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- Ultrasound (3)
- DMA (2)
- Compression set (1)
- Cure monitoring (1)
- Dichtungen (1)
- Dielectric relaxation (1)
- Differential Scanning Calorimetry (1)
- Dynamic Mechanical Analysis (1)
- Dynamic mechanical analysis (1)
- Elastomere (1)
- Elastomers (1)
- Epoxy (1)
- Ferroelectric polymer (1)
- High pressure DSC (1)
- High temperature (1)
- Incoming goods inspection (1)
- Leakage rate (1)
- Low temperature (1)
- Modulus (1)
- Moulding compound (1)
- P(VDF-HFP) (1)
- Phenolic resin (1)
- Poly(vinylidene(fluoride - hexafluoropropylene) (1)
- Post curing (1)
- Process optimization (1)
- Prozesskontrolle (1)
- Reaction kinetic (1)
- Rheologie (1)
- Rubber seals (1)
- Tieftemperaturverhalten (1)
- Ultraschall (1)
- Uniaxial stretching (1)
- Urea rsin (1)
- Vulcanization (1)
- Vulkanisation (1)
- tan delta (1)
Rubbers are widely used as main sealing materials for Containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste containers. The save enclosure of the radioactive container inventory has to be guaranteed according to legislation and appropriate guidelines for long term storage periods as well as down to temperatures of -40 °C for transportation. Therefore the understanding of failure mechanisms that lead to leakage at low temperatures is necessary to ensure a proper material choice which is certainly also influenced by additional factors as e.g. the aging behavior.
The investigation of low temperature properties of elastomeric sealing materials by means of thermo-analytical methods is a sound way to get information about the glass transition process.
The breakdown temperature of the sealing function of O-ring seals was measured in a component test setup depending on material and degree of compression.
An in depth explanation of the observed component tests behaviour is currently in preparation. It requires the results of thermo-analytical methods and measurements as the compression set (not shown here). With that, a model was developed to describe the correlation between physical material parameters and observed component behaviour.
Rubbers are often used for seal applications due to their special material properties and easy use. In many applications the material is exposed to low temperatures during Operation. Therefore it is important to know the material behavior at low temperatures to determine the temperature ränge that allows a Safe Operation of the seal, e.g. in storage and transport Containers for radioactive materials.
The seal function of an elastomer is limited in temperature by the rubber-glass transition during which the material properties change from rubber-like to stiff and glass-like. For a given application this correlation is not trivial and therefore needs an in-depth investigation under consideration of the physical properties and the
application conditions.
In this work different analytical methods are used to characterize the material behavior at low temperature in the ränge of the glass-rubber-transition and are compared with the quality of Operation of a component which is here defined by the detected leakage rate.
Making Cure Visible
(2005)
The prospects of modern thermoanalytical methods for characterisation
of flow, curing and final mechanical behaviour of
moulding compounds were demonstrated. Using urea resin
moulding compounds from different manufacturers the possibilities
of the various techniques could be shown. With comparatively
low effort, fundamental information can be gained
before production process had been started. On this basis it is
possible to make appropriate material selection at an early
point in the process chain. On the basis of thermoanalytical
data an incoming goods inspection can be established. Also it
is easy to control the compliance with the conditions of delivery.
In some cases it could also be helpful to have stored analysis
data especially when problems appear in manufacturing
process or unexpected part damages occur
With the ultrasound measuring system it is possible to transfer
the findings from the analytical methods directly to the processes
in the mould. The application of ultrasound provides
Dynamic Mechanical Analysis in the mould. Beside quality
assurance ultrasound can also be used for process optimisation,
especially for reduction of cycle time. In an advanced form
ultrasound information can be used as a basis for improved
machine control based on material state. The ultrasound measuring
system developed by ISK Iserlohn and BAM can be
obtained from the ISK.