Well-made plastic products look good and are easy to keep clean. In addition, modern plastics are highly durable. They are most often cast in industrial plants, since plastic molding requires certain conditions that are difficult to achieve at home. But sometimes those who make models of ships, planes or cars with their own hands need to make a part from this material.
You will be rescued by "semi-finished products"
Scrap plastic can be found everywhere. Old broken things are constantly appearing at home, the street is full of bottles and packages. An amateur to do something with his own hands may have an idea to collect all this, grind and melt it into something valuable.
A beginner "caster" should not do this, since each type of plastic has only its inherent properties, so it would have to melt at different temperatures. In addition, in production, parts are usually cast in special installations where high pressure is maintained.
Even if you can pick up pieces of the same kind of plastic and grind them, you will get bubbles when melting. So it's best to go to a hardware store and buy liquid plastic, from which the parts are just as durable as the factory ones. Epoxy can also replace plastic. You will also need:
- silicone;
- large capacity;
- lithol.
If you do decide to make something from plastic scrap, do not do it indoors. Plastic vapors are toxic.
Making the shape
To cast multiple plastic parts at home, you will need a master model. You can make it out of anything. Suitable for you:
- plasticine;
- gypsum;
- wood;
- paper and many other materials.
Make a model of the part to be cast. Coat it with lithol or other grease. After that, make the shape. Silicone molds are becoming more and more popular. This is understandable, it is easy and convenient to work with this material, but several circumstances must be taken into account. First, there are two types of silicone, filling and coating. Secondly, each species has its own elongation coefficient and its own viscosity. As for the first parameter, silicone with a coefficient of 200% or more is suitable for molding plastics.
Pay attention to the viscosity index. The smaller it is, the more accurate the shape will be. This is especially important if you intend to work with potting silicone. Also take into account the polymerization time. If you have potting silicone, place the master model in a flask (it can be made of steel or, for example, bronze) and fill it with silicone. Apply the lubricant carefully with a brush, taking into account all the unevenness. Let the silicone cure and then remove the master model.
The flask is a metal container. It should be slightly larger than the master model.
Pouring detail
The casting process largely depends on what exactly you are making the part from. Polyester resins and liquid plastics are great because you don't have to melt anything, but they differ in viscosity and pot life. These parameters are indicated in the characteristics. Lubricate the mold and fill it with liquid plastic as instructed. Let the plastic harden, then remove the product from the mold.
