Polymer Engineering and Science articles from April 2002

Polymer Engineering and Science archives from April 2002

In memoriam Bryce Maxwell 1919-2001.(Obituary)
April 1, 2002... Bryce Maxwell, Professor Emeritus at Princeton University, passed away on October 25, 2001, at the age of 82. Born in Glen Cove, New York, Bryce received a B.S.E. degree in Mechanical Engineering from Princeton, and after three years in the...

Reactive extrusion of recycled bottle waste material.(Abstract)
April 1, 2002... INTRODUCTION A major part of polymer waste consists of polyolefins and especially high-density polyethylene (HDPE). HDPE is the primary material for blow molded bottles for milk, water, detergents or shampoo, which account for 40% of the...

Ejection force modeling for stereolithography injection molding tools.(Abstract)
April 1, 2002... INTRODUCTION Injection molding is a method of fabricating plastic parts by utilizing a mold or cavity with a shape and size identical to the part being produced. Molten polymer is injected into the cavity, resulting in the desired part...

A comparison of induction time and crystallization rate for syndiotactic polystyrene.(Abstract)
April 1, 2002... INTRODUCTION The present study was initiated to measure the crystallization parameters for syndiotactic polystyrene to support a computer simulation this material in an injection molding application. Preliminary results from this study...

3-D numerical analysis on the mixing performance for assemblies with filled zone of right-handed and left-handed double-flighted screws and kneading blocks in twin-screw extruders.(Statistical Data Included)(Abstract)
April 1, 2002... INTRODUCTION Twin screw extruders (TSEs) have been widely used for blending and pumping apparatuses in the polymer industry. By changes in their geometry and operating conditions, TSEs can be used to promote and control the elemental...

The mass transport of ethyl acetate in syndiotactic polystyrene.
April 1, 2002... 1. INTRODUCTION Ishihara et al. (1) were the first to synthesize syndiotactic polystyrene (sPS), and distinguished sPS from isotactic and atactic polystyrenes by NMR, IR spectroscopy, and X-ray diffraction. They found that sPS had a planar...

Thermal and dynamic mechanical characterization of polypropylene-woodflour composites.(Abstract)
April 1, 2002... INTRODUCTION In recent years, wood-fiber thermoplastics composites have received considerable attention from the wood and plastic industries. Although woodflour has been used as filler for thermosetting polymers for a long time, wood...

Gross melt fracture elimination: the role of surface energy of boron nitride powders.(Abstract)
April 1, 2002... INTRODUCTION It is known that the rate of production of many commercial polymer processing operations, such as extrusion, blow molding, film blowing and various coating flows, is limited by the onset of flow instabilities (1-4). These...

Effects of flow on polymeric reaction.(Abstract)
April 1, 2002... INTRODUCTION Blending has been used for decades to obtain desired properties superior to the individual polymers used in the blend. Various blending processes have been applied to achieve property enhancements. Among these processes,...

Metal injection molding: 3D modeling of nonisothermal filling.(Abstract)
April 1, 2002... INTRODUCTION Injection molding of powdered metal and ceramic compounds (PIM) opens new opportunities in the manufacturing of complex parts for medical, automotive, aerospace, leisure, and telecommunication industries. The technique...

Modeling of a cokneader for the manufacturing of composite materials having absorbent properties at ultra-high-frequency waves. Part I: modeling of flow from residence time distribution investigations.(Abstract)
April 1, 2002... INTRODUCTION This study deals with the elaboration of composite materials having absorbent properties at ultra-high-frequency waves. These materials are typically polymers filled with carbon black particles, and their end-use properties...

Improved cathodic disbondment performance of polyethylene blends.(Abstract)
April 1, 2002... INTRODUCTION Buried pipelines are normally physically protected from the environment by a coating, in conjunction with cathodic protection (CP) by way of an impressed current (1). Polyethylene, one of the most widely used corrosion...

Oxygen plasma treatment of sisal fibers and polypropylene: effects on mechanical properties of composites.(Abstract)
April 1, 2002... INTRODUCTION The growing need for environmentally friendlier materials has stimulated research in composite materials of thermoplastics reinforced with lignocellulosic fibers. Besides improvement in mechanical properties, the partial...

Influence of elasticity on dispersed-phase droplet size in immiscible polymer blends in simple shearing flow.(Abstract)
April 1, 2002... INTRODUCTION Although new polymers can be synthesized, they do not always fulfill industrial and technological needs. Moreover, conceiving and synthesizing new polymers involves exorbitant costs and time. Blending is an attractive...

Melt processed microporous films from compatibilized immiscible blends with potential as membranes.(Abstract)
April 1, 2002... INTRODUCTION Microporous polymeric membranes are conventionally produced by phase inversion processes that use solvents to dissolve, usually, amorphous polymers. Semicrystalline homopolymers having much higher solvent resistance, e.g....

Recycling of poly(ethylene terephthalate) as polymer-polymer composites (*).(Abstract)
April 1, 2002... INTRODUCTION First introduced as a material for synthetic fibers (Trevira) in 1953, poly(ethylene terephthalate) (PET) has progressively found new and interesting applications, in many cases without any competing alternative. In its most...

Numerical analysis of polymer melt flow in the nipping region.(Abstract)
April 1, 2002... INTRODUCTION The use of extrusion coated products in various commercial fields has rapidly increased during the past few decades; yet, in spite of this trend, few reports regarding the extrusion coating process have been published, and in...

Modeling of structural reaction injection molding. Part II: comparison with experimental data.(Abstract)
April 1, 2002... INTRODUCTION Reactive polymer processing, in which the chemical reaction is activated by mixing two or more reactants, can be divided into three types (1): reaction injection molding (RIM), reinforced reaction injection molding (RRIM), and...

Chemical modification of polyurethane for two-component injection molding.(Abstract)
April 1, 2002... INTRODUCTION Multi- or 2-component (2C) injection molding as a special field of injection molding is receiving more and more significance because elaborate sticking, joining and mounting may be saved. The most important fields of...

SI metric units.(Brief Article)
April 1, 2002... The following list shows the names, symbols, and equivalence of the more common quantities allowed in the SI metric system. The prefixes and the symbols for the more common multiple units are also shown. Neither list is complete. Full details...