The various factors from the plunger tip, plunger gap, shot sleeve, temperature and other factors are important to get right to avoid scrap.
In this article, Paul Robbins, with Castool Tooling System, identifies multiple methods to improving die casting processes of injecting molten alloy to the die cavity.
(Illustration provided by the Hill and Griffith Company)
Factors to consider
The best opportunities for improvement is found in the delivery of the alloy to the die. Both the shot sleeve and the plunger offer opportunities for improvement. Read the entire article here, on the Castool.com site.