HOW 3D PRINTING WORKS

OVERVIEW

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• Accessible
• Increased in quality
• Useful to engineers and others
• Can print many different materials

PARTS

BASIC PARTS

• Heat sync
• Extruder
• Nozzle
• Print bed

MOVEMENTS

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• X = left and right
• Y = forward and backward
• Z = up and down
• Print bed moves
• Pulled by motors connected to bands

PLASTICS

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• Many different plastics
• Most popular: PLA (Polylactic Acid) with chemical make up C3H4O2
• Metal infused
• Abs
• Rubber infused
• Ect.
• Other L-Lactic acids

PROCESS

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• Filament is pulled into extruded
• Heated up by heat sync
• Pushed through the nozzle
• Extruded onto print bed
• Cooled and solidifies

THE END

John Witt
Work cited
https://www.sciencedirect.com/science/article/pii/B9781437744590000019
https://biodeg.net/fichiers/Polylactic%20Acid%20Synthesis%20Properties%20an...
https://www.techopedia.com/definition/29379/polylactic-acid-pla
https://www.creativemechanisms.com/blog/learn-about-polylactic-acid-pla-pro...







































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John Witt
Ms.Moran
Extensive Research Project
How a 3d Printer Works

3d printing over the years has grown greatly. I used to be an idea that w2as not commonly thought of, but because of modern technology, we can have one on our desk at work or home! Many would say that it is a complicated process to work a 3d printer, but really it is not. If one know how the printer works, moves, and reacts with plastic you will be completely understanding of the process and be able to fix any issues. There are some parts that are complicated to understand, but once one learn about them you will be much more aware about 3d printing. It is also necessary to understand the flow of the plastic. To understand where it moves to, how it moves, and what is moving it will be very beneficial to the user. To completely understand 3d printing, one will need to know how the parts of the printer, what type of plastic one are using, how heat reacts with the plastic, and all the things necessary to know after the plastic has been extruded.

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3d printing is a complicated process for beginners, but the best way to excel in this field is to understand what type of mechanics one is working with. In a FDM ( Fused Deposition Modeling) printer, the filament starts on the exterior of the printer. When the printer is a indicated to start, the plastic will be pulled through plastic tubing. The filament is pulled by a motor connected to two gears that are usually located in the extruder. The extruder is where the filament will be heated up by the heat synch and pushed out through the tip of the extruder called the extruder nozzle. The nozzle can be multiple different sizes to accomodate the needs of the user. The heat synche inside of the extruder is connected to wires that are connected to a power source. This is the most efficient way for the FDM printer to work because of the required space for plastic to be melted. It also keeps the printer as compact as possible to fit the needs of the owner. The printer when extruding is moving on an x, y, and z axis. The extruder is only moving of the x and y axis and being pulled by sets of motors and strong bands connected to the motors. The build plate (where the model is being extruded onto) is the part that is moving on the z axis. The printer prints the part one layer at a time. When the printer is done with a layer, then the motors connected to the build plate, pull the plate down to position the extruder on layer higher to print on.
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There are many plastics that are used in the 3d printing field. One would need to understand what type of plastic they are using because of its reactions with heat, cooling process, and other side effects of the plastic. The most common plastic used in 3d printing is PLA (Polylactic Acid). It is most commonly used for many reasons including it does not melt at high temperatures. PLA is biopolyester polymer that is commercially made for 3d printing. This means that it is biodegradable and does not emit as many toxic chemicals into the air when heated. Polylactic Acid has the chemical formula of (C3H4O2). The plastic is made up of these elements because the compound needs to melt and solidify in such a way that only this chemical formula can be true. There are many other filaments that are used in 3d printing that have different strengths and weaknesses. PLA is the most used because of its happy medium between strengths and weaknesses so that it can be used for a greater variety of uses.
PLA, just like all other filaments, is required to be malleable to a point where it can be shaped into what the user would like it to be in. The way all FDM printers do that is by melting the plastic so that it can easily be manipulated. The plastic melts when it passes through the heat synch in the extruder. There are two types of PLA. One type is an L-Lactic acid and the other is a D-Lactic acid. The type of PlA used in 3d printing is L-Lactic acid. This means that the
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compound is melted and solidified when exposed to heat or combustion. When PLA is melted it goes through a direct condensation polymerization. This causes the plastic oxygen molecules to completely separate and the carbon molecules to link up with three hydrogen molecules. This leaves an extra oxygen and hydrogen molecule that also combine. This form is a low weight prepolymer. The compound is once again changed when a chain coupling agent is present to make the compound complete when another hydrogen atom is added. This is when the compound is once again solidified. The solidified compound is also a low weight prepolymer.
After the compound is extruded it needs to be on the print bed with good adhesion or else the print will not be successful. The printer’s extruder is needed to be a certain distance from the build plate in order to force the melted plastic to be solidified on the build plate. If the extruder is too far away the plastic will solidify either too early for it to reach the plate or early enough that it does not have a strong enough connection to last through the duration of the print. If one look closely at the build plate on the printer they will see its course surface. That is there to allow the melted plastic to mold around the course surface and increase adhesion to the plate. Adhesion can also be increased by adding an adhesive to the surface of the build plate to reinforce the connection to the
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plastic. The adhesion can also be depending on the quality of the cooling system. This means that if the fan on your 3d printer is not facing the extruder exactly or if it does not work efficiently, then you may need to look into a different system. The cooling system is very important because it rapidly cools the plastic to keep up with the speed of the printer. If one’s printer is working rapidly but the plastic is not cooling at a quicker rate, you may find the plastic to be dragging, peeling, or even balling up.
3d printing over the years has been incorporated in everyday life and in many jobs. If the user has a good understanding of what is happening with a 3d printer, it may get them a job. 3d printers have been a tool only big companies have access to, but now it is available to almost everyone. To completely understand 3d printing, one will need to know how the parts of the printer, what type of plastic you are using, how heat reacts with the plastic, and all the things necessary to know after the plastic has been extruded.