Polymer Engineering and Science articles from July 2003

Polymer Engineering and Science archives from July 2003

"Emerging Technologies for the New Millennium," SPE Topical Conference 2001.
July 1, 2003... Humankind has evolved by developing tools that have enhanced the quality of life of individuals and groups. From the beginning, materials were critical for progress from the stone age to the iron and bronze ages, and more recently to the age of...

Expansion mechanisms of plastic/wood-flour composite foams with moisture, dissolved gaseous volatiles, and undissolved gas bubbles.
July 1, 2003... INTRODUCTION Wood-flour is gaining increasing acceptance as a filler material, as it significantly increases the stiffness and lowers the cost of the resulting composites (1-12). However, the applicability of plastic/ wood-flour composites...

Continuous extrusion of microcellular polycarbonate.
July 1, 2003... INTRODUCTION Microcellular foams are defined as cellular structures having cell sizes on the order of 10 [micro]m or below, and cell densities greater than [10.sup.9] cells per cubic centimeter of unfoamed polymer. The main interest in...

Effects of die geometry on cell nucleation of PS foams blown with C[O.sub.2].
July 1, 2003... INTRODUCTION Foamed polymer products possess many unique characteristics compared to their solid counterparts, such as higher specific tensile strength, higher toughness, and better thermal and sound insulation properties. Generally, in...

Rheological effects of polyethylenes in film blowing.
July 1, 2003... INTRODUCTION Film blowing is one of the major polymer processing operations but the least understood. This is largely due to the complex rheology of polymer melts in non-uniform biaxial, non-isothermal flow. From a practical point of view,...

Optimization of blow molded part performance through process simulation.
July 1, 2003... INTRODUCTION Product designers in today's global environment are under increasing pressure to reduce part development time to a minimum, while ensuring the maximum part quality and minimum manufacturing costs (better, faster, cheaper). The...

Three-dimensional simulation of multi-material injection molding: application to gas-assisted and co-injection molding.
July 1, 2003... INTRODUCTION Gas-assisted injection and co-injection molding are increasingly used since they present many advantages over traditional injection molding. Gas-assisted injection molding requires lower injection-packing pressure, smaller...

Simultaneous biaxial deformation behavior of isotactic polypropylene films.
July 1, 2003... INTRODUCTION Biaxially oriented films are mostly produced through a sequential tentering process, in which films are cold drawn in two consecutive steps in two perpendicular directions at different temperatures. Recently, a novel...