Plastics. They can be found all around us. From LEGO®toys to car engine fuse covers, they have become the material of choice due to the ease with which they can be molded, cast, or drawn into a variety of shapes. Compared with other materials like metals and ceramics, plastics are also less expensive and can be used as a replacement in products where high strength and temperature resistance are not key requirements.
Until the proliferation of 3D printers, plastic products had to be made in huge volumes from specially designed molds. For injection molding processes, the mold alone can cost tens of thousands of dollars to manufacture and subsequent design changes can be costly. As a result, there is very little to no product customization when manufacturing plastic products using conventional techniques, and businesses often struggle to justify the cost of producing products in low quantities. 3D printing, on the other hand, enables mass customization and 3D Printing does not require any special molds or tooling for producing plastic parts. The result is greater freedom of design and the ability to produce one-offs without incurring prohibitive manufacturing costs. With 3D printing, the cost of producing fewer than a thousand parts can now easily be justified by businesses.
In addition, 3D printing eliminates the design restrictions imposed by conventional manufacturing methods. Product designs can now be modified in ways which were not possible before, making them more efficient and elegant. The technology empowers anyone with decent Computer Aided Design (CAD) skills to become a creator, inventing products that in years past would have seemed impossible to realize without significant financial expenditure. Established product manufacturers are also taking note, cutting down costs via the use of customized 3D printed jigs and fixtures, 3D printed prototypes, and in an increasing number of cases, 3D printing the end products themselves. This trend has led to an increasing amount of interest not only in the technology, but also the specific types of plastic materials which fuel the process.
3D printed plastics are not equal. Thermoplastics, for example, can be recycled whilst thermosets cannot. PLA (Polylactic Acid) is biodegradable and derived from renewable resources whilst ABS (Acrylonitrile Butadiene Styrene) is made from petroleum products and is non-biodegradable. TPU (Thermoplastic Polyurethane) is flexible and has a tensile strength ten times lower than that of Nylon-12, an engineering plastic. As a result, the type of plastic used in any product depends heavily on the expected operating temperatures, loads, environmental sustainability requirements, and service life. The table below provides details on the uses and characteristics of some common plastic materials suitable for 3D printing.
The different 3D printed plastics
Once a suitable material for making a plastic product has been determined, the full advantages of 3D printing technology must be considered whilst designing the product. For example, material can be removed in areas where they are not necessary, resulting in a lightweight, organic design that can be produced at a lower cost. In addition, multiple components can be consolidated into fewer parts, reducing assembly time and eliminating the risk of mechanical failure due to jointed ends. Multifunctionality can also be introduced into plastic products as the added complexity does not translate into increased costs and production time.
In summary, the advent of 3d Printing technology has democratized manufacturing and empowered anyone with decent design skills to translate what is in their minds into a physical product. It has broken down barriers to the use of materials that were previously confined to the warehouses of giant manufacturing companies and is stirring up a maker culture all over the world. 3D printing is enabling manufacturing firms to reduce their product development cycles and costs, allowing them to improve efficiencies with customized jigs and fixtures, and by tweaking the design of certain components or devices in their production line.