Week 8 - Challenge 6 - Core & Cavity Design

Aim: To create core and cavity block for switch Bezel considering all plastic design rules.

Objective:

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

Tooling Axis:

• The ejection from the mold after manufacturing the interior trim must have the nominal 3-degree draft angle.
• Hence the tooling directions created by considering the above factor and bisecting method is used.
• The base surface of the class-A was extracted to create a reference point on the surface using the point, create a line in the z-direction and an axis system was inserted to the point
• then using projection intersection along the yz plane is created and the two inclined lines were drawn inside the positioned sketch.
• then bisecting lines with the two inclined lines were created.

Parting Surface: The parting surface of a mould are those surfaces of both mould plates adjacent to the impressions which butt together to form a seal and prevent the loss of plastic material from the impression. The various factors to be considered while selecting the parting surface are Shape of the Components, Type of Mould, Method of Ejection, Method of Manufacture, Location and Type of Gate, Aesthetics of moulding. In general the parting surface is classified into two types, they are Flat parting surface, Non-flat parting surface.

Core:

The core design is started with extracting the parting surface that becomes the datum for the core and cavity. Extract the A surface and C surface and trim with extrapolated B surface.The achieved surface is converted to enclosed rectangular box by extruding rectangular profile at a distance from the parting line along tooling direction. Hence it is closed and joined together to form closed surface which is converted to solid body in part model.

Cavity:

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 same profile used in core for rectangular block to extrude along the tooling direction.

CORE & CAVITY:

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. Generally injection mold has two major components , They are the movable halve and the fixed halve, during the injecction molding process, these two halves are pressed tightly from a sealed hollow to avoid the melt flow leakage and maintain certain holding pressure, the pressed surface are called parting surface, usually parting surface are the biggest projection outline of the part. Parting surface design directly affects the product quality, ease of construction and operation of the injection mold, the mold design is one of the key factors to success.

Conclusion:

Thus core and cavity is created as per the given part profile along tooling Direction.