Mold Layout

The first phase consists of determining the mold principle. It is also often called qualitative design. This phase includes the decision on whether to use a single-cavity or multi-cavity mold, for example, or which type of mold (standard- or spUts-mold, article ejection or other form of removal, heating/cooling arrangement) is to be employed. 

The second design phase includes the dimensioning of the fimctions complexes and modules selected in the first phase. This phase is described as quantitative design. The layout of the mold according to rheological, thermal, and mechanical considerations can be produced at the same time. It is now possible to produce this layout by a computer-aided method (CAE). 

In the third phase, production documents are compiled. In principle, this could be considered part of the quantitative design phase. Nowadays, it is produced by a computer-aided method (CAD) in many cases. 

The dimensioning of the mold (phase II of the mold design) essentially includes the rheological, mechanical, and thermal mold layout. These aspects of the layout can be further divided into several steps, each with its own special emphasis  

The dimensioning of the mold temperature control system requires corresponding knowledge of the heat transfer subject. 

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Figure 17.1 Examples of mold layouts, configurations, and actions...

According to this formula, a CD with a wall thickness of 1.14 mm (0.045 in) requires a cooling time of approximately 2.6 seconds. In this context, also refer to Chapter 8.3.3 Thermal Mold Layout . (For wall thickness in inches, the formula for cooling time is L = 2000 s. )... 

What is meant by mechanical, thermal and rheological mold layout ... 

Phase 2 Mold layout (rheological, thermal, mechanical)... 

The fllling characteristics of the cavities are determined in the rheological mold layout. The filling phase and holding pressure phase determine the properties of the molded part. The rheological mold layout can include several steps ... 

The shorter the cooling time, the shorter the cycle time will be. The thermal mold layout also includes several stages ... 

The mechanical mold layout is also produced in several stages. For example, factors related to kinematics and rigidity in the clamping direction are considered. 

Long parallel molds with extrusion direction parallel Poor mold layout or design... 

An important thing to remember is that the mold layout usually determines the overall size of the mold and in many cases the size of the mold determines the size of the molding machine. If these choices are intentional, that is fine, but if they are made by default, or done without thinking, you may force yourself into using a machine that is larger—and more expensive to run—than you really need. This is particularly important with multicavity tools. 

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