3D printing typically utilizes digital material printers. While previously used in mold making and industrial design for model creation, it is increasingly being used for the direct manufacturing of some products, with some companies already using parts printed using this technology. This technology has applications in jewelry, footwear, industrial design, architecture, engineering and construction, automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, firearms, and other fields.
3D printing technology uses a computer-designed three-dimensional model as a blueprint. Through software layering and discretization and numerical control molding systems, special materials such as metal powder, ceramic powder, plastic, and cell tissue are deposited and bonded layer by layer using laser beams, hot melt nozzles, etc., and finally stacked to form a solid product.
3D printing materials are mainly divided into nine categories:
The first category is photosensitive resin materials, mainly including photocurable resins such as acrylic resins, epoxy resins, and polyester resins. These materials can undergo a polymerization reaction and cure under ultraviolet light, generally appearing in a liquid state. They can be used to manufacture structural parts such as blades and gears for aerospace applications.
The second category consists of engineering plastics, primarily including ABS, polycarbonate, and polyamide. ABS combines toughness, hardness, and rigidity, making it widely used in machinery, electrical, textile, automotive, aircraft, shipbuilding, and chemical industries. Polycarbonate exhibits excellent impact resistance, heat distortion resistance, fire resistance, and high hardness, making it suitable for manufacturing various parts for cars and light trucks, mainly in lighting systems, dashboards, heating plates, defrosters, and bumpers. Polyamide, also known as nylon, is characterized by its strength, wear resistance, self-lubrication, and wide operating temperature range. It primarily replaces copper and other non-ferrous metals in the manufacture of mechanical, chemical, and electrical parts, such as diesel engine fuel pump gears, water pumps, high-pressure seals, and fuel lines.
The third category: metallic materials, mainly including titanium alloys, stainless steel, aluminum alloys, and other precious metals. Titanium alloys have high strength and high heat resistance. Compared with other metals, titanium alloys also have advantages such as good corrosion resistance, good low-temperature performance, and high chemical activity, therefore they are widely used in the manufacture of aircraft engine compressor components, rockets, missiles, and high-speed aircraft structural components. Stainless steel has advantages such as easy weldability, corrosion resistance, strong polishability, and heat resistance, and is widely used in the construction, food processing, catering, brewing, chemical, and medical device fields. Aluminum alloys have characteristics such as low density, low melting point, and high plasticity. Aluminum alloys are currently the most widely used alloys, and are widely used in aviation, aerospace, automotive, machinery manufacturing, shipbuilding, and chemical industries. Other precious metals, such as gold, have characteristics such as good electrical and thermal conductivity and high stability, and are mainly used in fields with special material requirements, such as electronics, chemical industry, and aerospace.
The fourth category is ceramic materials, mainly including natural silicate materials such as clay and kaolin, and high-purity synthetic materials such as oxide ceramics, nitride ceramics, and carbide ceramics. Because most ceramic materials have very high melting points or even no melting point, they are difficult to directly shape using external energy. Most require post-forming processing (drying, sintering, etc.) to obtain the final product, which limits the widespread use of ceramic materials in the 3D printing industry. However, ceramic materials possess advantages that polymers and metals lack, such as high hardness, high temperature resistance, and stable physicochemical properties. Therefore, they have broad application prospects in aerospace, electronics, automotive, energy, and biomedical industries.
The fifth category is biomaterials, mainly including biomedical metallic materials, biomedical polymer materials, biomedical ceramic materials, and bio-derived materials. Bio-derived materials are biomedical materials formed from specially treated natural biological tissues, also known as bioregenerative materials. The application of biomaterials in 3D printing can be divided into two areas. The first category utilizes biomaterials in food processing and packaging due to their degradability, low melting point, biological properties, and environmental friendliness. The second category, based on the renewability, tissue compatibility, inductive properties, mechanical compliance, and degradation compliance of biomaterials, is widely used in the medical field. The application of biomaterials in the medical field can be divided into three levels: prosthesis manufacturing, indirect 3D cell assembly manufacturing, and direct 3D cell manufacturing.
