3D Printing Photopolymerisation: What is it and how does it work?
Suppose you are a fan of technology and innovation. In that case, you will undoubtedly have heard of 3D printers and their revolutionary potential in various fields, from engineering and art to medicine and manufacturing. But what if we told you that a 3D printing method allows you to create objects from nothing, almost like magic art? No, this is not a science fiction film, but a real innovation called photopolymerisation! In this article, we will guide you through the beautiful world of photopolymerisation in 3D printing, discovering what it is and how it works. This fantastic technique opens the door to new frontiers of the possible. Prepare to be amazed!
Definition of 3D printing
3D printing is a revolutionary technology that allows three-dimensional objects to be created from a digital drawing. This technique, also known as additive manufacturing, relies on the superimposition of thin layers of material to build the desired object. Among the different 3D printing methods, photopolymerisation is particularly interesting for its precision and versatility.
Photopolymerisation is a process that uses light to selectively harden a liquid photopolymer, thus creating the desired three-dimensional object. This technique can create objects with remarkable resolution and detail through lasers, digital light processing (DLP) projectors, and LCD screens. The most common photopolymerisation techniques are SLA (StereoLithography Apparatus) and DLP, which have different characteristics and advantages.
How 3D printing works
Stereolithographic 3D printing (SLA) is a photopolymerisation technology that has gained notoriety due to its ability to produce objects and prototypes with precise detail, waterproof, and different materials. This technique achieves a smooth surface finish and accurate information through light-sensitive, thermosetting resins.
ALS uses a light source, usually a laser or projector, to polymerise the liquid resin into a solid plastic. The process occurs inside a tank containing the resin and develops layer by layer, resulting in the desired 3D object. As a result, objects made with SLA printing have better resolution, precision, and surface finish than objects made with other 3D printing technologies.
Available 3D printing technologies
3D printing is an ever-evolving technology with various techniques available to meet the needs of different industries. Fused deposition modelling (FDM) is viral among hobbyists and those looking for inexpensive 3D printers. This method uses thermoplastic filament that is heated and extruded to create the object layer by layer.
Stereolithography (SLA) is another widely used 3D printing technology, especially for producing models and prototypes with high resolution and precise tolerances. This method uses photopolymerisation, a pool of light-sensitive resin hardened utilising a beam of ultraviolet light or a laser.
Finally, selective laser sintering (SLS) is suitable for producing complex and robust parts. In this process, a laser melts a material powder to build the desired object. SLS allows the creation of objects with intricate geometries without additional support.
File formats for 3D printing
3D printing requires specific file formats to convert digital models into physical objects. Among the most common formats is the STL file, an abbreviation for ‘stereolithography’, created for photopolymerisation-based SLS printers.
Another standard format is OBJ, which includes more information on the 3D model’s textures and colours. In recent years, other formats, such as 3MF and AMF, have also emerged to ensure greater interoperability between 3D printing software and hardware.
Materials used for 3D printing
Various materials are used to make objects in 3D printing. These include thermoplastic and thermosetting plastics, which are particularly popular due to their versatility and properties, and metals, ideal for more potent and robust objects.
Thermoplastics, such as PLA and ABS, are heated and moulded into the desired shape and can be recycled and reused. In contrast, thermosetting plastics, used in the photopolymerisation technique, react chemically when exposed to light or heat, hardening permanently.
Regarding metal 3D printing, the most commonly used alloys include stainless steel, titanium, aluminium, and copper. These materials offer high mechanical performance, corrosion resistance, and durability, making them ideal for industrial and aerospace applications.
In conclusion, the choice of material for 3D printing depends on the specific needs of the object to be produced and the mechanical and functional properties required.
Differences between SLA, DLP and LCD 3D printers
SLA, DLP, and LCD 3D printers are three different 3D printing technologies based on photopolymerisation. The SLA printer uses a laser to bake the resin, while the DLP and LCD printers utilise a digital projector and LCD panel.
In SLA printers, the resolution depends on the diameter of the laser beam, while in DLP printers, it is influenced by the projector’s pixel size. On the other hand, LCDs rely on an LCD panel to block or allow UV light to pass through, thus determining the resolution.
Although SLA printers can offer greater precision, they are usually slower than DLPs and LCDs, as the laser must travel a precise path. On the other hand, DLP and LCD printers may be faster but not have the same quality of detail as SLAs.
In conclusion, the choice between SLA, DLP, and LCD depends on the specific application, personal preference, accuracy, speed, and print quality.[15][16]
3D printer resolution
Resolution in 3D printing concerns the level of detail and final quality of 3D prints. It is influenced by the XY planes (length and width) and the Z dimension (height), which characterise the printed object.
Different printing technologies, such as stereolithography (SLA), fused deposition modelling (FDM) and digital light processing (DLP), have different resolutions depending on their construction technique. Considering these differences, it is crucial to understand the resolution’s role in choosing technology and the final result.
Specifically, photopolymerisation is a 3D printing process that uses light-sensitive resins selectively hardened by UV light. This technique makes it possible to obtain parts with high precision and resolution, ideal for complex parts and high-quality finishes
Industrial applications of 3D printing
3D printing, also known as additive manufacturing, has numerous applications in various industrial sectors. This technology makes it possible to produce three-dimensional objects of any shape from a digital model using thin plastic, metal or powder layers.
One of the fields in which 3D printing is most widely used is the automotive industry, where prototypes and vehicle components are produced with great precision and speed. This technology is also commonly used in architecture and construction engineering, allowing models and structures to be created quickly and cost-effectively.
In the medical sector, 3D printing produces customised prostheses, surgical instruments, and artificial organs. This technology has become essential for creating unique and innovative pieces in jewellery, art, and design.
Lastly, 3D printing extends to education and research, contributing to student training and the realisation of advanced scientific projects. In all these sectors, the possibility of experimenting and customising products without limits of shape and material makes additive manufacturing an indispensable technology for the industry’s future.
Online 3D printing services
Online 3D printing is becoming increasingly popular due to its convenience and accessibility. Services allow anyone to upload their 3D models, choose the desired material and size, and receive the finished product directly to their home or office.
One of the main advantages of online 3D printing services is the possibility of accessing a wide range of printing materials and technologies, including photopolymerisation. Many of these services also offer the possibility of editing and optimising 3D models directly on the platform, thus guaranteeing a high-quality result.
Numerous 3D printing services are available online, each with features and competitive rates. Thanks to these services, 3D printing has become affordable for everyone, allowing professionals and enthusiasts to benefit from this innovative technology.
Ask for an online quote on the Fama 3D website for individuals or companies!
3D printing trends for the future
Future trends in 3D printing show an industry that continues to grow and develop. One of the main directions is the industrialisation of the sector, with the adoption of large-format and large-scale 3D printing systems. This will enable more outstanding production and lower costs for various industries.
Sustainability is another important theme for the future of 3D printing. Interest in reducing waste, adopting greener materials and processes and promoting more responsible production is steadily increasing. Advances in technology and sustainability awareness will contribute to the growth and spread of Additive Manufacturing worldwide.
Finally, the sector will continue to innovate, constantly developing new materials, processes, and applications. Research and knowledge exchange will be vital to advancing the 3D printing industry and enabling it to meet future challenges.
