TPU stands for Thermoplastic Polyurethane. They’re a type of TPE (Thermoplastic Elastomers) that is widely used in 3D printing filaments. TPU is easy to work with and can be handled well by extruders since it combines both soft segments and hard segments to form a single polymer that has a better TPU filament in terms of elasticity, flexibility, and rigidity.
Properties TPU Filaments
TPU filaments and the most prefers type of TPE due to their unique characteristics. Here are the reasons why TPU filaments are considered to be reliable in terms of production quality and workability:
- Flexible
- Durable
- Elastic
- Hygroscopic
- Recyclable
- Easy to color
- Abrasion-resistant
- High impact strength
- Minimal shrinkage
- Minimal warping
- Medium water resistance
- Minimal fumes production
- Poor bridging characteristics
- Possibility of blobs and stringing
- Medium to high chemical resistance
- Resistant to oils, greases, and solvents
- Withstands high temperatures of up to 80°C
Pros and Cons
TPU is a product that delivers a set of unique characteristics. Of these, some of them may be considered to be advantageous while others may be considered to be disadvantageous. Let’s have a look at the pros and cons separately:
PROS
- Good shelf life
- Excellent vibration dampening
- TPU can bend easily without any effect on the design
- Retains effective porosity under mechanical pressures
- Has superior biocompatibility with PVDF
CONS
- Difficult to print compared to other filament materials
- There’s the possibility of blobs and stringing
- Using TPU with some 3D printers may be problematic
- Prints made using TPU don’t have a final polished and smooth look
Common Application of TPU Filaments
The fact that TPU is resistant to oils, greases and a lot of solvents makes it suitable for industrial use. TPU is also commonly used to make products that are required to bend easily during their use. Common applications include:
- Footwear
- Sporting goods
- Power tools
- Drive belts
- Medical devices
- Inflatable rafts
- Phone cases
- Caster wheels
- Extruded film
- Tubes and gaskets
- Hydraulic hoses
- Spiral and pneumatic tubing
- Automotive instrument panels
Tips And Tricks – Using TPU in 3D Printing
When it comes to using TPU filaments in 3D printing, it’s important for you to understand all the properties as well as all their strengths and weaknesses. This is the only way you’ll be able to get the most out of its usage.
Below is a list of tips and tricks for when you’re using TPU:
- Optimize the feed rate
You should use a consistent feed rate so that the elastic filament can be controllable if there’s a sudden change in the speed. High feed rates might lead to compression of the filament.
- Use a negative tolerance and not using rafts
Using a negative tolerance ensures that the flexible part can stretch easily over the other body.
You should also not use rafts since their base layers have a higher rate of extrusion which could be problematic
- Optimize the retraction setting
Optimizing the retraction setting helps you to limit the movements and have a successful print job. You should start with smaller amounts of retraction while using a slower speed to help manage any oozing that might happen from the extruder.
- Shorten the distance
The shorter the distance, the less the path that the filament needs to travel. This will prevent it from coiling or kinking.
- Placement of the stool
The spool should be mounted on top of the printer so that the filament will unwind downwards. This reduces resistance.
