Set up your 3D printer table
If you’ve ever printed with ABS plastic, you know how difficult it is to get the first layer of an ABS model to grab onto the table. There are some problems with PETG too, but the opposite. he holds up too well. If you do not take the necessary measures, you can get a finished model that cannot be removed from the table without damage.
Because of the high temperature of PETG printing, you still need a preheated build plate. A sudden drop in temperature will almost certainly cause warping if your 3D printing table is too cold. For PETG plastic it is recommended to set the table temperature between 70 ° and 80 ° C. If at these settings you still have problems with adhesion to the layer, you can gradually increase the temperature up to 100 ° C.
To ensure that the printed 3D model is removable easily enough, it is recommended to use an adhesive that will be removed with the model, such as glue stick or hairspray. Do not print directly on the glass to avoid scratching the table surface. Do not use BuildTak, as every time you work with PETG plastic you will almost certainly damage the BuildTak surface (which can be quite expensive).
Since PETG has no adhesion problems, there is no need to set the nozzle too low for the base coat. This is a technique used to “press” the first layer against the table and improve the adhesion of the base layer. If you already have a run-in nozzle height setting for ABS or PLA, you can safely set a value that is two or three times higher for PETG. To improve aesthetics, use values as high as possible, so you can start with the maximum values and gradually lower them if you have any problems with adhesion.
If you want to calibrate the nozzle height accurately, setting 0.02–0.05 mm from nozzle to table is a good starting point. You can set this to both the initial height of the nozzle and the height for the rest of the 3D model.
3D printing temperature, speed and retraction
The main reason PETG is compared to ABS is because it prints at relatively high temperatures. Typically a range of 220 ° to 265 ° C is used, but recommendations from your plastic manufacturer may vary slightly. Although PETG virtually eliminates any folding problems, you will still face other challenges.
The first thing you need to do is determine if your 3D printer is capable of reaching the required temperatures. Some 3D printers provide temperatures of 250 ° C, especially those that use PTFE tubing inside the extruder assembly. If you try to print with the wrong equipment, you end up ruining not only your model, but also your extruder.
Sets the 3D printing speed. it is a matter of the right balance to take into account the 3D printing temperature as well Printing at high speed, if your temperature is too low, can result in “skipping” in the extruder because the material is not soft enough to exit the nozzle. However, printing quickly at very high temperatures can result in residual material between the voids of the model.
It is worth starting with a relatively moderate speed of 25 mm / s. If there are no problems with this setting, then you increase the speed to 50 mm / s. This should be enough to get a good PETG model without spending too much time. You can find information about PETG printing at a speed of 60 mm / s, but this is probably the absolute maximum if you do not want to have problems with material residues between the walls of the model.
We fight the remains of plastic between the walls of the model
One of the most common problems when using high temperature materials. these are the remnants of plastic mentioned above, cobwebs between the walls. This occurs when molten material seeps out of the nozzle as the print head moves. Such plastic residues are especially unpleasant when using PETG, as the material is durable and difficult to remove.
Unfortunately, the material that melts at high temperatures also has a low viscosity, which makes it even more prone to forming this very cobweb. If this problem occurs when you 3D print PETG plastic, the first step is to lower the temperature and print speed a little, although this will definitely reduce the total time it takes to print any model.
Another variant. enable retraction on your 3D printer, if possible. The retract allows the extruder mechanism to “pull in” a small amount of material to relieve pressure on the molten material that is right at the tip of the nozzle. You can refine some parameters, such as retract distance or speed, until any signs of plastic residue disappear.
Reducing the speed of the cooling fan
PETG prints great and retains a good level of detail without a cooling fan. Lack of cooling will also lead to better adhesion between layers. PETG print with cooling fan off. this is quite a normal option.
Some users feel that the fan should not be used for only the first two layers, and then print with 100% fan. This can be a good case if your 3D model has a lot of bridges and protrusions, or if you want your product to be as detailed as possible. In any case, watch out for any signs of cracks or layers that come off during 3D printing, as PETG prints at high temperatures and does not like sudden changes in temperature.
PETG plastic. optimal 3D printer settings
One of the positive features of 3D printing using FDM technology. there is a huge variety of materials you can work with. There are flexible materials, some that mimic the finish of wood, and some even have some degree of electrical conductivity.
The flip side of the coin of having all these filament options is that each of them requires some specificity in use. In this article we will look at how to get good quality 3D printing using PETG plastic, which, judging by the trends, will soon become one of the most popular. What are the best 3D printer settings for PETG? What problems can you face when printing PETG plastic??
The key to success. experiments
PETG can be easier to work with than ABS, but if you’re just getting started with it, it’s worth getting to grips with its specifics. Different grades of PETG materials can also behave differently and unpredictably. It may take some time to properly adjust the 3D print temperature, bed temperature, print speed and retract parameters. But when you find that sweet spot, you can reap the full benefits of PETG without having to face many of the problems that are common with other plastics.
