Often see some beautiful 3D printed model dolls, animals, such as the following picture of this deer. It is printed from photosensitive resin material.
So what is photosensitive resin material?
Photosensitive resin material is a common 3D printing model material, photosensitive resin material is generally liquid, composed of photoinitiator and monomer or pre-polymer, mainly composed of copolymers, additives and diluents, additives for photoinitiator. The addition of photoinitiator, through a certain wavelength of ultraviolet radiation, can cause the polymerization reaction of the copolymer, so that the liquid photosensitive resin material curing, the process is called liquid light-curing resin process, commonly used in three-dimensional light-curing 3D printing technology.
The performance of photosensitive resin material is similar to ABS resin, high mechanical strength, no volatile odor, wide application, convenient storage, short preparation process of photosensitive resin material, easy to cure, high molding accuracy, good surface effect, suitable for light-curing molding (SLA) rapid prototyping equipment. Under the laser or UV irradiation of 250~300nm, the photoinitiator present in the photosensitive resin material absorbs the UV light and forms excited state molecules, which then rapidly decompose and trigger the polymerization reaction of the polymer in the photosensitive resin. The whole triggering process is short and the photosensitive resin material can be cured in a short time. To improve the curing, the photosensitive resin material can be scanned and stacked layer by layer using 3D printing modeling equipment to obtain the desired finished 3D printed product and to realize the design model. Using the photosensitive resin material obtained by this technology, 3D printed products with high molding accuracy can be produced.
As can be seen from the above, photosensitive resin material has many advantages and is an ideal material for 3D printing models. The products obtained from this material have high surface precision, which can show better details of the 3D printed products, and the products have fine surfaces, which are suitable for precision material processing, especially in precision parts. However, it also has disadvantages. For example, UV resins are expensive to produce compared to most polymer polymers and are the nobility in the polymer field. Therefore, the high preparation cost has limited the development of UV resin materials in 3D printing to some extent.
Currently, there are more studies on the application of photosensitive resin materials in the field of 3D printing materials, but there are fewer reports of large-scale applications in the commercial field. It can be seen that the commercialization of photosensitive resin 3D printing model materials still has a long way to go. In addition to photosensitive resins, acid anhydride, PUA and vinyl ester resins are also among the widely used photosensitive resin materials. Acid anhydride, in particular, is more popular among researchers because of its moderate viscosity, which facilitates the molding process during 3D printing. However, acid anhydride material has low mechanical strength, low molding degree, high hardness, easy shrinkage, which is not conducive to obtaining the ideal size model; in contrast, PUA material has good optical properties, wear resistance and toughness, but PUA material also has disadvantages in some aspects, the polymerization process is not easy to control, the coloring degree is difficult to control and adjust; vinyl ester resin material has good chemical stability, high mechanical strength, molding material is not easy to shrink It is a better material for photosensitive resin 3D printing. However, the high viscosity of vinyl ester resin material, poor fluidity polymerization process using a long time, is not conducive to molding, to the 3D printing process brings a certain degree of difficulty, affecting the product molding process. Therefore, acid anhydride, PUA, vinyl ester resin materials have their own characteristics, both advantages and disadvantages, therefore, in the process of selecting 3D printing materials, in order to obtain suitable photosensitive resin materials for the application, as far as possible to play the advantages of the material play the advantages of the material, will use a mixture, different materials mixed in a certain ratio.