LET'S SPEAK 3D PRINTING!
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3D PRINT
TEHNOLOGIJE
ABS
Acrylonitrile butadiene styrene (ABS) is a commonly used plastic material that melts at about 220 degrees C, then quickly re-forms into a tough, glossy, impact-resistant material. It is made from crude oil and is nontoxic; it can be easily dyed and retains color well. Legos are made of ABS for this reason: it's easy to shape but tough to break. However, ABS does release some unpleasant (and possibly poisonous) chemicals when heated or burned.
These properties make ABS very suitable for 3D printing. You do need a large heater to reach that 220degrees C melting point, but ABS flows easily when heated and sets quickly to form the print. You'll need a 3D printer with a heated print bed that can reach about 100 degrees C, as ABS becomes sticky at this temperature and will adhere to a glass print bed.
A print using ABS will be very tough, as anyone who has stepped on a Lego will tell you. The print will also be water- and chemical-resistant. ABS does produce a slightly unpleasant smell of burnt plastic when heated, and it can contain some nasty chemicals, so you'll need to make your prints in an area with good ventilation. Because ABS is broken down by UV radiation, it isn't suitable for long-term outdoor use.
Prednosti, Nedostaci i Opisi
PLA
Polylactic acid (PLA) is a relatively new polymer plastic, made from biological materials like cornstarch or sugarcane. It is similar to the material used in biodegradable plastic packaging, which melts at between 180 and 200 degrees C, depending on other materials that are added for color and texture. PLA then quickly cools to form a tough, resilient material with a matte, opaque quality, but it is not as tolerant of heat as ABS is. PLA begins to deform at temperatures above 60 degrees C. There is a slight smell when it is heated, rather like microwave popcorn.
PLA is generally the preferred option for low-cost 3D printers, because it is easier to print with than ABS, as it sticks to other surfaces and itself better. It will stick well to the print base using white glue or blue painter's tape, which means that a printer with a heated print bed is not needed. The material is also biodegradable; like other corn- or sugar-based materials, it is slowly consumed by many common bacteria. It will last a long time in normal conditions, though. It's only when buried that it breaks down. That said, PLA is not safe for use with prints that come into contact with food, and it doesn’t stand up well to heat. It is also somewhat brittle, making prints prone to shattering under stress. However, chemicals can be added that make it less brittle and more heat-tolerant, creating what some manufacturers call tough PLA.
PVA
Polyvinyl alcohol (PVA) is one of a new class of 3D printing materials that are used to make supports. A synthetic polymer, PVA is used in biodegradable products, such as fishing lures and medical devices that need to work, but then dissolve away. It melts at about 200 degrees C, and can release some nasty chemicals if heated to higher temperatures. Another interesting property: it's water-soluble.
This is why PVA is often used in 3D printing. It can be melted for printing by a standard 3D printer extruder to form parts that support other objects, and it sticks to a heated, glass print bed well. Once the printing is complete, if the material is immersed in water, the PVA parts will dissolve, leaving the rest of the print behind. This makes it easier to print complex models that require supports, or even models that include moving parts. If you do use water to dissolve PVA, you'll need to properly dispose of the water, as dissolved PVA can clog drains. Check with your local water company for the recommended disposal method.
Nylon
The name nylon can be used for any one of a number of synthetic polymers originally created as replacements for silks. Nylon is a tough material that has a very high tensile strength, meaning that it can hold a lot of weight without breaking. It melts at about 250 degrees C and is nontoxic.
Nylon's use as relatively a 3D printing material is relatively new, but the material is becoming popular because the prints it produces are very tough and resistant to damage. It is cheap, because nylon is widely used in other industries, and it's not damaged by most common chemicals. However, nylon does require high temperatures to print: 250 degrees C is hotter than many extruders can manage. And it is harder to get it to stick to the print bed than with ABS or PLA. Generally, nylon requires both a heated print bed and white glue to stick while printing.
HDPE
High-density polyethylene (HDPE, though it's also known as high-impact polystyrene, or HIPS) is used in pipes and recyclable packaging such as plastic bottles and packages (ones with the recycling ID code 2). It is a light, flexible material that sticks to itself and other materials well. HDPE is also easy to dye and mold. It melts at about 230 degrees C, but releases unpleasant fumes if accidentally heated to higher temperatures.
In 3D printing, HDPE is often used instead of ABS, as comparable prints turn out lighter and stronger than ones with ABS. HDPE does require higher temperatures to print, though, and can release unpleasant fumes if overheated. It is resistant to most chemicals, though you can dissolve HDPE with limonene, a solvent commonly used in industrial cleaners. HDPE does have a tendency to warp, though; as the material cools, it contracts slightly, which can lead to warped prints as different parts cool at different rates.
