When shopping for a smartphone case, your material choices are often silicone, polycarbonate, hard plastics, and thermoplastic polyurethane (TPU). If you’re wondering what TPU is, we’re going to break it down (figuratively).
What is a thermoplastic?
Plastic, as you probably know, is a (mostly) synthetic material made from synthetic polymers. Polymers are substances made up of monomers. Monomer molecules form long chains with their neighbors, creating huge macromolecules.
plasticity is the property that gives plastics their name. Being plastic simply means that a solid material can be permanently deformed. Plastics can be formed by casting, extruding or pressurizing.
Thermoplastics get their name from the way they react to heat. Thermoplastics become plastic at certain temperatures, which is when they are molded as needed. When they cool, their new shape becomes permanent until heated again.
The temperatures required to make thermoplastics flexible are much higher than, for example, your phone is ever exposed to. There is therefore little chance that a thermoplastic product will lose its shape under normal use.
Fused Deposition Modeling 3D printers, currently the most common 3D printer on the market, use thermoplastics. A filament of the plastic is fed through an extruder and the printer creates its product in layers that quickly cool and solidify.
What about polyurethane?
Polyurethane (PU) refers to a class of organic polymers linked by urethane linkages. “Organic” in this case refers to organic chemistry, which focuses on carbon compounds. Carbon is the basis for life as we know it, hence the name.
One of the things that makes polyurethane special is that it is not a specific chemical compound. Polyurethane can be made from a number of different monomers. This is why it is a “class” of polymers.
Because you can make PU from different materials, this means that different PUs have different properties. Foam is made from most polyurethanes, such as kitchen sponges.
Why TPU is great for protecting devices
Although TPU is made from a variety of materials, products made from TPU generally have elasticity, transparency and light weight. TPU can be quite thin and retain its strength. The combination of elasticity and strength makes TPU a good choice for protective cases, as the material will not crack, tear or break under the types of forces a dropped device is normally subjected to.
Another bonus feature of TPU is its strong resistance to oils and liquids. So the natural oil and the sweat from your fingers shouldn’t stain it!
TPU is everywhere
TPU has such a wide range of uses that you almost certainly have a lot of stuff laying around. Car dashboard panels, power tool housings, hoses, tubing, cable sleeves, shoes and more are made of or use TPU.
It’s also a great choice of material for a smartphone case, but your phone is already made from some incredible materials like polycarbonate and Gorilla Glass. So maybe you don’t have to make a choice at all, and you can be one of the brave people who don’t have a case. On the other hand, if you really want to customize the look of your phone, there’s an argument for having multiple phone cases.
RELATED: Why you should use multiple phone cases