Comprehensive interpretation: 3D printing process and materials

3D printing is a form of additive manufacturing technology in which three-dimensional objects are created through successive physical layers. Compared with other additive manufacturing technologies, 3D printers have the advantages of high speed, low price, and high ease of use. A 3D printer is a device that can "print" a real 3D object. Like the laser forming technology, the 3D printer uses layered processing and superposition molding, that is, by adding materials one by one to generate 3D solids, and traditional removal processing. The technology is completely different. The so-called "printer" refers to its technical principle, because the process of layering is very similar to inkjet printing. 3D printing technology is widely used in jewellery, footwear, industrial design, construction, automotive, aerospace, dental and medical applications.

Print step

The printing process of each layer is divided into two steps. First, a layer of special glue is sprayed on the area to be formed. The glue droplet itself is small and does not easily spread. Then a uniform layer of powder is sprayed on the powder. The powder will quickly solidify and adhere to the glue, and the area without glue remains loose. In this way, the solid model will be “printed” under the alternation of a layer of glue in a layer of powder. After the printing is completed, the model can be “planned” as long as the loose powder is removed, and the remaining powder can be recycled. Printing consumables are transformed from traditional inks and papers into glues and powders. Of course, glues and powders are special materials that are processed. Not only do they require curing reactions, they have a direct impact on the strength of the model and the “printing” resolution.

techinque level

The current 3D printing technology can achieve 600 dpi resolution, each layer thickness is only 0.01 mm, even if the model surface has text or pictures can print clearly. Of course, limited by the principle of jet printing, the printing speed will inevitably not be fast. At present, more advanced products can achieve a vertical speed of 25 mm per hour, which is 10 times higher than that of earlier products, and can use colored glue to realize color printing. The color depth is up to 24 bits. Due to the high printing accuracy, the quality of the printed model is naturally good. In addition to the design that can show the appearance curve, the structure and the moving parts are not to mention.

If used to print mechanical assembly drawings, gears, bearings, tie rods, etc. can all move normally, and the cavities, grooves and other morphological features are accurately positioned to meet even the assembly requirements. The printed entities can also be polished, drilled, and plated. And other methods for further processing. At the same time, the powder material is not limited to sand-type materials, but there are other materials such as elastic stretching, high-performance compounding, investment casting, and the like. However, even though the prices of 3D printers are constantly declining, many manufacturers, design institutes, universities, etc. are starting or preparing to equip them, but the prices of products are still high. The new InVisionLD entry-level desktop product from 3D Systems is priced at US$15,900, while the Z510 mid-range model from ZCorporation is priced at US$100,000. Fortunately, the cost of consumables for 3D printers is not an exaggeration. For example, printing a cell phone model costs about US$20 in material costs, which is much lower than other molding techniques.

printing material

The type of printing ink used in 3D printing is extremely wide, and even a 3D printer can be used to print a chocolate that is exactly the same as its own smiling face. First, the photos in the iPhone or the ordinary card machine are converted into 3D modeling software such as 123D or Photofly. After uploading 3D image data to a computer, it has its own 3D design. "Ink" is liquid chocolate. After melting the chocolate into the printer's memory and pressing the "Print" button, the printer will stack the liquid chocolate layer by layer into your smiley shape based on the image data. After each layer of chocolate is printed out, it must be solidified to start the next layer of printing. The addition of an insulation and cooling system ensures the consistency and temperature of the chocolate.

In the area of ​​raw materials, Xerox PARC is also developing printed materials for sensors, transistors and other electronic products. Once successful, it will mean that consumers can design their own mobile phones or MP3s. In the field of application software, engineers and programmers share code and designs from time to time, and more and more free and open source software emerges, which reduces the design costs of 3D printing, such as 123D, OpenSCAD, and Tinkercard.

3D printing advantages

Compared to traditional manufacturing processes, 3D printing technology has two advantages. First, it saves raw materials and labor. Thanks to the "additive manufacturing technology," its materials are only 1/3 to 1/2 the original, and the printing speed is four times faster. At the same time, labor costs can be reduced by eliminating production lines and part of the assembly process. The second advantage is that you can make different types of items. In theory, as long as the computer can design the styling, 3D printers can be printed out. The 3D printing vehicle Urbee, which was exhibited in Canada in 2011, has attracted a lot of attention with its streamlined and stylish appearance.

The limitations of 3D printing technology are mainly reflected in the materials. The current printing materials are mainly plastics, resins, and metals. Research on organic materials such as bones is also ongoing and preliminary results have been achieved. Due to material limitations, the original application of 3D printing was limited to the fields of modeling and industrial design. But now, 3D printing technology has gradually begun to be used in production. It is suitable for small batch processing. Since no mold is needed, no additional cost will be added to the product modification. Simply modify the design drawing. This also means that the cost of personalized customization in small batches is reduced. In the future, it will be more cost-effective to customize personalized furniture, food, crafts and other products.

3D printing, which was still at the forefront of technology three years ago, has now become an emerging strategic area in manufacturing. In August 2012, US President Barack Obama allocated US$30 million to establish a state-level 3D printing additive industry research center in Ohio and plans to invest US$500 million in 3D printing for the first step to ensure that US manufacturing does not continue to shift to China and India. Wohlers Associates, a consulting firm that tracks the 3D printing industry for a long time, said that in 2011, the market size of 3D printers will be about 1.7 billion U.S. dollars. By 2015, the market will reach 3.7 billion U.S. dollars.