In recent years, it has been in a very chaotic and fuzzy state: on the one hand, it is a popular printer made of PLA material, which is only used for non-test applications for basic appearance evaluation; on the other hand, it is the application of industrial-grade standard test-level equipment and materials, even using FDM principles Metal material printing. The price range between them is ten thousand yuan to one million yuan, and the difference between the two is only visually observed: the difference between the volume that can be placed on the table and weighs more than 1 ton, and the interior is the high-temperature resistant moving parts of the equipment forming warehouse. Motion control software, repetition accuracy guarantee based on different materials, and many other essential differences.
Under the general term FDM, the core is not only the difference between the high-temperature closed molding chamber and the real engineering plastics. In order to understand what materials are needed to produce durable parts, we have a general introduction from personal printers to industrial printing. PLA, 25% ABS plus PLA, PETG are consumables used in popular desktop printers, but these are far from high-quality and industrial application-level materials.
ABS, PC, nylon, PPS, these are high-temperature FDM plastic sequences for industrial 3D printing, which are currently extended to high-grade engineering materials such as ULTEM and PEKK. The simultaneous guarantee of the molding accuracy and material performance of these high-grade materials is industrial-grade equipment The embodiment!
Plastics with excellent properties are very useful in the aerospace field. Of course, it cannot be used for plastic printing rocket motors. Its thermal stability has not yet reached such a high level, but it is very suitable for making various parts around. An example is the “climate control” project of Stratasys and Atlas V. Rockets, where 16 plastic parts were printed instead of 140 metal parts, making it faster, lighter and more economical. This is not a theoretical project, it has already flown into space.
Another example is aviation. The application range of aircraft interior and airtight parts is very large. In order to reduce the weight of the parts, try to switch to plastic when possible. When aircraft manufacturing involves details of engine parts or fuselage frames, metal can be printed directly, but structural elements with less load (such as cabin ventilation and interior parts) are best made of high-performance plastics. Currently, mainstream airlines are increasingly accepting this trend.
We return from the sky to the ground: What is interesting is the other properties of engineering plastics. Chemical resistance, high temperature resistance, anti-static, biocompatibility, etc. may enable 3D printing to create part structures that cannot be obtained by traditional processes. Compared with metal printing, plastic printing is cheaper. The printed products can be more used in medicine, oil and gas industry and chemical industry.
Why not launch PLA into space and use ULTEM materials to make the air vents of the aircraft cabin? Engineering plastics are used in a series of requirements related to high temperature, low temperature, fire resistance, and mechanical strength. Generally speaking, these requirements are integrated rather than one of them. Therefore, when it interacts with PLA and the environment, burning and floating debris are uncontrollable. At present, such engineering plastics must actually be completed in industrial printing equipment using higher basic FDM/FFF technology.
Polycarbonate is a commonly used plastic in industry, with high impact resistance and transparency, and can also meet the needs of FDM printing. This material can maintain temperature better than ABS, is acid resistant, but is sensitive to ultraviolet radiation and decomposes under the influence of petroleum products.
The maximum operating temperature of polycarbonate products is 130°C. Polycarbonate is biologically inert and its products can be sterilized, which allows you to use it for printing pharmaceutical packaging and accessories.
Stratasys PC, PC-ISO (available for Fortus printers). The first is for general use, and the second is for medical use with biocompatibility certification.
PC-ABS combines the inherent wear resistance and toughness of ABS, with higher impact and working temperature. Maintain strength at low temperatures (up to -50°C). Unlike pure PC, it is more suitable for situations where it is necessary to eliminate the layered structure of parts by sanding or sandblasting.
Application: Used for parts and small batch production of housing and control components, replacing batches of plastic parts in equipment.
Nylon polyamide is used in the production of synthetic fibers, which is a very popular printing material that uses selective laser sintering (SLS) for printing. When printing with FDM/FFF technology, nylon 6 (nylon), nylon 66 (nylon) and nylon 12 are mainly used. Common characteristics of nylon-based filaments include chemical inertness and friction resistance. Nylon 12 is more flexible and elastic than PA6 and PA66. The maximum working temperature is 100°C, and the maximum temperature can reach 120°C.
First of all, nylon is used to print gears. The best material for this purpose, you can use it to work on a regular 3D printer with a closed camera. Wear resistance allows you to make traction, cams, sliding bushes. In the production lines of many manufacturers, there are nylon-based composite filaments with higher mechanical strength.
