Jump to main content
Jump to site search

Issue 18, 2019

Online determination of chemical and physical properties of poly(ethylene vinyl acetate) pellets using a novel method of near-infrared spectroscopy combined with angle transformation

Author affiliations

Abstract

Melt flow rate (MFR) and vinyl acetate content (VAC) are the target parameters for quality control of poly(ethylene vinyl acetate) (EVA) pellets in production processes. Standard test methods for these two properties are too time consuming to meet the actual instant needs in industry. In order to solve this problem, an online near-infrared spectroscopy (NIR) system was integrated in this study to determine the MFR and VAC of EVA pellets in process. When collecting spectra, the difference of sample loading density and optical path will cause noise and decrease the spectral and prediction precision of quantitative models of the MFR and VAC. Although routine spectral pre-treatment methods, including the first order (1st) derivative and multiplicative scatter correction (MSC), are effective in reducing noise, the standard error of prediction (SEP) values of partial least squares (PLS) models of MFR and VAC using the pretreated spectra are still much larger than the reproducibility requirement of standard methods. The key aim of this present study is to explore a novel method based on angle transform to improve the online models. Before establishing models, the original spectra are transformed to angular spectra that reflect the composition information of the sample and are not influenced by the spectral intensity. This method can effectively reduce the severe noise and improve the performance of the models. The SEPs of PLS models of the MFR and VAC using angular spectra are 0.08 and 0.21, respectively. These two values are lower than the reproducibility requirement of standard test methods for the MFR, 0.1 and VAC, 0.3. A new online method of NIR spectroscopy combined with PLS using angular spectra has been successfully established to simultaneously determine the chemical and physical properties of EVA pellets. This research solves a tough technical problem existing in online NIR analysis of pellet samples carried by conveyor belts or pipelines with diffuse reflectance mode.

Graphical abstract: Online determination of chemical and physical properties of poly(ethylene vinyl acetate) pellets using a novel method of near-infrared spectroscopy combined with angle transformation

Article information


Submitted
06 Mar 2019
Accepted
03 Apr 2019
First published
03 Apr 2019

Anal. Methods, 2019,11, 2435-2442
Article type
Paper

Online determination of chemical and physical properties of poly(ethylene vinyl acetate) pellets using a novel method of near-infrared spectroscopy combined with angle transformation

J. Xie, H. Yuan, C. Song, X. Yan, H. Yan and X. Li, Anal. Methods, 2019, 11, 2435 DOI: 10.1039/C9AY00475K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements