3D resin printing has become increasingly popular for its ability to create highly detailed models and prototypes. However, one challenge with resin prints is properly cleaning them after printing to remove any excess uncured resin.
Ultrasonic cleaners provide an effective solution for cleaning and finishing resin prints.
In this article, we’ll look at using an ultrasonic cleaner to get professional-quality results with 3D-printed resin models. We’ll cover the basics of how ultrasonic cleaning works, what type of cleaner to select, proper cleaning solutions and settings, and tips for getting your prints ultra-clean.
With the proper ultrasonic cleaning process, you can give your resin prints a smooth, professional finish ready for painting or display.
Table of Contents
How Do Ultrasonic Cleaners Work?
Ultrasonic cleaners use high-frequency sound waves, typically above 20 kHz, to agitate a solution. The ultrasonic waves create millions of microscopic bubbles that grow and rapidly collapse. This process is called cavitation. The bubbles act like tiny scrub brushes to lift residue off the surface of objects placed in the cleaning solution. You can learn more about how ultrasonic cleaners work here.
Choosing the Right Ultrasonic Cleaner for 3D Printing
When selecting an ultrasonic cleaner for 3D-printed resin models, there are key features and specifications to look for that make the cleaning process more manageable and prevent print damage.
- Size Matters—Look for an ultrasonic cleaner that comfortably fits your largest prints. Measure your build platform to determine the minimum tank size needed. Allow extra space for cleaning multiple objects at once.
- Heat Control Is Key—Precise temperature control allows dialing in the ideal heat for the resin used. Heating helps cleaning, but too much heat can make some resins gummy. Look for a cleaner with a temperature range of at least 90-180°F (32-82°C).
- Adjustable Timer—An adjustable timer allows controlling exposure to safe limits. Most prints only require a few minutes of ultrasonic cleaning time. Longer exposures can damage delicate details. A timer of up to 10 minutes is usually sufficient.
- Power Level Options—Higher wattage provides more aggressive ultrasonic cleaning, but too much power can damage prints. Look for a unit with power levels adjustable from at least 50-200 watts to customize cleaning strength.
- Dedicated Baskets—Ultrasonic cleaning baskets are designed to lower prints into the cleaning solution make the process safer and easier. Baskets prevent direct contact between the pieces and ultrasonic transducers.
Choosing the Proper Cleaning Solution
When selecting an ultrasonic cleaning solution, there are a few key considerations to ensure optimal performance:
- Read the Label—Look for solutions formulated explicitly for cleaning 3D printing resins. General-purpose cleaners may not be compatible with printer resins. The label should indicate if the solution works with your resin type.
- Follow Dilution Ratios—Mix concentrate and water at the dilutions recommended. Using too strong or weak of a solution can impact cleaning performance. Stick to manufacturer guidelines for best results.
- Consider Wash & Cure Combo—Some 3D resin printers include branded wash and cure solutions. Using the paired combo provides an optimized cleaning and curing process.
- Mind Expiration Dates—Ultrasonic resin cleaning solutions have a limited shelf life like other chemicals. Check expiration and discard old solutions to ensure peak effectiveness.
- Try DI Water Dilution—Using distilled or deionized water to dilute concentrate helps avoid mineral deposits that can interfere with cleaning. Tap water may leave residues.
- Refresh Solution—Be sure to change out the cleaning solution periodically. The used solution collects dissolved resin and loses potency over time. Refreshing prevents recontamination.
Proper Ultrasonic Cleaning Techniques for 3D Printing
How you use an ultrasonic cleaner can significantly impact cleaning effectiveness and prevent print damage. Following proper techniques is critical to getting the best results.
- Pre-Rinse Prints—Before ultrasonic cleaning, rinse prints with isopropyl alcohol to remove any loosely adhering resin. This pre-rinse prevents oversaturation.
- Load Print Properly—Carefully place prints into mesh baskets, avoiding contact with tank bottom. Suspending prints prevents abrasion. Arrange objects to allow total solution circulation.
- Select Time and Temperature—Consult cleaner and solution guidelines for recommended time and temperature settings. Start on the low end with delicate prints. Heat helps cut grease, but too much can make resin gummy.
- Post-Rinse Thoroughly—After ultrasonic cleaning, rinse prints thoroughly with clean alcohol to fully flush away residue. Multiple rinse baths may be needed for intricate pieces.
- Let Prints Dry Completely— Allow prints to dry thoroughly before further handling or curing. Residual solvent can inhibit curing under UV. Drying times will vary based on size and geometry.
- Adjust Settings As Needed—If prints show damage or residual resin after cleaning, adjust time, temperature, or power levels accordingly for the next batch. The goal is thorough cleaning without detriment.
