For this investigation conventional polyamide 6 with monomodal molecular mass distribution, and the newly developed bimodal one were used. Conventional polyamide 6 was used as a reference material in order to emphasize prospects of using bimodal material for medical applications from the point of view of sterilization resistance and improved creep behavior. Time-dependent mechanical properties of testing samples were characterized by torsional creep measurements in non-ster-ilized state and after sterilization with three different techniques: with autoclave, ethylene oxide, and hydrogen peroxide plasma. Results show that the two materials exhibit pronounced difference in morphology and consequently, mechanical properties. Both of them were not significantly affected by any of used sterilization techniques. However, bimodal material, originally being noticeably more time-stable in comparison to monomodal one, retains these preferences also post steriliza-tion.
COBISS.SI-ID: 29026265
Characterization of time- and/or frequency-dependent material properties usually requires shifting of the measured segments according to the Time-Temperature Superposition principle. This paper presents a closed form mathematical methodology (CFS) which completely removes ambiguity related to the manual shifting procedures. The derivation of the shifting algorithm is presented, and its validation using several simulated- and real- experimental data. It has been shown that error caused by shifting performed with CFS is at least 10–50 times smaller then the underlying experimental error.
COBISS.SI-ID: 11702043
Powder injection molding is applied for manufacturing complex and precise components from metal, ceramics or cemented carbide powder. It consists of mixing the powder and a polymeric binder, injecting this mixture in a mold, debinding and then sintering. Among the debinding techniques applied, catalytic debinding of polyoxymethylene (POM) stands out due to the high debinding rates and low risk of cracking. In this work, the potential use of a bimodal POM-based material as the main binder component was evaluated by comparing its thermal and time-dependent properties to a standard monomodal POM.
COBISS.SI-ID: 11702555