LESSON 02 MOLD TOOLING DESIGN USING SOLIDWORKS

In this lesson we will create a mold for plastic part used in a food mixer.

Upon successful completion of this lesson, you will be able to:

 To position an imported body

 Create a parting line
 Create shutoffs
 Create a parting surface
 Create a tooling split the mold into the core and cavity
 Use of the core command to review geometry for:
o Side cores
o Core pins
o Ejectors
 Make an assembly from the multi-body mold design
OPENING A PART

TO OPEN THE PART:

Browse to C:\MoldToolDie101\Lesson02\ Class_Example_Part.x_b and Double Click to open the part in
SolidWorks

Not necessary to run import diagnostics on the

part but on a real customer part it is
recommend to run this to fix any gaps and
errors.

SELECTING A UNIT SYSTEM

TO SELECT A UNIT SYSTEM:

1. Click on Tools > Options > Document

options > Units > MMGS

2. You can also change this from the Status

bar as shown in the right.
POSITION THE PART

Typical parts for mold tool design are imported from 3rd party CAD systems; often the part is not
oriented correctly for the desired tooling to be created. This is achieved using the Move/Copy Body
command

TO POSITION A PART:
1. Click on Insert > Feature > Move/Copy…

2. Select the body.

3. Expand up the Rotate group in the

PropertyManager. Observe the Triad on
the screen.

4. Mouse over the blue Z axis rotation ring

5. Drag with the LMB (Left Mouse Button)

and this will rotate the part

6. Type -180 into the X-axis to get a precise

position

7. Click OK to close the command.

Before Rotation After Rotation

This command can also position the part in X,Y, Z by dragging with the LMB and it can make copies of
the body
APPLY SHRINKAGE

Plastic molded parts will shrink when they eject from the mold and cool to room temperature. So we
need to build the mold to be slightly bigger than the actual part so when the part shrinks we get the
right dimension part.

TO APPLY SHRIKAGE:

1. Click on Insert > Molds > Scale

2. Use Centroid

3. Check Uniform scaling

4. Enter a scaling value of 1.066

5. Click OK
PERFORMING DRAFT ANALYSIS

An appropriate draft angle will aide in the removal of the part from the mold. Without the proper draft
angle parts may become hung up or stuck upon ejection and mold damage may occur. Be sure there are
draft angles on all bosses, ribs, and nominal walls.

TO REVIEW DRAFT ANGLES ON PART:

1. Click on View > Display > Draft Analysis

2. Select a planar face that is parallel to the

parting plane

3. Select the draft angle that you require e.g.

1.5 degrees

4. Enable the checkbox for face classification

The various model faces are now coloured

according to their draft angle, the numbers of
faces in each classification are shown

Using the button you can hide and show

individual classes of faces

You can also change their colour using the

button

Exiting the command with the button will

leave the analysis active so you can:

 You can then correct any erroneous draft

 Watching the results change
CREATE PARTING LINES

This is used to estimate and select a parting line based on the boundary between positive and negative
draft of the mold.

TO CREATE A PARTING LINE:

1. Click on Insert > Molds > Parting Line

2. Rotate the part so the parting line is at the top. Select

a plane e.g. the top of one of the bosses

3. Click the Draft Analysis button

4. The system automatically selects the correct parting

line, shown in blue

5. Click OK.
Selecting partline line edges

 You can press Y instead of Add selected edge

 You can press N instead of Select next edge
CREATE SHUT-OFF SURFACES

Create shut-off surfaces to fill holes in the core and cavity.

TO CREATE SHUT-OFF SURFACES:

1. Click on Insert > Molds > Shut-Off Surfaces.

Based on the previously created Parting Line
feature, the draft angle transitions and open
loops (holes), the system will try to auto select
the loops that need to be filled. Show the
preview to see if any surfaces are not selected.

