How to use optical brightener in plastics?
Example: Optical brightener Oribrite OB-1 in white PVC sheet application
| Octyltin Thiol | 2.8%~3.0% |
| Epoxidized soybean oil octyl ester | 1.0%~1.5% |
| Glycerol fatty acid ester | 1.2% |
| Butyl stearate | 1%~1.3% |
| Impact modifier MBS | 5%~6% |
| Processing modifier K—120N | 1.8%~2.5% |
| Optical brightener Oribrite OB-1 | 0.01%~0.05% |
| Calcium carbonate | 20%~30% |
Whitening process:
PVC resin and additives—kneading—cooling and mixing—sieving—extrusion—die head shaping—drawing—cooling and shaping—cutting—winding —Finished product.
- According to the above formula, first put the PVC resin and calcium carbonate into the kneader. Knead at low temperature and low speed.
- When the temperature rises to 60°C, add stabilizer, stir for 1~2mins, and then carry out high-speed kneading.
- When the temperature rises to 80°C, add modifier.
- When the temperature reaches 100°C, add other additives.
- When the temperature rises to 110°C, the kneading is completed, and the kneader changes from high speed to low speed.
- The kneaded material was discharged to the cooling mixer, and the mixture was stirred and cooled at low speed.
- The cooled material is fed into the twin-screw extruder, and the temperature of the screw is controlled to be 110°C, the temperature of the body is controlled at 190~160°C, the temperature of the head is controlled at 180~175°C, and the pulling temperature is controlled from 120°C to 100°C, 85°C, 45°C, gradually reduced. The temperature of the cooling roll is 20~25°C, the extruded material is shaped into a thin sheet by the die head, and then pulled by the tube through the edge trimming frame and enters the winding machine to obtain a rolled product.
