PROTOTYPE DEVELOPMENT

STAGED PROTOTYPE APPROACH

In the product development process it is essential to confirm design concepts and ideas. A physical prototype can answer a lot of questions with regards to the product’s functionality, look and feel. Prototypes are also an effective means of securing funding or conducting early market tests.

Each product however requires a unique prototyping approach. The Product Development Technology Station (PDTS) therefore tailors each product’s prototype strategy to ensure a low risk and cost effective product development process.

The station for example assisted in developing a commode attachment for a walking frame. A major problem facing retirement homes and care centres are elderly patients falling at night on their way to the toilet. The proposed device was a cost effective clip-on commode for a standard walking frame.

To confirm the initial viability of the device, the PDTS produced a simple laser cut wood prototype. It was tested by occupational therapists to obtain the necessary feedback. Testing confirmed that the product could add value and make a practical difference. A cost effective limit run rotor mould prototype was produced to be tested by patients and to confirm the strength of the device.

Thereafter the device was redesigned for mass manufacturing and a 3D printed prototype produced.

VACUUM CASTING

Silicone mould tooling and vacuum casting enables the production of components in a wide range of available polyurethane resin, specifically chosen to mimic properties of the intended thermoplastic mass-production materials.

The process is an economical way of producing near production parts for exhibitions, market research and batch prototyping or in some instances low volume production. It furthermore enables the reproduction of sculptures and statues in exclusive limited batches.

Polyurethane vacuum cast components provide valuable feedback in terms of design, intended production material and actual look and feel. The process is ideal when requiring limited quantities of a product or final prototypes in need of specific material properties, colours, translucency and other general aesthetics.

The Product Development Technology Station makes use of the process to give innovators and product developers access to limited functional batches of their newly developed products, which in-turn allows for testing, market exposure and final re-design prior to full scale production and official market entry.

RTV silicone moulds are produced by means of a master pattern responsible for creating the required component geometry and finish. If a master pattern does not yet exist, a suitable high resolution 3D printed prototype is hand-finished to the required specifications. Limited run production requirements are made possible via multi-cavity or multiple sets of silicone mould tooling. Depending on the specific component geometry and chosen polyurethane, moulds can normally produce 20 – 40 castings per impression.

CONVENTIONAL MANUFACTURING

Conventional manufacturing is a way of manufacturing parts of or a product by using manual machining processes. Standard machines, that operate manually, are used as part of the production process and no computer numeric control programming is utilised.

Milling and turning is one of the methods used by the Product Development Technology Station in conventional manufacturing. This is ideal for manufacturing smaller quantities of a product and also when manufacturing large and long scale components. It is more cost effective when manufacturing products for these purposes.

Another example where conventional manufacturing is used, is with frame manufacturing and the main structures of products. Raw material such as sheet metal, mild steel sections or stainless steel sections are used and cut to desired sizes. Bending, rolling, drilling or punching of the material forms part of this process.

Assembly of the different parts of the product follows and this can be done by welding, such as Arc-, MIG-, TIG welding and brazing or fasteners.

3D PRINTING

Additive manufacturing, commonly known as 3D printing, produces objects by selectively adding material layer by layer. This is a method of rapidly producing prototypes or complex final parts.

The Product Development Technology Station (PDTS) utilizes desktop printers, Fused Deposition Modelling, to quickly test design concepts and create physical models to determine user experience and functionality of products. This allows multiple design changes to occur rapidly and cost effectively. Once the design is finalized, high quality samples of the product can be produced on high end 3D printing systems or used as masters for silicone mould tooling and vacuum casting.

This allows clients to make informed decisions and interact with the product in all phases of development, reducing the risk and cost of product development.

The PDTS works closely with the Centre for Rapid Prototyping and Manufacturing (CRPM) at the Central University of Technology, Free State, in Bloemfontein, to create tailored additive manufacturing solutions for clients. This interaction with the CRPM allows access to a range of EOS selective laser systems that produce parts in nylon, Alimide, PrimeCast, titanium and tool steel (MS1), as well as an Objet Connex system that can produce prototypes of varying hardness.