3D printing is revolutionizing manufacturing and enabling hobbyists and professionals to create customised and complex parts. An important decision here is choosing the right material. In this article, we explore the differences between flexible PLA (Soft PLA) and TPU (Thermoplastic Polyurethane), two popular materials for flexible 3D printing applications.
What is flexible PLA?
Flexible PLA, often referred to as soft PLA, is a variant of standard PLA (polylactide) that is characterized by its flexibility and elasticity. It retains many of the beneficial properties of conventional PLA, such as easy printability and low toxicity, but offers additional pliability.
Properties of Flexible PLA
- Printing temperature: 200-220°C
- Print bed temperature: 45-60°C
- Shore hardness: 90A (depending on manufacturer)
- Flexibility: High elasticity, pliable and soft
- Adhesion: Good adhesion to the print bed, usually without additional adhesives
- Biodegradable: More environmentally friendly than many other plastics
Flexible PLA is ideal for applications where a certain degree of flexibility and pliability is required, such as cell phone covers, flexible toys and orthopaedic aids.
What is TPU?
TPU, or thermoplastic polyurethane, is an extremely versatile and resilient plastic that is characterized by its high flexibility and abrasion resistance. TPU is often used in industrial applications, but it is also becoming increasingly popular in 3D printing.
Properties of TPU
- Printing temperature: 220-250°C
- Print bed temperature: 50-70°C
- Shore hardness: 85A to 95A (depending on manufacturer)
- Flexibility: Very high elasticity, extremely stretchy and tear-resistant
- Adhesion: Good adhesion to various print bed surfaces, sometimes an adhesive is required
- Weather resistance: High resistance to oil, grease and abrasion
TPU is ideal for applications that require high resilience and flexibility, such as protective covers, seals, flexible connections and soles of sports shoes.
Comparison: Flexible PLA vs. TPU
Printability
Flexible PLA is easier to print due to its similarity to conventional PLA. It warps less and does not require special printing equipment. TPU, on the other hand, can be more challenging as it tends to clog in the extruder due to its elasticity and requires more precise temperature control.
Flexibility and hardness
While both materials are flexible, TPU offers greater stretch and tear resistance compared to flexible PLA. This makes TPU the better choice for highly stressed parts.
Adhesion and processing
Flexible PLA adheres very well to the print bed and usually requires no additional adhesives. TPU can be more demanding depending on the print bed surface and sometimes requires a special bonding agent to avoid warping.
Areas of application
- Flexible PLA: Ideal for applications where moderate flexibility is sufficient and printability is paramount. Examples: Flexible housings, toys, prototypes.
- TPU: Suitable for demanding applications that require high flexibility and durability. Examples: Protective equipment, seals, flexible connections.
Conclusion
Both flexible PLA and TPU offer excellent properties for 3D printing, depending on the specific requirements of the project. Flexible PLA scores with easy printability and sufficient flexibility for many applications. TPU, on the other hand, offers maximum elasticity and durability, but is more challenging to process.
By choosing the right material, 3D printing enthusiasts can optimize their projects and achieve the best results. The decision should be made based on the specific requirements and the desired application.
