What Is Additive Layer Manufacturing?

Additive layer manufacturing is a type of manufacturing that adds elements to a substrate, rather than subtracting them. Subtractive manufacturing is more common than additive layer manufacturing, but both can adequately make products. There are many additive methods, such as processing the substrate with a laser or using an industrial three-dimensional (3D) printer to make products from powder. The benefits to using additive manufacturing include making less waste and increasing the ease of creating custom parts.

Subtractive manufacturing is the most common type of manufacturing, and it also is the opposite of additive layer manufacturing. With subtractive manufacturing, a substrate such as metal or wood is used. Tooling machines drill, cut and work into the substrate, subtracting from the overall material until the product’s shape manifests. This type of manufacturing is traditional and stable, which is why it tends to be more common, but it may leave a mess of unusable waste material.

With additive layer manufacturing, material is added to the substrate instead of being removed. This usually is done layer by layer, with a small amount of the substrate added each time until the entire product is built. While this may seem slower, the additive process usually is about the same speed, and sometimes faster, than subtractive. As of 2011, this manufacturing is not used as often because the technology is not stable enough for all products and substrates.

Creating a product through additive layer manufacturing can be done in many ways. With 3D printing, powder is clumped together with great force. A computer 3D model is used as the product’s master mold, and the printer clumps the powder together, layer by layer, until the 3D model is printed. Another typical technique is through laser manufacturing. The laser hits part of the substrate, usually metal, and melts it so more metal can be added to the substrate until the product is formed.

While additive layer manufacturing is not used as often, there are many benefits to this manufacturing process. With subtractive manufacturing, the material that is removed from the main product may be melted down and reused if it is plastic or metal, but many other materials may be wasted. Additive manufacturing does not remove material, so less material often is needed overall. Products also may be simpler to customize, especially with methods such as 3D printing, in which the master mold can be easily changed for any need.