Stratasys nylon 6, nylon 12, nylon 12CF. The latter is a composite material filled with filament carbon fibers.
You can use polycarbonate or polyamide on a regular 3D printer. The following filaments are more complicated. They need to be printed with other extruders and maintain the temperature in the working room, that is, you need special equipment for printing with high-temperature plastics. However, there are exceptions. For example, in the National Aeronautics and Space Administration (NASA), in order to conduct experiments, they modernized the popular Lulzbot TAZ in the United States to use high-temperature filaments.
The working temperature of PEEK products reaches 250°C, and it can be heated to 300°C for a short time-reinforced filament indicator. PEEK has two disadvantages: high price and moderate impact resistance. The rest are advantages, self-extinguishing, heat-resistant, and chemically inert. PEEK produces medical equipment and implants, and its wear resistance allows it to print out the details of the machine.
The plastic developed by Ultem SABIC has slightly lower PEI characteristics than PEEK, but the cost is much lower. Ultem 1010 and 9085 are Stratasys’ core materials for printing functional parts. The aerospace industry has great demand for PEI, which is much smaller than aluminum alloy. The working temperature of the product can reach 217°C depending on the manufacturer, and it can reach 213°C according to the result of Stratasys test.
PEI has the same advantages as PEEK, chemical resistance and high temperature resistance, and high mechanical strength. It is this material that Stratasys promotes, which can replace metals in aerospace, for the manufacture of drones, molding tools, and rapid printing of functional parts in trials.
In the example at the beginning of this report, the Atlas V rocket cooling system components and plastic components for an Airbus aircraft are made of Ultem 9085.
Another material that combines temperature resistance, mechanical strength and chemical resistance. Stratasys PPSF has been certified for aerospace and medical applications. It is positioned as a raw material for the production of auxiliary medical equipment, which can be sterilized in a steam autoclave. It is used in the manufacture of parts for laboratory equipment in the chemical industry.
The original color of the material is white, it is biocompatible (ISO 10993 USP VI) and can be sterilized by gamma or EtO. Usually used in food and pharmaceutical packaging and medical device manufacturing. The strength and medical compatibility of materials can be used for conceptual modeling, functional prototyping and end-use parts. This material can be printed with Stratasys Fortus series equipment.
Most materials used for FDM printing are available in composite versions. If we talk about PLA, add metal or wood powder to PLA to change its aesthetic properties. Engineering plastics are reinforced with carbon fiber to increase the rigidity of the parts. The effect of these additives on the properties of plastics depends not only on their quantity, but also on the size of the fibers. If fine powder can be regarded as a decorative additive, fiber has significantly changed the characteristics of plastics. The word “carbon” in the material name does not mean excellent performance, you need to check the test results. For example: Stratasys Nylon12CF has almost twice the tensile strength of Nylon12 when tested along the layer.
A special option is the continuous enhancement that Markforged has achieved. The company provides reinforced filaments for FDM co-printing with other plastics.
Engineering plastics not only have high temperature resistance and mechanical strength. For housings or boxes used to store electronic devices, and under working conditions with flammable volatile liquids, materials with antistatic properties are required. In the Stratasys product line, ABS-ESD7 and Nylon12 CF materials are suitable.
Conventional ABS is not resistant to ultraviolet radiation, which limits its use outdoors without a protective coating. As an alternative, ASA is proposed, which is similar to ABS except for its excellent UV resistance.
Plastic can replace metal in many areas because it surpasses metal in terms of lightness, heat and electrical insulation, and durability. However, in areas with high requirements for special alloys and mechanical strength, the best FDM materials currently printed cannot reach the physical indicators of metal products.
in conclusion. In short: the printing materials considered above are different from conventional materials with higher printing temperatures. These require special equipment for printing, and the manufactured parts have high heat resistance and mechanical strength.
In order to use this kind of wire, you need to use an industrial-grade 3D printer with an extruder working temperature of 350°C and a thermally stable molding space. As a personal hobbyist or elementary education, you can use desktop printing equipment. They do not require most professional Knowledge, but if you are an engineer or a professional who customizes parts based on production engineering materials, please be sure to choose an industrial-grade equipment and corresponding materials that can meet your needs, or a comprehensive service supply that can provide services with such equipment Quotient.
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