Ensuring bed adhesion is a very important step in 3D printing. Without it, your plastic model will not stick to the build plate and your finished project could lack accuracy or can fail with curled edges and shifted layers. Fortunately, makers have found ways to ensure their 3D printing surfaces properly work our plastics of choice onto the build plate.
Different materials, such as aluminium, stainless steel, glass, BuildTak, Kapton tape, PET tape, masking tape and PEI film are commonly used for 3D printing beds. But because no single material works best for the adhesion of all types of filament – let alone several filaments at once. Let’s now talk about the key elements that affect bed adhesion as well as some strategies for increasing your chances of obtaining a flawless attachment.
Bed adhesion comes down to three factors:
- How well the plastic “wets” the build plate
- Thermal expansion
- How to level the bed is
Optimizing Build Plate Wetting
Wetting is the process of a liquid conforming to and sticking to a solid surface; for 3D printing, this refers to filament sticking to the build plate or bed. Increasing surface area is one way in which adhesion and quality can be improved, as more contact surface area results in greater adherence and strength of the finished item. Adhesion aides like brims can be added to the base of prints when parts become larger, as it increases the surface area between them and the plastic and thus improves adhesion significantly. In these cases, the filament must stick firmly with no warping in order to achieve proper print quality.
Understanding the Phenomenon of Thermal Expansion in Materials
Thermal expansion can have a detrimental effect on 3D printing. It describes changes that happen to the size of an object at different temperatures, and temperature differences between the parts in a 3D-printed object can cause it to peel up at the edges. This occurs more frequently when using materials like ABS which need a heated build plate for successful printing. The issue lies in striking the right balance between thermal expansion and 3D printing: layers must be cooled enough to create an object with its various components being bound together, but not so much that warping happens because of edge-peeling.
Fortunately, proper precautions can be taken to help reduce issues with bed adhesion. The temperature of both the bed and the printing enclosure needs to be maintained evenly in order to achieve effective adhesion that will be more resistant to warping. It is also important to keep the air inside of the printer at a constant temperature that is lower than the layers being printed. This combination of regulated temperatures allows for more successful 3D prints and better results overall.
Achieving High Precision 3D Prints through Proper Leveling Techniques
It is essential to accurately adjust the nozzle height from the build plate in order to stick filament and create successful prints. The distance between the nozzle and the build plate must be just right for the filament to effectively adhere but not too close that it will pull away printed parts already stuck on the bed. For more information about how to ensure that your nozzle height is correct, refer to our troubleshooting guide which discusses best practices in detail.
There are numerous ways to create a good surface for 3D prints to adhere to.
Regular Build Plate Inspections
The best way to ensure a good stick and a successful print is to clean the build plate before starting, using rubbing alcohol and a microfiber cloth. When choosing any type of build plate material, you must always double-check that it’s chemically safe for use with rubbing alcohol. Glass beds are generally very compatible with this method of cleaning, but consider other materials beforehand – some rubbers are not recommended. Cleaning your build plate eliminates contaminants that could prevent the plastic from sticking correctly, leaving you with a superior finished product.
The next step is levelling. This is an important part of achieving good adhesion and preventing distortion of prints due to uneven contact with the build plate. To check this, simply measure the distance of the filament from the build plate surfaces at different points and adjust as necessary until all measurements are equal.
3D Printed Aids
If a print is not sticking well to the build surface, reinforcing it with a brim or raft can help. Brims improve adhesion by increasing the surface area contact of the print to the bed – more contact equals more holding force. Rafts are used as an offset – instead of trying to print perfectly on the build surface, a raft can be printed that carries even complex geometries without issue.
The prints will then be supported on top of the raft and separated from any potential adhesion issues with the build plate. The tradeoff here is that the print finish on a raft may look less than perfect since it is effectively floating in the air – but if a smooth finish is less important than staying connected, this may be your best option for improving bed adhesion.
For those looking for precision printing results draft shields are a great tool. By using residual heat to create a more consistent temperature within the space surrounding the print, draft shields can help reduce warping caused by large temperature differences between the print and its environment.
Slicer Settings Optimization
Hot end temperature is an important factor in 3D printing as it affects the quality and accuracy of a print greatly. Too small of a temperature difference between the plastic being extruded and cooled may lead to disappointing results; warping is a common issue when using materials such as ABS. This happens because of thermal expansion forces when the range of temperatures (210-250 °C) causes heated plastic to cool at different rates, tugging on the edges.
