The materials used for 3D printing are as diverse as the products that result from the process. As such, 3D printing is flexible enough to allow manufacturers to determine the shape, texture and strength of a product. Best of all, these qualities can be achieved with far fewer steps than what is typically required in traditional means of production. Moreover, these products can be made with various types of 3D printing materials.
In order for a 3D print to be realized in the form of a finished product, a detailed image of the design in question must first be submitted to the printer. The details are rendered in standard triangle language (STL), which conveys the intricacies and dimensions of a given design and allows a computerized 3D printer to see a design from all sides and angles.
Basically, an STL design is the equivalent of multiple flat designs in one computerized file.
The industry for 3D printing is expected to surpass the 10-figure mark in the near future and plastic is set to be the main material to drive this market. As concluded recently in a SmarTech Markets Publishing study, the market for 3D printing is likely to exceed $1.4 billion before 2020. With an ongoing market expansion, the industry has sought new ways to yield plastics, including the use of organic ingredients like soybean oil and corn. Consequently, plastics are set to become the most environmentally friendly option in 3D printing.
Out of all the raw materials for 3D printing in use today, plastic is the most common. Plastic is one of the most diverse materials for 3D-printed toys and household fixtures. Products made with this technique include desk utensils, vases and action figures. Available in transparent form as well as bright colors — of which red and lime green are particularly popular — plastic filaments are sold on spools and can have either a matte or shiny texture.
With its firmness, flexibility, smoothness and bright range of color options, the appeal of plastic is easy to understand. As a relatively affordable option, plastic is generally light on the pocketbooks of creators and consumers alike.
Plastic products are generally made with FDM printers, in which thermoplastic filaments are melted and molded into shape, layer by layer. The types of plastic used in this process are usually made from one of the following materials:
- Polyastic acid (PLA): One of the eco-friendliest options for 3D printers, polyastic acid is sourced from natural products like sugar cane and corn starch and is therefore biodegradable. Available in soft and hard forms, plastics made from polyastic acid are expected to dominate the 3D printing industry in the coming years. Hard PLA is the stronger and therefore more ideal material for a broader range of products.
- Acrylonitrile butadiene styrene (ABS): Valued for its strength and safety, ABS is a popular option for home-based 3D printers. Alternately referred to as “LEGO plastic,” the material consists of pasta-like filaments that give ABS its firmness and flexibility. ABS is available in various colors that make the material suitable for products like stickers and toys. Increasingly popular among craftspeople, ABC is also used to make jewelry and vases.
- Polyvinyl Alcohol Plastic (PVA): Used in low-end home printers, PVA is a suitable plastic for support materials of the dissolvable variety. Though not suitable for products that require high strength, PVA can be a low-cost option for temporary-use items.
- Polycarbonate (PC): Less frequently used than the aforementioned plastic types, polycarbonate only works in 3D printers that feature nozzle designs and that operate at high temperatures. Among other things, polycarbonate is used to make low-cost plastic fasteners and molding trays.
Plastic items made in 3D printers come in a variety of shapes and consistencies, from flat and round to grooved and meshed. A quick search of Google images will show a novel range of 3D-printed plastic products such as mesh bracelets, cog wheels and Incredible Hulk action figures. For the home craftsperson, polycarbonate spools can now be purchased in bright colors at most supply stores.
Today’s more state-of-the-art 3D printers use powdered materials to construct products. Inside the printer, the powder is melted and distributed in layers until the desired thickness, texture and patterns are made. The powders can come from various sources and materials, but the most common are:
- Polyamide (Nylon): With its strength and flexibility, polyamide allows for high levels of detail on a 3D-printed product. The material is especially suited for joining pieces and interlocking parts in a 3D-printed model. Polyamide is used to print everything from fasteners and handles to toy cars and figures.
- Alumide: Comprised of a mix of polyamide and gray aluminum, alumide powder makes for some of the strongest 3D-printed models. Recognized by its grainy and sandy appearance, the powder is reliable for industrial models and prototypes.
In powder form, materials like steel, copper and other types of metal are easier to transport and mold into desired shapes. As with the various types of plastic used in 3D printing, metal powder must be heated to the point where it can be distributed layer-by-layer to form a completed shape.
One of the more limiting and therefore less-used materials in 3D printing is resin. Compared to other 3D-applicable materials, resin offers limited flexibility and strength. Made of liquid polymer, resin reaches its end state with exposure to UV light. Resin is generally found in black, white and transparent varieties, but certain printed items have also been produced in orange, red, blue and green.
The material comes in the following three categories:
- High-detail resins: Generally used for small models that require intricate detail. For example, four-inch figurines with complex wardrobe and facial details are often printed with this grade of resin.
