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US 5,633,018 AGranted
Apparatus for forming crystalline polymer pellets
AssigneeE. I. Du Pont de Nemours and Company
InventorsJan M. Stouffer, Elwood N. Blanchard, Kenneth W. Leffew
Life of this patent
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Abstract
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.
Claims20
An apparatus for producing pellets of a polymer from its polymer melt, comprising:
- (a) a pellet former comprising a rotatable container having a plurality of outlets, defining openings each having a maximum cross-sectional dimension in the range of about 0.5 mm to about 5 mm, for metering a polymer melt onto the surface of a conveyor;
- (b) a conveyor comprising for receiving, from the pellet former, the polymer melt in the form of a plurality of droplets or crystallizing pellets, which conveyor comprises a surface which is adapted for movement relative to the pellet former and for conveying the pellets through a crystallization section;
- and
- (c) a crystallization section extending from the point at which the pellets are received onto the surface of the conveyor and along a portion of the conveyor,
- the crystallization section further comprising a means for adding or removing heat for controlling the temperature of the surface above 50.degree. C. within a predetermined temperature range as the surface passes through the crystallization section.
2 more elements
An apparatus for producing pellets of a polymer from its polymer melt, comprising:
- (a) a means for producing a polymer in melt form which comprises at least outlets connected to a conduit for transporting the polymer melt towards a pellet former;
- (b) a pellet former comprising a rotatable container having an inlet for the polymer melt and a plurality of outlet openings, each 0.5 to 5 mm in diameter, for metering the polymer melt onto the surface of a conveyor;
- (c) a conveyor comprising a surface moving relative to the pellet former, for receiving from the pellet former, the polymer melt in the form of a plurality of droplets or crystallizing pellets, which conveyor is adapted for conveying the pellets through a crystallization section;
- and
- (d) a crystallization section extending from the point at which the pellets are received onto the surface of the conveyor, and along a portion of the conveyor,
- the crystallization section comprising a means for adding or removing heat for controlling the temperature of the surface to within a predetermined temperature range above 50.degree. C. as the surface on which the pellets are supported pass through the crystallization section.
3 more elements
Dependencies are inferred from the claim text.