Your fan speed is another factor to consider when printing for better adhesion. In general, running the fan slower will ensure that the plastic stays in a molten state for longer, enabling it to adhere better. However, it’s important to remember that too little cooling can cause issues with the shape and structure of your printed parts – especially if your plastic cools too quickly.
Lastly, It is important to note that Each individual project presents unique challenges that necessitate slight variations in the printer settings. For this reason, we recommend researching the best settings for your printer and filament type in order to get the most ideal result. There is a lot of information available online that provides instructions on how to achieve good results when it comes to perfecting your first-layer adhesion so that every print job turns out perfectly.
There are some other ways you can try in order to improve the adhesion of your plate. Depending on your budget and printing requirements, these range from adding a simple protective coating to the built plate, right up to upgrading the bed by incorporating a heating element.
Installing a Heated Bed
If the temperature is too low, it will be harder for the filament to successfully stick to the build plate and start printing properly. Increasing the temperature slightly can help melt the filament so that it sticks better and gives it more of an opportunity to do so. However, one must be careful not to increase it too much – if this happens, your finished print could look melted or warped because layers may be squished together before they are sufficiently cooled down. Simply adjusting it by 5 degrees at a time can help you find the right balance between temperatures that leave your good prints looking neat and in line with their intended dimensions.
With the help of these methods, the print is essentially “glued” to the build surface.
- Salt solutions are one of the best ways to ensure smooth 3D printing. They work by changing the morphology, or structure, of filament material.
- Since Aqua Net hairspray doesn’t contain any disruptive ingredients, it performs quite well. Other hairspray brands are acceptable, but they should include a few additives to function well for bed adhesion.
- A disappearing purple glue stick is an ideal option for those looking for a clean and assured build plate. The unique colour of the glue allows you to visually track the coverage you’ve given all over the plate, as once it dries, it blends in with its surroundings.
- Wolfbite adhesive is designed and developed specifically to provide a secure bond between prints and the print bed. With different types of Wolfbite available for each type of filament, you can be sure that your prints will stick without fail no matter what kind of material you are 3D printing with.
Installing a New Bed
If the above-mentioned techniques are not working when attempting to repair a build plate, another option could be considered. Replacing the build plate altogether is an expensive but relatively straightforward solution.
As previously mentioned, there are a variety of different types of beds, that have their own unique pros and cons. Glass beds offer an affordable option for those on a budget but require extra adhesive to keep objects securely attached. PEI sheets come in both smooth and textured options and offer the flexibility to easily remove parts from the build plate. However, they can pose issues with z-offset settings if not adjusted properly. Lastly, polypropylene (PP) beds also provide affordability while being able to handle higher bed temperatures; though they can sometimes encounter first-layer issues.
What to Do When Prints Still Won’t Stick?
If you’ve tried all the usual tricks for getting your prints to stick and are still struggling, fear not! There are two unorthodox methods that should help get your large, unruly prints into place.
The Pros and Cons of Roughening
This is an ingenious method for improving print adhesion without having to invest in an expensive build plate replacement. Thanks to the same science that results in a bumpy texture when sanding paper mache or coating wooden surfaces—creating microscopic surface area.
Printers can apply fine-grit sandpaper (600 or above) to lightly scratch a frosted glass bed and create microstructures for their prints to stick to. This method gives printers an advantage over the traditional polished glass, creating a slightly more matte finish as well as providing adhesion benefits.
Use of Duct Tape During Printing
If you’ve ever had the heart-sinking feeling of seeing your dream print warping and peeling halfway through a job, you’ll be relieved to know that there’s a relatively simple way to fix it! All you need is duct tape. It may sound unorthodox, but it’s an effective way to reattach any edges that might be lifting off the build plate during the print job. Just pause the process and use a few strips of tape to bond everything back down and then resume printing – it really does work but not in the long term.
I am Bheema Shankar. I have worked on SLS, CJP, DLP, SLA and FDM technologies at Think3D. Currently working as Process and application engineer at VEER-O-METALS PRIVATE LIMITED. I am always fascinated by the process of creating things layer by layer. This fascination led me to pursue a career in 3D printing technology. I am passionate about how 3D works and enjoy exploring new ways to improve the 3D printing process.