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The Use of Stable Fluorescent Artifacts for Calibration of Brightness Levels in Polyolefin Films and Plastic Sheets Using a Precise Set of Fluorescent Calibration Standards

IP.com Disclosure Number: IPCOM000005926D
Publication Date: 2001-Nov-15
Document File: 12 page(s) / 93K

Publishing Venue

The IP.com Prior Art Database

Related People

Jerome J. Workman, Jr.: AUTHOR [+4]

Related Documents

US 5,286,543: PATENT [+5]

Abstract

A specific set of materials and methods are used to create uniform fluorescent calibration standards over an extremely wide range of fluorescence intensities. These standards can be formulated for a specific optical brightness (OB) level and can be formulated using a variety of optical brighteners and fluorescent materials. These materials are used to create calibration standards suitable for multiple instrument types for standard brightness measurements of films or plastic sheets. Such standards can be custom made to any optical brightness suited to the unique measurement characteristics of the wide variety of fluorescent measuring instruments or meters. The fluorophore or brightening agent is prepared using a series of concentrations to bracket the desired film or plastic brightness level(s). Once bracketed, the appropriate fluorophore or brightener concentration is added to the base material in the correct concentrations resulting in a precise level of optical brightness for each calibration standard comprising a linear set of reference standards.

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The use of stable fluorescent artifacts for calibration of brightness levels in polyolefin films and plastic sheets using a precise set of fluorescent calibration standards

Jerome J. Workman, Jr., Debbie Graverson, Robert C. Pilecky

 Kimberly-Clark Corporation, West Research & Engineering, 2100 Winchester Road, Neenah, Wisconsin 54956

Art Springsteen

Avian Technologies LLC/Avian Group USA, P.O. Box 1076/1 Morgan Ridge Rd.        

New London, NH 03257-1076

ABSTRACT

     A specific set of materials and methods are used to create uniform fluorescent calibration standards over an extremely wide range of fluorescence intensities. These standards can be formulated for a specific optical brightness (OB) level and can be formulated using a variety of optical brighteners and fluorescent materials. These materials are used to create calibration standards suitable for multiple instrument types for standard brightness measurements of films or plastic sheets. Such standards can be custom made to any optical brightness suited to the unique measurement characteristics of the wide variety of fluorescent measuring instruments or meters. The fluorophore or brightening agent is prepared using a series of concentrations to bracket the desired film or plastic brightness level(s). Once bracketed, the appropriate fluorophore or brightener concentration is added to the base material in the correct concentrations resulting in a precise level of optical brightness for each calibration standard comprising a linear set of reference standards.

Introduction

     Unlike paper measurements, which demand the use of a fluorophore that 'exactly' duplicates the excitation and emission spectrum of the optical brightener in paper, the calibration of a series of instruments for measurement of optical brightness in polyolefin films and plastic sheets can be accomplished by use of a number of standards that meet the following criteria:

1.  Stability of artifact standards over a long period of time under ambient storage conditions;

2. Ability to establish linearity of the sensor by use of a calibrated and gradient series of artifacts that cover a range of brightness that cover the expected range of the products to be measured.

3. Use of these artifact standards as transfer standards to establish linearity of similar instruments.

MATERIALS AND METHODS

     A fine powdered optical brightener or fluorophore is thoroughly mixed into a PTFE fine powder having a particle size diameter within 0.1 to 5 times the fluorophore. The materials are thoroughly mixed; the mixing time is predetermined by testing the final standard reproducibility between test tiles made from a specific batch of material. The deviation cannot exceed more than 2 percent relative OB reading from batch to batch for a pre-specified fluorophore or brightener concentration when using a pre-specified fluorescent meter. The PTFE is sintered to produce a final OB or fluorescent standard tile block and is tested for optical quality and values using any...