TPE Filament 101
What is TPE filament?
TPE stands for “Thermoplastic elastomers” or it can be more commonly known as thermoplastic rubber. This type of filament is a rubber and plastic polymer blend. TPE is a common filament used for 3D printing and is often confused with TPU. The biggest difference being that although TPU is much firmer, it is also far easier to print than its TPE counterpart.
Where is TPE seen in everyday life?
TPE is an incredibly soft plastic. Because of this TPE is very easily molded and can be seen in many places throughout your daily life. TPE is a common choice for making bottlecap liners or soft grips on some items.
Where TPE really shines though is in the automotive industry. Because TPE is a thermoplastic it is the perfect choice for wiring insulation and cables in cars. Of course, it can be and is used in all kinds of wiring in many different industries such as home appliances and also in many HVAC systems.
Is TPE environmentally friendly?
TPE is more environmentally friendly than many other plastics, that’s because its a blend containing rubber and has been designed to decompose over time. Whilst TPE lasts long enough to serve its purpose it will break down given enough time spent in a landfill, or processed and recycled for reuse. Just like other rubbers and plastics, TPE has no problem being melted down and repurposed again. Unlike some filaments such as ABS which lasts hundreds of years, this makes TPE one of the most environmentally sustainable filaments.
How long does TPE last?
Because TPE is designed to be both degradable and recyclable it doesn’t have the longest shelf life. It could last 50 years and still retain its strength if well maintained. For example, wiring in a car could, in theory, last that long. More likely it will begin to break down naturally and be gone within one hundred years.
Realistically though TPE will just be reused and recycled as it was designed to be, it can be used for 20 years and then be processed back down for use again. It can be costly to recycle but doing so does mean it has the ability to last so much longer.
Is TPE toxic?
Even though TPE has been designed with non-toxicity in mind, by removing many harmful chemicals such as PVC and lead, many people are not really sure. These harmful chemicals have been removed, but the remaining chemicals in TPE filament have not yet been studied enough to 100% confirm its not toxic. Although TPE is toxic when the fumes are being inhaled during printing it isn’t believed to be toxic afterward.
Is it food safe?
TPE is actually food safe. Despite some people being unsure whether TPE is toxic to inhale, it has been made available for use in food packaging. One of the examples given earlier for its use was bottlecap liners, it can also be molded into lids for Tupperware containers. TPE is also regularly used to make soft spoons for babies or the lids of their bottles. So yes, TPE is food safe or it wouldn’t be usable in these applications.
Tips for printing TPE:
TPE is one of the hardest filaments to print with because it is so soft and flexible. There are a few things you can do to increase your chances though: Make sure that the filament path is fully secured as any gaps or blockage could lead to the filament flowing through any gaps and make a mess or causing damage to the printer.
The printing temperature for TPE should be around 220 degrees celsius, It could potentially go as far as 10 degrees either way from that but as this filament is so temperamental to use its best to stick as close to 220 as possible.
The printing bed should be between 65 and 75 degrees celsius for the best results. Some of the lower quality TPE may potentially adhere to the printing bed so its recommended to go for the better quality stuff.
Some brands of filament want a lower print bed temperature, but they will specify. Print speed should be very slow for this print, 10-15mm/s is ideal and 30mm/s is the absolute very maximum you are aiming for.
How should it be stored?
TPE like every filament is best stored away in a box to avoid absorbing moisture out of the air. When storing this filament using a polyethylene bag inside a box is the best way to keep it from being water damaged.
If the material has been left to sit in storage or a very humid area its best that you either pre-dry the filament before use or throw it out. Because TPE is so expensive you really want to avoid wasting any, it can be a costly mistake.
How much does it cost?
TPE is not cheap. If you’re looking for an affordable filament to start printing with you will want to look somewhere else. Costing as much as around $80 for a one-kilo spool this filament can become very expensive very fast.
There are of course cheaper brands out there but you’re sacrificing a lot of quality to save money. It is better to just bite the bullet and pay for the higher quality filament if TPE really is what you need.
Where can you buy it from?
TPE is less commonly available than filaments such as ABS but it is still possible to get your hands on it. The bigger 3D printing sites will have it and its possible to find on amazon. One of the best quality and more readily available TPE filament is ninjaflex and is available from the manufacturer.
The Pros of TPE:
Great for shock-absorbing. TPE does a great job of withstanding shock and maintaining its structural integrity afterward. Because it is so springy it can shrug off much higher impact than more brittle filaments, such as PLA. TPE is one of the most environmentally friendly filaments available.
If you’re an environmentally conscious person this might be a big decision make for you. If you are looking into using TPE as a company and are capable of recycling this filament too it could make your business model much more sustainable. Being food safe opens up a lot of avenues for real-world applications. It is far less restricting than some of its non-food safe counterparts.
The Cons of TPE:
TPE is one of the most expensive filaments, this can mean it is not really a viable option for people who are printing as a hobby, not as part of their business. If this filament does end up being what you need it can be worth the money but this one is definitely not for hobby printers.
Very hard to print with. Even experienced users may find this filament a bit tricky, if you are new to 3D printing maybe you should give this one a miss.
If you do decide to go with this one, follow the guide above and the manufacturer’s recommendations closely for the best results. It is not designed for structural purposes. Although TPE has plenty of mechanical uses such as wiring its not rigid and strong enough for any real weight-bearing tasks.
How does TPE matchup with other filaments:
If you’re looking for the most environmentally sustainable filaments PLA and TPE are the front runners. Both degrade relatively quickly and both can be recycled.
The major difference here is that the PLA degrades much faster. If that’s not an issue that’s great if you’re looking for more longevity TPE would be best. If you’re looking for a filament for mostly mechanical purposes, especially heat resistance it is really a toss-up between ABS and TPE.
Whilst TPE offers a lot more flexibility and holds up better under stresses where its ability to have a little give can be an advantage, ABS is much stronger. ABS is able to hold greater weights and keep its structure whereas TPE might just crumple under the same weight. If you’re looking for something that’s food safe you are deciding only between TPE and PETG. TPE is more expensive and has more limited food-related uses because it is designed to be more flexible.
PETG is much more rigid and is designed to be tougher. For example, if you were to print food containers with a flexible plastic lid you would use PETG for the container and TPE for the lid. If TPE was the filament type you are looking for TPU could be the alternative you are looking for.
It is very similar to TPE except its more rigid and far easier to print. TPU can also be expensive but may be easier for you to find at a good price.
TPE could be the right choice in varying situations but there are always multiple options. If you are looking for a filament that is food safe and flexible its great choice. If you are looking for a strong and cheap filament this one is absolutely not the way to go.
I hope this article contains enough information for you to make an informed decision about whether TPE is the correct filament for you. With this particular filament, it mostly comes down to budget and application. As always when it comes to actually making this choice, only you know best. Learn about other filament types.