Premium
In‐line monitoring of polyethylene density using near infrared (NIR) spectroscopy
Author(s) -
Nagata Takefumi,
Ohshima Masahiro,
Tanigaki Masataka
Publication year - 2000
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11238
Subject(s) - materials science , polyethylene , polyolefin , low density polyethylene , near infrared spectroscopy , plastics extrusion , melt flow index , infrared spectroscopy , composite material , analytical chemistry (journal) , polymer , optics , organic chemistry , chemistry , physics , layer (electronics) , copolymer
Density and melt index are two key properties in grading commercial polyolefin polymers. For quality assurance, these properties must be controlled as accurately as possible in the production plant. However, the lack of suitable in‐line sensors for these properties makes feedback quality control difficult. In this study, an in‐line density sensor using near infrared (NIR) spectroscopy is developed. The NIR spectra of molten polyethylene in flow are collected by a fiber‐optic device attached to a single screw extruder. By the ratio of the absorption intensity at 1170 nm to that at 1213 nm, the densities of 14 grades of polyethylene were successfully measured. The results were very promising for quality control in the polyethylene production process.