Why are photosensitive resin materials more popular

Now photosensitive resin materials are mostly used for 3D printing materials. Because of the unique characteristics of photosensitive materials, they are favored by the industry. Photosensitive resin, commonly known as UV curable shadowless adhesive, or UV resin, is mainly composed of polymer monomer and prepolymer, in which photoinitiator or photosensitizer is added. Under the irradiation of ultraviolet light with a certain wavelength (250 ~ 300nm), it will immediately cause polymerization and complete the solid-state conversion. Today, let's look at what photosensitive resin is composed of.

1. Fast curing rate. Generally, the thickness of each layer is 0.1 ~ 0.2 mm for curing layer by layer during molding, and one part needs to be cured for hundreds to thousands of layers. Therefore, if the solid is to be manufactured in a short time, the curing rate is very important. The exposure time of a laser beam to a point is only in the range of microseconds to milliseconds, which is almost equivalent to the excited state lifetime of the photoinitiator used. Low curing rate not only affects the curing effect, but also directly affects the working efficiency of the molding machine, so it is difficult to be suitable for commercial production.

2. Small swelling. In the process of model forming, the liquid resin has been covered on some cured workpieces, which can penetrate into the cured parts and swell the cured resin, resulting in the increase of part size. Only when the resin swelling is small can the accuracy of the model be guaranteed.

3. High light sensitivity. Because the SLA uses monochromatic light, it requires that the wavelength of the photosensitive resin and the laser must match, that is, the wavelength of the laser should be near the z-large absorption wavelength of the photosensitive resin as much as possible. At the same time, the absorption wavelength range of photosensitive resin should be narrow, so as to ensure that curing occurs only at the point irradiated by laser, so as to improve the manufacturing accuracy of parts.

4. High curing degree. The shrinkage of the post curing molding model can be reduced, so as to reduce the post curing deformation.