Generally speaking, blister mold divided into plaster molds, electroplated copper molds, and aluminum molds.
Gypsum is molded in a semi-wet state, and then it is finished after drying. The plaster mold is low in cost and can be easily modified. However, the accuracy of the plaster mold is not high enough, the surface is not smooth, and it is fragile and not durable. Therefore, it is often used to proofing, copper electroplating molds or some of the small batch production which have low requirements.
Electroplating Copper Molds
After the samples are made of plaster molds, and then electroplating a copper shell, that is an electroplated copper mold. The cost is higher than the plaster mold, but it is much cheaper than the aluminum mold. Because of its smooth and durable surface and low cost, the electroplated copper mold is the most commonly used plastic mold.
It use aluminum ingots, machined from machines (lathes, milling machines, CNC, etc.). Aluminum mold with high precision, smooth surface and durable, but the price is very expensive, aluminum molds are generally used in the plastic mold products that require higher precision which the copper mold can not reach.