Mould Tools Introduction
This factsheet refers to the basic principles of the
SolidWorks mould design tools. The following are the
stages involved in the creation of a core and cavity of a
lid shaped component with a single opening or shutout in
the centre. The component to be moulded is shown
opposite. Model the component as follows:
length = 100mm, Width = 60, Height = 30, draft angle 10
degrees, Fillets R10, Shutout hole diameter 20mm.
Draft analysis
Run draft analysis to determine if all surfaces have
sufficient draft. This will indicate that the hole requires
draft. Add a 5 degree draft to the hole ensuring that a
minimum diameter of 20mm is maintained and that the
shutout is against the core.
Parting line detection
Parting line detection analyses the component to
determine the outermost edge of the component. This
edge will be the line of separation of the core and cavity
halves when the mould opens.
In addition to generating the parting line, SolidWorks
attempts to generate surfaces to model the core and
cavity. This is unsuccessful with this part, as there is an
opening (or shutout) which needs to be addressed or
‘plugged’.
Generate ‘Shut-off’ (Shutout) surfaces
Using this tool SolidWorks searches for openings within
the part boundary. SolidWorks detects the single opening
as shown. Solid Works invisibly creates a surface to
patch up this opening. (The consequences of this surface
will be seen later).
Solid Works also reports that it is now possible to
generate a core and cavity.
On completion of the above SolidWorks generates 2 sets
of surfaces. These surfaces are located in the Surface
Bodies folder.
These surfaces can be
examined by selecting each in
turn and selecting [Isolate].
(The shut out surface
mentioned earlier forms part of
both of these surface groups).
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Generating parting surfaces
The simplest way to generate the parting
surface, the separation between core and cavity
halves of the mould, it to radiate the parting line
outwards.
This is achieved by selecting the Parting
Surface command, then using the
‘perpendicular to pull’ option, specifying a radial
distance for the surface to extend.
Generating the mould base
To generate the mould base a rectangular sketch is
drawn representing the size of the mould
perpendicular to the line of pull.
To successfully create the mould base, it is
necessary that the parting surface extends beyond
the dimensions of the mould in all directions.
On completing of this step, Exit the sketch.
Finally select the Split Tool command and select the
sketch defining the mould outline.
Using this sketch, combined with the contents of the
 Core surface
 Cavity surface
 Parting surface
and a core and cavity block thickness specified by
the user, Solid Works creates the mould tool
required to mould the component. The finished tool
should look as shown opposite.
Surface bodies are central to the mould generating
process. In order to generate a split mould three
sets of surfaces are required, Cavity surfaces, Core
surfaces, Parting surfaces. All three sets of surfaces
must meet at t common point.
Summary of Mould creation procedure:STEP 1: Run draft analysis to ensure all surfaces have sufficient draft.
STEP 2: Scale part to compensate for shrinkage.
STEP 3: Generate Parting Line to determine the outermost edge of the component
STEP 4: Generate Shut-offs surfaces - only required if the part has internal openings.
STEP 5: Generate parting surfaces. The may be generated automatically or manually.
STEP 6: Generate the split tool or ‘Tooling Split’ – this creates a core and cavity block.
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