cracked model

cracked model

cracked model

Possible Causes

1. The temperature of the resin is insufficient
   
2. The printer placement is unstable
   
3. Exposure time is insufficient
   
4. Not enough time for liquid resin reflux, especially when printing models with big solid base or using resins of high viscosity
   
5. Resin is insufficiently mixed
   
6. Slicing file data error
   
7. Hollow model without digging holes
   
8. The resin tank is damaged or approach its lifespan
   
9. Resin type is not compatible

Diagnostic Steps

1. The temperature of the resin is insufficient
   Diagnosis: Low temperature decrease resin liquidity, making resin reflux more difficult and resulting in cracking due to insufficient resin in the printing area.
   Solution: Enable the preheating function of the printer and maintain the ambient temperature between 20℃-22℃ with air conditioner or additional heater.
   Reference article: How to enable the preheating function
   
2. The printer placement is unstable
   Diagnosis: the instability of the printer during printing affects the connection between layers resulting cracks.
   Solution: Adjust accordingly the level of the 4 wheels and block them.
   Reference video: How to level and block the 4 wheels of printer
   
3. Exposure time is insufficient
   Diagnosis: The insufficient exposure time will cause the incomplete curing of layers causing cracks.
   Solution: Increase the exposure time accordingly in UNIZ Dental V2.
   
   Increase the exposure time

   
   
   
4. Not enough time for liquid resin reflux, especially when printing models with big solid base or using resins of high viscosity
   Diagnosis: The big solid base and the high viscosity of resin need more time for resin refluxing.
   Solution: Increase Cool Down Time/ Rise Height and reduce Motor Speed accordingly in UNIZ Dental V2.
   
   Increase Cool Down Time/Rise Height, and reduce Motor Speed

   
   
   
5. Resin is not sufficiently mixed
   Diagnosis: The resin will sediment after being stored for a long time, that photopolymeric material cannot distribute uniformly.
   Solution: Shake up the resin before adding, and mix up well the resin in the resin tank with a scraper before printing.
   
   Resin sedimentation
   Resin well mixed

   
   
   
6. Slicing file data error
   Diagnosis: The model data error may be caused by the design or slicing software.
   Solution: Check the slicing file with UNIZ Dental V2, make sure all layers are well connected, without suspended layers or points.
   
   Check slicing file
   
   
7. Hollow model without digging holes
   Diagnosis: For hollow model without digging holes, there will be an internal and external air pressure difference during printing that will cause cracks.
   Solution: Digging holes in the bottom of the model ensuring a good ventilation for the internal space.
   
   Dig holes in UNIZ Dental V2
   
   
8. The resin tank is damaged or approach its lifespan
   Diagnosis: Any damage of the resin tank film such as scratch, clouding can block or deviate the collimated UV light at that location, causing cracks or other defect.
   Solution: Make sure the resin tank film is in good condition. If there is damage, the film needs to be replaced.
   Reference article: How to change resin tank film
   
   
9. Resin type is not compatible
   Diagnosis: The shrinkage properties of the resin may be very strong, making it unsuitable for ultra-high-speed UNIZ printers such as NBEE.
   Solution: Print using UNIZ brand or UNIZ officially certified resin. You can see all certified resin in UNIZ official website.
   
   

Conclusion