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What are the 3D printing materials ?
3D printing manufacturing technology is mainly composed of three major elements: accurate three-dimensional design; powerful molding equipment; materials that meet product performance and molding process.
At present, there are more than 200 kinds of 3D printing materials , which generally have extremely high requirements for heat resistance, flexibility, stability, and sensitivity. They are all developed for 3D printing equipment and processes.
It can be seen that as the 3D printing storm sweeps the world today, 3D printing materials as a key part of it are undoubtedly helping to stir the storm. As 3D printing " ink " , 3D printing materials development difficult, high cost, is still constructing 3D constraint in the printing ecosystem.
Today, let's " break the news " about these 3D printed materials.
As the most widely used class of 3D printing materials, engineering plastics account for more than 90% of commercial 3D printing materials . They are used in FDM equipment and are plastics with excellent strength, impact resistance, heat resistance, hardness and aging resistance. Mainly include thermoplastic materials and thermosetting materials. At present, the common engineering plastics are mainly the following categories:
ABS : One of the most popular FDM thermoplastics at present , usually filamentous; with good hot melt and impact strength, it is the engineering plastic of choice for 3D printing through fusion deposition . The advantage is that the printed parts have good mechanical strength and high stability. It can also be used with soluble support materials. It can be a variety of colors, or even custom colors, such as Stratasys 's ABS plus material FDM can provide aid art as selected tooth color, white, black and other nine colors.
PC : White engineering plastic that can be combined with FDM technology to create durable models, tools, or final product parts. Compared with ABS plastic, PC material has better strength, high temperature resistance, impact resistance and other advantages, so it can be used as the final component for the application of super engineering products. Samples made using PC materials can be directly assembled and used, and are widely used in automotive manufacturing, aerospace, medical equipment and other fields.
PA : High mechanical strength, with certain flexibility, heat resistance and friction resistance. Stratasys ' FDM Nylon 12 has excellent strength characteristics and fatigue resistance, and is resistant to moderately corrosive chemicals. It is suitable for repeated closing, snap-on and vibration-resistant parts, while Stratasys ' FDM Nylon 6 also has advantages over other The strength and toughness of thermoplastics can withstand rigorous functional tests, making them ideal for product manufacturers and development engineers in the automotive, aerospace, consumer products, and industrial manufacturing industries.
Due to the fast curing speed, the photosensitive resin has excellent surface drying properties , and the appearance of the product after molding is smooth, and it can be transparent to translucent frosted. Because of its good fluidity and instant photo-curing properties, liquid photosensitive resins have become the materials of choice for 3D printing consumables for high-precision product printing. There are currently three main categories:
Oligomers: Low-molecular polymers containing unsaturated bonds. There are many types, and all types of acrylic resins are the most common. Oligomers are the most basic materials in photo-curable materials, and determine the basic physical and chemical properties of the photosensitive resin such as viscosity, hardness, elongation at break.
Reactive diluent: is a small molecule solvent containing double bonds. The reactive diluent adjusts the viscosity of the system, reduces the viscosity of the oligomer, and prevents the nozzle from being blocked due to too high viscosity. Reactive diluents also participate in the photocuring reaction, affecting the kinetics of the polymerization reaction, the degree of polymerization, and the physical properties of the cured product.
Photoinitiator: The most critical component determines the quality of the photocurable material and the speed of the photocuring reaction. It can be divided into ultraviolet initiator and visible light initiator according to the energy of initiating radiation. Since violet advantage agent having a storage-stable outer photoinitiator, now 3D light printing market, the initiator is used in an ultraviolet photoinitiator.
3D printed metal materials exist in the form of metal powder, metal foil, and wire. At present, the market share of metal materials is small, but the expansion rate is the fastest.
Metal materials can be used in industrial-grade 3D printers such as selective laser sintering ( SLS ), direct metal laser sintering ( DMLS ), and electron beam melting ( EMB ) . If metal materials are added to some engineering plastic materials (such as ABS ), it can be made into wires with certain metal properties suitable for FDM models.
In the process of 3D printing metal materials , factors such as solid-liquid phase change , surface diffusion, and heat conduction of the metal need to be considered , and the shape of the metal powder directly affects the quality of the 3D printed product. Common metal materials today include titanium alloys, stainless steels, cobalt chromium alloys, and aluminum alloys. Precious metal powders such as gold and silver are occasionally used to print jewelry or artwork.
Aluminum silicate ceramic powder can be used for 3D printing ceramic products, which are generally in powder form and are usually used in selective laser sintering ( SLS ) printers. Ceramic powder for 3D printing is a mixture of ceramic powder and a binder powder.
The ratio of ceramic powder and binder powder will directly affect the performance of ceramic parts. The larger the amount of binder, the easier the sintering process, but the larger the part shrinkage during the post-processing process, which will affect the dimensional accuracy of the part. If the amount of the binder is small, it is difficult to sinter.
Ceramic materials have the advantages of high strength, high temperature resistance and corrosion resistance, and have the potential to be used in aerospace and automotive fields. At the same time, ceramic materials can choose many colors, which can print products with vivid shapes and rich colors, which are ideal choices for crafts, architecture and sanitary products.
Biological 3D printing materials mainly include scaffold materials and direct cell printing materials. 3D printing materials of scaffolds need to meet: good biocompatibility, non-toxic to cells and the body; good biodegradability, can be completely absorbed or excreted by the body; good mechanical properties, have certain mechanical strength and plastic The structure can be kept stable for a long time and has a high porosity; good surface compatibility is conducive to cell adhesion and growth on the surface of the material. It is mainly divided into the following categories:
PLA : The best raw material for 3D printing at first, with a variety of translucent colors and glossy texture. It is derived from renewable resources - corn starch and sugar cane, is non-toxic and tasteless, and is an environmentally friendly plastic that can degrade.
PETG : It has outstanding thermoformability, toughness and weather resistance, short thermoforming cycle, low temperature, high yield, and has the advantages of both PLA and ABS.
PCL : It is a biodegradable polyester with a low melting point. It is often used for special purposes such as drug delivery equipment, sutures, etc., and also has shape memory. In the medical field, it can be used to print heart stents, etc.
Carbon fiber material is an emerging 3D printing material. Its strength is five times that of steel but its weight is only 1/3 of that. It also has the advantages of high temperature resistance and corrosion resistance.
Conductive printing materials are a type of thermoplastic material that can be used to make 3D printed products with electronic or mechanical functions , such as circuit boards, flashlights, and wearable lighting equipment.