The Cleaning Process
Ultrasonic cleaning involves several key steps performed in sequence to safely and effectively clean 3D-printed resin models.
- Mix cleaning solution according to manufacturer’s directions and fill the ultrasonic cleaner tank. Use fresh solution for the best results.
- Pre-rinse prints briefly in isopropyl alcohol to remove loose resin.
- Load prints into cleaner mesh baskets, avoiding contact with the tank bottom.
- Set time and temperature based on resin printer/solution guidelines. Start conservatively.
- Initiate ultrasonic cleaner and allow the entire cleaning cycle to complete.
- Remove prints and post-rinse thoroughly in clean alcohol to flush residue.
- Allow prints to air dry thoroughly before further handling. Drying time varies.
- Inspect prints and adjust cleaner settings if needed for the next batch.
- Change out used solution regularly to maintain peak cleaning power.
This precise process will allow you to achieve professional results with ultrasonic 3D print cleaning.
Using IPA for Cleaning
Isopropyl alcohol (IPA) plays a key role before and after the ultrasonic cleaning process for 3D resin prints. Using it properly improves results.
- Use 90%+ purity IPA. Higher water content reduces effectiveness.
- Pre-rinse prints in IPA first to remove loose resin before the ultrasonic bath.
- Use multiple fresh IPA rinse baths after ultrasonic cleaning to fully flush residue.
- Agitate prints and change out IPA baths until rinse the IPA runs clear.
- Suspend prints in rinse baths to allow 100% circulation around all surfaces.
- Thoroughly air dry prints after rinsing before further handling or curing.
- Allow used IPA to fully settle before decanting. Filtered IPA can be reused.
- Properly dispose of or recycle used dirty IPA according to local regulations.
- Work in a well-ventilated area and avoid skin contact when using IPA.
What is IPA?
IPA, short for Isopropyl Alcohol, is an organic compound. It is used as a solvent because it can dissolve substances like uncured 3D printing resin. Use IPA as a simple yet powerful tool for pre-cleaning and post-rinsing ultrasonically cleaned 3D-printed resin models.
Benefits of Using IPA
IPA offers significant advantages in the ultrasonic cleaning process for 3D-printed resin models.
- Effectively dissolves and rinses away uncured resin residue.
- High-purity IPA maximizes cleaning and solvent properties.
- Pre-rinsing prevents the oversaturation of prints before the ultrasonic bath.
- Post-rinsing removes the remaining dissolved resin after the ultrasonic bath.
- Allows full flush of intricate print geometries when appropriately used.
- Quick IPA drying enables prints to fully air dry after cleaning.
- Settled used IPA can potentially be reused after filtration.
- Relatively inexpensive and widely available.
Proper IPA usage helps ensure that your prints achieve the desired smooth, residue-free finish after ultrasonic cleaning. Its solvent properties are uniquely suited for this application.
Disadvantages of Using IPA
While providing important benefits, using an IPA cleaning solution has some drawbacks to consider when ultrasonically cleaning 3D-printed resin models.
- Highly flammable, requires careful handling and storage
- Drying time can be lengthy for large or intricate prints
- It may not entirely remove some resin residues without combinational cleaning
- Fumes require working in a well-ventilated area
- Used IPA requires proper hazardous waste disposal
- Repeated exposure can dry out skin, and gloves are recommended
- Less environmentally friendly compared to some aqueous solutions
- Settled IPA must be filtered well before reusing as a rinse bath
Being aware of these limitations allows steps to be taken to safely and effectively integrate IPA into the ultrasonic 3D print cleaning workflow.
Other Cleaning Solution Options
A highly alkaline or caustic solution with added detergent may work well to remove some resins. The detergent helps the solution thoroughly wet and dissolve the support material.
Other support materials like wax may require flammable solvents with low flash points that can dissolve the wax. And for supports made of materials like LFS, high flash point solvents or semi-aqueous solutions containing solvents could be effective.
The key is choosing a removal solution that is formulated to break down and dissolve away the specific support material used in the molding process.
It’s essential to follow the solution manufacturer’s directions in all cases. When in doubt, please contact our Chem-Crest professionals.
Optional Equipment and Cleaning Procedures for 3D Printed Parts
Small, delicate parts like jewelry or dental implants can be cleaned using isopropyl alcohol or a similar volatile solvent. Place the pieces in beakers filled with solvent and submerge the bottom of the beakers in an ultrasonic benchtop cleaning tank containing water and a few drops of dish soap.
Alternatively, you can place the parts into small fine mesh baskets that fit inside the beakers. Make sure to use baskets that allow the beaker to be loosely covered during ultrasonic cleaning. Covering the beaker minimizes the solvent vapor that escapes into the air. The baskets containing the parts must sit low enough in the beaker to be fully immersed in the solvent. This allows the ultrasonic waves to fully penetrate and cavitate the solvent around the parts for thorough cleaning.
