Molds are made using silicon rubbers, and used for a variety of purposes
Silicone mold making products are designed to replicate original parts, old or new to exact dimensions. There is an infinite variety of applications for these materials. From art work and picture frames to figurines to prototypes to candy, it is all possible!
Application Examples
Industrial Mass Production
For small production runs in a variety of different designs: MOLDSIL flexible molds have proven to minimize unit mold costs.
In particular this applies to models or industrial mass production of :
• Plaster working molds and models for porcelain and sanitary ceramics manufacture
• Ornamental door panels and window frames , mirrors and picture frames
• Reproduction furniture
• Hand-painted figurines and sculptures from filled casting resin
• Shaped foodstuffs (chocolates, portions of butter, decorations for ice cream)
• GRP laminates (boats, surfboards, tanks, etc)
• Electroforming of dashboards, automotive interior trim, etc.
Rapid Prototyping
In the light of increasingly demanding requirements of the industry, processes such as rapid prototyping must be able to reproduce an original model with honest reproduction in large quantities. This is usually done by vacuum casting in silicone elastomer molds.
The technique is used to produce prototypes for
• Display models
• Design models
• Functional models
• Pre-series models
• Wax Models
• Small series
For any model and any reproduction material, the PLATINSIL range of silicone rubbers offers an ideal grade for vacuum casting (soft tooling).
Restoration
Easy to process and requiring no expensive equipment, MOLDSIL and PLATINSIL grade rubbers are ideal for hobbyists, but are also valued
by restorers, conservationists, archeologists and museum technicians for in-situ reproduction of originals.
A main application is the production of complex and creative parts, such as :
• Replicas of irreplaceable originals for display purposes
• Decorative prefabricated concrete parts
• Garden furniture
• Designer Candles
• Wax positives for investment casting of high-melting metals by the lost wax technique
• Ornamental frames, buttons ….
• Artificial Jewellery
• Electroformed articles
Which product to choose? Questions to consider
• What material will be cast into the mold?
• What are the temperature requirements?
• How hard or soft must the mold be?
• What are the cure time requirements?
• How complex in shape is the original?
• Are there many undercuts in the original?
• Is color a consideration? Transparency required?
• Is there a reason a container cannot be built around the original to
to contain the silicone rubber?
• What is the original made of?
• Does the original contain sulfur amines, butyl, tin soap catalysts, etc.?
• How much shrinkage can be tolerated?
• What are the viscosity requirements of the uncured silicone rubber?
Silicone Drivers :
Cost Competitiveness Metal tooling may cost more
Fast Metal tooling can take weeks to make
Accurate Snap fits can even be made
User Friendly Easy to process
Simpler Molds Fewer parting lines means less finishing work
Good Mold Life 15 to 25 duplicates may be needed
Silicone mold making materials :
Silicone Features and Benefits
Attributes : Detailed reproduction, long mold life, easy de-mold
| Features | Benefits |
| • Low surface energy wets part for superior detail reproduction • Flexible and ease of release • Superior chemical and high heat Resistance • Low shrinkage • High elasticity |
• Faithful reproduction of even the most complex originals • Easy de-molding of undercuts • Provides long mold life (multiple parts) even with aggressive resins which develop high exothermic temperature during cure • Excellent dimensional stability • Readily stretched for easy part removal |
Silicone Material Properties :
Attributes : Detailed reproduction, long mold life, easy de-mold
| Features | Benefits |
| • High Tear Strength • Fast Curing • Flexible Cure Cycle • Food contact Possibilities • Low shrinkage |
• Molds resist tearing when stretched for part removal • Silicone molds can often be built quicker than competitive materials (Ex: latex metal …) • Adapts to a wide range of requirements • Excellent dimensional stability • Platinum cure systems meet food contact requirements |
Material choices for different applications: Comparison
| Condensation Cure RTV | Addition Cure RTV |
| • MOLDSIL (Tin Catalyst) • Low durometer (5-40) • Soft, flexible, captures detail • Room temperature cure only • Low viscosity for easy pour • Low shrinkage (0.1%-0.3%) • Resistance to sulfur-based clays • Moisture-dependent cure • Alcohol, water by-product |
• PLATINSIL (Platinum Catalyst) • High durometer (25-70) • Dimensional stability • Room temperature or heat accelerated • High viscosity • Extremely low shrinkage (<0.1%) • Recommended patch test for cure inhibition; excellent for epoxies and urethanes • Self-contained cure • No by product |
For full-fledged comparison charts detailing the technical comparison of mold making rubber grades and silicon rubber grades, write to us on response@elink.co.in
Types of Molds
• BLOCK MOLD: Where the rubber mold completely fills the area between the master and mold support. The exterior of the mold does not conform to the shape of the master.
• SKIN MOLD: A thin mold which closely follows the contours of the master. This type of mold is typically applied with a brush and is prepared in multiple layers. This process uses less material and is more flexible than a block mold.
• GLOVE MOLD: A hybrid of a skin and block mold. Usually measures 3/8″ in thickness and requires a mother mold. It can be poured in one application.
• MOTHER MOLD: A structure built around the silicone mold in order to maintain proper dimensions of produced parts during the casting process.
Mold making – typical process steps
• The Master Part
• Building the Mold
• Prepare the Silicone
• Pour/Cure Silicone
• De-mold
• Duplicate Part
Most mold making material manufacturers are also willing to custom design a product based on customer requirements. Contact us for more information response@elink.co.in
