First things first: Rubber is not 3D printable. Yet.
At least not yet, and not using a typical polymer 3D printer. Recall that polymer 3D printing relies heavily on thermoplastics, which are a family of plastics that can retain their essential properties when melted, extruded, and then allowed to cool again. Rubber is an organic compound that undergoes a process called vulcanization to harden, and cannot be melted without burning it.
There is a sub-group of polymer elastomers that exhibit elasticity not unlike rubber. The degree of elasticity in the material depends on the type of elastomer and the chemical structure of the grade. In addition, this grade of elastomers come with the processing advantages of thermoplastics which is what allows them to be 3D printed.
A note about shore hardness…
It is not unusual to see an elastomer accompanied or defined by it’s shore hardness. The shore hardness is a reference to the materials elasticity and resistance to indentation. The smaller the number the softer and more malleable the material will be.
A note about shore hardness…
It is not unusual to see an elastomer accompanied or defined by it’s shore hardness. The shore hardness is a reference to the materials elasticity and resistance to indentation. The smaller the number the softer and more malleable the material will be.
Flexible filaments include the following:
- TPU – Thermoplastic Polyurethane
- TPC – Thermoplastic Copolyester
- TPA – Thermoplastic Polyamide
TPU – Thermoplastic Polyurethane
Thermoplastic polyurethane is the most common type of TPE used in 3D printing. Compared to other flexible filaments, it exhibits greater rigidity, allowing it to extrude more easily. It also has decent strength and high durability.
Features
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Acceptable printability
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Can be Semi-transparent
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Better chemical resistance to oils and greases
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High abrasion resistance
TPC – Thermoplastic Copolyester
Thermoplastic copolyester are copolyether esters with alternating, random-length sequences of either long-chain or short-chain glycols. They have both hard and soft segments. Hard segments are typically short-chain ester units whereas soft segments are usually aliphatic polyethers and polyester glycols.
TPC is considered to be an engineering-grade material, which might explain why it doesn’t appear as much in the hobbyist 3D printing world.
Features
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Shore hardness between 40 and 72D
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Good chemical resistance
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High strength
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Good thermal stability
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High temperature resistance
TPA – Thermoplastic Polyamide
Thermoplastic polyamide (TPA) is a chemical co-polymer of TPE and highly flexible nylon. The result is a combination of a smooth, lustrous texture, coming from nylon, and the flexibility of TPE.
Features
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High flexibility
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Exceptionally durable
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Good printability
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Good heat resistance
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Good layer adhesion