Other

University of Ontario Institute of Technology

Remon Pop-Iliev

Scott Brian Nokleby

Chul B Park

Guobin Liu

Fangyi Liu

Kimbery Anne Christian

Salvatore D'Uva

Emad Samy Abdalla

Benjamin Zhang

The nature of the rotational molding process is cyclic. It requires the temperature of the rotating mold and the plastic it is charged with to be elevated from room temperature to beyond its melting temperature and then cooled back to room temperature. Consequently, rotational molding cycle times are lengthy, which is often considered as the fundamental drawback of this plastic fabrication process. The motivation and objectives of this disclosure are twofold. The presently proposed invention focuses on developing an innovative extrusion-assisted rotational foam molding processing technology for the manufacture of integral-skin cellular composite moldings having adjacent, but clearly distinct, layers of non-cellular and cellular structures, consisting of identical or compatible polymeric grades. Its primary goal is to significantly reduce the processing cycle time in comparison with respective currently implemented technologies by employing melt extrusion in order to maximize the speed of controlled polymer melting.

Rapid rotational foam molding process

Compositions and processing conditions are disclosed for the production by rotomolding of polypropylene foams, hither to satisfactorily produced only by injection molding and extrusion molding. Rheological properties of the polypropylene resin, processing conditions and choice of composition of the chemical blowing agent were found to play important roles in obtaining high quality polypropylene foam structures. High strength fine-cell polypropylene foams could in particular be formed by first melt compounding a suitable chemical blowing agent with the resin under conditions which allow for homogeneous mixing without appreciable decomposition of the blowing agent.

Production of foamed low-density polypropylene by rotational molding

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Mississauga, Canada

Remon Pop-Iliev