For companies that are exploring the possibilities that exist for miniaturisation of plastic parts and components, there are some seemingly daunting obstacles that exist, not least the vagaries of the micromoulding process itself. Moulding at the micro scale renders redundant many of the rules associated with macromoulding, and the process requires a completely new perspective in terms of considerations such as rheology, tooling, gating and handling and assembly, to name but a few. Because of this, most OEMs that embark on a micromoulding product development process engage with specialist micromoulding experts that can navigate inherent issues and through experience have honed the art of micromoulding to optimise manufacturing outcomes.
Craig Tappe has been with Accumold for nearly eleven years; he has worked as a machinist, lead toolmaker and today is one of the company’s sales engineers. In this interview, he discusses various aspects of the micromoulding process and why it is important to ensure that the correct questions are asked when shortlisting preferred suppliers.
What is design for micromoulding (DfMM) and how does it play a crucial role in the success of a micromoulding project?
Craig: DfMM refers to the process of developing and optimising designs specifically tailored for micro-scale injection moulding. Micromoulding is a highly precise manufacturing technique used to produce miniature plastic parts with intricate details and dimensions in the micrometre range. Designing for micromoulding involves considering factors such as material selection, part geometry, tooling requirements and process limitations unique to micro-scale production. The goal is to create designs that maximise manufacturability, ensure quality and enhance functionality of the part within the constraints of micromoulding technology. Attention to detail, such as minimising wall thickness variations, incorporating proper gating and venting, and addressing potential issues related to part ejection and mouldability, is crucial in achieving successful micromoulding outcomes.
DfMM is critical in the success of micromoulding because often the challenges of moulding microfeatures require complex tool designs that test even the most experienced and well equipped toolrooms in the world. Accumold works upfront with customers to focus on thin-walled features, techniques for designing and moulding undercuts, and material selection. Most of our customers don’t realise the extreme capabilities we have when it comes to feature sizes, thin walls, and feature definition on micromoulded parts.
What are some of the challenges faced when transitioning from prototype development to large-scale production in micromoulding? How does Accumold address these challenges effectively?
Craig: Transitioning from prototype development to large-scale production in micromoulding can present several challenges. One of the key difficulties is scaling up the production process while maintaining the same level of precision and quality achieved during prototyping. Factors such as material behaviour, tooling design and process parameters need to be carefully optimised to ensure consistent and reliable production. Additionally, issues related to cycle time, cooling and part ejection become more critical when moving to large-scale production, as they can significantly impact productivity and cost efficiency. Managing the increased complexity of tooling, maintaining tight tolerances and addressing potential defects or variations that may arise during high-volume manufacturing are also crucial challenges. Effective communication and collaboration between designers, engineers and manufacturers become paramount in overcoming these hurdles and achieving successful large-scale production in micromoulding.
Lots of times, prototype moulders will ask for part design changes that will eliminate microfeatures on parts as their tool machining processes are unable to achieve the required tolerances. Accumold produces hard steel prototype tooling with electrical discharge machined cavity/core details to produce prototype parts with final production-like quality.
In your experience, what are the key factors to consider when selecting a micromoulding company that has the capacity to scale up to large-scale production? How does Accumold demonstrate this capability?
Craig: When selecting a micromolding company with the capacity to scale up to large-scale production, several key factors should be considered. First and foremost, the company’s expertise and experience in micromoulding at larger volumes is vital. They should have a proven track record of successfully transitioning from prototype development to high-volume manufacturing. Additionally, the company's manufacturing capabilities, including advanced machinery, quality control processes and ability to handle increased production demands, should be assessed. Effective project management, strong communication channels and a commitment to continuous improvement are also important factors to ensure a smooth transition and sustained success in large-scale micromoulding production.
More specifically, look for a large onsite toolroom that can handle multiple large projects at once, sustainability initiatives (recycling plastic), on-site automation team/capabilities to reduce cost and open production floor space/press capacity to scale quickly. Accumold has everything I just listed.
