is Irradiation Processing? Return
The use of irradiation as a major industrial processing tool
began more than 30 years ago. Spurred by solid-state electronics
and innovative wire, cable, and heat-shrink applications,
the UV/EB industry has grown to become an international multi-billion
dollar per year industry. Today, ultra-violet curing has become
commonplace while electron beam systems are replacing traditional
chemical sterilization methods in the medical supply industry.
At the same time, electron accelerators have become workhorse
tools for tire manufacturers and plastics processors, as well
as for companies in the gemstone industry.
Irradiation is a very powerful form of high-energy
radiation processing, which when properly used, produces profound
effects in materials. These effects cannot be produced in
any other way and offer efficiencies that help keep the unit
cost of treatment exceptionally low. Irradiation can sterilize
fully packaged and sealed medical supplies at room temperature
(particularly important for plastic, single-use products),
cure rubbers and plastics with an “on-off” control
unattainable with conventional chemical techniques, and cure
solvent-less paints and coatings with unmatched speed. In
all cases, the highly directed radiation beam and computer
control make the technology an energy-efficient, fast, and
versatile industrial manufacturing alternative to conventional
processing. Although well established in the plastics industry,
this technology is in various stages of development for a
variety of other applications, such as electronic components,
water stream treatment, weapons destruction, and biomaterials.
It’s important to note that the products
and materials irradiated by ETC’s electron accelerators
for the production of industrial products WILL NOT
BECOME RADIOACTIVE! ETC uses electron accelerator
systems that can be switched off, thereby immediately eliminating
How Can Irradiation
Processing Improve Materials? Return
During the irradiation process, the energy from the radiation
source is transferred to the processed material. This results
in a variety of chemical reactions that alter the molecular
structure of the material. There are five fundamentals:
of polymers, where a network of polymer chains are joined.
- Degrading of polymers, where the molecular
weight of the product is reduced through chain scissioning.
- Grafting onto polymers, where a different
monomer is produced and grafted onto a polymer chain.
- Polymerizing (curing) of monomers and
oligomers by irradiation. Irradiation curing (as in the case
of coatings) is a combination of radiation polymerization
- Modifying crystal lattice for semiconductors
Careful selection of irradiation processing conditions
can result in improvements of material properties, including
mechanical properties, thermal properties, chemical resistance,
particle size, melt properties, material compatibility,
surface properties, and other characteristics.
Are The Benefits
of Irradiation-Treated Products? Return
Using the electron beam in industrial applications has many benefits. Cross-linking
changes thermoplastic materials into thermosets and cures rubber. In addition,
the molecules within the material are changed and tend to move rather freely.
As temperature rises, uncross-linked materials soften and eventually melt.
When they are irradiated, the molecules are cross-linked. In other words,
they slow down, become more resistant to heat, and lock together to form more
Benefits of this crosslinking include:
- Increased material strength
- Increased material stability
- Resistance to deformation
- Resistance to chemical solvents
- Shrink memory
- More stress cracking resistance
In terms of biological benefits, the benefits
are numerous. With respect to foodstuff, the benefits include
the disinfestation or elimination of insects from grain, tobacco,
and other unprocessed bulk crops. The second benefit involves
the complete sterilization of medical products and aseptic packaging
of materials for foods. In other words, the electron beam can
be used to sterilize medical equipment and food packaging.
Accelerators Return to top
The ETC facility has two accelerators that are capable of
producing small-to-medium e-beam streams.