When buying, you should choose a filament made of polyethylene terephthalate from a reliable manufacturer and work only with it, without changing the manufacturer. Before you can get the optimal settings, you will most likely have to print a few unsuccessful models. But do not despair, keep optimizing the settings and after a while working with PETG will become easier.
What is PETG?
PETG is a derivative of the highly popular polyethylene terephthalate (PET). The letter “G” in PETG stands for “increased glycol”. The addition of a glycol group makes PETG slightly stronger and less brittle. It also has better optical properties and is easier to work with than PET. It has excellent chemical resistance and is a good moisture barrier.
In the 3D printing world, PETG is often touted as the best of the two most popular materials, PLA and ABS. It prints at high temperatures, which provides good heat resistance. However, it does not have a high shrinkage factor and has better adhesion between layers, which means that it does not have serious problems with deformation. It also does not emit harmful gases during printing, which is one of the worst aspects of printing using ABS.
Thus, PETG gives you almost all the mechanical and chemical benefits of ABS with the same ease of processing as PLA. It is a good choice for functional parts that need to withstand constant movement or pressure. Using PETG plastic, almost completely transparent products can be obtained, which makes it an excellent material for decorative elements.
Printer settings for PETG plastic
Before printing, it is necessary to check the distance from the nozzle to the surface of the table at the four extreme points. A standard sheet of paper should pass between the table and the nozzle. To fix the first layer, you can use masking tape, blue tape, various adhesives.
Further, in the used slicer (for example, cura), you need to set the settings corresponding to the used printer and plastic, such as print speed (about 55 mm / s), plastic feed rate, extruder temperature, layer thickness, nozzle diameter and others.
PETG is not as easy to work with as PLA, so you will likely have to experiment a little with the settings before you get good results.
How to print PETG with plastic
To print PETG plastic, a heated table from 50 ° C to 70 ° C is required. The use of blue masking tape gives very good results. Hairspray can be used when printing on glass. The first two layers, to increase adhesion, can be printed without a fan, the next layers. by turning on the fan to cool the plastic by 100%.
Particular attention should be paid to the location of the supports, since they are rather difficult to remove when processing the finished product. Honor also points out that PETG printing may produce fine hairs on the surface of the print.
PETG plastic for 3D printer
Although ABS and PLA filaments for 3D printing are the most famous and widespread, other, alternative types of plastics are gaining popularity.
One such option is PETG. PETG is a type of well-known and widely used PET (polyethylene terephthalate) plastic, which is used to make food containers, water bottles, clothing fibers.
The addition of glycol during polymerization results in the formation of “glycol-modified” PET or PETG. Chemical formula PETG. (C10H8O4) n. Glycol makes plastic more durable, less brittle, cleaner and easier to use.
Application of PETG plastic
PETG is impact-resistant, but not suitable for outdoor use as it loses transparency, turns yellow and loses mechanical strength under the influence of ultraviolet radiation.
For objects that may be exposed to constant or shock impact, such as mechanical parts, 3D printer parts and protective pads, PETG is the ideal option.
PETG’s durability and sterilization properties make it ideal for the manufacture of instruments, medical devices and prostheses. PETG is popular in the food industry. It is used to make protective packaging, containers, bottles for water and drinks.
PETG plastic properties
PETG is a thermoplastic. This means that it can be repeatedly heated to its melting point (260 ° C), converted into a liquid, and cooled again until it returns to a solid state without destruction and changes in properties.
In contrast, thermosetting plastic (such as epoxy or melamine) can only be heated and cast once, but the resulting product can no longer be reheated as it will simply burn out.
PETG is hygroscopic, so PETG filaments should be stored in a cool, dry place and dried if exposed to humid air for too long. Wet PETG printing can lead to hydrolysis, which will alter the plastic at the molecular level, which will degrade its mechanical properties.
PETG is more elastic than PLA, easier to bend and less brittle than PLA. It is also less rigid than ABS, but not much.
PETG products lend themselves well to machining including cutting, drilling, bending and polishing. PETG resists shock well and is harder to break than PLA and ABS.
This plastic has a higher layer adhesion when printing, which also improves its mechanical strength. The plastic is resistant to weak alkalis and acids. Insoluble in water and many organic solvents.
PETG is slightly more temperature resistant than PLA, but less than ABS. PETG begins to soften at 80 ° C, while PLA at 70 ° C and ABS at 105 ° C. This plastic is approved for use in products in contact with food.
PETG in its natural state (no dyes) transmits about 90% of the light, making it suitable for printing transparent or translucent parts. PETG produces odorless printing unlike ABS and PLA.
Products made from this plastic are recyclable and easily stained with acrylics.
Adhesive for PLA plastic
You can glue the various parts of a PETG product using any instant cyanoacrylate adhesives or epoxy. The adhesion result can be significantly improved by sanding, cleaning and degreasing the area.
Epoxy can be used to fill in gaps in a print and give a product a crisp, smooth outer skin. It is worth noting that the lines of the 3D printing layer will be visible under the epoxy coating.
Epoxy is generally classified as an irritant. Epoxy hardeners can be corrosive and toxic. Gloves must be worn when using epoxy and avoid contact with skin.
