High temperature processability and warp-free stiffness.
Ultrason E Dimension is said to have high stiffness at temperatures between 120 and 220[degrees]C, as well as high dimensional stability. Nevertheless, says BASF, its viscosity is still so low at processing temperatures that it can fill complex injection moulds. Its good flow characteristics have also made it possible to increase the glass fibre content beyond that achievable with conventional PESU grades and BASF says it is a strong - and economical - alternative to polyetheretherketone.
The new material addresses the problem of maintaining dimensional stability of high temperature materials: stiff, semi-crystalline high-temperature polymers such as PEEK or polyphenylene sulphide often warp during injection moulding, while the dimensionally stable amorphous thermoplastics such as polyether sulphone are usually more difficult to process. The problem becomes more pronounced when glass fibres are incorporated to increase stiffness.
BASF has added "a new component" to a classic Ultrason E formulation which it says contributes to increased stiffness at elevated temperatures while simultaneously improving the flow characteristics of the PESU melt significantly and without noticeably compromising the dimensional stability of the material. The elastic modulus of Ultrason E Dimension still achieves values of over 10,000 MPa even at 120[degrees]C, making it comparable to PEEK or PPS compounds.
The new Ultrason's coefficient of thermal expansion is about as high as that of aluminium, and in contrast to semi-crystalline polymers, the new material exhibits almost linear and isotropic thermal expansion between 25 and 200[degrees]C. At similar performance, the new Ultrason also frequently represents a more economical alternative to other high-performance polymers, says BASF.
Compared to aluminium, the new plastic is easier to process, since mouldings do not require subsequent finishing with a drill or milling tool. The material offers potential, such as for use as pistons, switches or gears that come into contact with hot oil above 140[degrees]C, which suggests applications in the automotive sector, but BASF points out that Ultrason E Dimension is also suitable for food contact.
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|Title Annotation:||engineering materials|
|Comment:||High temperature processability and warp-free stiffness.(engineering materials)|
|Publication:||British Plastics & Rubber|
|Date:||Dec 1, 2010|
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