Nina Woicke

Mechanical behavior of plastic components are not only dependent on the pure load or load case (e.g. bending vs. pure compression), but also on the loading time and temperature. In this paper a simplified viscoelastic deformation model, based on the Findley creep model, has been derived to take these factors into account.

Mechanical behavior of plastic components are not only dependent on the pure load or load case (e.g. bending vs. pure compression), but also on the loading time and temperature. The impact of these two factors will be discussed in this paper based on different testing results for polypropylene. Additionally a simplified viscoelastic model has been...

This paper will outline the mechanical properties of polymer fills and discuss the influence of different parameters (like design, foil thickness, PP vs PVC) as well as the influence of the boundary in cooling tower surrounding.

This paper will discuss the benefits and thermal performance levels of modular splash fills vs. common film fill mediums in cooling towers and the change of those levels over the useful life of the fill. We will also examine the typical life cycle, durability and maintenance of modular splash fill. Last, we will review the advantage from being able...

The design of air/water counterflow mass transfer devices with high specific surface polypropylene packings, used to enlarge the transfer surface, is frequently based on the pure-component data of the involved components of water, air and polypropylene. The low surface energies of non-polar thermoplastic material, in particular, indicate bad wettin...

Nach dem einleitenden Überblick über das Sortiment der anwendungstechnisch und wirtschaftlich wichtigen Kunststoffe, ihrer Ausgangs produkte, typischen Eigenschaften und Verarbeitung, werden in den folgenden Kapiteln die einzelnen Kunststoffsorten anhand der jeweils charakteristischen Typen vorgestellt. Wie Bild 1–4 zeigt, steht von diesen — gemess...

In the introduction to this book, and to this chapter in particular, the polymer engineering process is presented from a holistic point of view, i.e., with all of its material sources and ramifications. In the sections that follow, this point of view will be demonstrated on the basis of a number of examples of structural component development from...

While PVC is long known as a flame retardant polymer, other plastics have the reputation of high flammability. Whereas this is true for standard polyolefin materials, modern polypropylene products with high efficient flame retardant additives can even beat the good fire properties of normal PVC.In this study film fills for cooling towers made of PV...

Nach dem einleitenden Überblick über das Sortiment der anwendungstechnisch und wirtschaftlich wichtigen Kunststoffe, ihrer Ausgangsprodukte, typischen Eigenschaften und Verarbeitung, werden in den folgenden Kapiteln die einzelnen Kunststoffsorten anhand der jeweils charakteristischen Typen vorgestellt. Wie Bild 1–4 zeigt, steht von diesen — gemesse...

Influence of Modern Nucleating Agents on the Crystallization of PA6.

Rapid Prototyping of PEEK Parts by the Means of Laser-Sintering

In this thesis the visco-elastic behaviour of isotactic polypropylene in the regime of the glass transition is investigated. A mechanical model for this material has been created. Basis for this model are transient, cyclic and relaxation experiments under tension, compression and shear strain for the example material Moplen HP501L. To identify the...

In dieser Arbeit wurde das viskoelastische Verhalten von isotaktischem Polypropylen am Beispiel des Moplens HP501L im Bereich des Glasübergangs untersucht. Grundlage für die Modellbildung waren dabei transiente, zyklische und Relaxationsversuche unter Zug-, Druck- und Scherbelastung. Die Belastungsgrenzen des Materials wurden idendifiziert, um mech...

The aim of this study is to minimise the testing effort for material characterisation in the linear viscoelastic region. Results derived from Dynamic-Mechanical-Analysis (DMA) and bulk tests are combined and compared with the elasticity modulus (E) measured by tensile tests. Using the thermorheologic simple theory a time-temperature shifted relaxat...

Temperature and strain rate dependent simulation of high speed tensile tests of I-PP

Rußunterstütztes Lasersintern von Thermoplasten

Messverfahren zur Bestimmung der Querkontraktion

Selective laser sintering (SLS) with CO 2 lasers is only used commercially with polyamide (PA) and polystyrene (PS). This is because only these polymers absorb enough energy to melt properly in the SLS process. In a new approach, carbon black is added to the thermoplastic polymer powder. Carbon is sensitive to the wave length of Nd:YAG lasers and c...

The aim of this work was to determine the three-dimensional thermorheological behavior of isotactic polypropylene (i-PP) in the region of its glass transition temperature (Tg) by a master curve. The i-PP is a widespread polymer with a Tg ∼ 0°C. Dynamic mechanical analysis (DMA) at varying frequencies and temperatures and bulk tests at varying tempe...

Three-Dimensional Thermorheological Behavior of Isotactic Polypropylene Across Glass Transition Temperature

Finite element analyses (FEA) of thermosets are often performed on the basis of rheological data for fully cured resin. For the FEA of thermosets during curing, a material model is established and a technique is demonstrated, which allows the rheological data of the linear viscoelastic material to be derived. As the moduli are sensitive to conversi...