Main Menu
| What is Plaster Molds? |
|
Plaster mold casting is a prototype manufacturing process for simulated die-castings. Although there are several variations of this process, it usually begins with a master shape of the die-casting.
It is not absolutely necessary to include draft in the walls at this stage, but it can help. A silicone rubber reversal is then molded over the master. A second silicone rubber is molded into the first. This provides a silicone rubber positive of the original model. Plaster is molded around the second silicone rubber positive to provide a plaster cavity. Metal is poured into the plaster cavity. After solidification of the metal, the plaster is broken away. The rubber version of the master is required so that it can easily be withdrawn from the plaster mold. It is also possible to mold epoxy off of the master and pour plaster over this. The epoxy molds will have a greater life than those made from rubber. Typical leadtimes from the manufacture of the master model to manufacture of 10 castings is about 8 days, and two weeks to produce 30 to 50 castings. However, three to four weeks is a more typical delivery time. The cost of prototyping with this process is about two to five percent of the cost of a production die, so it is considered to be a good insurance. The advantages of the process are low mold cost and good surface detail. Also, it's possible to produce reasonably large parts with this process. One disadvantages is lower cooling rates, which means poorer mechanical properties. This can lead to parts with a yield strength that is 20 percent lower than conventional die-casting. Another disadvantage is that you must produce a new mold for each casting. And finally, slightly different alloys are used for plaster casting compared to die-casting.
About First-rate Mold Solution Co., Ltd. About www.firstratemold.com |