Modelagem e simulação de um escoamento multicamadas no processo de fabricação de filmes planos de poli (etileno tereftalato)

AUTOR(ES)

Nilson Andreis Witkoski

DATA DE PUBLICAÇÃO

1996

RESUMO

Nmnerical simulations of a multilayer flow has been undertakenin a process for producing Poly (Ethylene Terephtalate) flat films. Viscosity functions are fitted by Bird-Carreau models. The temperature dependence of viscosity follows the Arrhenius equations. The motion equations are solved by POLYFLOW, a Finite ElementMethod program for viscous and viscoelastics flow simulations. Bidimensional numerical simulations of the entry flows in a bicomponent coextrusion are carried out to study the interface development. The effects of the layers entry velocity matching, layer viscosity ratio and channel geometry are investigated based on the interface shear and extensional deformations. Correlations of the interface behaviour with the occurence of interface instabilities are proposed. Bidimensional numerical simulations of a 4-layer assymmetric parallel coextrusion are made to investigate the residence time distribution, the role of viscous and conductive heat-transfers i11the flow and the layers thickness variations due to opera6ng conditions changes. Three dimensional simulations of the flow inside a linearly tapered coathanger fiat die are carried out, but limited to one fluid only. These simulations are aimed at studying the effects of the process parameters and the die geometry on the trhoughput uniformity along the die width. Considerations are made about the behaviour of the multilayer flow in the same die. The calculated results have correlated well with experimental values obtained in the industrialline, so, the proposed model may be applied to improve the understanding of the coextrusion flows as well as to the design of new equipments

ASSUNTO(S)

processo de extrusão modelos matematicos filmes finos fluxo viscoso poliesteres viscoelasticidade

Documentos Relacionados

• Simulação de escoamentos multicamadas de polimeros viscoelasticos a base de poli(etileno tereftalato)
• Pos-condensação em estado solido de poli(etileno tereftalato)
• Desenvolvimento e caracterização de blendas Poli(tereftalato de etileno) - PET/ Poli(naftalato de etileno)- PEN
• Simulação do processo de sopro de garrafas de poli(tereftalato de etileno) a partir de pré-formas disponíveis através do método de elementos finitos
• Modelagem e simulação do processo de fabricação de ASB