Makeup Artistry - Jess Brown

After creating the master mould, the life cast can be used to begin sculpting. The sculpting process is the most important step when creating prosthetics. The sculpt is what the final prosthetic will look like, so attention to detail is key here.  To prepare the cast, it can be painted the same colour as the sculpting clay that will be used. This is helpful because it allows the sculpt to blend in with the cast and not look so odd, but it also helps the cast and clay to be seen as one uniform piece. Figure 1 - Painted ear casts (Brown, J. 2020) Once this has dried, it is important to make sure a separator has been applied over the top. When the basic sculpt has been finished, the clay will be floated off of the cast in water and transferred to the smaller cores. The separator is necessary to do this. Figure 2 - Separator for floating off sculpts (Neillsmaterials, no date) For this sculpt, Chavant NSP was used. This clay is a very popular choice as it is non-hardening and doesn't dr...

Now that a silicone mould has been made and prepped, the next step is to create the polyurethane positive/core for the snap mould. "Polyurethane is a plastic material, which exists in various forms. It can be tailored to either be rigid or flexible". (polyurethanes, no date). According to Dalchem, polyurethane is made of two components, those being urethane and polymers. These polymers are bonded together by urethane groups which then creates a versatile solution that can take many different forms. (Dalchem, no date).   Polyurethane has many different uses, such as insulation of fridges and freezers, car parts, mattresses, tyres and even shoe soles. (Polyurethanes, no date).  The polyurethane used was Axson F40 polyurethane resin. This resin has a quick setting time, a low shrinkage rate (meaning it won't shrink as it sets) and high abrasion resistance. (Neillsmaterials, no date). A catalyst is required for this, so isocyanate F40 was used, as per manufacturer's instr...

Snap moulds (also called conformed moulds, contoured moulds or squash moulds) are used to create a 3D prosthetic. They consist of a negative mould of the sculpt/piece, and a positive life cast that squash together. They can be made out of plaster, however these can easily break and chip, so a polyurethane mould will be created. Polyurethane is also lighter and more resistant than plaster, although it can be costly. As said by Todd Debreceni, "conforming moulds are becoming more commonly used in prosthetic application due to the ease and precision of the application process". (Debreceni, T. 2019). He goes on to say that this type of mould may not be suitable for all appliances, but he recommends them for smaller pieces.  As these are used to create individual prosthetics, they only need to be around the size of that piece. For example, if a nose prosthetic is being created, the mould only needs to be of the nose. This is accomplished in the first step using the master mould. A...

After the silicone mould has been made, the next step is to create a fibreglass jacket. This will support the mould and help it keep its shape when it is being used.  Figure 1 - Fibreglass jacket (Brown, J. 2020) Fibreglass is a reinforced plastic material that is embedded with glass fibres. Fibreglass is supplied as a flattened sheet called strand matt, which comes in different grades (or thickness) from 300g to 600g. When this is combined with resin, it creates a very strong, durable composite. (Fibreglassdirect, 2017). This process is also known as laminating.  Fibreglass can be used for an array of different things, not just in prosthetics. For example, it is used widely in the automotive industry, in cooling towers, mining, the chemical industry and more. The properties of fibreglass makes it useful in all these areas. It is a good electrical insulator, it is incombustible, doesn't rot, has low thermal conductivity and has high mechanical strength. (Phelps, no date). Fibr...