3D MOULDING AND CASTING

Assignment week eleven is also a creative week.This week, we have to create an object in 3D softwear that can be milled into a positive mold. This requires us to make a negative mold and a positive item.This week, Niel explained to us in detail the molding and casting processes as well as the many materials that are utilized in these processes. To go through all the steps is interesting.

Objectives

GAROUP Assignment

• Review the safety data sheets for each of your molding and casting materials
• Make and compare test casts with each of them

INDIVIDUAL ASSIGNMENTS

• Design a 3D mould around the stock and tooling that you'll be using, mill it (rough cut + (at least) three-axis finish cut), and use it to cast parts.

learning Out comes

• Design appropriate objects within the limitations of 3 axis machining
• Demonstrate workflows used in mould design, construction and casting

Obout Assignments

The safety data sheets for each of the molding and casting materials in our lab must be reviewed as part of the group project. With each of them, create test casts to compare.Talk to the group members about the parameters. We separated the materials and tested their properties for the group assignment in our lab, which has a variety of materials including HydroStone, Silicon Rubber, FlexWax, Machinable Wax, Epoxy Resin, and Paraffin Wax.For testing purposes, one of our members also tried using Medimix soap.

Feature to be considered for molding material sellection

• Room temperature cure.
• Low viscosity - easy flow and excellent detail reproduction.
• Excellent mechanical properties - suitable for deep undercut moulding.
• Good chemical resistance - compatible with various casting materials.

Catalyst

The choice of catalyst depends on the application method and the speed of cure needed. Moldsil-15 can be cured in to elastomeric products using the following cure options:

• CAT-24 : Slow catalyst,Takes about 24 hours at room temperature .
• CAT-16 : Medium speed Catalyst,Takes about 16 hours at room temperature.
• CAT-04 : Rapid Catalyst,Takes about 4 hours at room temperature

Handling Precautions and Safety

mouldsil-15 PLUS contains constituents that have been found to be safe. Hence special handing precautions except general industrial hygiene need to be followed. Catalysts (CAT-24, CAT-16 and CAT-04) contain organo-tin compounds and are flammable and might cause irritation upon contact with eyes and skin. Adequate protective measures are recommended. Refer to Material Safety Data Sheet (MSDS) for safe use of the product.

The result of mixing is as shown in the following image.

About Wax

A wax-plastic material for making molds quickly, easily, and inexpensively. Simply melt it, then brush it on or dip the object into it. Flexwax melts at 120°F (49°C) , a comfortably warm temperature. It cools in a few minutes to form a tough, flexible mold.

work content(PRACTICE PICTURES)

SUMMARY

• Moldsil Silicone is the good moulding material for hard casting.
• The curing time is more than 16 hours if uesd catalyst-16.
• Take atleast 10% more material than required.
• safety precautions are very important while handling material.
• wax material is very soft do not apply much pressure on it.
• Removed the casted material slowly,other wise the mould get deformed.