|
RadTech
UV/EB Technology Conference & Expo 2008
May 4-7, 2008
Lakeside Center at McCormick Place
Chicago, Illinois - United States of America
ELECTRON
BEAM
Low Energy Electron Processors and Their Innovative Application to the Product
Sam V. Nablo, Consulting physicist
Abstract: Low Energy Electron Processors and Their Innovative Application to the Product: S.V.Nablo Other presentations in this session have shown the advantages of low energy (100-200 keV.) electron processors for energy coupling into the product. Many of the desirable eb applications involve 3 dimensional objects and special attention must be focused on the presentation of the product to the electron beam and the energies required to reach all surface areas. Several of these processes will be reviewed, including treatment of the interior/exterior surfaces of an open-mouthed container, treatment of particulate matter in a fluidized bed, in-flight polymerization of electrostatically sprayed droplets and surface disinfestation of agricultural products. Data on the product throughputs possible for some of these applicatios will be presented.
Enhanced Conversion of EB Curable Systems with Low Dose Irradiation
Mikhail Laksin, Ideon LLC
Abstract: Significant benefits in curing of various Electron Beam (EB) curable coating & ink systems have been demonstrated under multiple exposures to low dose Electron Beam irradiation. Higher conversion rate and chemical resistance of the EB curable systems may lead to increased product performance benefits, including broader compliance with Food Law regulations and enhanced product resistance. Multiple exposures to low dose EB irradiation can open up some new opportunities in EB emitter designs, reduction of nitrogen consumption and other processing benefits. Hybrid Ultraviolet (UV) and EB curing may offer significant product performance enhancement in applications, traditionally limited to UV curing only.
Dosimetry Challenges
in Low Energy Application
Hans J. Wiegert, Cryovac, Sealed Air Corporation
Abstract:
A power point presentation highlighting the challenges of dose measurements
in industrial applications at low energies (70 to 300 keV) including:
- History
of Technology and Equipment
- Overview
of available Dosimetry Systems
- Practical
use of ASTM 51818
- Equipment
Performance and K-Factor.
- Process
Variables
Low-voltage
Electron Beam Dosimetry
Marshall R. Cleland, RDI - Member of
the IBA Group
Abstract: A determination of "dose" in terms of
kiloGrays can be derived from Monte Carlo calculations for low-voltage
electron accelerators provided factors such as voltage, window thickness,
air gap and target material and its composition (such as a dosimeter
and its backing) are defined. Corrections can be applied to account
for the interference from a window support grid and the partial
penetration into a dosimeter which was calibrated using radiation
with higher penetration. The dose versus beam current and area through-put
equation can then be used with flat sheets or webs to relate dose
with beam current, web width and line speed and to compute the proportionality
factor "k."
Challenges of and New Methods for Using Radiachromic Films as Dosimeters for Low Voltage Electron Beams
Anne Testoni, Advanced Electron Beams, Inc.
Abstract: Thin radiachromic films are commonly used to determine the quantity of electron dose applied to surfaces. The advantages of these films are that they are widely available, inexpensive and require relatively simple equipment to process and measure. However, there are many challenges when users attempt to use them as accurate and repeatable metrology tools for low energy (£ 150kV) electron beams. In this paper we report on the results of a systematic study of the stability, precision, repeatability and accuracy of using two common brands of radiachromic films and make recommendations for storage, exposure and measurement procedures and equipment to allow the most accurate and precise measurements to be made of low voltage electron beam dose.
Routine
Low-voltage Dosimetry with Thin Gauge Polyethylene Films
Mark Driscoll, SUNY College of Environmental
Science and Forestry
Abstract: Dosimetry in the low-voltage electron beam (EB)
area presents challenges given the limited electron penetration
into materials. There is a dose-deposition profile in dosimeters
that are used in high-voltage EB when exposed to low-voltages. Using
FTIR, the development of a transvinylene peak in thin gauged (25
micron) polyethylene (PE) films is shown to be indicative of EB
exposure and can be correlated with reference dosimeters and calibrations
based on modeling which rely upon Monte Carlo codes. PE films are
made in very constant gauges and not subject to environmental factors
such as humidity or ambient light.
Sources of Dose Variability and a Dose Prediction Model Benchmark for Low Energy Electron Beams
Douglas E. Weiss, 3M Company
Abstract: In this PowerPoint presentation, the types of dose
variability observed in a low voltage electron beam are characterized.
Sharp gradients at low voltage make direct measurement of the true
surface dose (first micron) difficult since the thin film dosimeters
that must be used capture a gradient dose that represents only an
average through a thickness of at least 10 microns. A method for
calculating a surface dose at low voltage is illustrated using a
model of the problem and Monte Carlo code (ITS). Such model predictions
must always be benchmarked against dosimetry. This brings into play
a variety of issues associated with dosimetry measurement, model
building and the characteristics of a specific piece of equipment
that all must come together in order to achieve agreement. This
is demonstrated using an example to illustrate the value that these
predictions provide when operating at voltages in the range of 80
- 120 keV.
Standards
in Radiation Processing
Anthony J. Berejka, Ionicorp
Abstract: The evolution of standards pertaining to industrial
radiation processing will be presented, including a discussion of
the relationships between the International Organization for Standardization
(ISO), ASTM International, and national laboratories. RadTech's
development of ASTM D-5403, which in turn was adopted by the Environmental
Protection Agency as part of its Method 24, will be reviewed. An
overview of current activities in the development of dosimetry standards
for low-voltage electron beam processing will be presented.
Interested
in Registering >>>
Return
to Technical Conference >>>
|
