How a 3D printer works: from printed text to printing houses

Today we can safely say: it is impossible to imagine modern civilization without 3D printing technology, and one can hardly name another so rapidly developing technology.

Through history pages

According to many computer experts, the Englishman Babbage became the founder of 3D printing and the developer of the first conventional printer. In 1822 he set about creating the so-called "big difference machine", designed to make calculations and print them out. Like all great things, Babbage's ideas were far ahead of their time and, after 20 years, never fully realized, the project was closed.

Babbage's Great Difference Engine

More than 100 years passed before a second, more successful attempt at a printer was made. The first black and white printer was released in 1953. 23 years later, IBM creates the first inkjet color printer. Today, the number of printers in offices and other organizations is second only to the number of computers.

In the second half of the 1980s, another technological breakthrough took place. In 1986, American Chek Hull formulated the concept of three-dimensional printing, and two years later his compatriot Scott Crump, based on it, developed the FDM technology - molding through the decomposition of a melting material. All currently operating three-dimensional printers owe their appearance to her.

How a 3D printer works

Compared to a print printer that transfers electronic text onto flat paper, a 3D printer deals with 3D information. In short, he recreates the object as it is.

How does a 3D printer print? First, a digital model of the object is created on a computer using a special program. It sort of "dismembers" the model into layers, after which the printer takes over. Like its printing "brother", the 3D printer has its own ink, however, consisting of a composite powder.

About 10 years ago, only one type of "ink" was used - ABC plastic. Today there are more than a hundred of them - polypropylene, concrete, cellulose, nylon, metal powders, gypsum, chocolate and many others.

In the process of work, the starting material turns into a mass, which is applied layer by layer onto the working surface through a special nozzle. After applying the next layer, an adhesive coating can be applied on top of it, then again a layer of "ink". And so on until the complete reproduction of the object. You can watch the work of a 3D printer in the video.

But this is the general principle of a 3D printer, the so-called rapid prototyping technology. Several methods have been developed on its basis. Here are just a few of them.

Stereolithography (SLA)

One of the first 3D printing technologies. As a building material, a mixture of liquid polymer with a hardener reagent is used, somewhat similar to epoxy resin. Polymerization and subsequent hardening of the mixture occurs under the action of an ultraviolet laser.

The model is formed in thin layers on a movable support with holes attached to a microlift-elevator, which moves up or down to a depth of one layer. When immersed in a liquid polymer, the laser beam is fixed at the points to be cured. Once one layer is formed, the workpiece is lifted (lowered).

Multi-jet modeling

This technology was developed by 3D Systems. It has a lot in common with inkjet technology. The peculiarity of the device and the principle of operation of this 3D printer is that several (up to several hundred) nozzles are involved here, arranged in rows on the print head.

The ink becomes liquid by heating and hardens after layering on the work surface at room temperature. The head moves in the horizontal plane, and the vertical displacement as each new layer is formed is carried out by lowering the working table.

Selective laser sintering (SLS)

The real breakthrough was the introduction of 3D printing technologies in metalworking. How does a metal 3D printer work? A feature of this technology is that the function of the working fluid is performed by a composite powder consisting of particles with a diameter of 50 to 100 microns. The powder is applied horizontally in uniform thin layers, and at the final stage, certain areas are sintered with a laser beam.

One of the main advantages of laser sintering is its unique cost-effectiveness and almost complete zero-waste compared to traditional mechanical methods of metal processing - drilling, milling, cutting, casting and others, as well as minimal finishing.

A necessary condition for laser sintering is a nitrogen environment with a minimum oxygen content, since the process takes place at high temperatures.

The list of 3D printing technologies is far from limited to this. It is complemented by layer-by-layer bonding of films, layer-by-layer fusion, layer-by-layer printing with a molten polymer thread, and ultraviolet irradiation through a photomask.

What else to print

Having figured out how a 3D printer works, it's time to tell about what you can do with it today. Like fashionable and very comfortable clothes, it is "tried on" by representatives of various branches of science and industry. As it turned out, you can print almost everything from consumer goods made of plastic, to solar panels, car bodies, parts for jet engines and medical prostheses.

The military and builders have "laid eyes" on 3D printing technology. Not so long ago, a 3D printer, developed by NASA's order, was delivered aboard the ISS, with the help of which several necessary instruments were manufactured in zero gravity. It is quite possible that in this way, during a future Mars mission, individual parts will have to be manufactured directly on board the spacecraft.

The option of erecting Martian houses using the 3D printing method is also being considered, for which special construction printers will be delivered there from Earth. The base of the "ink" for them will be the Martian soil.