complete shoe upper body requires graphic design, not a part of a shoe body. Below five independent videos showcase the entire process of water based transferring graphics onto shoes.
🔝1/5. A tan of water is separated into compartments, where each sheet of graphic film (graphic side up) is placed afloat. This one sheet is able to cover roughly 2 pairs of shoes based on size.
🔝2/5. Before applying graphics onto shoes, a thin layer of lacquer thinner is sprayed to dissolve the actual graphics from film. If you pay close attention the graphic film expands once the lacquer is sprayed. Afterwards each rack of shoes are placed upside down.
🔝3/5. After couple of seconds each rack of shoes are taken out, and put into a tunnel of water spray to wash off any unwanted substances.
🔝4/5. After water spray tunnel, shoes are put back into another set of water tanks, where a foam of shoe last was taken out. Up to this point water is the main source of tools to keep away unwanted substances stick onto graphics.
🔝5/5. Last stage of process is putting shoes into a heated tunnel to be dried. With heat graphics can further secured onto a surface without potential peeling off, which is a sign of defective products.
Environment Issues
You have probably noticed the muddy water during the entire process. I had the same thought when I was visiting this factory. However, I was ensured by factory owner they replace water quite often. On the other hand, this muddy water is directly related to a much serious footwear manufacturing topic: industrial waste. This water based transferring graphics to shoes creates water waste containing all types of chemicals that dumped back to sewage. I am not certain if all factory areas have separate industrial waste sewage system to residential sewage system. That is one major fact that there are not many footwear manufacturers operating water based graphic film transferring method, which leads to my next much more advanced transferring method that essentially remove water waste completely.
