To make a large kitchen knife out of plastic (like a ceramic knife), you will need about ten bottles with a capacity of 0.5 liters. Moreover, two of them must be painted with a marker in bright colors (for example, orange and dark blue), and the rest can be used as is, without painting over. Bottles need to be cut into tape, and then into small pieces.
We put baking paper on a baking sheet, and on top we pour chopped pieces of plastic on top of a hill. The edges of the paper need to be slightly bent so that the molten mass does not spread over the entire baking sheet. Then put the “dish” in the oven or microwave and “bake” for several minutes at a temperature of - 240 ℃.
Blade machining and sharpening
Remove the pan from the oven and cool for about half an hour. After that, we apply a kitchen knife to the resulting workpiece and circle its contours with a marker. We cut out the template with a hand jigsaw with a saw blade for metal. We process the edges of the workpiece with a file to remove burrs and irregularities.
The next step is the sharpening of the cutting edge of the knife blade. First, it is necessary to treat the plastic surface with P80 sandpaper with a grain size of 200-250 microns, then diamond grinding P140.
Next, proceed to the "jewelry" sharpening, using the sandpaper P1000, P2500 and P5000. Then the grindstones 12,000 and 30,000 are used. The result is a very sharp blade that cuts paper easily. The step-by-step process of making a plastic kitchen knife with your own hands, see the video on the site.
