A new type of 3D printer has the potential to open up new possibilities for the technology by turning wool and wool blend yarns into fabric objects including apparel.

Developed by Carnegie Mellon University and Disney Research Pittsburgh, the device looks like a cross between a 3D printer and a sewing machine and produces 3D objects made of a form of loose felt.

Scott Hudson, a professor in CMU's Human-Computer Interaction Institute who developed the felting printer with Disney Research support, said the results are reminiscent of hand-knitted materials.

Like other 3D printers, the machine can make objects by working directly from computerised designs, giving it the potential for rapid prototyping of objects and to customise products.

In fact, the operation of the machine is similar to Fused Deposition Modeling, or FDM, the most common process used in low-end 3D printers. In a FDM printer, melted plastic is extruded in a thin line into a layer; subsequent layers are added to achieve the object's desired shape, with the layers adhering to each other as the plastic cools.

In the felting printer, however, the printer head feeds out yarn instead of lines of melted plastic. A barbed felting needle attached to the printer head then repeatedly pierces the yarn, dragging down individual fibres into the yarn in the layers below, entangling the fibres and bonding the layers together.

The printer doesn't achieve the same dimensional accuracy as conventional 3D printers because the yarn is much thicker than the layers of plastic deposited in FDM printing. Also, the felt is not as strong as typical fabric, the researchers say.