Can you provide examples of how Accumold has successfully managed to scale up from prototyping to large-scale production while maintaining quality and efficiency?
Craig: The key requirements for a micromoulding company to successfully scale up from prototyping to large-scale production while maintaining quality and efficiency include expertise in micromolding at larger volumes, advanced manufacturing capabilities, effective project management, strong communication channels and a commitment to continuous improvement.
At Accumold, we’ve taken multiple projects for fortune 100 medical companies from the early engineering/DFM stages into prototyping on one-cavity tooling, then into full-scale production with multiple 16 and 32 cavity tools. We currently run projects with 200 million part-per-year volumes and have capabilities/scalability to produce billions of parts per year.
What are the advantages of vertical integration when micromoulding? How does Accumold leverage vertical integration to enhance its capabilities and provide better value to customers?
Craig: The advantages of vertical integration in micromoulding include enhanced control over the entire production process, improved coordination between design and manufacturing stages, reduced lead times, better quality assurance and increased cost efficiency. We vertically integrate our tooling, automation, processing and quality systems at Accumold to provide a very logistically smooth and easy process for our customers. This vertical integration allows us to hold quick lead times and efficiently collaborate to solve problems and produce quality products.
How does collaboration between design teams and micromoulding experts facilitate the optimisation of product design for the micromoulding process? Can you share any success stories where this collaboration led to significant improvements?
Craig: We work with customers to establish part designs that are not only ideal for the finished product but fit well with the moulding process. This combination allows for a robust manufacturing solution and consistent part quality. We run mould flow simulations, provide feedback on snap features, work to provide solutions for moulding complex undercuts and share our expectations for finished part characteristics based off microfeature designs.
We worked with a wearable diabetes patch maker to redesign the cannula portion that is inserted into the patient’s skin that the insulin is dosed through. The old cannula design was an expensive multi-step manufacturing process. It used a polyimide tube that had a tipping and flaring operation and a separate hub that this polyimide cannula was glued onto. These parts had lots of fallout and quality issues from the gluing and were very expensive. Accumold worked in our innovation lab to provide a solution for this problematic, thin-walled drug delivery cannula. We were able to produce a single piece cannula that fit our customer’s design requirements and is produced at a fraction of the cost.
What role does quality control play in micromoulding, especially when scaling up production? How does Accumold maintain consistent quality throughout the entire manufacturing process?
Craig: Quality is very important. We utilise automation wherever we can during the process to reduce human error. Some of our tool build processes use automation, our electrode cutting, electrode measurement and touch off systems utilise automation to eliminate human error and ensure that every cavity from tool to tool are identical for high-volume projects. The electrodes are used to electrical discharge machine the fine cavity/core details into our mould steel. All our production cells use automation and most of our measurement techniques utilise automation as well. Accumold has strict preventative maintenance and calibration standards on all equipment and tooling.
How does Accumold stay up to date with the latest advancements and technologies in micromoulding? Can you discuss any recent innovations that have significantly impacted Accumold’s operations?
Craig: We are constantly attending technology and equipment trade shows to ensure we have the latest and greatest equipment on the market. A year or two ago we brought in our first (we have two now) Nano Dimension Fabrica 2.0 additive micromanufacturing machines. This has helped us with rapid front end prototyping for low-cost quick turnaround front end development. We are now close to utilising this technology for 3D printed prototype tooling. We plan to use a new high temp 3D printing resin to 3D print the mould core and cavity components for prototype tools.
Can you share some micromoulding insights, such as likely changes in demand/markets? How is Accumold preparing for these anticipated changes?
Craig: All components are getting smaller and multiple functions are being designed into each component. Wearable medical devices, microelectronics and surgical tools are just a few markets in which components continue to get smaller and smaller. Accumold works to stay on top of and bring in new capabilities as soon as they are available. We also have an innovation lab specifically dedicated to providing solutions to challenging moulding projects that we foresee potentially coming our way in the future.
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