Shaping the future of micro moulding

The world of micro moulding can be complex and varied. Aaron Johnson, Accumold, talks us through the changing face of the technology and how the business reacts to present and future manufacturing needs.

Accumold has been using its micro moulding expertise for over 20 years. How has medical manufacturing changed over that time and how has micro moulding been able to adapt to those changes?

In the mid-1980s as Accumold was beginning, the height of microelectronics was embodied in devices like Motorola’s, grey, ‘brick’ cell phone. It was big, practically took two-hands to use, and only made phone calls. But as time has shown, advancements in electronic design, computing power and software development ushered in the highly-sophisticated and complex devices we know today. Medical device manufacturing is an offshoot of these advancements and the industry is only taking advantage.

The medical device manufacturing industry may have been slower to commercially adopt the latest technologies, the demand within however was not. R&D departments followed right along with consumer electronics as these companies looked to make their products better for doctors and patients. Of course, there are all sorts of good and obvious reasons why medical devices take their time to reach the market, however, the medical device industry is full-steam ahead on providing the best diagnostics and care products possible through as many technological advancements creativity will allow.

What Accumold has observed over these years specifically in medical device manufacturing has more to do with the services around micro moulding than the moulding itself. Initially it’s the micro moulding technology that creates interest. We have seen tremendous growth in the medical space as the OEMs surge growth through technology. Reducing form factor, wall thickness, cost and other major trends in device design have grown the need for micro plastic parts and components. But what we’ve seen lately, behind this miniaturisation drive, is the growing demand for scalability and sustainability.

The tremendous pressures medical OEMs are under today when dealing with regulations, reimbursements, and the politics of it all, are trickling down to the suppliers like never before. This pressure has changed what medical OEMs demand from their supply base. Not that long ago it was just preferred that suppliers were ISO 13485 certified, had cleanroom facilities or were capable of IQ/OQ/PQ strategies-now these kinds of services are flat-out necessary if a suppler wants to participate in this market. 

Along with the increase in demand for services from suppliers, medical OEMs are experiencing a lot of consolidation efforts. Not only consolidation through acquisition of other companies, but consolidation and/or reduction in the supply base. Risk management has driven medical OEMs to take longer and harder looks at suppliers. The risk is not just quality. With all the economic pressures the OEMs can’t afford any time wasted with a supplier that can’t provide the best of services.

What do you see as the biggest challenges in manufacturing at the moment and how does micro manufacturing help overcome them?

Micro moulding has enabled device designers to break barriers between the possible and the impossible. Because advancements in computing power and electronic device design is capable of some incredible computations and analysis, the form factor designs need to keep up. For example, medical devices like blood glucose monitoring need to find the most efficient ways to deliver samples to the sensor. This design constraint pushes the limits of the supply base to produce smaller and smaller features, in complex little carriers, all while being disposable. Traditional moulding methods may fall short when working to achieve high precision micro structures for these kinds of applications.

What design characteristics can present the biggest challenges for micro moulding? How do you go about overcoming them? What decisions influence material choice?

While micro moulding can produce some very complex micro-sized parts, there are limits to what can be achieved. The most common constraints usually fall in designs with thin-wall sections and high aspect ratio features. A lot can be achieved. One can ‘technically’ build the moulding tools with these features. However, once the material is introduced to the process several challenges occur. Sometimes a desired feature would require such long, thin steel that during the moulding operations the tool would simply break. Long, small diameter core pins have the same problem. The steel is just too fragile at times for the pressures of the moulding process.

In addition to the fragile steel, most often the challenge is the material itself. There is such a variety of materials to choose from and they will all reach to filling small spaces differently. It’s literally the physics getting in the way. We have found there is a direct correlation between the material choice and the feature performance of a given design.

To solve this challenge projects must start with a design for manufacturability (DFM) phase. The first question our engineering team asks after looking at the model and drawing is, ‘what’s the material?’ We know from our vast experience what materials have what chance of filling any given geometry. Working though this DFM process will not only address any material concerns, it will also walk through the design to ensure the best opportunity for success is developed.

The biggest challenge is when the chosen material is just not compatible with the design. It’s very common for PEEK to be chosen for many medical applications because of its natural properties. The problem is, it can push like cement into small spaces. Not all the same extreme features can be accomplished with PEEK that an LCP, PC or other higher-flowing materials will. This can be frustrating since the desired geometry can be achieve, just not with the desired resin. In these cases, compromises are usually made to ultimately build the device.

How big a part does cost play in the overall manufacturing process?

Cost of course, is always of concern. Everyone wants to maximise the efficiencies of any given project. The challenge comes when there is a disconnect with the value. It’s common for one to expect that since micro moulding makes small plastic parts they should be cheap - at least cheap in relation to larger, less complex moldings. The general rule is the smaller, more complex, and/or the tighter the tolerances, the higher the cost can be. The infrastructure to produce micro moulded parts can be quite sophisticated. Sometimes part handling or measuring dimensions can be more challenging then the moulding itself.

It’s not only piece part price that can be more expensive, the tooling and engineering also requires expert tool builders and equipment to achieve such fine details. Cutting steel to microns is skill that can require more time in the tool shop then less detailed work. It’s a very delicate process to produce such tooling.

In the end, micro moulded parts are usually designed to achieve more. Reducing the form factor, or adding more functionality to a device should more than make up for the costs involved in producing them.

What steps do you take to maximize performance of the part?

At Accumold we tend to work from the end goal first. During the DFM process we will often ask questions about the desired goals for any given project. Understanding the annual volumes, critical features, or areas of concern in the beginning, help ensure a robust process can be developed. The more we know about the part, its function, and environment the more we can drive to efficiencies. In addition, we will suggest a quality plan so everyone knows what success will look like.

In the UK and Europe we are hearing more and more about Industry 4.0 - what’s Accumold’s take on this and how do you see it affecting manufacturing processes going forward?

At Accumold Industry 4.0 is already well integrated. Many years ago, we began developing systems and processes around connected machines and organised data to help us achieve and stay competitive. Manufacturing in the US has changed a lot from decades past and we saw the kinds of innovations Industry 4.0 is encouraging as necessary for survival. There is no doubt the future of manufacturing is heading more and more that way.

As a service provider how do you go about offering more than just manufacturing?

At Accumold we are deeply committed to three things – capability, scalability, and sustainability. We have worked hard to provide the most innovative micro moulding capabilities we can. We know it can’t just stop there. In today’s manufacturing world there is little room, if any, for disruption. That’s why building an organisation that can grow with our customers and sustain the years to come is as important as the moulding capabilities themselves. We’ve tripled our facility in the last five years. Our latest addition is a hardened structure designed with dedicated resources to provide assurance of supply. We believe our customers need to know they can rest assured when they partner with Accumold - their future is ours too.