Flex is a very strong and flexible material. There are many use cases when hard plastic is not the best option. Whether you need a phone cover, an action camera case
or wheels for your RC car, flexible is the way to go.
Flex has a very good abrasion resistance, remains flexible in cold environments, and is resistant to many solvents. It doesn’t shrink much when cooling down, so you can be fairly accurate with your measurements and models requiring a perfect fit.
In reality, TPE is a broad class of copolymers (and polymer mixtures), but it is nonetheless used to label many commercially available types of 3D printer filament. Soft and stretchable, these filaments can withstand punishment that neither ABS nor PLA can tolerate. On the other hand, printing is not always easy, as TPE can be difficult to extrude.
Thermoplastic polyurethane (TPU) is a particular variety of TPE, and is itself a popular 3D printer filament. Compared to generic TPE, TPU is slightly more rigid – making it easier to print. It’s also a little more durable and can better retain its elasticity in the cold.
Thermoplastic copolyester (TPC) is another variety of TPE, though not as commonly used as TPU. Similar in most respects to TPE, TPC’s main advantage is its higher resistance to chemical and UV exposure, as well to heat (up to 150°C).
WHEN SHOULD I USE TPE, TPU, OR TPC (FLEX)?
Use TPE or TPU when creating objects that need to take a lot of wear. If your print should bend, stretch, or compress, these are the right 3D printer materials for the job. Example prints might include toys, phone cases, or wearables (like wristbands). TPC can be used in the same contexts, but does especially well in harsher environments, like the outdoors.