Virtual Mold Design Firstly we transform our surface plastic part model into Extended Z Map. Then we do draft analysis to detect undercut. Secondly we explode the part into core and cavity face groups. Our Extended Z Map is used to classify the part face into core, cavity, both direction, and undercut face groups. There is no parting line search or selection process until the next step. We don’t use the parting line to separate the core and cavity faces. Our method does not need to traverse the B-rep edge face relation map. Thirdly we perform the parting edge and hole edge loop search on the exploded core and cavity faces groups

1. PartingAdviser
A Mold Design Tool
Product Design and Development GroupProduct Design and Development Group

2. research
Independent PartingAdviser

3. Parting is Cavity Design
Core insert
Cavity insert
Parting face
Parting line

4. See-through walls
See-through top
research
Look from Another Angle

5. Firstly we transform our surface
plastic part model into Extended
Z Map. Then we do draft
analysis to detect undercut.

6. Secondly we explode the part
into core and cavity face groups.
Our Extended Z Map is
used to classify the part
face into core, cavity, both
direction, and undercut
face groups.
There is no parting line
search or selection
process until the next step.
We don’t use the parting
line to separate the core
and cavity faces.
Our method does not need
to traverse the B-rep edge
face relation map.
The solid based mold cavity design needs to
use extract region function to extract core or
cavity sheet. Their extract region operation
needs to traverse the B-rep edge-face relation
map, which in turn needs a manifold solid.

7. Thirdly we perform the parting
edge and hole edge loop search
on the exploded core and cavity
faces groups.
 The search algorithm
is a very simple
borderline search.
There is no need to
traverse the B-rep
edge-face relation
map.
 The parting edge
loops are used to
form the parting
faces. The hole edge
loops are used to fill
the holes

8. Then the searched holes
are automatically filled.
 There is no need to
pick the hole
boundary edges,
which is a very
time-consuming
process.
 However, the filling
formula can be
adjusted
afterwards.
 This will provide
the same flexibility
as the manual hole
filling.

9. Finally the searched parting line loop
is used to form the parting face. This
parting face is used to form the core
and cavity. This parting face is not
used to split the part.

11. DiscussionDiscussion

12. STL Format
• //Solid_STL.h
• typedef struct Stl1
• {
• unsigned char color;
• float nm[3], v1[3], v2[3], v3[3];
• struct Stl1 *next;
• }Stl;
• extern Stl *FirstStl, *spi;

13. Future Work
• Phase 1
– Parting line generation from mesh edges
– Selection and call back using OpenGL buffer
– Adjust parting line by moving mesh
• Phase 2
– Control parting line over vertical walls
– Boolean operation for mesh
– Precision issue – Web3D for CAD