Abstract
A previous test confirmed that the post-curing process is critical for producing highly accurate 3D prints. The print accuracy can be varied when using the same resin but different UV boxes. However, the quality of the resin has a greater effect on print accuracy. During the polymerization process, the volume of the print can change. Even immediately after post curing, the polymerization process can still be active for a short period of time. The difference between the size of the original model and the final print is called the “scaling ratio”.
In this experiment, we review and reaffirm the importance of resin calibration and stability of our new resin, CURO Model. We make a comparison between CURO Model and two other resins that are readily available and that we purchased online.
Method:
We use the same STL file for all prints in this experiment. To test the difference between the calibrated and uncalibrated resins, one model is printed with a rescaling ratio and another is printed without the re-scaling ratio. In addition, two other resins are also tested in this experiment. To understand the rescaling effect of the different resins, the unscaled IBF file is used for printing the other two resins. We measure the accuracy with a desktop 3D scanner to determine how many scanned digital points are the same as the original STL file. The scanning process occurs immediately after the post-curing process and then again 24 hours after post curing.
Testing group:
- CURO Model 2.0 Without re-scaling ratio
- Brand A resin without re-scaling ratio
- Brand B resin without re-scaling ratio
Results:
| 3D Scan Accuracy | CURO Model
(without Scale Ratio) |
Resin A
(without Scale Ratio) |
Resin B
(without Scale Ratio) |
|
| Immediately after Post curing | 79% | 83% | 73% | |
| 24hrs after post curing | 82% | 57% | 21.7% |
CURO Model – Without Re-scaling Ratio
| Scan immediately after post curing |  |
 |
 |
| 78.98% | Lower Limit: 11.80% | Upper Limit 90.78% | |
| 24 hours after post curing |  |
 |
 |
| 82.18% | Lower Limit 11.85% | Upper Limit 94.03% |
| Observation immediately after post curing | Observation after 24 hours | Observation after 4 days |
| Smooth surface; No significant defects. | Smooth surface; No significant defects. | Smooth surface; No significant defects. |
———————————————————————————————————————————————————–
Resin A – Without Re-scaling Ratio
| Scan immediately after post curing |  |
 |
 |
| 83.16 | Lower Limit: 14.13 | Upper Limit 97.28 | |
| 24 hours after post curing |  |
 |
 |
| 57.28 | Lower Limit: 38.048 | Upper Limit 95.329 |
| Observation immediately after post curing | Observation after 24 hours | Observation after 4 days |
| Smooth surface; No significant defects. | Oil/liquid secreted around the sample. | Oil/liquid secreted around the sample. |
———————————————————————————————————————————————————–
Resin B – Without Re-scaling Ratio
| Scan immediately after post curing |  |
 |
 |
| 57.28% | Lower Limit 38.05% | Upper Limit 95.33% | |
| 24 hours after post curing |  |
 |
 |
| 20.66% | Lower Limit 37.90% | Upper Limit 58.56% |
| Observation immediately after post curing | Observation after 24 hours | Observation after 4 days |
| Part of the resin turns white as shown. | Oil/liquid secreted around the sample. Color faded slightly. | Oil/liquid secreted around the sample. Color faded slightly. |
|
Conclusion:
Different resins have different properties which have a distinct effect on the accuracy of the prints. There is a wide range of factors that can affect the accuracy of prints, such as environmental conditions, the duration of the curing time, and the resin that is used to produce those prints.
In this experiment, we assessed the quality of the 3D printing resin. With the CURO Model resin, not only is the resin shrinkage ratio tested, but the print stability and integrity is maintained much more better than the other resins after a period of four days. To achieve the highest printing accuracy, we strongly suggest buying the 3D printing resin from a reliable supplier.
In addition to adopting a uniform workflow and operating in a controlled environment, it is always best to commit to using the same resin so that you are able to produce consistent results.