"If it has to move, WD-40. If it must stay put, duct tape." That phrase seems taken from a commercial, but millions of people swear by its effectiveness. Now, the WD-40 formula is a secret, and there's not much we can say about its manufacturing, however, if you want to know more about duct tape, the properties that make it so resistant, and why it revolutionized the DIY world, you've come to the right place.
What we know today as duct tape is actually the civilian version of the original product created by Vesta Stoudt as a solution to the problem of opening ammunition boxes. During World War II, soldiers took up to a minute per box, and that could cost them their lives at the front. Ignored by her bosses, Stoudt sent a letter to President Roosevelt explaining the situation, who in turn ordered the War Production Board to assign its manufacturing to Revolite (Johnson & Johnson).
More than 80 years later, the popularity of duct tape remains intact, but it didn't escape absurdity, because in some regions (e.g., California) its use to seal ducts was banned, the activity that gives it its English name, duct tape. With its history a bit more defined, the question is: How is duct tape manufactured? What is the process behind its fabulous properties?
Manufacturing duct tape
Everything starts with a cotton fabric whose threads follow a cross pattern. The base of the adhesive is rubber, processed and mixed with a set of resins until it reaches a consistency similar to pizza dough. The mixture undergoes heat treatment that exceeds 93 degrees Celsius, and from that point, it's ready for application. The fabric is trapped between the adhesive layer and the silver surface. At the same time, it's responsible for giving the tape its tensile strength, and makes it easy to cut by hand.
Finally, the silver surface with hydrophobic properties is made of polyethylene, the same that we find almost everywhere, from supermarket bags to toys. The most effective method to join these three components is coextrusion, a kind of layer fusion that prevents delamination. The last phase requires cutting and splitting a giant cylinder of tape that weighs more than a ton. Each of those cylinders equals 30,000 rolls, which are packaged and distributed. Duct tape is synonymous with improvisation, but its uses have no limits. Art, clothing, scientific experiments, anything goes. It's an excellent idea to have a couple of rolls at home, and the best part: it's not that expensive.
