Views: 0 Author: Site Editor Publish Time: 2024-11-21 Origin: Site
3D printing or additive manufacturing (AM) technologies create three-dimensional parts from computer-aided design (CAD) models by successively adding material layer by layer until physical part is created.
While 3D printing technologies have been around since the 1980s, recent advances in machinery, materials, and software have made 3D printing accessible to a wider range of businesses, enabling more and more companies to use tools previously limited to a few high-tech industries.
Today, professional, low-cost desktop and benchtop 3D printers accelerate innovation and support businesses in various industries including engineering, manufacturing, dentistry, healthcare, education, entertainment, jewelry, and audiology.
All 3D printing processes start with a CAD model that is sent to software to prepare the design. Depending on the technology, the 3D printer might produce the part layer by layer by solidifying resin or sintering powder. The parts
are then removed from the printer and post-processed for the specific application.
3D printers create parts from three-dimensional models, the mathematical representations of any three-dimensional surface created using computer-aided design (CAD) software or developed from 3D scan data. The design is then exported as an STL or OBJ file readable by print preparation software.
3D printers include software to specify print settings and slice the digital model into layers that represent horizontal cross-sections of the part. Adjustable printing settings include orientation, support structures (if needed), layer height, and material. Once setup is complete, the software sends the instructions to the printer via a wireless or cable connection.
Some 3D printers use a laser to cure liquid resin into hardened plastic, others fuse small particles of polymer powder at high temperatures to build parts. Most 3D printers can run unattended until the print is complete, and modern systems automatically refill the material required for the parts from cartridges.
Depending on the technology and the material, the printed parts may require rinsing in isopropyl alcohol (IPA) to remove any uncured resin from their surface, post-curing to stabilize mechanical properties, manual work to remove support structures, or cleaning with compressed air or a media blaster to remove excess powder. Some of these processes can be automated with accessories.
3D printed parts can be used directly or post-processed for specific applications and the required finish by machining, priming, painting, fastening or joining. Often, 3D printing also serves as an intermediate step alongside conventional manufacturing methods, such as positives for investment casting jewelry and dental appliances, or molds for custom parts.
Plastic 3D printing processes mostly fall into three categories: material extrusion (e.g. FFF, FDM), vat polymerization (e.g. SLA, DLP), and powder bed fusion (e.g. SLS, MJF). FFF and SLA are readily available in consumer and professional desktop machines, while powder bed fusion (PBF) is best for industrial use.
The most common type of plastic 3D printing technology is Fused Deposition Modeling (FDM) or Fused Filament Fabrication (FFF). The FDM name is trademarked by the Stratasys company, whose founder Scott Crump invented the technology. In this process, a heated nozzle melts and extrudes thermoplastic filament onto a build plate.
Some material extrusion printers can 3D print plastic pellets instead of filament. Pellets are touted to reduce print times and, as they are mass-produced for conventional manufacturing methods like injection molding, drastically lower costs.
The most common FDM 3D printing materials are ABS, PLA, and their various blends. More advanced FDM printers can also print with other specialized materials that offer properties like higher heat resistance, impact resistance, chemical resistance, and rigidity.
| Material | Features | Applications |
|---|---|---|
| ABS (acrylonitrile butadiene styrene) | Tough and durable Heat and impact resistant Requires a heated bed to print Requires ventilation | Functional prototypes |
| PLA (polylactic acid) | The easiest FDM materials to print Rigid, strong, but brittle Less resistant to heat and chemicals Biodegradable Odorless | Concept models Looks-like prototypes |
| PETG (polyethylene terephthalate glycol) | Compatible with lower printing temperatures for faster production Humidity and chemical resistant High transparency Can be food safe | Waterproof applications Snap-fit components |
| Nylon | Strong, durable, and lightweight Tough and partially flexible Heat and impact resistant Very complex to print on FDM | Functional prototypes Wear resistant parts |
| TPU (thermoplastic polyurethane) | Flexible and stretchable Impact resistant Excellent vibration dampening | Flexible prototypes |
| PVA (polyvinyl alcohol) | Soluble support material Dissolves in water | Support material |
| HIPS (high impact polystyrene) | Soluble support material most commonly used with ABS Dissolves in chemical limonene | Support material |
| Composites (carbon fiber, kevlar, fiberglass) | Rigid, strong, or extremely tough Compatibility limited to some expensive industrial FDM 3D printers | Functional prototypes Jigs, fixtures, and tooling |
Stereolithography (SLA) printers are also quite popular for plastic 3D printing. They have become very affordable in recent years, with some models available for under $200. SLA printing is a vat polymerization process: a laser or light source polymerizes (solidifies) a vat (tank) of resin.
SLA photopolymer materials encompass a range of different thermal and mechanical properties. Options include brittle materials to more durable polycarbonate-, polypropylene-, and ABS-like materials.
SLA 3D printing is highly versatile, offering resin formulations with a wide range of optical, mechanical, and thermal properties to match those of standard, engineering, and industrial thermoplastics. Resin 3D printing also offers the broadest spectrum of biocompatible materials.
