In serving diecasting, no single component of the production process should be examined or evaluated individually. Each interacts with at least one other complementary element of the process. If the interacting elements are equally efficient, they will reinforce and enhance the function of each other. Only if the entire process is considered as an integrated system, with all parts working together in common cause, can maximum efficiency be approached.
To meet the challenging standards of quality required by the automotive sector, vacuum assistance is a prerequisite.
When vacuum was introduced in diecasting several years ago, the diecaster needed an extreme application to justify its use because, at that time, the vacuum valve required so much maintenance. The vacuum valve is an important component in the production system but only one link in the chain of interacting components that must function flawlessly if the diecaster intends to serve the automotive industry.
A vacuum can be created only in a totally enclosed space. This makes the seal between the plunger and the shot sleeve critical to effective vacuum-assisted diecasting. Castool Tooling Systems, Uxbridge, Ontario, Canada, accomplishes this with close temperature and dimensional management of both the shot sleeve and of a special plunger tip.
Today, almost any product can be profitably made with a vacuum-assisted diecasting system. The improved Castool valve now works profitably while supported by a thermally controlled shot sleeve and plunger tip combination that create a secure seal using a minimal amount of a special benign lubricant.
If possible, discuss your production process (tolerances, finish, etc.) with the part designer to be sure production is no more difficult than it has to be.
Although improved steel may be metallurgically superior, its cost seldom can be justified. However, once design and process have been optimized, a better steel may help.
Triggering the closing of the vacuum valve more quickly with a vacuum controller adds to the complexity of the vacuum system. It may help to prevent alloy and pollution from entering the valve and causing downtime. But it is better to focus on the cause, and keep the valve as simple as possible.
Use the minimum amount of lubrication and put it in the right places. (Not in the casting)
Most diecasters can produce large, thin, complex aluminum castings for the automotive industry. It is already being done quite satisfactorily and profitably in large quantities. Knowing how to do it and actually doing it, however, are two different things. When theory is replaced by reality, the most fundamental precept of diecasting for the automotive industry can be found in the old adage, a chain is only as strong as its weakest link.