Solubility in limoleme means that HDPE is often used for printing supports for 3D prints made with other materials. After the printing is complete, the supports can be dissolved by immersing the print in limonene, which won't affect materials such as ABS or PLA. HDPE does require an extruder that can reach 230 degrees C, though, and a heated print bed.
PETT
Polyethylene terephthalate (PETT) is the chemical name of a material sold as t-glase. It is a polymer that is similar to polyester, used to make clothes. It melts at about 230 degrees C, but cools into a rigid, clear solid that resembles glass. It can be dyed while still retaining its glass-like qualities, so it is available in multiple colors. T-glase is approved for food use by the FDA, so you can use it to make dishes, cups and the like.
For 3D printing, t-glase can be printed onto a print bed heated to about 70 degrees C. It is mainly sold by Taulman, which introduced the material. While t-glase itself is strong and resilient, it has to be printed rather slowly to make sure that layers adhere properly. So printing with t-glase is typically much slower than with other materials.
Wood Filament
The name is a little confusing here: these filaments are not made out of wood, but instead contain very fine wood particles combined with PLA and a polymer that binds them together. This means that, when printed and polished, the finished material can look a lot like wood. Versions are available for many different types of wood, from bamboo to ebony and mahogany. Some of these filaments allow you to change the color of the printed material by varying the temperature; at higher temperatures, the wood particles take on a darker, burned look.
These materials are printed in the same way as PLA filaments, with similar extruder temperatures and the addition of white glue to help the print stick to the print bed. The addition of the wood particles does make the process more prone to problems, though, and each different filament may have slightly different requirements. This means that often a lot of experimentation is required for successful prints with each individual type of wood filament. The material also often requires extra work, such as sanding or mild abrasive treatment, to bring out the look of the wood particles.
Metal
Filament
Metal filaments aren't just long strips of metal. Instead, they are made of very finely ground metals combined with PLA and a polymer glue that sticks the particles together. This means that they print like PLA, but have the look and feel of metals. They work on any standard printer that supports PLA filament.
Available versions include steel, brass, bronze and copper particles to create the look and feel of those respective metals. The addition of the metal does change the characteristics of the filament, though, so often experimentation is required to find the right settings on your 3D printer for a successful print. These filaments also require a good sanding or polishing to create the metallic look. Right off the printer, they generally look like ceramics, but brushing with steel wool and a metal polish will remove some of the PLA and glue to expose the metal particles.
Metal filaments are not as heavy as solid metal, so a print of a statue with a bronze filament will not weigh as much as a cast bronze version. Also, since the particles of metal are separated by the PLA and glue, these filaments generally won't conduct electricity.
Carbon
Fiber Mix
If you take one of the printing materials listed above, a bit of glue and particles of carbon fiber and mix them all up, this is what you get. Carbon fiber filaments — like this one from MatterHackers that uses nylon, or this one from Proto-pasta that uses PLA— throw a bit of carbon fiber into the mix that gives you some of the characteristics of that material: excellent rigidity and strength at very low weight. However, this should be approached with caution. Carbon fiber is a very abrasive material that can wear away the hot end of the extruder very quickly, so you'll need to get a reinforced extruder or replace it after a few prints.
At present, there's is only one company making true carbon fiber 3D printers: MarkForged. Its Mark Two, Onyx and Mark X printers can print using the company's own pure carbon fiber filament. But those printers aren't cheap; the Mark Two will cost you a cool $13,499, while the carbon fiber filament it uses costs $149 a reel.
Flexible
Filament
Most 3D printing materials strive for rigidity, creating prints that are strong. That's not always what you need, though, and flexible filaments like NinjaFlex, PolyFlex or TrueFlex produce prints that are stretchable and flexible. These rubber-like materials can be used to make things like phone covers, flexible joints and wearable parts that need to flex with your body.
However, this flexibility also poses a problem. FDM 3D printers work by pushing the filament into the heated extruder, where it melts. You can't do that as easily if the material is flexible, so most printers will require modification to use these flexible filaments. 3D printer maker LulzBot, for instance, offers a replacement print head, called the Flexystruder, that's designed to handle flexible filaments
Other manufacturers offer what they call semiflexible filaments, like MakerBots Flexible Filament or the new TPU95 A from Ultimaker. These aren't as flexible as the ones above, but they still provide some flexibility; for instance, the MakerBot filament becomes flexible when you put it in hot water, allowing you to reshape or squish a print into a tight-fitting spot before the material cools and becomes rigid again.
