Make a kitchen knife from recycled plastic

With this mould you are able to inject 3 ergonomic knife handles. The mould is designed for different blade sizes up to 2cm wide. With a handle weight of 25g your injection machine need to inject 75g to fill the mould. With the Precious Plastic injection machine with a capacity of about 100g this is not a problem. For the blades you need to 3D-Print inserts that matches the blades at the right spot. The plastic type Polypropylene is recommended for this product and is also milled into the mould. Also the "Precious Plastic" branding is milled in. If you don´t have blades available you can order them also at the Precious Plastic Bazar. The product design, the mould design and the insert design for the Precious Plastic blades are opensource, so you are able recreate the mould or change it to your needs. If you are just interested in the knifes you can order them on the bazar. If you need help with the mould or the inserts let me know. Happy recycling! Thomas @johannplasto

3-4 weeks

Hard

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7 steps

1 Mill the Mould

Download the .stp-files and the blueprints for the mould for CNC milling. Metal examples for CNC Milling: Aluminium: Aluminium - 7050 Aluminium - 7075-T6 Aluminium - 7075-T651 Steel: Mild steel 1045 CNC mill the mould accourding to the blueprint and insert 8x10mm Dowel pins.

2 Get your blades

You can use blades up to 2cm wide (at the insert spot) or order the Precious Plastic blades on the Precious Plastic Bazar. These are high quality & super sharp blades from Solingen (Germany). Material: Stainless steel 1.4116 You can get the Precious Plastic blades here: https://bazar.preciousplastic.com/extras/precious-plastic-blade-for-knife-making/?action=preview

3 3D-Print the inserts

If you use the Precious Plastic blades you can download the .stl-file of the insert for 3D-Printing. If you use other blades use the .stp-file of the insert and change it to your needs.

4 Assemble the mould

Slide the inserts on the blades and align them into the mould so they fit the right spot of the handle (see the picture). Close the mould with M8x40 screws.

5 Inject

Fill the injection machine with about 100g Polypropylene, heat up for 10-12min, check the viscosity of the outcoming plastic, if everything is alright inject fast and hold a strong pressure for about 30sec.

6 Deassemble & Finishing

Unscrew the mould, use the demoulding pockets to open the mould if necessary, knock out the sprue, cut the runners and finish the handle with a knife and flame.

7 Video

Check out the story behind the knife and see the process of making the knife in the Johannplasto workshop. Just interested in the knife? Get them here: https://bazar.preciousplastic.com/products/household/johannplasto-eco-friendly-kitchen-knife-recycled-plastic-unique-colors-precision-blade/?action=preview The entire process has been carefully evaluated by Life Cycle Assessment expert Francesco Nenna from the GEA Factory in Italy. The result? A significant reduction in carbon footprint compared to industrially produced knives – our knife emits just 0.064kg CO2, half that of its industrial counterparts. Check out the LCA-Report: https://drive.google.com/file/d/1GQn4Dhw4PXNQJ3Y8XJ7ANdzhSV7VNrWO/view?usp=sharing

Precious Plastic is a project by One Army.Please sponsor the work or help us build the software.