PURPOSE: To obtain polyester particles having favorable workability in film-making or filament-making process by a method wherein heat treatment is carried out under the condition that the ratio of water to the polyester particle and the temperatures of the polyester particle and of the water to be added are set to lie within specified ranges.
CONSTITUTION: Rectangular parallelepiped polyethylene terephthalate copolymer having the predetermined diameter, for example, is charged from a polyester particle charging port 4 in a device. Next, polyester particles are heated by heating medium through both the spraying of water heated up to the predetermined temperature from water spraying nozzles 7 provided at the upper part of the device and the agitation of agitating blades 9. The weight ratio of the polyester particle to the water to set to be 100:0.5-100:10. Steam developed through the spraying of the water is discharged through a steam suction port 8, resulting in keeping the interior of a main body at normal pressure. After the predetermined period of time, the spraying of the water is stopped and the polyester particles are taken out of the device through a polyester particle discharging port 5. No fusion of the particles occurs in the drying process of the obtained polyester particles. Further, the obtained polyester particles are suitable for the forming of film or the like.
| WO/2006/111313 | METHOD FOR SURFACE TREATING BEAD POLYMERS |
| WO/2022/146968 | POLYMERIC MICROPARTICLE COMPOSITIONS |
| JP4233215 | Continuous extraction method of polyamide |
TANBA OTONAO
FURUYAMA HIDETOSHI