2. Select the ventilation loops in the right hand of

the part using any of these techniques:

a. Zoom in tight, change to wire frame

hidden
b. RMB > Select Tangency over an edge
c. RMB > Select Loop over an edge
d. Pick an edge and select the cyan
propagation icon select the

to select the last edge and finish

the loop
e. Repeat step d for other slots as well.
Pick each edge one at a time
 3. Select the ventilation loops in the left hand of
the part.

a. Zoom in tight, change to a wire frame

view and turn off preview
b. Pick one of the circular edges at the top
of each vent and press the button
to propagate the selection around the
loop
c. Repeat for each of the vents in turn

4. Create the telescopic shutoff for the complex

hole:
a. Zoom in tight
b. Enable the preview checkbox
c. Change the patch type to Tangent
d. The can then be flipped to
create the telescopic shut-off in the
desired direction
e. The message should now be green

5. Exit the command

It’s a good idea to keep the preview checkbox turned off for performance reasons, especially if there
are contact patches that the system can’t create
CORE AND CAVITY SURFACES
When the user exits the Parting Line or Shut-Off
command with a green message pane, the system
will create the core and cavity surface sets:
• Folders are created at the top of the FM
• One for the cavity surface
• One for the core surfaces

The contents of the folder hierarchies can be set at

each level:
• Show/hide
• Have their appearance set

There is a checkbox on the Parting line and

Shut-Off surface PM to disable knitting of the
surfaces

If you manually build the shut-off surfaces,

user should manually create the surface and put a
copy in the core and the cavity surfaces folders
CREATE PARTING SURFACE

Create a parting surface to split the mold block in combination with the core and cavity surfaces.
Usually this is based on the first parting line feature in the part, this also supplies the pull direction to
the command

The Parting surface may be created with the

following procedure:
1. Click Insert > Molds > Parting Surface

2. Set Perpendicular to pull for Mold

parameters

3. Enter 37.5mm for Distance

4. Click OK to create parting surface.

CREATE TOOLING SPLIT

Use tooling split to create the core and cavity mold blocks.

1. Click Insert > Molds > Tooling split

2. The system will prompt you to select a plane or

planar face to sketch the cross section of the
mold blocks on. in this case we can use the
parting surface because it is planar and in the
correct location.

3. Sketch the outline of the mold blocks, such

that the sketch fits inside the boundaries of the
parting surface

4. Enter 25.00 mm for Depth in direction1.

5. Enter 50.00 mm for Depth in direction2.

6. Exit the sketch and the system will activate the

Tooling Split commands own Property
Manager
SEEING INSIDE THE MOLD BLOCKS

Now that we have the core and cavity blocks we need to move them apart so we can work on creating
cores, ejectors etc. Use the following procedure.

1. Click the ConfigurationManager.

2. RMB Default and select New Exploded View

3. Move bodies to see the core, cavity and part.

4. Click OK.

5. Collapse the exploded view

SIDE CORES, LIFTERS, INSERTS, CORE PINS AND EJECTOR PINS

Various pieces of geometry ‘cores’ are extracted from the core and cavity bodies to assist in modelling:

 Side Cores
 Lifters
 Inserts
 Core pins
 Ejector pins

1. This is achieved by creating a sketch on an appropriate planar face or plane that defines the
outline of the core
2. This is then extruded through the mold block cutting out a solid which can then be used to
model the retract or insert piece for the mold
3. The user can add draft in the pull direction, for a side core by including it in their sketch of the
core profile
4. Draft in the retract direction for the side core is added in the core command

Due to lack of time we will review the part which contains these features.

Browse to C:\MoldToolDie101\Lesson02\BuiltParts\Class_Example_Part_completed.sldprt and

Double Click to open the part in SolidWorks. Review how the following features were created:

 Cores, ejector pins and core pins

 Save bodies feature to save this as a sub-asssembly

SAVING AND CLOSE ALL THE FILES

Congratulations! After completing this tutorial, you now have the basic skills required to create a basic
mold base for your plastic part.