|Is there any easy way to mold plastics?
The easiest way to mold plastics is to form them directly inside a mold. Most plastics are made by attaching small molecules to one another in a process called polymerization. You begin with one or more small molecules or "monomers" and cause them to link together into in a "polymer." You can initiate this polymerization with chemical catalysts, light, or even heat. There are many plastic-forming systems that you can buy commercially. You simply mix a few chemicals together, pour the mixture into a mold and wait. Once the polymerization has finished, you have a molded piece of plastic.
If you don't want to do the polymerization yourself, you can start with a finished plastic and melt it. Most plastics that haven't been vulcanized into one giant molecule (as is done in rubber tires) will melt at high enough temperatures (although some burn or decompose before they melt). These molten plastics can be stretched, squeezed, or poured into molds to make just about any shape you like.