In either case, be sure to degas the solution for around 10 minutes without a load before proceeding.
For larger parts, utilize an ultrasonic tank designed for higher flash points or semi-aqueous solutions. Lower the parts into mesh baskets in the tank filled with the appropriate cleaning liquid. If using a combustible solution, add a polypropylene tub inside the stainless steel tank as a safety precaution. When finished, remove and rinse the parts in clear water.
Finally, you can use purpose-built explosion-proof ultrasonic systems for industrial operations involving large quantities of 3D-printed parts. These systems allow the safe ultrasonic cleaning of parts in IPA or other low flash point solvents. Proper ventilation is critical when working with flammable liquids. Always follow safety protocols and equipment guidelines.
Best Practices for Cleaning Resin Prints
When working with 3D-printed resin models, following certain best practices for post-print cleaning is crucial for achieving professional-quality results.
- Test Prints First—When first using an ultrasonic cleaner for resin prints, test the process on lower-value print samples. Check for any damage or residue left behind. Adjust times and temperatures accordingly before cleaning more intricate or valuable prints.
- Clean Prints Immediately—For best results, clean resin prints soon after printing, before the cured resin has time to harden significantly. The ultrasonic process will be most effective on fresh prints.
- Use Proper Rinsing—After ultrasonic cleaning, thoroughly rinse prints with clean 90%+ isopropyl alcohol. This helps remove any residue dissolved by cleaning but not thoroughly flushed away.
- Let Prints Fully Dry—Allow prints to air dry fully after rinsing. Residual solvent can impact the curing and finishing steps. Drying times will vary based on print size and geometry.
- Finish Sanding If Needed—If any leftover residue persists, gentle sanding with fine grit sandpaper can remove it. Be careful not to damage fine print details. Proper ultrasonic cleaning minimizes the need for sanding.
Removing Supports and Excess Resin
After ultrasonically cleaning 3D-printed resin models, some additional steps help finalize print preparation by removing supports and any lingering residues.
- Use flush cutters to clip support structures from the print as close to the surface as possible.
- Gently use a plastic scraping tool to remove any stubborn supports and detach the build plate.
- Lightly rinse the print with isopropyl alcohol using a brush to dislodge particulates.
- Carefully inspect the print under bright light for any remaining visible resin residue.
- Gently wipe the print with a microfiber cloth soaked in IPA to eliminate spots of excess resin.
- If needed, use fine-grit sandpaper to lightly sand away any bits of cured resin without damaging details.
- Rinse print again with IPA and allow to fully air dry before final curing.
Taking the time to properly remove supports and fully clean prints after ultrasonic cleaning ensures the best results before final curing.
With the right ultrasonic cleaner and dialed-in process, you can achieve professional-quality, smooth, clean resin prints ready for finishing and use. Ultrasonic cleaning is an excellent tool for bringing out the best in 3D-printed resin models.
How Long Should I Ultrasonically Clean a 3D Print?
The general guideline is to clean for 5 to 10 minutes at around 30°–50° C (higher temperatures can make some resins stickier). However, considering various factors, including resin type, print size, and your ultrasonic cleaner specifications, is essential. Monitor the process to determine the optimal cleaning time for each print.
Can Ultrasonic Cleaning Damage or Warp Some 3D Printed Materials?
Yes, ultrasonic cleaning can distort or warp certain 3D printed materials if they are incompatible with the process. It’s important to consider its effects on the dimensional accuracy and integrity of the printed parts when selecting this method.
What Risks or Hazards Exist With Using Flammable Solvents In Ultrasonic Cleaning?
Flammable ultrasonic cleaning solvents pose serious fire, chemical exposure, and environmental contamination hazards if improperly handled. Proper protective equipment, ventilation, and explosion-proof systems are crucial precautions when using these chemicals.
Is Protective Gear Needed For Ultrasonic Cleaning Of 3D Prints?
Protective equipment like gloves, goggles, and masks are highly recommended for ultrasonic cleaning to guard against solution splashes and vapor inhalation. Proper ventilation and temperature control also help ensure safety.
Can I Use Water As My Ultrasonic Cleaning Solution?
Most ultrasonic cleaners require a cleaning solution to be used along with water. Water alone will not be effective enough in removing resin and support material from the prints. Therefore, it is recommended to use a cleaning solution designed explicitly for resin prints.
Can An Ultrasonic Cleaner Be Used For Cleaning Other Components Besides Resin Prints?
Yes, you can use an ultrasonic cleaner for cleaning various components besides resin prints. It is commonly used in manufacturing, automotive, and jewelry industries for cleaning small parts and objects.