Week 8 - Challenge 6 - Core & Cavity Design

Aim/Objectives: Create the Core and cavity blocks for the switch bezel designed in the earlier challenge.

Steps Followed:

• Tooling Axis creation
• Checking Draft analysis for created tooling Axis
• Creating a parting Surface
• Creating Core Side
• Creating cavity side.

1). Tooling Axis:

The tooling axis is the axis in which the core cavity opens during the completion of injection molding. To create the tooling axis, we need the proper orientation or view that gives the correct features and draft available in the component.

Component view from the Z direction gives the tool the proper view to see the geometry's features. To create the tooling axis from the Z direction we need the tooling axis from the X direction since it gives the draft available at the slanted part.

The tooling axis is created from the X Direction By the following Steps:

1. The class A surface is Extracted
2. Then the center point is created using the point, on the base surface at 0mm.
3. At the point axis system is created.
4. After switching the view of the model to the X direction and creating the tooling Axis.

Using the intersect in the ZX plane to get the boundary lines.

Then the lines are created along the slant surfaces.

Then these two lines are bisected to get the tooling axis for the X direction.

1. Next, switch in the Y direction and intersect the switch Bezel part in the ZX direction to get the intersecting Lines.
2. Using the axis center point, a line is drawn in sketch mode and it is constrained at an angle of 6 degrees.
3. At last, both the lines are bisected to get the final tooling axis.

The below line represents the tooling axis for the surface.

2). Draft Analysis:

The draft analysis enables you to detect the part we drafted will be easily removed. This type of analysis is performed on the base of color ranges identifying the zones on the analyzed element where the deviation from the draft direction at any point, corresponds to specified values.

1. Go to insert
2. Click on the compass icon and align it with the tooling axis and click on the surface, we will get our result

3). Parting Surface:

Generally, injection mold has two major components: movable halves and fixed halve. During the injection molding process, these halves are pressed tightly from a sealed hollow to avoid melt flow leakage and maintain certain holding pressure, the pressed surface is called the parting surface, usually parting surface is the biggest projection outline surface of the part.

Parting surface design directly affects the product quality, ease of construction, and operation of the injection mold

4). Parting Line:

Parting lines are where the two halves of the mold meet. This generally create a physical line on a part that is both visible and noticeable to the touch. These lines however can be hidden or minimized when placed along edges of the part. It is represented by the dotted line in the below picture

CORE AND CAVITY design for switch bezel:

core and cavity:

A core is one part of the mold. and it is responsible for half of the molded part. actually core is the projection of the body and the cavity is the depression of the body. these core and cavity combine to form a mold. then the plastic material is injected into this mold to get a plastic part.

5). Core design:

• To extrapolate class A surface
• Trim class A with class c to get an inside portion
• Now, trim the B surface with an output of Class A & C that will be parting the surface with respect to area. Extrude the sketch overall throgh the tooling direction are trim it with a parting surface
• Final output of core design

6). Cavity Design:

The cavity is the part where the injector and filling of the molten plastic happens. The cavity block is prepared by trimming extrapolated B surface and the same profile used in the core for the rectangular block to extrude along the tooling direction.

The achieved surface is filled and joined to create a closed surface as shown picture

Core and Cavity Design:

The mold core and cavity are shaped sections in either half of the mold tool, giving the plastic product its final shape. The hot molten material is injected into the core and cavity and then sets hard into shape. The design of the core and cavity is essential in the correct formation of the product. The sequence of events during the injection mold of a plastic part is called the injection molding cycle. The cycle begins when the mold closes, followed by the injection of the polymer into the mold cavity. A core is usually made of the best quality sand and is placed into the desired position in the mold cavity. Core prints are added to both sides of the pattern to create impressions that allow the core to be supported and held at both ends

The intersection of All Core, Cavity & main components are:

Conclusion: Thus I have designed the core and cavity of the switch Bezel