- Paintable resin: Sometimes used in smooth-surface 3D prints, resins in this class are noted for their aesthetic appeal. Figurines with rendered facial details, such as fairies, are often made of paintable resin.
- Transparent resin: This is the strongest class of resin and therefore the most suitable for a range of 3D-printed products. Often used for models that must be smother to the touch and transparent in appearance.
Transparent resins of clear and colored varieties are used to make figurines, chess pieces, rings and small household accessories and fixtures.
The second-most-popular material in the industry of 3D printing is metal, which is used through a process known as direct metal laser sintering or DMLS. This technique has already been embraced by manufacturers of air-travel equipment who have used metal 3D printing to speed up and simplify the construction of component parts.
DMLS printers have also caught on with makers of jewelry products, which can be produced much faster and in larger quantities — all without the long hours of painstakingly detailed work — with 3D printing.
Metal can produce a stronger and arguably more diverse array of everyday items. Jewelers have used steel and copper to produce engraved bracelets on 3D printers. One of the main advantages of this process is that the engraving work is handled by the printer. As such, bracelets can be finished by the box-load in just a few mechanically programmed steps that do not involve the hands-on labor that engraving work once required.
The technology for metal-based 3D printing is also opening doors for machine manufacturers to ultimately use DMLS to produce at speeds and volumes that would be impossible with current assembly equipment. Supporters of these developments believe 3D printing would allow machine-makers to produce metal parts with strength superior to conventional parts that consist of refined metals.
In the meantime, the use of 3D parts is taking flight in the aerospace industry. In what has been the most ambitious push of its kind, GE Aviation plans to print engine injectors at an annual rate of 35,000 units by 2020.
The range of metals that are applicable to the DMLS technique is just as diverse as the various 3D printer plastic types:
- Stainless-steel: Ideal for printing out utensils, cookware and other items that could ultimately come into contact with water.
- Bronze: Can be used to make vases and other fixtures.
- Gold: Ideal for printed rings, earrings, bracelets and necklaces.
- Nickel: Suitable for the printing of coins.
- Aluminum: Ideal for thin metal objects.
- Titanium: The preferred choice for strong, solid fixtures.
In the printing process, metal is utilized in dust form. The metal dust is fired to attain its hardness. This allows printers to bypass casting and make direct use of metal dust in the formation of metal parts. Once the printing has completed, these parts can then be electro-polished and released to the market.
Metal dust is most often used to print prototypes of metal instruments, but it has also been used to produce finished, marketable products such as jewelry. Powderized metal has even been used to make medical devices.
When metal dust is used for 3D printing, the process allows for a reduced number of parts in the finished product. For example, 3D printers have produced rocket injectors that consist of just two parts, whereas a similar device welded in the traditional manner will typically consist of more than 100 individual pieces.
Composites such as carbon fiber are used in 3D printers as a top-coat over plastic materials. The purpose is to make the plastic stronger. The combination of carbon fiber over plastic has been used in the 3D printing industry as a fast, convenient alternative to metal. In the future, 3D carbon fiber printing is expected to replace the much slower process of carbon-fiber layup.
With the use of conductive carbomorph, manufacturers can reduce the number of steps required to assemble electromechanical devices.
Graphite and Graphene
Graphene has become a popular choice for 3D printing because of its strength and conductivity. The material is ideal for device parts that need to be flexible, such as touchscreens. Graphene is also used for solar panels and building parts. Proponents of the graphene option claim it is one of the most flexible of 3D-applicable materials.
The use of graphene in printing received its largest boost through a partnership between the 3D Group and Kibaran Resources, an Australian mining company. The pure carbon, which was first discovered in 2004, has proven to be the most electrically conductive material in laboratory tests. Graphene is light yet strong, which makes it the suitable material for a range of products.
As a common material in medical implants, nitinol is valued in the 3D printing world for its super-elasticity. Made from a mixture of nickel and titanium, nitinol can bend to considerable degrees without breaking. Even if folded in half, the material can be restored to its original shape. As such, nitinol is one of the strongest materials with flexible qualities. For the production of medical products, nitinol allows printers to accomplish things that would otherwise be impossible.
Designs can be printed on paper with 3D technology to achieve a far more realistic prototype than a flat illustration. When a design is presented for approval, the 3D-printed model allows the presenter to convey the essence of the design with greater detail and accuracy. This makes the presentation far more compelling, as it gives a more vivid sense of the engineering realities should the design be taken to fruition.
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Ultimately, companies that master this technology are bound to have an edge over their competition. Browse our 3D-print plating page to learn more about the options and contact us today for a free quote.