As industries such as medical, electronics, automotive, and optics demand increasingly smaller, more intricate components, the pressure on micro moulders to deliver high-precision, high-quality parts has never been greater. Quality assurance in micro moulding is not just a desirable attribute; it is an absolute necessity.
Also read: Micro Moulding: Delivering Precision and Scalability for Industry Leaders
The Challenge of Miniaturisation in Micro Moulding
As micro moulding technology advances, parts are becoming increasingly smaller, often with features that are difficult to see with the naked eye. According to Cara Bloom, Senior Quality Engineer at Accumold, "as parts get smaller, generally the tolerances get smaller as well." This presents a unique challenge, as maintaining consistent quality assurance in micro moulding at such minuscule scales requires extreme precision. The margin for error is practically non-existent.
Micro-moulded components are used in applications where failure is not an option. Whether it is a microfluidic medical device, a micro-optical lens, or a high-frequency RF component, even the slightest deviation from the intended design can compromise performance, functionality, or even safety. This means manufacturers must invest in sophisticated metrology and validation processes to ensure that every part meets exact specifications.
Embedding Quality Throughout the Micro Moulding Process
At Accumold, quality assurance in micro moulding is not an afterthought; it is embedded into every stage of production. The company’s vertically integrated approach ensures that validation, metrology, and quality control are seamlessly integrated from the initial design phase through to final production.
A key aspect of maintaining quality in micro moulding is having the right metrology tools. "We need to have equipment that can handle the precision and accuracy needed by these challenging projects," says Bloom.
For exact projects, Accumold utilises Zygo’s NewView 8300 Optical Profiler, a non-contact white light interferometry system capable of sub-nanometer precision. This technology allows for the measurement of critical features such as lens prescriptions and flatness values, some of which have tolerances as tight as tenths of a micron.
The Role of Accurate Measurement in Micro Moulding
One of the biggest mistakes companies make when selecting a micro moulder is assuming that if a manufacturer can mould a part, they can also measure it effectively. However, micro metrology presents its own unique challenges—if you cannot measure it, you cannot make it.
This highlights the importance of integrating measurement development into the early stages of product development. Accurate and repeatable measurements are essential for process validation, ensuring that moulded parts consistently meet design intent.
At Accumold, measurement development and Gage Repeatability and Reproducibility (Gage R&R) studies are key components of the company’s quality assurance process. By working closely with customers on design for manufacturability (DFM) and design for micro moulding (DfMM), Accumold helps optimise part designs for both mouldability and metrology.
Overcoming the Challenges of Micro Moulding Quality Assurance
Achieving quality in micro moulding is far more complex than in traditional injection moulding. One major challenge is part size and tolerances. Micro-moulded parts can be dimensioned in microns, with features that require magnification of 10x or greater to even be visible. Measuring such small parts demands non-contact methods such as laser scanning, white light interferometry, or high-resolution vision systems.
Another challenge is part fixturing. Ensuring repeatable and reproducible measurements requires precise fixturing. At Accumold, custom steel or 3D-printed plastic fixtures are designed in-house to securely hold parts during measurement, ensuring accuracy and consistency.
Surface roughness also presents a challenge, especially in applications such as optics and medical devices where surface finish is critical. Traditional tactile measurement tools can alter or damage the surface of delicate micro parts, making non-contact metrology the preferred method. As already mentioned, white light interferometry allows Accumold to measure surface roughness without compromising part integrity.
Additionally, there is an ongoing discussion regarding in-lab versus in-process metrology. While traditional metrology was often confined to lab environments, modern micro moulders increasingly integrate in-process metrology for real-time quality control. Accumold strategically assesses metrology requirements based on part complexity, volume, and tolerance levels to determine whether in-process or lab-based measurement is most appropriate.
Continuous Improvement in Micro Moulding Quality Assurance
Ensuring consistent quality in micro moulding is an ongoing effort. As new metrology technologies emerge, micro moulders must continually evaluate and adopt new equipment and methodologies to stay ahead.
"We continually evaluate new equipment that may help us improve our measurements, either in efficiency or accuracy, as new metrology equipment enters the market," Bloom explains. This commitment to continuous improvement ensures that Accumold remains at the forefront of micro moulding quality assurance.
Additionally, automation is playing an increasingly vital role in micro metrology. Automated vision inspection (AVI) systems, integrated into moulding processes, allow for rapid, repeatable inspections without human intervention. This reduces variability and increases throughput, ensuring that quality control keeps pace with high-volume production demands.
For companies looking to leverage micro moulding, the emphasis must always be on quality. It is not enough to select a manufacturer based solely on cost or turnaround time—quality assurance in micro moulding must be the defining factor.
When evaluating a potential micro moulding partner, it is crucial to assess their metrology capabilities, ensuring they have the necessary equipment and expertise to measure parts accurately. Process validation should also be a key consideration, with quality control integrated throughout the entire manufacturing process.
Collaborating with a micro moulder that prioritises design for manufacturability and metrology optimisation ensures that the final components will be both functional and precise. Furthermore, a commitment to continuous improvement and investment in advanced quality control methods are indicators of a reliable and forward-thinking micro moulding specialist.
Summary
The fundamental requirement for quality assurance in micro moulding cannot be overstated. As parts shrink in size and tolerances tighten, manufacturers must ensure that their chosen micro moulding partner has the expertise, technology, and commitment to deliver precision without compromise.
By prioritising metrology, process validation, and continuous improvement, micro moulders can ensure that every component meets stringent requirements, reducing risk and enhancing overall product performance.
In a world where quality is non-negotiable, choosing a micro moulding partner that takes it seriously is the only viable path forward.
