Miralde Kotze – Page 3

WIRE EDM SERVICES

Facilities that form part of the CNC machining at the Product Development Technology Station (PDTS) include an Accutex 500iA wire Electrical Discharge Machining (EDM). The machine makes use of a 0.25 mm brass wire that cuts through metals by means of an electrical erosion process. This technology enables the station to cut hardened steel with high precision.

The wire EDM technology supports precision machining and tooling processes and cutting of 3D printed metal parts. The machine produces numerous components for the firearm and tool making industries.

A local newspaper for example needed assistance to manufacture replacement components for a printing press. The only method that could cut the hardened steel rollers was by means of the wire EDM process, which the PDTS assisted with. This locally provided service reduces downtime of the printing press and therefore helps ensure productivity at the newspaper.

The movement of the machine is X-500 mm, Y-300 mm and it can accommodate a workpiece of up to 265 mm in height. The machine is extremely accurate and produces a very fine surface roughness of 25 microns.

CNC MILLING

The workshop of the Product Development Technology Station (PDTS) includes a faithful Dahlih 720 MCV vertical milling centre, which is the workhorse behind the tooling projects.

This machine handles anything from machining tool steel mould bases to machining intricate specialised parts from soft metals. Work done on it includes the machining of moulds for plastic products, wheelchair components and laboratory apparatus.

A local abattoir for example requested the PDTS to assist with the design and manufacturing of a plastic injection mould. This is used to produce a special plastic clamp utilised during meat processing. The CNC milling machine was utilised to mill all the parts needed for the mould. Localised manufacturing of these clamps accelerated meat processing and also reduced costs.

The machine movement is X-720 mm, Y-460 mm and Z-510 mm and the maximum spindle speed is 8000 rpm.

TURN-MILL SERVICES

The Product Development Technology Station (PDTS) is a proud owner of a Leadwell T-7 AM CNC turning centre with live tool capabilities in the Z- and X-axis. This combines turning and milling operations in one machine.

The turn-mill is responsible for machining components for various medical devices such as wheelchair hubs. Other products include an extruder for a large scale 3D printer, tooling and general machining projects.

A hobby rocket enthusiast for example approached the PDTS to machine a few sets of rocket motors from aluminium. The client was pleased to manufacture the motors locally as his only other option was to import it at a more expensive cost.

The station utilises the turn-mill for one-off components to series production components.

The machine has a maximum clamping capacity of 200 mm and can accommodate work pieces of up to 500 mm in length. The maximum spindle speed is 4500 rpm.

THERMOPLASTIC URETHANE DEVICE COVER

Safety is of utmost importance in mines. Therefore Electro Diesel Group (EDG) wanted to develop proximity awareness technology, which senses vehicle and people movement, in order to warn about danger and take over vehicle controls to avoid collisions.

EDG approached cStream to develop the technology and Technimark was asked to do the industrial design of the enclosures. One of these enclosures was for a mobile unit, which contractors use when entering mines. It is connected to their vehicles to integrate it into the system and radio network.

The main enclosure of the unit is made from machined aluminium and needed to be covered with a rubber enclosure. But the cost, based on the limited quantities required, did not justify an injection mould.

Technimark requested the Product Development Technology Station (PDTS) to further their development and to be able to supply a final product that is of injection moulding quality, but without the high cost involved.

For this purpose the PDTS tested the capability of the modular mould base concept in order to manufacture a mould or cover of thermoplastic urethane. This features large undercuts to fit snuggly over the device.

Products like these are conventionally very expensive to produce with injection moulding. This is due to the difficulty of removing the product from the mould as it often requires human intervention or in a high production environment even robots.

To reduce tooling costs the PDTS designed a mould to produce the covers in low numbers in order to test the economic viability.

The first 500 units were delivered at a unit cost and of a quality that could not have been achieved with any other manufacturing method. The PDTS therefore assisted to validate the longevity of the mould and test the commercial lifespan of the product.

HANDLES FOR AVIATION RADIOS

A manufacturer of portable ground to air radios used in aviation requested the Product Development Technology Station (PDTS) to manufacture plastic handles for a radio. The handles were injection moulded.

The station was responsible for the injection mould design after the client provided the CAD model for the handle. The handle consists of two parts that fit over a sheet metal to form the handle.

The client required a low number of handles for market testing purposes. Therefore the PDTS made use of aluminium inserts for the cavities and 3D printed the cores in MS1 tool steel to keep costs as low as possible.

The PDTS produced 100 sets of radio handles in polycarbonate plastic for durability. The mould produced by the station was manufactured at a very low cost when compared to conventional tooling and was the perfect solution for a limited run product.

COFFEE BREWING SPOON

The coffee industry has seen major growth over the last few years. The general market is moving away from instant powder coffees towards the use of freshly grounded beans.

