The advantages of foam physicist in the injection
INJECTION
Nitrogen are used as expansive agent in foamed MuCell procedure (N2) or carbon dioxide (CO2). The gas is liquefied at high pressure and injected in mass cast in the interior of the cylinder of the plastificadora unit. With the fall in pressure that occurs to be injected, the expansive agent recovers his gaseous state and foam plastic material in this way.
Because the postpresión and cooling phases are shorter, the technique MuCell can reduce the time duration of the cycles in more than 30 per cent compared with the conventional production. In certain circumstances, be resigns completely to the phase of postpresión, that bubbles of gas in the Microcellular foam generate a uniform pressure across the component, which also occurs in those furthest from the point of injection parts. In addition, the material cools into the mould more quickly, that the internal pressure of this foam press the component against the surface of the mold, thus improving the evacuation of the heat.
The expansive agent reduces the viscosity of the melt, so closure pressure decreases or increases the speed of injection. In addition, the material can be treated at temperatures below the cylinder and the molds, due to the lower viscosity of the melt. This further shortens cooling times.
Through the foam microcelular reduces the weight of the component in comparison to the solid components. There are often feasible reductions in weight over 20 per cent. The savings of material reduces the total cost in the thermoplastics technical, due to the relatively high price of the material.
This must be added that the compensation of pressure in the Microcellular foam prevents occurring phenomena of contraction and internal tensions during the cooling. Components manufactured according to this procedure are therefore a good dimensional accuracy and a reduced tendency for the takedown.