In many sectors of industry and many areas of everyday life, irradiation technology makes an important contribution to achieving and improving the characteristic properties of products. As well as radiation sterilization and the radiation crosslinking of plastics, which are now both used on a large industrial scale, products in numerous other applications can be optimized by beta and gamma rays. The energy from the rays acts on the products, triggering changes at a molecular level which can often not be achieved by conventional methods.
Example of applications
Application fields improving Polymer raw materials
In many polymer raw materials, irradiation triggers chemical reactions which strongly influence their subsequent processing behaviour. Based on the chemical nature of polymers, either degradation reactions or increases in molecular weight or long-chain branches can be deliberately induced on the molecular level. This allows a very precise adjustment of molecular weight, which for example has a strong influence on the rheology (flow characteristics) and processing properties of polymers.
Examples are the irradiation of polypropylene (PP) which reduces the molecular weight. The resulting material acts as a nucleating agent in PP, causing increased degrees of crystallisation and much faster setting time of PP during injection moulding, reducing processing times and increased heat resistance, stiffness and impact strength of the moulded part.
If PP is irradiated under the exclusion of oxygen, the molecular structure is modified in a way which significantly improves melt strength, a property which is important during foaming. Similar effects are also known for PE.
With other polymer raw materials (e.g. starch and cellulose), the molecular weight can be accurately and reproducibly modified by irradiation. This can have a beneficial effect on the processing rheology or other properties of the products.
Colour modifications of gems, glass and other materials
Exposure to beta or gamma rays causes changes in the crystal lattice of precious stones and other solids. In this way, specific colour changes can be produced in gemstones for aesthetic purposes. Glass, pearls and other materials can also be irradiated to produce specific aesthetic effects.
Enhancing switching behaviour in semi-conductors
When semiconductors are exposed to beta rays, lattice defects are produced which permanently affect their switching behaviour. Due to the high penetration of high-energy electrons, a very homogenous adjustment of charge carrier lifetime can be achieved. This allows a very precise tailoring of switching behaviour, recovery times and other electrical properties in power electronics. Applications are silicon wafers, diodes, IGBT and PPTC.
Radiation hardness testing
Many components used in the nuclear industry or in aerospace industry need to be certified for their life expectancy in these environments. Examples are satellite components, cables and wire, coating and compounds, pumps or other functional devices.
Your own project?
The application of ionizing radiation in different applications is still developing rapidly. For BGS it has been always been very important, to be part of this innovative process to find new applications to use the potential of this technology, which can be used in a very broad range of technical fields. We want to encourage you to discuss your development ideas with our application specialists, which might lead to new and sometimes surprising solutions for your technical problems! BGS is since many years a partner of industry taking part in project work. May it be a research project or a project focussed to develop towards a well-defined target, BGS is used and experienced to be involved in a more complex co-operation of different parties over time. Our specialists will contribute with their background in the application of high energy radiation to find the best solution, which can be a sterilization project, development of a new plastics component or a research project looking for more fundamental understanding.Print