Week 8 - Challenge 5 - Core & Cavity Design

CORE & CAVITY DESIGN OF SWITCH BEZEL

AIM
1. To create the switch bezel plastic component through the given class-A-surface and at the
performing the draft analysis on the model.

2. Creat the core and cavity design of the switch bezel component

OBJECTIVE
•  To ensure proper tree structure is followed.
•  Geometrical sets should have a proper name based on the sketches present inside of them.
•  All the sketches should be created under a geometrical set.
•  Use of the close surface feature to make a solid body from the surface.
•  To publish the tooling axis, Class A, B and C surface.

PROCEDURE
First import the class A surface of switch bezel model in CATIA V5.

• The mould core and cavity are the shaped section in either half of the mould tool which gives 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 mould of a plastic part is called the injection molding cycle.
• The cycle begins when the mould closes, followed by the injection of the polymer into the mould cavity.
• A core is usually made of the best quality sand and is placed in to the desired position in the mould 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.

PARTING SURFACE

Extract the boundary from the class-a surface and extrude the edges outside.

Offset the extruded surface 3mm downward and exude the boundary in the tooling direction.

Trim the offset with the class-a surface and boundary extrude. then you will get Parting Surface.

CORE
• The core design is started with extracting the parting surface that becomes the datum for the core and
cavity. The parting surface in most of the cases is kept at the B class surface to avoid close and tight
contact between the core and cavity.
• At first the A-class surface is extrapolated with some length and later it is trimmed with a C surface.

Sketch

Extrude

Trim extrude with parting plane

CORE

CAVITY

• The cavity is the part where the injector and filling of the molten plastic happens. The cavity block is
prepared by first extruding the outer boundary along the tooling direction.

• This outer surface is trimmed with the B class surface and then it is filled and thickened.

CORE & CAVITY WITH SWITCH BEZEL

DRAFT ANALYSIS

CLASS-A SURFACE

CORE

CAVITY

TREE STRUCTURE