Week 8 - Challenge 6 - Core & Cavity Design

Aim :- To design the Core and Cavity blocks for the switch bezel plastic component.

Objective :-

1. To create a proper tooling direction.
2. To perform draft analysis of the plastic component.
3. To create the core and cavity blocks with proper parting surface for the switch bezel plastic component.

Tooling Direction :-

The tooling direction is basically the direction that the mold pulls apart. The ejection of the part from mold depends on the draft. A zero draft can result in difficult or no ejection due to shrinkage. It is recommended to add a minimum of 0.5 to 1 degree of the draft for non-textured surface & 3 to 5 degree of draft for textured surfaces.

Procedure to create the tooling axis using bisecting method :-

• First of all base face is extracted and point is created at the center of extracted face.
• Intersecting curves are created of Class-A surfaces.
• Bisecting line is drawn between the two side faces.
• Thus we get the tooling direction in Y-axis.

Similarly tooling direction is created in X-axis

Intersecting curves are created of Class-A surfaces and line is drawn from the center point at 6 degree angle from the side face.

Bisecting line is drawn between the tooling direction lines of X and Y axis. Thus we have created the final tooling direction.

Draft Analysis :-

Draft angle reduces the chance of damage to the part due to friction during release as well as it reduces wear and tear and chances of damage to the mold.

It ensures a uniform, smooth, unscratched finish when required.

Draft analysis is performed based on colour ranges identifying zones on the analyzed element where the deviation from the draft direction at any point, corresponds to specified values. Minimum draft angle is considered as 3 degree.

Draft Analysis of Class-A Surface :-

Draft Analysis of Solid Body :-

Core and Cavity Design :-

The core & cavity are the shaped sections in either half of the mould tool which give the plastic product its final shape. The hot molten material is injected into the core & cavity and then sets hard into shape. The design of the core & cavity is essential in the correct formation of the product.

Parting Surface :-

A parting surface is a surface that separates the mold block into two parts i.e the core and the cavity.

Parting Line :-

Parting line is the intersection between the Parting surface and the plastic component.

Core Block :-

The core is the male part which forms the internal shape of molding.

Cavity Block :-

The cavity is the female part which forms external shape of molding.

Core and Cavity :-

Intersection of Core and Cavity :-

Tree Structure :-

Views of Model

Front View :-

Top View :-

Left Side View :-

Isometric View :-

Conclusion :-

Thus the core and cavity blocks has been designed for the switch bezel plastic component.