In-depth analysis: 3D printing technology and polymer materials
The concept of 3D printing, also known as three-dimensional printing or rapid prototyping, can be traced back to the United States in the 19th century. It is a technology that produces three-dimensional objects directly from digital models by depositing materials. Records indicate that 3D printing technology began to be used in practice as early as the 1980s, earning the name "Rapid Prototyping Manufacturing." Currently, 3D printing technology has brought about comprehensive and profound changes in product design, manufacturing processes, manufacturing equipment, material preparation, biomedicine, and other fields, becoming a key symbol of the Third Industrial Revolution and attracting significant attention worldwide. my country's 3D printing industry started relatively late, with generally low technical standards and a relatively small scale of industrialization. However, it has shown strong development momentum, and its application in polymer materials is still in the exploratory stage.
Principles and Characteristics of 3D Printing Technology
1. Technical Principles
3D printing technology is fundamentally similar to laser prototyping technology. Simply put, it uses layered processing and additive manufacturing to create a 3D object by gradually adding material. It is called a "printer" because of its technical principles; the layered processing of a 3D printer is very similar to that of an inkjet printer. First, a 3D model of the desired component is designed using a computer. Based on process requirements, this model is then discretized into a series of ordered units according to a specific pattern, typically in the Z direction with a specific thickness. This transforms the original 3D CAD model into a series of layers. Processing parameters are then input based on the contour information of each layer, and the system automatically generates NC code. Finally, the layers are formed and automatically connected to create a 3D physical entity.
2. Advantages
1. The most direct benefit is material conservation, eliminating the need for scrap, improving material utilization, and reducing costs by eliminating the production line.
2. It can achieve a high degree of precision and complexity, not only capable of expressing curved designs.
3. It eliminates the need for traditional tools, fixtures, machine tools, or molds; any shape can be generated directly from computer graphics data.
4. It can automatically, quickly, directly, and accurately convert computer designs into models, and even directly manufacture parts or molds, effectively shortening product development cycles.
5. 3D printing can produce parts in just hours. It allows designers and developers to make the leap from flat drawings to physical objects.
Sixth, it can print pre-assembled products, significantly reducing assembly costs. It can even challenge mass production methods.
3. Disadvantages
Any product should be functional, but currently, due to limitations in materials and other factors, the practicality of products manufactured via 3D printing is questionable. ① Strength: While houses and cars can certainly be "printed," whether they can withstand wind and rain and operate smoothly on the road remains a challenge. ② Precision: Due to the "step effect" of layered manufacturing, although each layer is very thin, at a certain microscopic scale, it still forms "steps" of a certain thickness. If the surface of the object to be manufactured is curved, this will cause accuracy deviations. ③ Material limitations: Currently, the materials available for 3D printers are very limited, consisting of plaster, inorganic powders, photosensitive resins, and plastics. The materials that can be used in 3D printing are very limited, mainly plastics, and printers are also very picky about the materials they use.
Application of 3D printing technology in polymer materials
1. Types of polymer raw materials
As an important part of 3D printing, materials also play a vital role. Currently, commonly used 3D printing polymer materials include polyamide, polyester, polycarbonate, polyethylene, polypropylene and acrylonitrile-butadiene. There are many types of polymers in photocuring 3D printing, among which the most commonly used ones include polyurethane acrylic resin, epoxy acrylic resin, polyacrylic resin and amino acrylic resin.
2. Common application processes
Currently, the most commonly used 3D printing polymer material technologies include photocuring 3D printing (SLA), fused deposition modeling (FDM), selective laser sintering (SLS) and so on [5].
Photocuring 3D printing
The working principle of photocuring 3D printing (SLA) is similar to that of inkjet printing. Under the control of digital signals, the liquid photosensitive resin in the working chamber of the nozzle forms droplets in an instant. Under the action of pressure, the nozzle sprays it to the specified position, and then the photosensitive resin is cured by ultraviolet light. After curing, it is stacked layer by layer to obtain a formed part. The forming process is as follows: First, the print head is controlled to move in the X and Y directions according to the cross-sectional shape of the component. The solid material is printed in the relevant solid areas of the given cross-section, and support material is printed in the support areas. These materials are then cured under UV light. The build platform then descends to a certain height in the Z direction, and the print head prints and cures the next layer. This process continues layer by layer until the workpiece is complete. Finally, the support material is removed to obtain the desired part.
Photocurable 3D printing materials consist of a solid material and support material. Support materials can be further categorized as phase-change wax support materials and photocurable support materials depending on their curing method. Photocurable support materials, commonly known as photosensitive resins, primarily consist of oligomers, reactive diluents (active monomers), photoinitiators, and other additives. Due to an earlier start in the field and the availability of 3D printers to support research, 3D printing with photosensitive resins is more mature overseas. Currently, the leading companies overseas are OBJET of Israel and 3D Systems of the United States, which dominate the 3D printing photosensitive resin market. However, these companies consider photosensitive resins their key technology, rarely publicly releasing their research results. They bundle these resins with their photocurable 3D printers for sale.
The polymer raw materials used in photocurable 3D printing to produce biodegradable scaffold materials include poly(hydroxypropyl fumarate) (PPF), poly(D,L-lactide) (PLA), poly(-caprolactone) (PCL), polycarbonate, and natural polymers such as protein polysaccharides, modified with photosensitive molecules. To reduce the viscosity of the liquid resin raw materials, small molecule solvents or diluents are added. Commonly used ones include diethyl fumarate (DEF) and N-vinylpyrrolidone (NVP), which participate in the photopolymerization reaction, and ethyl lactate, which does not. The 3D molding materials produced by this technology have controllable pore size, porosity, and pore distribution.
