Foams, microcellular

Key words infiltration, particle reinforced metals, metal matrix composites, metal foams, microcellular aluminium... 

Applications cold moulded high resilience flexible PU foams, semiflexible and integral skin PU foams, microcellular elastomers (shoe soles) ... 

AA-TMP/glycols (branched) Flexible foams, microcellular elastomers, coatings... 

Rigid, flexible/slabstock foam, microcellular plastomers,and integral skin foam Rigid, flexible, integral skin, flexible molded,microcellular foam, coatings, and elastomers... 

Carbon nanofiber (CNF) is one type of cylindrical nanoparticle. PS/CNF nanocomposite is studied for batch foam. With the addition of CNFs, microcellular foams with uniform cell size distributions were obtained. A single screw extruder was used to prqrare PS/CNF extrusion foam. Microcellular foam with cell size of 4.1 microns is made with 5% weight fi action of CNF in PS. 

Microcellular elastomers16 bridge the gap between solid elastomers and low-density foams. Although they may appear to be noncellular, these materials have a microscopic cell structure and so are by definition high-density foams, with densities between noncellular solids and standard foams. The most commercially important applications include shoe soles, carpet backing, chair armrests,... 

Patel, S.V. Venditti, R. A. and Pawlak, J. J. (2010). "Dimensional changes of starch microcellular foam during the exchange of water with ethanol and subsequent drying," BioResources, 5,121. 

In practical application, it was reported that the platinum particles dispersed in highly porous carbonized polyacrylonitrile (PAN) microcellular foam used as fuel-cell electrocatalyst160 have the partially active property. The fractal dimension of the platinum particles was determined to be smaller than 2.0 by using the potentiostatic current transient technique in oxygen-saturated solutions, and it was considered to be a reaction dimension, indicating that not all of the platinum particle surface sites are accessible to the incoming oxygen molecules. 

Injected parts transparent, filled to a greater or lesser degree, possibly crosslinked and/or foamed in microcellular form for tyres (light uses), kneepads, footwear, soles, sports and technical items, buoys, flexible toys, protective caps. .. 

Based on microcellular thermoplastic foam technology, the MuCell process uses a blowing agent (typically CO2) that in a supercritical state creates foams with evenly distributed and uniformly sized microscopic cells, 5-50 qm for example. This foam... 

Ramesh, N. S., Rasmussen, D. H., and Campbell, G. A., The Heterogeneous Nucleation of Microcellular Foams Assisted by the Survival of Microvoids in Polymers Containing Low Glass Transition Particles. Part 1 Mathematical Modeling and Numerical Simulation, Polym. Eng. ScL, 34, 1685 (1994)... 

Olefins or alkenes are defined as unsaturated aliphatic hydrocarbons. Ethylene and propylene are the main monomers for polyolefin foams, but dienes such as polyisoprene should also be included. The copolymers of ethylene and propylene (PP) will be included, but not polyvinyl chloride (PVC), which is usually treated as a separate polymer class. The majority of these foams have densities <100 kg m, and their microstructure consists of closed, polygonal cells with thin faces (Figure la). The review will not consider structural foam injection mouldings of PP, which have solid skins and cores of density in the range 400 to 700 kg m, and have distinct production methods and properties (456). The microstructure of these foams consists of isolated gas bubbles, often elongated by the flow of thermoplastic. However, elastomeric and microcellular foams of relative density in the range 0.3 to 0.5, which also have isolated spherical bubbles (Figure lb), will be included. The relative density of a foam is defined as the foam density divided by the polymer density. It is the inverse of the expansion ratio . 

Table 2 Die dimensions and residence time for microcellular foam extrusion ...

STUDY OF SHEAR NUCLEATION THEORY IN CONTINUOUS MICROCELLULAR FOAM EXTRUSION... 

A theoretical analysis based on shear energy was carried out with the aim of illustrating the mechanism of shear nucleation through a slit channel die in continuous microcellular foam extrusion. The shear energies for different positions and for different experimental conditions were calculated to demonstrate the various contributions to the surface free energy required for bubble nucleation. 14 refs. 

Journal of Applied Polymer Science 88, No. 12, 20th June 2003, p.2842-50 MICROCELLULAR FOAM OF POLYMER BLENDS OF HDPE/PP AND THEIR COMPOSITES WITH WOOD FIBER Rachtanapun P SeUce S E M Matuana L M Michigan,State University... 

Journal of Injection Molding Technology 5,No.3, Sept.2001,p.l52-9 MICROCELLULAR FOAM PROCESSING IN RECIPROCATING-SCREW INJECTION MOLDING MACHINES Jingyi Xu Pierick D Trexel Inc. 

An overview is presented of TrexeTs MuCell microcellular foam extrasion technology and a description is given of its application to the manufacture of thermoformable PP sheet. The results of pilot scale thermoforming trials carried ont to optimise forming conditions and obtain data abont potential cycle time effects, measurements of the densities, flexnral modnlns and wall thicknesses of the sheets and containers made from the sheets and cell stmcture analysis are presented and discussed. 

A study on the batch processing and characterisation of microcellular foamed HDPE/isotactic PP blends is reported. The blends were used to produce materials with a variety of crystaUine and phase morphologies to enhance the subsequent microcellular foaming. Much finer and more uniform foams were produced with the blends than with neat HDPE and isotactic PP. The mechanical... 

Toronto, 27th April-2nd May 1997, p.2060-4. 012 MICROCELLULAR CROSSLINKED EVA FOAM BY INJECTION MOULDING PROCESS LeeJJ... 

Journal of Vinyl and Additive Technology 2, No.2, June 1996, p.167-9 MICROCELLULAR FOAMING OF POLYPROPYLENE CONTAINING LOW GLASS TRANSITION RUBBER PARTICLES IN AN INJECTION MOULDING PROCESS Chicheng Wang Cox K Campbell G A Clarkson University... 

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