Research on grid replacement technology and two-dimensional isothermal simulation on melt flow of blown film
College of Computer Science, South-central University for nationalities Hubei Wuhan, 430074, China
Established a melt flow model of two-dimensional isothermal simulation for spiral mandrel blow-film die, analysed die swell-effect at the die exit of blown film extrusion process by grid replacement technology, obtained the pressure distribution in the internal flow of blow-film die, and analysed the shape change of free surface at die extrusion section with different viscosity materials. The results showed that the resistance force of the melt flow under internal flow of blow-film die mainly from the spiral direction, with depth of spiral groove gradually shoaled, the direction of resistance force changed from spiral direction to axial direction. When high viscoelastic material entered blow-film die being extruded, the shape of free surface at die extrusion section would change significantly, meanwhile, the gradient of radial velocity of melt flow in the internal die became gradually reduced.