Used materials are much more available and less expensive than new manufactured materials. Whether you are looking for plastic, metal, paper, rubber or glass, you can often find these items at your local recycling yard. With the right equipment, you can actually melt some of these materials down and reshape them to become parts of your new invention.
Brainstorm some ideas about your new invention. If you have something specific in mind, you can skip this step. If you don't have an idea, you need to do some planning. Take an ordinary product that already has a market and figure out how you can make it from recycled materials. Or, invent something that the world needs. Think about who might use the product, what function it will serve, and whether this function is enough to make the invention worth it. Then, think about how complicated and economical it will be to make the project.
Make a list of needed materials. If you are planning to produce a lot of product, you may need to contact several recycling yards to gather the amount of material needed. Sometimes recycling yards will let you take junk for free, but often you will have to pay a small amount for the material you take. Make sure you know the value of what you need before paying someone for used material. Also, you'll need to make sure that the materials are compatible with each other such, as different metals or types of glass. Sometimes these products will not perform together as you would expect them to.
Assemble the necessary processing equipment. You'll need to transform the used materials into pieces for your new invention, and this process may require some equipment. Metal and glass workers have forges, kilns, tools and torches, and this equipment would be necessary if your invention requires any reshaping of the recycled material. Plastic can be melted down and poured into new moulds to create new shapes and pieces. According to modcottage.com, plastic grocery bags can be melted together to form a thick, Tyvec-like fabric that is reusable. This process needs no more than an ordinary fabric iron.
Test your new product. Determine if your invention fulfils the original project goal, and how much of the material is recycled. Write down the cost of the materials, equipment use, and the time it took to create each product. If you can sell the products for more money that it costs to make them, they may be worth producing.