Complex medical parts get the VISI treatment

A mould maker producing tools for thermoplastic materials and die castings is relying on the specialist VISI Analysis module to discover critical areas at an early stage of the design process, which greatly simplifies its work.

Mecca TP serves a variety of industry sectors, including medical, automotive, household appliances, furniture and eyewear. Co-owner Antonio Tognon says that the company’s moulds have to be produced swiftly and accurately, first time every time, without the need for changing them unless requested by the customer.
“And in those cases, the amendments have to be carried out quickly,” he states. “Using VISI to design and machine our mould tools means we can guarantee they’ll give a high mechanical performance with precision movements, along with a high aesthetic quality of the moulded products, for long production periods.”
Tognon says the company is also playing an increasingly proactive role in working with customers to co-design the finished, moulded products. “In addition, we support our customers with precision machining, mechanical equipment construction, reverse engineering and reconstruction of damaged mechanical parts, or those without design documentation, as well as dimensional checks.”

Founded in 1985, the company is now run jointly by Tognon and Renato Prosdocimo, based in a 2000 sq m production unit in Bigolino di Valdobbiadene, Treviso, Italy, with an annual turnover of around €1.5m.
“Over the years we’ve developed our production process in order to minimise manual intervention on the moulds, controlling the machining operations,” says Tognon. The company has always adopted advanced technologies, from two- and four-axis wire EDM, to high-speed three- and five-axis milling, along with Mecca TP’s CADCAM VISI software. VISI is proving to be a vital aspect in ensuring that the moulds are consistently manufactured to the precision required, from the design process through to the mould tools being cut.
Mecca TP produces between 40 and 80 moulds a year, ranging in size from 200 x 200 x 200 mm to 600 x 800 x 700 mm, using a variety of metals. VISI Mould is used to carry out the design, while electrodes are modelled and machined with VISI Machining 3D, which is also used for cutting plates and moulding parts, along with Machining Strategist and VISI Wire.
“Our in-house team follows the mould design, adopting various solutions for mould movements, conditioning circuits, and injection and extraction systems,” says Tognon. “In order to optimise the final product and the moulding activity, we pay precise attention to the analysis, proposing possible improvements.”
Tognon says VISI is used in the preliminary stage, before the design process begins, to analyse details such as drafts, undercuts and thicknesses, and draw up possible dimensions of the finished moulds.
“We import customer STEP, IGES or Parasolid files and analyse the geometry in depth, to define the quality of the mathematical model, while correcting incomplete or inaccurate geometries.”

The company moves on to create the mould basement and define details, before sending the component parts to the different CAM stations for milling, wire cutting, and electrode modelling and construction.
Tognon cites an example of a stainless steel mould that Mecca TP has developed to replace an existing mould used by a medical sector client: “The mould was needed to produce a small circular component with a diameter of approximately 40 mm; the part had to be moulded in a white chamber on eight impressions, within a complete discharge cycle of less than 20 seconds.
The product is described as being complex, with irregular surfaces and a different front and back finish, and a shiny, mirrored surface on one side.
“We created a completely new movement, very different from the mould originally being used by the customer,” says Tognon. “Our proposal optimised the intrinsic characteristics of the impressions, and the operational flexibility, ensuring the highest level of productivity. Each imprint has a completely interchangeable matrix and punch, which are fixed to the mould by screws. This means we can replace them when they are worn out, without changing the entire mould, even if the mould is inside the machine. It also means we can produce different products using the same mould.”
Tognon says the main challenge was to find a way to free undercuts, and to create the movements necessary to obtain a high-quality piece – moulded from soft adhesive PVC – in the correct way, avoiding possible wastage. The team used VISI Analysis to import, prepare and validate what was required.
“Being able to identify complex mathematics in advance let us discover critical areas at an early stage of the project, and greatly simplified our work,” he says. “It also led to a significant reduction in both design and production times.”

Pointing out that VISI Mould handles the entire design process, Tognon says it provides the company with specific automation that guides the operator throughout the project’s development: “It’s a simple procedure, with the help of numerous catalogues of main suppliers’ components, which facilitates everything we need.”
VISI gives Mecca TP the capability of managing and graphically displaying mould creation and any required changes in real time.
“This means we can check the results immediately and effectively, giving us maximum design freedom to combat the complexity we have to face in order to satisfy our customers’ ever-changing needs.”
In conclusion, Tognon says VISI optimises the company’s entire process from design to delivery, and means the company can comply with increasingly tight delivery times: “We see very complex moulds every day. Calling them ‘moulds’ is almost reductive. I’d rather define them as ‘advanced equipment’.”
For further information www.visicadcam.com

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