US 5,886,058 A · Inline solid state polymerization of pet flakes for manufacturing plastic strap

Abstract

The present invention describes a process of making strap using both post consumer and non-post consumer PET of wide distribution intrinsic viscosity (IV) through direct solid state polymerization in a flaked state to produce PET with increased, heterogenous IV suitable for high performance strap extrusion. The process increases the IV of post-consumer resins, consisting principally of polyethylene terephthalate (PET), by chopping the post-consumer plastic into flakes and chunks, rolling the flakes and chunks, preheating the flakes, and further heating the flakes and chunks in an atmosphere of hot nitrogen gas, thereby increasing the intrinsic viscosity. PET polymers having increased viscosities according to the present invention provide a polymer useful in manufacturing high performance strap.

Claims18

Dependent claims

A process for making a polyethylene terephthalate (PET) material, comprising the steps of:

collecting diverse PET material having a wide distribution of intrinsic viscosity (IV) values, primarily within the range of 0.60 dl/g to 0.80 dl/g, but as high as 0.90 dl/g, and wherein the difference in said IV values of said collected PET material is at least 0.20 dl/g;
co-mingling said collected PET material and reforming said co-mingled PET material into a heterogeneous IV mixture of PET material comprised substantially of a plurality of non-uniform flake-like and chunk-like pieces;
and
directly subjecting said heterogeneous IV mixture of PET material to solid state polymerization (SSP) so as to form a heterogeneous PET material having an average IV value of at least 0.85 dl/g.

1 more element

Dependencies are inferred from the claim text.

Inline solid state polymerization of pet flakes for manufacturing plastic strap

Life of this patent

Inline solid state polymerization of pet flakes for manufacturing plastic strap

Life of this patent

Abstract

Claims18