The specific material availability is highly dependent on the manufacturer and printer. Formlabs offers the most comprehensive resin library with 40+ SLA 3D printing materials.
| Formlabs Materials | Features | Applications |
|---|---|---|
| Standard Resins | High resolution Smooth, matte surface finish | Concept models Looks-like prototypes |
| Clear Resin | The only truly clear material for plastic 3D printing Polishes to near optical transparency | Parts requiring optical transparency Millifluidics |
| Draft Resin | One of the fastest materials for 3D printing 4x faster than standard resins, up to 10x faster than FDM | Initial Prototypes Rapid Iterations |
| Tough and Durable Resins | Strong, robust, functional, and dynamic materials Can handle compression, stretching, bending, and impacts without breaking Various materials with properties similar to ABS or PE | Housings and enclosures Jigs and fixtures Connectors Wear-and-tear prototypes |
| Rigid Resins | Highly filled, strong and stiff materials that resist bending Thermally and chemically resistant Dimensionally stable under load | Jigs, fixtures, and tooling Turbines and fan blades Fluid and airflow components Electrical casings and automotive housings |
| Polyurethane Resins | Excellent long-term durability UV, temperature, and humidity stable Flame retardancy, sterilizability, and chemical and abrasion resistance | High performance automotive, aerospace, and machinery components Robust and rugged end-use parts Tough, longer-lasting functional prototypes |
| High Temp Resin | High temperature resistance High precision | Hot air, gas, and fluid flow Heat resistant mounts, housings, and fixtures Molds and inserts |
| Flexible and Elastic Resins | Flexibility of rubber, TPU, or silicone Can withstand bending, flexing, and compression Holds up to repeated cycles without tearing | Consumer goods prototyping Compliant features for robotics Medical devices and anatomical models Special effects props and models |
| Silicone 40A Resin | The first accessible 100% silicone 3D printing material Superior material properties of cast silicone | Functional prototypes, validation units, and small batches of silicone parts Customized medical devices Flexible fixtures, masking tools, and soft molds for casting urethane or resin |
| Medical and dental resins | A wide range of biocompatible resins for producing medical and dental appliances | Dental and medical appliances, including surgical guides, dentures, and prosthetics |
| Jewelry resins | Materials for investment casting and vulcanized rubber molding Easy to cast, with intricate details and strong shape retention | Try-on pieces Masters for reusable molds Custom jewelry |
| ESD Resin | ESD-safe material to improve electronics manufacturing workflows | Tooling & fixturing for electronics manufacturing Anti-static prototypes and end-use components Custom trays for component handling and storage |
| Flame Retardant (FR) Resin | Flame retardant, heat-resistant, stiff, and creep-resistant material for indoor and industrial environments with high temperatures or ignition sources | Interior parts in airplanes, automobiles, and railways Custom jigs, fixtures, and replacement parts for industrial environments Protective and internal consumer or medical electronics components |
| Alumina 4N Resin | 99.99% pure alumina technical ceramic Exceptional thermal, mechanical, and conductive properties | Heat and electrical insulators Heavy-duty tools Chemically resistant and wear-resistant components |
Selective Laser Sintering (SLS) is a PBF process that produces high-quality 3D plastic parts suitable for functional prototypes and even small production runs. In SLS, a laser sinters powder particles together. This technology can produce very complex geometries as well as moving parts that do not require assembly. One downside to this technology, and the reason why SLS is not suitable for consumer use, is that parts require tedious, time-consuming post-processing.
The material selection for SLS is limited compared to FDM and SLA, but the available materials have excellent mechanical characteristics, with strength resembling injection-molded parts. The most common material for selective laser sintering is nylon, a popular engineering thermoplastic with excellent mechanical properties. Nylon is lightweight, strong, and flexible, as well as stable against impact, chemicals, heat, UV light, water, and dirt. Other popular SLS 3D printing materials include polypropylene (PP) and the flexible TPU.
| Material | Description | Applications |
|---|---|---|
| Nylon 12 | Strong, stiff, sturdy, and durable Impact-resistant and can endure repeated wear and tear Resistant to UV, light, heat, moisture, solvents, temperature, and water | Functional prototyping End-use parts Medical devices |
| Nylon 11 | Similar properties to Nylon 12, but with a higher elasticity, elongation at break, and impact resistance, but lower stiffness | Functional prototyping End-use parts Medical devices |
| Nylon composites | Nylon materials reinforced with glass, aluminum, or carbon fiber for added strength and rigidity | Functional prototyping Structural end-use parts |
| Polypropylene | Ductile and durable Chemically resistant Watertight Weldable | Functional prototyping End-use parts Medical devices |
| TPU | Flexible, elastic, and rubbery Resilient to deformation High UV stability Great shock absorption | Functional prototyping Flexible, rubber-like end-use parts Medical devices |
To explore our 3D printing services, please contact dgyixun@yixun-dg.com.
