The cavity and the core are very important parts in forming the shape of the molded product, and the method of their preparation can be divided broadly into two types.
These types of the method of preparing are "Integrated Structure" and "Spliting Structure".
The "integrated structure" is one in which, as the name implies, the cavity and the core are prepared as a single integrated component.
The "Spliting structure" is one in which the cavity and the core are divided into 2 or more components which are assembled together.
Each of these methods has its own advantages and disadvantages which are listed in Table 1. Further, some actual examples of the different structures are shown in Fig. 1.

Fig. 1 Cavity and core integrated structure and divided structure

（Evaluation: = Excellent,　= Good,　= Partially satisfactory,　= Not suitable.）

Comparison item Integrated structure Divided structure Component count Ease of machining - - Cost of machining - - Material cost Corner part shape accuracy Ease of polishing Air vent effect Ease of maintenance

The decision of whether to use an integrated structure or a Spliting structure should be made considering the shape of the molded product, the life of the mold, the type of plastic, etc., after weighing the pros and cons. We are frequently asked which structure is good, and our answer is that which type is good or bad is determined based on the preconditions for selection.