There are various means of brewing coffee on the market. Most of these take a lot of time to prepare and can be somewhat messy and expensive.

The Product Development Technology Station (PDTS) created a cost effective and innovative product, called the Coffee Brewing Spoon. The spoon makes a suitable quick cup of coffee without much effort or mess, requiring no consumables.

The Coffee Brewing Spoon consists of two halves. The coffee is scooped with the bottom half, ensuring the correct amount of coffee. The top half clips onto the bottom half. The spoon is then put into a mug and hot water poured onto it, infusing the coffee through the stainless steel mesh. In order to clean it, the spoon is opened and the bottom half with the coffee grind released into a dustbin, after which the spoon is rinsed out.

A comprehensive product development process was followed to produce a final injection mould ready design. The PDTS manufactured a limit run injection mould to confirm the market demand and functionality.

The cost effective limit run process reduced the risk of commercialisation, market entry and allowed further funding to be acquired to produce a high production injection mould tool.

LOW COST INJECTION MOULD SOLUTION

The Product Development Technology Station provides a cost effective injection moulding solution for prototype moulding or limited run production. This is especially useful when a client requires low numbers of a new plastic product for testing purposes or market research in the final material.

Moulds like these are used for products such as enclosures for electronic devices, plastic screws, radio handles, fittings and brackets. Plastic products intended for medical applications also need to be tested in final material to be given CE certification.

A low cost injection mould solution is made possible, by catering for various clients or products, through using only one mould base. Each product has its own set of cavity and core inserts, support plate and ejector pin inserts. Therefore changing the product design during the mould development process will have much lower cost implications than conventional tooling. It allows the client to only invest in mould inserts and not the entire mould base.

Clients can therefore make changes to the design or product, without replacing expensive cavity plates. The cavity inserts are machined from aluminium, which cuts down on machine time when compared to tool steel.

It also reduces the capital risk for product developers, by providing a viable alternative for the manufacturing of injection moulded products.

WEESTAND URINAL

Normal urinals are made from ceramic and is dependent on water usage. With water saving in mind, a client approached the Product Development Technology Station (PDTS) to develop an idea of a waterless urinal.

The aim was to use these urinals in areas where there is a high shortage of water. The Weestand Urinal was made from plastic, which is also cheaper to manufacture and quicker to install than existing urinals.

For this purpose a urinal, which can be used by males or females, was designed from Low Density Polyethylene (LDPE) material. It is waterless and water is only used when the urinal is cleaned.

Existing client designs of the product were redesigned for rotational moulding purposes to produce the units.

A 3D printed valve was also developed, with the assistance of the Centre for Rapid Prototyping and Manufacturing at the Central University of Technology, Free State, in Bloemfontein. From that a vacuum casting mould was developed to produce the valves. The valve, that also does not use water, fits onto the urinal in order to prevent odour when urine passes through.

A total of 175 units of the Weestand Urinal was produced and assisted the client with a water saving product.

DUAL FRAGRANCE CONTAINER

Converting a roll-on and deodorant spray into one portable packaging was an idea with which a client approached the Product Development Technology Station (PDTS). The aim was to develop a Dual Fragrance Container for the user to only make use of one unit instead of two. It is ideal when traveling, going to the gym and it also makes shopping easier.

The PDTS developed a High Density Polyethylene (HDPE) packaging by integrating the two different parts of cosmetic products into one portable packaging.

With the help of the Centre for Rapid Prototyping and Manufacturing at the Central University of Technology, Free State, in Bloemfontein a 3D printed product was developed to incorporate the two parts. Examples of existing roll-on and deodorant spray were used to fit them onto the 3D printed container.

Once the client was satisfied with the look of the product, it was redesigned for injection and blow moulding purposes. This design was used to make tooling for the moulding processes.

The station produced 50 prototypes of the final product, a dual body odour protection-packaging that provides convenience and effectiveness, for the client.

COFFEE SCOOP AND CLIP

Keeping a bag of ground coffee closed to ensure freshness and having a proper scoop close by are often common frustrations faced by coffee drinkers. The Product Development Technology Station (PDTS) designed a device to enhance the user experience and address these issues. The Coffee Scoop and Clip are a two in one solution, sealing a coffee bag and always having the correct scoop at hand.

The station assisted in all aspects of the development process, which included research of user needs and technical requirements.

In-house prototyping allowed for nine iterative prototypes to be produced in only a week and therefore converted a basic idea into a fully developed design.

The ability to have tangible prototypes in the conceptualization phase dramatically speeds up the decision making process, while confirming the user experience and functionality. The PDTS refined the design for mass manufacturing, adapting the necessary features for injection moulding. A limit run injection mould tool was produced, which allowed the client to enter the market within only two months.

Branding and display units for the product were also developed by the station. The product is currently retailed throughout South Africa.