Continuum - PE - The Dow Chemical Company

Kunststoffe international, 2005-11-21, Bank Rating: Leadership – An Important Rating Factor
...mpany's rating. Leadership styles often occur in mixed forms. The boundaries are fluid, as is shown in Fig. 1. The criterion chosen to appraise the leadership style here is the leadership skill: "Decision-making". The leadership style continuum allows an initial appraisal of the management style predominantly prevailing in a company. Situational Leadership Style As has already been shown, styles of leadership cannot be evaluated in absolute terms. What has been proved is that when ...

Kunststoffe international, 2005-11-21, FE Method: Design Concept for Stacked-type Spiral Dies
...al line, a CAD system can generate a wire model of the stacked-type spiral die. Fig.2 shows such a wire model containing four spiral channels and the flights between them. Flow simulation by finite element analysis requires a discretisation of the continuum flowing through the channel structures. The FEA network is generated by means of shell elements, with local increase of the discretisation density in the inlet and outlet regions in order to improve the computational accuracy. Fig.2 is a deta...

Kunststoffe international, 2005-11-21, Inflow Behaviour in Single-screw Extruders
...he plastic particles into the first screw flights is neglected. Most standard studies and mathematical models focus on the third zone (Δp > 0). This is mainly because solids conveying has so far primarily been described in terms of the laws of continuum mechanics. However, bulk solids are disperse systems that behave neither like solids nor like liquids. Consequently, the results of such studies have been limited in their usefulness. As still no satisfactory model exists for describing the...

Kunststoffe international, 2005-11-21, Load-bearing capacity: Analysis of Underground Plastic Components
...ysis with an integral component-soil model: Flexible plastic components in the soil withdraw from the loading by deformation and in the process activate the supporting effect of the soil. This interaction can be taken into account by means of a “continuum model” of finite elements. The component can be represented by means of beam, shell or volume elements (Fig.4). The surrounding soil and the load-distributing parts, such as a reinforced concrete slab or an asphalt layer above the plastic compo...

Kunststoffe international, 2005-11-21, Market and Trends: Nanomaterials: Opportunities and Risks
...Plastics Where is the dividing line for nanotechnology? In a strict sense, as illustrated in Fig.4, a clear dividing line exists when, with decreasing size, the material properties can no longer be described by continuum mechanics, but require quantum mechanics. For quantum dots, the material properties change with diameter. Below a diameter of 60nm, yellow-coloured, electrically conducting gold becomes a red semiconductor. Fig.5 shows CdSe semiconductor nanoparticle dispersions with size-depend...

Kunststoffe international, 2005-11-21, Optimisation of Screws with Small L/D Ratio: Custom-made Screws
...lights in the metering zone, however, affects the melt homogeneity. For small screw diameters, the melting lengths are shorter than is computed by known melting models [2, 3]. With these models, a “solid bed” is assumed, which is considered as a continuum consisting of compacted pellets. This solid bed is progressively melted by thermal conduction and by dissipation in the melt film close to the cylinder. The melt collects in the “melt pool” on the driving flank of the screw. If the flight depth...

eMagazine "Journal of Plastics Technology", 2016-05-01, CFD simulation of plastics plasticizing in an extruder with a continuously grooved cylinder and barrier screw
... model for CFD simulation has been developed, which assists to reflect virtually the melting processes in plastic processing machines. The model allows the parallel consistent rheological and thermodynamic illustration of solids and melt in just one continuum and thus enables the use of common CFD solvers. The use of the model to calculate the plasticizing of a PE-HD material in a 100 mm extruder with barrier screw and optionally smooth or continuously grooved cylinder demonstrates the power and...