Zinc alloy because of convenient molding,plasticity,low cost,high processing efficiency,widely used in zippers,bags,shoes and apparel accessories.Most of the slider
is made of zinc alloy,but the manufacture of theses products is a great knowledge production,to produce a good product is not only the final plating,and coating to do,from the selection to the design mold such as each process are closely related.
The influence of die-casting process:The key is to reduce the amount of gas mixed into the die casting,the ideal metal flow velocity should be accelerated from the nozzle through the diversion cone and runner into the cavity to form a smooth and consistent with direction of the metal flow.At this point the use of conical flow channel design,the sprue area from the nozzle to the inner runner gradually reduced,can achieve this goal.In the filling system,the mixed gas is formed by the mixing of the turbulence with the metal liquid,and it is evident from the study of the simulation of the die casting process that the molten metal enters the cavity from the molten metal.
It is clear that the sharp transition and the incremental pouring Channel cross-sectional area,will make the metal flow appears turbulent and volume gas,smooth metal liquid is conducive to the gas from the runner and cavity into the
overflow tank and exhaust slot,the air out of the mold.For water lines,cold embossed,can improve the mold temperature,increase the flow rate of alloy within the runner,or in the cold compartment to increase the overflow tank,to reduce the appearance of cold embossed.In addition,to control not to open the mold too early to eject the top of the casting,the mold temperature may be too high.Due to the existence of a large number of bubbles within the casting,when the liquid metal solidification time is not enough,the strength is not established,and premature open die casting,compressed air bubble bulging up casting surface and produce thermal cracks.