초록 ▼

This invention relates to a process and apparatus for forming a polyester polymer into particles. More particularly, this invention relates to a process and apparatus for forming crystalline, uniform pellets from an amorphous polyester melt. The polyester pellets have utility, for example, as feedst

This invention relates to a process and apparatus for forming a polyester polymer into particles. More particularly, this invention relates to a process and apparatus for forming crystalline, uniform pellets from an amorphous polyester melt. The polyester pellets have utility, for example, as feedstock for a process for producing higher molecular weight polyesters.

대표청구항 ▼

[ What is claimed is:] [1.] A process for producing pellets of a polyester polymer having a glass transition temperature T.sub.g greater than about 25.degree. C., from its polymer melt, comprising:(a) forming the polymer melt into molten droplets, wherein the molten pellets are formed by a droplet f

[ What is claimed is:] [1.] A process for producing pellets of a polyester polymer having a glass transition temperature T.sub.g greater than about 25.degree. C., from its polymer melt, comprising:(a) forming the polymer melt into molten droplets, wherein the molten pellets are formed by a droplet former comprising a rotatable container having a plurality of outlets, each 0.5 to 5 mm in diameter, for metering a polymer melt onto a moving solid surface; and(b) collecting the molten droplets or crystallizing pellets, as they are formed, onto said surface, the surface being maintained within a predetermined temperature range above 50.degree. C. within a crystallization zone by adding or removing heat, such that the crystallizing pellets are maintained in contact with the surface within the crystallization zone for a predetermined period of time during crystallization, thereby producing crystallized polyester particles 500 microns to 2 cm in average diameter.