Warping is a defect in 3D printing characterized by dimensional distortion of printed parts, i.e., the print’s corners lifting and separating from the build plate due to uneven shrinkage during cooling and printing. The defect also occurs in custom plastic machining due to temperature differences between layers as the plastic contract while cooling. As a result, machining services must ensure proper temperature to prevent warping.
Although warping can occur in any plastic, it is more frequent with ABS plastic and can lead to the printed part being non-functional or visually unacceptable. ABS plastic warping occurs majorly due to the great temperature difference during cooling. However, it may occur under the conditions below:
- Unleveled printed bed
- High print speed
- Unstable printing temperature
- Dirty printing bed
- Weak adhesive
To prevent the defect, this article will introduce warping in liaison with ABS plastic and how to avoid the defect during printing.
Tips to Avoid ABS Plastic Warping
ABS plastic is highly susceptible to warping. However, you can avoid this defect by following the following tips below:
1. Use a Heated Bed
Using a cold bed can cause the ABS plastic part to harden before it can lay flat. Furthermore, it can also result in temperature differences between the first layer and subsequent layer during cooling. As a result, warping can occur, leading to a failed print.
To prevent this, you use a heated bed. A heated bed ensures that the print bed’s temperature is higher than the ambient temperature. As a result, the first extruded layer stays soft for a long time. This gives more time for the first layer adhesion to occur. Furthermore, a balanced temperature reduces uneven shrinkage of subsequent layers and the force of curling and contraction.
To prevent ABS printing from warping, a heated bed between 90 and 100-degree Celsius is necessary. Furthermore, avoid setting your heated bed at a temperature higher than ABS’ glass transition temperature as the print’s initial layers may melt due to overheating.
2. Clean the Print Surface
Dirt and grease weaken the adhesion of the first printed layer to the print bend, further encouraging warping. Therefore, ensure that the print bed is clean and smooth before printing. You can clean with ammonia-based cleansers, water, and soap solution, or isopropyl alcohol. However, ensure that the cleanser is compatible with the print surface
Note: The human fingerprint contains oil residues. As a result, avoid touching the print bed surface before, during, and after printing.
3. Tune Your First Layer Settings
The first layer of your print serves as the bonding layer. As a result, it must be perfect to avoid warping. Therefore, you need to adjust some slicer settings
- Initial Layer’s Extrusion Width: To create a solid foundation for the model, you can increase the initial layer’s extrusion width. This helps the layer adhere to the bed more.
- Initial Layer’s Height: Lower the extruder depending on the layer’s width so that the molten plastic can compress to the bed and create a greater surface contact. The first layer’s height should be 90% of the layers above.
Note: Avoid excessive bonding because it will make it harder for you to remove the final print.
4. Print in an Enclosure
Place an enclosure around the printer to maintain temperature conditions. An enclosure is one of the best ways to prevent ABS plastic warping. This works because it maintains a warmer ambient temperature to prevent your print from cooling quickly and drafts from cooling your model.
Enclosures are highly recommended for ABS printing because they create a controlled environment during printing. Furthermore, they protect the printer from external forces such as dirt and fumes and stabilize the print.
5. Use an Adhesive
Using an adhesive to prevent warping is a practical technique in ABS printing as it keeps the first layer firmly attached to the print surface. As a result, the good adhesion ensures that the first layer of the part does not curl up as they cool. Furthermore, it serves as a layer for glass protection. Common adhesives you can use include Painter’s tape, PEI sheets, and washable glue sticks.
5. Use a Brim or Raft
A raft is a platform for printing parts. It consists of a base made of a 3D-printed structure that resembles a grid and extends past the initial layer of the model. Compared to rafts, a brim’s appearance is similar to a skirt that does not extend past the print’s edge.
Brims and rafts improve bed adhesion during ABS plastic printing. As a result, this prevents warping. Furthermore, they establish a solid foundation for the upper layers of your part.
Note: Raft takes considerably longer to print than the brim.
Other ABS Plastic Defects
ABS plastic printing has other defects such as:
1. Cracking (delamination)
Cracking is a printing defect where the layers of a part separate because of unsecured bonding. Unsecured bonding occurs when subsequent layers cannot adhere to one another due to a temperature difference. Using an enclosure to control the room temperature is the best solution.
2. Z-wobble
Z-wobble occurs when a printer’s z-axis movement component is skewed or inclined. This ultimately causes the printhead to move incorrectly. To prevent this, tighten all z-axis components.
3. Stringing
Stringing is when tiny plastic strings remain on a 3D-printed model. This often happens when the extruder moves to a new spot and plastic leak out of the nozzle. You can avoid stringing by changing the printing speed and using unclogged nozzles.
4. Layer Shifting
This happens when the layers of the printed part move from where they are supposed to be. It is caused by an abnormal X and Y axis motion leading to the extruder head becoming misaligned. To avoid this, reduce the printing speed.
5. Overheating
This happens when the cooling rate of the plastic is low, you are printing too fast, or the printing temperature is high. Overheating results in melted plastic parts. However, you can prevent this by controlling the cooling rate and the printing/print bed temperature
Conclusion
Warping ranges from a minor, aesthetic flaw to a problem that completely undermines the part’s functionality. As a result, it is a serious plastic printing defect. Warping is prominent in ABS plastic printing. This article explained how to prevent ABS plastic warping and other defects. Using our plastic machining service, you can also consider switching to custom plastic machining if printing processes are challenging.