Category 6: Rubber materials. Rubber materials possess a variety of elastic material characteristics, such as Shore A hardness, elongation at break, tear strength, and tensile strength, making them very suitable for applications requiring non-slip or soft surfaces, such as consumer electronics, medical devices, and automotive interiors.
Category 7: Sand and gravel materials, primarily quartz sand. In 3D printing, based on its traditional functions and properties, sand and gravel materials are mainly used in construction to manufacture building materials or structures. Low cost, high efficiency, and environmental friendliness are the advantages of sand and gravel materials in the field of 3D printed construction.
Category 8: Graphene materials are a new type of material with a single-layer two-dimensional honeycomb lattice structure formed by sp² hybridized carbon atoms tightly packed together. Graphene materials possess excellent optical, electrical, and mechanical properties and can be used to replace various traditional materials, making them a revolutionary material for the future. With the development of graphene preparation and application technologies, graphene materials will be able to be applied in more downstream products and fields. According to the Chinese Academy of Sciences, by around 2024, graphene devices are expected to replace complementary metal-oxide-semiconductor devices and be applied in research fields such as nanoelectronic devices, photoelectrochemical cells, and ultralight aircraft materials.
Category 9: Cellulose materials, a type of macromolecular polysaccharide composed of glucose, insoluble in water and common organic solvents. Cellulose is a major component of plant cell walls and is the most widely distributed and abundant polysaccharide in nature, accounting for more than 50% of the carbon content in the plant kingdom. Researchers have been dedicated to developing methods for 3D printing using cellulose, and some breakthroughs have been achieved. Cellulose materials also have some drawbacks, such as high cost, poor scalability, and the potential for pollutants when combined with plastics.
3D printing technology is mainly divided into desktop and industrial types. Desktop 3D printers represent the initial stage of 3D printing technology, providing a clear and intuitive explanation of the printing process. Due to their relatively low price, portability, and ease of operation, desktop 3D printers are primarily used in homes and offices. Industrial 3D printers are mainly divided into rapid prototyping machines and direct product manufacturing machines. Industrial 3D printers are better suited for mass production of molds and metal parts, meeting the requirements for high precision and short production times. Using computer-controlled lasers or electron beams, industrial 3D printers can print complex and precise structures that traditional machining methods cannot achieve, eliminating unnecessary manufacturing processes and maximizing material utilization.
The emergence of 3D printing technology has reduced the complexity of product manufacturing, expanded the scope of production, shortened production time, improved production efficiency, increased raw material utilization, and enhanced the accuracy of product specifications. At the same time, 3D printing technology meets customers' personalized customization needs, enabling the development of a wider variety of products.
my country's 3D printing industry currently faces several shortcomings. Due to limitations in technology and equipment, Chinese 3D printing companies can only process small batches of small-sized parts, making it difficult to replace large-scale, mass production. Furthermore, the persistent shortage of 3D printing materials in my country remains unresolved, with the main source still relying on imports from the United States. This places high cost pressures on my country's already limited number of 3D printing companies, further restricting the scale and application scope of the industry.
The 3D printing industry is a highly promising sector. With the continuous increase in the world's population, the demand for housing will continue to rise, inevitably leading to increased building heights in the future. Increased building height will significantly raise the requirements for construction technology, labor, and material standards; simultaneously, the risks of construction will increase exponentially. Mature 3D printing technology can mitigate the risks of manually constructing high-rises, reduce the difficulty of construction, and improve efficiency. On the other hand, with humanity's continuous exploration of the universe and the continuous advancement of technology, plans to establish bases or establish colonies on other planets in the future are becoming possible. Mature 3D printing technology can be applied to future "interstellar colonization" activities to meet the manufacturing needs of astronauts in interstellar space and reduce the difficulty of preparing for related interstellar activities.
The applications of 3D printing technology are certainly not limited to what we are currently familiar with. The hidden value of this industry in the future remains to be explored.