Fused Deposition Modeling
Fused Deposition Modeling (FDM) uses a hot melt nozzle to extrude and deposit molten material along a computer-controlled path, where it solidifies and forms the desired 3D product. Layer by layer, the material is deposited and solidified, and the support material is removed to create the desired 3D product. The raw materials used in FDM technology are typically heat-shrinkable polymers, including acrylonitrile-butadiene, polyamide, polyester, polycarbonate, polyethylene, and polypropylene. This technology is characterized by high precision, good surface quality, simple molding machine structure, and environmental friendliness. However, its disadvantage is its high operating temperature.
In recent years, the use of FDM technology to prepare biomedical polymer materials has also gained increasing attention, particularly in the preparation of biodegradable scaffolds using aliphatic polyesters as raw materials, where considerable progress has been made. Material properties are affected by factors such as pressure gradient, melt flow rate, and temperature gradient. Polyester-inorganic particle composites can also be used in fused deposition modeling to create 3D scaffolds.
Selective Laser Sintering
Selective laser sintering (SLS) uses a laser beam to scan along a computer-defined path, melting, bonding, and solidifying powdered materials on a worktable. Once a layer is scanned, the worktable is moved to apply new powdered materials to the surface of the solidified layer. Scanning and bonding are repeated layer by layer to create a three-dimensional material. Unlike SLA technology, which uses UV light to induce polymerization or cross-linking reactions in liquid resin layer by layer, SLS technology uses laser-generated high temperatures to melt and bond the powdered materials to form a three-dimensional material. The raw materials commonly used in SLS technology include plastic, ceramic, metal powder, etc. Its advantages are fast processing speed and no need for support materials, but its disadvantages are that the surface of the molded product is rough and requires subsequent processing. Dust and toxic gases are generated during the processing, and continuous high temperature may cause the degradation of polymer materials, deformation of bioactive molecules or cell apoptosis. This technology cannot be used to prepare hydrogel scaffolds. Using biodegradable polymers as raw materials and SLS technology is also an effective way to prepare 3D medical polymer materials with controllable external morphology and internal structure. The main parameters that affect the performance of the scaffold include particle size, laser energy, laser scanning rate, partial bed temperature, etc.
Introduction to the application of 3D printing technology polymer materials
(1) Mechanical manufacturing: 3D printing technology is used to manufacture aircraft parts, bicycles, rifles, racing car parts, etc.
(2) Medical industry: In the medical field, 3D printing is used to make dentures, femoral heads, knees and other bone and joint technology. The application is also very wide and the technology is becoming more and more mature.
(3) Construction industry: Engineers and designers have accepted the use of 3D printers to print architectural models. This method is fast, low-cost, environmentally friendly, and exquisitely made, fully meeting the designer's requirements. At the same time, it can save a lot of materials. (4) Automobile manufacturing industry: 3D printing technology is used to manufacture automatic transmission housings for automobile companies. Automobile companies will test the transmissions under various extreme conditions, and some of the components are made using 3D printing methods. After the shape is finalized, the mold is opened and then mass production is carried out according to traditional manufacturing methods. This will greatly reduce costs. Comments from Mohou.com: 3D printing technology represents a new trend in the development of the manufacturing industry. It and the emergence of other digital production models will promote the realization of the third industrial revolution. It can fully apply the molding technology of polymer materials to prepare complex integrated polymer material devices. The polymer medical industry will bring development opportunities for 3D printing technology. At the same time, polymer materials will provide 3D printing technology with the characteristics of light weight, high strength and corrosion resistance.
In today's rapidly evolving manufacturing landscape, 3D printing has become a disruptive technology, revolutionizing how products are designed and produced. At the heart of this innovation lies the use of polymer materials, which play a crucial role in the 3D printing process. We delve into this fascinating intersection, exploring the impact of 3D printing on manufacturing and the crucial role polymer materials play in this transformation.
Huateng Metal Products (Dongguan) Co., Ltd. is a leading company leveraging 3D printing technology and polymer materials to drive innovation and meet the evolving needs of the market. The company specializes in precision engineering and advanced manufacturing solutions, leveraging the potential of 3D printing to provide cutting-edge products to its customers.
One of the key advantages of 3D printing technology is its ability to create complex geometries with unparalleled precision. This complexity is facilitated by the wide range of polymer materials that can be used in the 3D printing process. From thermoplastics to photopolymers, these materials possess a wide range of mechanical, thermal, and chemical properties suitable for a wide range of applications.
Furthermore, the use of polymer materials in 3D printing can produce lightweight and durable parts, making manufacturing more efficient and sustainable, which has significant implications for industries as diverse as aerospace, automotive, healthcare, and consumer goods.
As 3D printing technology continues to advance, the development of new polymer materials with enhanced properties is opening up even more possibilities. From biodegradable polymers to conductive materials, the potential for innovation is virtually limitless.
In short, the synergy between 3D printing technology and polymer materials is reshaping the manufacturing landscape, bringing unprecedented design freedom, cost-effective production, and sustainable solutions. As companies like Huateng Metal Products (Dongguan) Co., Ltd. leverage the power of this fusion, the future of manufacturing will be even brighter, driven by innovation and the unlimited potential of 3D printing technology and polymer materials.