PETG plastic printing temperature
Recommended extruder temperature is 230 to 265 ° C, depending on filament and 3D printer. Table temperature ranges from 50 to 70 ° С.
PETG plastic colors
PETG plastic comes in the same variety of colors as PLA or ABS. There are shades of green, red, blue, orange and yellow, as well as translucent or colored translucent options, making it an ideal choice for products that need to be translucent.
- melting point. 260 ° C;
- softening temperature. 81. 91 ° С;
- density. 1.27–1.29 g / cm3;
- tensile strength. 50. 56 MPa;
- bending strength. 50. 83 MPa;
- tensile elongation without rupture. 3. 5%;
- maximum operating temperature of the product. 51. 64 ° С;
- shrinkage from 0.2 to 0.6%.
In the old days, when extruders were large and printing speeds were slow, instructions for preparing plastic for printing began something like this: “Get a hot melt glue for your glue gun. “.
In the search for materials for 3D printing, the first enthusiasts drew attention to a rod for welding plastic, it was 3 mm in diameter. And for a long time, 3mm diameter remained the standard for hobbyist 3D printing.
But this diameter has a drawback: to work with such a rod, a sufficiently large force is required on the extruder, which required the installation of an additional gearbox.
Due to the desire to reduce the cost of equipment, the diameter of the bar has been greatly reduced and is now 1.75 mm, which has now become the standard. The small diameter of the filament allows it to be pushed by a gear that fits directly onto the extruder motor.
Due to its increased stiffness, a rod with a diameter of 3 mm is still loved by manufacturers of top-end 3D printers with a bowden extruder. For example, Ultimaker printers use it.
When choosing a plastic for printing, the function of the printed parts is of decisive importance. The characteristics of the printer used are also important, since not every plastic is suitable for every printer. in addition to the diameter of the filament, its melting point, hardness, the presence or absence of a heated platform and a closed chamber in the printer are important.
Let’s move on to considering the types of plastics:
ASA (Acrylonitrile Styrene Acrylate) is a weather resistant plastic. Similar to ABS, but more UV resistant. Does not turn yellow in the open air.
Breaking elongation. 15%
Tensile modulus. 1.12 GPa
Used for printing outdoor products in contact with the atmosphere, such as the exterior of cars.
Sports Equipment. In general. for printing products that must be used in all weather conditions.
UV resistance allows it to be used for the manufacture of products that are operated under the influence of direct sunlight.
Good combination of strength and resilience allows it to be used for the manufacture of mechanical products designed for a long service life.
A wide range of operating temperatures allows you to operate products made of it for technical purposes.
Simplicity of mechanical processing, in combination with chemical smoothing of the surface with inexpensive solvents such as acetone, allows you to make decorative products or cases with high surface quality.
Dislikes drafts when printing, which limits the use of cheap open-frame printers.
Due to the relatively high shrinkage, it is prone to delamination (delamination), requires a heated table, without it there are problems with the adhesion of the first layer to the table.
During the printing process, an unpleasant odor may form, it is better to print in a ventilated room or equip the printer with a special exhaust ventilation system with an exit outside the apartment.
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A detailed guide to choosing plastic for 3D printing
Wax (MOLDLAY) (casting wax). used to make burnout models for casting. The model is poured with plaster, after which it is burned / smelted out of it, a mold for casting metal is obtained.
Low melting point and low ash content
Wax printed models can be processed in a torch flame and smoothed with solvent, and are easily machined, which reduces the required machining of the final metal casting.
Widely used in the jewelry industry and in the manufacture of metal prototypes.
Manufacturing, jewelry, medicine, prosthetics.
Color-Changing. Another PLA or ABS composite, but in this case, capable of changing color as temperature changes.
Used when printing decorative items.
Depends on the base material. Varies with different manufacturers.
Depends on the base material. Varies with different manufacturers.
Ability to change color when temperature changes.
PEEK (Polyetheretherketone) is a modern semi-crystalline material that provides a unique combination of mechanical, chemical and thermal resistance. Refractoriness makes it impossible to print on most consumer 3D printers.
Very durable and high temperature resistant plastic. It is practically not used in household printing, due to the high requirements for the temperatures of the nozzle and the printer table. Requires a thermal camera when printing.
Breaking elongation. 45%
Tensile modulus. 2.3 GPa
Used for printing functional prototypes of products experiencing high physical and mechanical stress and operating at elevated temperatures.
Inert to oils and fuels, therefore it can be used in critical parts of cars.
High strength, allowing it to be used for mechanically loaded products.
Abrasion resistance for use in kinematic transmissions.
Very high temperature resistance for plastic.
The requirement for the mandatory presence of a thermal camera in the printer.
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This allows both durable engineering products and decorative crafts to be printed from it.
For home, 3D printing of parts, 3D printing of models, production, prototyping, prosthetics, 3D printing of housings and electronics, 3D printing of mechanisms, plastic for printing plates, industrial plastic for 3D printers, durable plastic for 3D printers, heat resistant / heat resistant plastic for 3D printer.