1. over time, the resin will absorb moisture from the air, resulting in soft wing bending of thin sections and volumes.
2. only helium-cadmium laser tube life 3,000 hour, prices are more expensive, while scanning the whole cross section of curing, forming a long time, so the production costs are relatively high.
3. Select material type is limited, must be a photosensitive resin, artifacts made from this type of resin in most cases cannot be durability and thermal performance testing and pollution to the environment and photosensitive resin, skin allergies.
4. the need to design artifacts support structures in order to ensure that in the process of forming ministries can make every structure and reliable positioning.