Polymer – surface interactions strongly influence many important industrial and rheological flows. In particular, polymer melts and solutions slip against the surface; this has long been associated with sharkskin and spurt in extrusion, and recent experimental observations suggest that slip also plays a role in the formation of enhanced concentration fluctuations in entangled polymer solutions....

In this paper the eccentric forward extrusion of sections has been simulated and analyzed using FEM Abaqus-explicit. The results have been compared to those obtained from upper bound theorem and experimental works. Close agreements was observed between the FEM and experimental work and as compared with the upper bound data more realistic and better predictions were made by the authors’ method. ...

We show how the viscous evolution of Keplerian accretion discs can be understood in terms of simple kinetic theory. Although standard physics texts give a simple derivation of momentum transfer in a linear shear flow using kinetic theory, many authors, as detailed by Hayashi & Matsuda 2001, have had difficulties applying the same considerations to a circular shear flow. We show here how this ma...

This paper focuses on the response of circular machine foundation resting on different soils (sand and clay) through studying the variation of soil shear strength parameters and strain with the number of cycles. The objective of the current study is to explore the results related to the parameters of the dynamic load (number of loading cycles and frequency of load) related to the circular footi...

Semisolid powder processing (SPP) is a promising approach for near net-shape forming of features in micro/meso-scale. By combining the concept of forming in the semisolid state and conventional powder metallurgy, SPP provides a novel solution to various processing and materials engineering challenges faced in micromanufacturing. Replacing bulk materials with powdered materials adds a new dimens...

3.1 Abstract Rheological behavior of reactively extruded starch-PCL nanocomposite blends was evaluated in an off-line capillary rheometer. Power law models for blends with different nanoclay volume fractions were developed using appropriate correction factors. Consistency coefficients K for blends containing starch were significantly higher than 100% PCL. Starch-PCL nanocomposite blends showed ...

sion/spheronization affects the properties of the resulting pellets. Pharmaceutical scientists originally directed their focus to extrusion, spheronization and drying which can be seen from the literature. Only a few authors reported investigations concerning the impact of the granulation step. Baert et al. investigated ternary mixtures of microcrystalline cellulose (MCC), a drug substitute and...

The extrusion of section from round billet poses a great challenge for theoretical modeling of the process using upper bound method. The greatest difficulty in three-dimensional upper bound method is to determine kinematically admissible velocity field. The SERR (Spatial Elementary Rigid Region) technique is fairly applicable for analyzing extrusion of sections having re-entrant corners. A modi...

In the nonlinear theory of isotropic elastic materials, there are relations between force-like quantities and deformation-like quantities which are independent of material properties. Such relations have been called "universal" relations [1]. The best known example is that of Rivlin for simple shear [2]. It relates components of normal and shear stress and the amount of shear. Another important...

Twist extrusion process is a rather new route to produce highly strained materials. In this process, severe plastic deformation is applied by large shear strains. In current article, required energy for twist extrusion by use of admissible velocity field together with the upper bound technique is predicted. The proposed model is capable of considering the effect of various parameters such as di...