Plastic Recycling Shredder

Hi there,
This instructable is about a plastic recycling shredder.

The idea of the machine is to provide means for plastic recycling.

The 3D model and drawings of the unit have been created in contemporary CAD software (Rhinoceros 3D).

The shredder has been created partly by using 3D printing technology using PLA filament, partly by utilising old metal from scrapyard and doing some fitter's work (for the shaft and top plates).

In the shared videos, PET plastic bottles have been shredded into plastic pellets, which could be used for 3D printing with pellet extruder.

The plastic recycling shredder has been modeled from scratch in contemporary 3D modeling software (Rhinoceros 3D). The software allows for creation of rendered images, 2D drawings, rendered animations, 3D model export in various file formats.

The 3D model and images were created in less than 5 days.

Kindly find attached a 3D model (in STL format) of the Plastic Recycling Shredder, available for preview in 3D, as well as some images rendered in artistic visual style.

Kindly find attached the 3D models of the shredder components in STL file format.

After creating the 3D model of the shredder in CAD, some 2D drawings and rendered images have been created.

Kindly find attached 2D drawings of the shredder components as well as a PDF with them.

The unit has been created partly by using 3D printing technology, partly by utilising old metal from scrapyard and doing some fitter's work.
Its design icludes an interesting and original shaft assembly consisting of two sliding bearings and two sets of rotating plates fitted with interference fit on a hexagon metal bar (S 32mm and length 310mm). The sliding bearings, manufactured by 3D printing, rotate in bearing covers (front and rear, also 3D printed), with only a small radial clearance of 0.5 mm between the bearing and bearing cap. That is an alternative of the rolling bearings typically used .

On the metal hexagon bar (utilised from scrapyard), rotating plates (two sets - 3D printed), are mounted also by means of interference fit. That is an interesting alternative of the laser-cut metal plates, used in other designs. The rotating plates and the sides of the Plastic Recycling Shredder have been created by means of 3D printing technology.

A "XYZ da Vinci mini" desktop 3D printer has been used, working with PLA filament. 3D printing operations were accomplished in more than 100 hours, using 400 meters of PLA filament (with a price of 60 Eur). Components, subjected to a bigger load (the rotating plates and the sliding bearings), have been 3D printed with 90% solid infill (honeycomb type), thus ensuring better mechanical strength and performance. Components, subjected to a lower load ( shredder sides and bearing covers), have been 3D printed with 50% solid infill (gyroid type), thus reducing the PLA filament needed (i.e. reducing costs).

The shaft has been manufactured by utilising an old metal bar from scrapyard (hexagon metal bar S 32mm, length 310mm). Aluminum plates with 3 mm thickness have also been utilised from scrapyard, and mounted on top of the rotating plates and side shims, thus minimizing the wear out of the plastic components during operation.

The output of the shredder is shredded plastic in the form of small stripes and bits, which could be further processed with a blender to finally receive plastic flakes/pellets. Those could be fed to a plastic pellet extruder for direct 3D printing, or fed to a filament extruder for creating a 3D printer filament.

Kindly find attached images of the components.

After 3D printing, the rotating plates (2 pcs), sliding bearings (2 pcs) and spacer (1 pc) have been mounted on the shaft by means of heating in hot liquid for 1-2 minutes (hot tap water). When heated, the 3D printed plastic components expand their volume, thus allowing for easy mounting on the shaft. After cooling to ambient temperature, the rotating plates and sliding bearings shrink slightly and form an interference fit with the shaft, ensuring good performance.

Aluminum plates with 3 mm thickness have been utilised from scrapyard, and mounted on top of the rotating plates, as well as on top of the stationary plates, thus minimizing the wear out of the plastic components during operation.

The shredder is rotated manually by using a handle.

Kindly find attached images of the assembled unit.

The rotating plates and the sides of the Plastic Recycling Shredder have been created by means of 3D printing technology. A "XYZ da Vinci mini" desktop 3D printer has been used, working with PLA filament. 3D printing operations were accomplished in more than 100 hours. Components, subjected to a bigger load (the rotating plates and the sliding bearings), have been 3D printed with 90% solid infill (honeycomb type), thus ensuring their mechanical strength and better performance. Components, subjected to a lower load ( shredder sides and bearing covers), have been 3D printed with 50% solid infill (gyroid type), thus reducing the PLA filament material needed (i.e. reducing costs).

Kindly find attached pictures (5 pcs) of the components, prepared for 3D printing with XYZ slicing software, showing various object information - print time, filament usage etc.

Thanks for watching the instructable and have a nice day!