Materials and recycling
Most 3D printed slides are made from flexible polymers called elastomers: thermoplastic polyurethane (TPU) for powder-bed and filament printing, and elastomeric polyurethane resins for resin printing.
The main materials
| Material | Used with | Notes |
|---|---|---|
| TPU powder | Powder-bed printing (SLS, MJF) | Tough and elastic; unused powder can be partly reused in later builds. |
| TPU filament | Filament printing (FDM) | Widely available; common in hobby and DIY slides. |
| Elastomeric polyurethane resin | Resin printing (DLP, LCD, DLS) | Allows very fine lattices; cured by light and often heat, so it cannot be re-melted. |
| EVA foam (for comparison) | Molding | The usual material of conventional slides; light and cheap, closed-cell. |
Hardness of these elastomers is usually given on the Shore A scale. Footwear lattices commonly use materials in the 80A to 95A range and get their softness from the lattice geometry rather than from a soft material.
Is printed footwear more sustainable?
It can be in some ways and not in others:
- Less overproduction. Printing to order means fewer unsold pairs.
- Fewer materials per shoe. A one-piece print has no glue and one material, which in principle makes it easier to recycle than multi-material shoes.
- Energy per pair. Printing is slow and energy-intensive per part compared with molding at volume.
- Durability. A pair that lasts longer has a lower footprint per wear; this depends heavily on design and material.
What happens at end of life
TPU is a thermoplastic, so in principle it can be ground and re-melted. In practice, recycling of worn footwear depends on take-back programmes run by individual makers, because most municipal recycling does not accept shoes. Cured resins are thermosets and cannot be re-melted; they can at best be ground into filler. If recycling matters to you, check whether the maker runs a take-back scheme.
Related: Lattice basics · Are 3D printed shoes waterproof?