How Sumitomo (SHI) Demag’s IntElect injection moulding machines are meeting the needs of tomorrow’s medical micromoulding market

by

Sam Carr, UK medical specialist, Sumitomo (SHI) Demag

By 2026, the global micro injection moulded plastic market is projected to reach USD1,692 million, at a compound annual growth rate (CAGR) of 11.2 percent from 20211. This boost in demand is largely attributed to significant activities and developments in the medical, health care and wellbeing sectors.

Aside from the pandemic, much of this growth is being driven by advances in the home healthcare sector and an aging population, which the WHO predicts will double by 2050. The ensuing paragraphs explore the opportunities this presents and how Sumitomo (SHI) Demag’s smaller tonnage IntElect direct-drive, all-electric injection moulding (IM) machines are responding to evolving production requirements. (Image 1)

Manufacturing extremely small, high-precision thermoplastic components with micron tolerances is an art. In some instances, components can be as small as a single grain of granulate. The limit of what can be moulded can be as light as 0.0003 g, with walls as thin as 0.0004 in (0.0010 cm) and dimensional tolerances to ±0.0005 in (0.0013 cm).

Typical items being micromoulded using this technique can comprise a wide range of surgical, endoscopic, point-of-care (POC) testing, diabetes management, drug delivery and DNA research and sequencing devices. Additionally, the expanding market includes catheter components, hearing aids, dental prosthetics, microfluidics, vials, caps, specimen cups, vacuum blood and serum collection tubes, syringes, and IV parts. One thing these applications all have in common is their diminutive size and their need for total accuracy and zero defects during the moulding process.

In reality, the process of injection micromoulding is not vastly dissimilar to creating larger parts. Shot-to-shot precision is where the main difference lies. If more material is allowed under the check valve on a 10 g part, it is not a huge issue. However, if the part weight is 0.1 g, it becomes a major problem.

Historically, injection micromoulders would have invested in really specialist plunger systems or hydraulic machines. The latter meant dealing with variations in oil temperature and compressibility. Those drawbacks are removed from the equation with the new generation of all-electric machines. The IntElect machines afford exceptional control, which enables them to deliver maximum precision as well as offering full mould safety so that the most sensitive cores and mould details are not damaged.

Last year, männer, with support from the Sumitomo (SHI) Demag medical team, developed a pipette tip production cell featuring an innovative cluster mould cavity concept and unique hot runner nozzle tip system. The accelerated injection speeds is testament to the level of control that can now be accomplished with these machines. Indeed, the IntElect S 130T cleanroom model, equipped with its highly dynamic, direct-drive motors, is one of the few compact, all-electric machines on the market with the mould space to accommodate a 64-cavity cluster tool and demoulding robotics. (Image 2)

The IntElect series thrives in the smaller tonnage as well as the mid-size range, with the ability to supply screw sizes as small as 14 mm on the 50T and 75T machines. This combination enables users to accomplish small shot weights but with the fine control that is required with micromoulded components. For increased production capacity, some moulders then opt for a larger screw and barrel to allow them to mould larger parts.

Meeting GMP requirements

Any airborne contaminants, such as dust and particles from the raw materials, as well as human contaminants like bacteria, could affect the function of a medical component. Although cleanrooms are not a requirement for all micromoulded parts, medical components should be manufactured and packed in a self-contained cleanroom environment to meet ISO Class 7 or 8 standards and comply with any GMP and FDA regulations. Design qualification (DQ), installation qualification (IQ) and operational qualification (OQ) documentation is automatically issued on installation of IntElect machines.

Many IM machines have complex, automated, end-of-arm tooling systems to remove medical device parts without damaging them. Moreover, vacuum extraction systems are often integrated within the automation cell to remove the parts, many of which can be smaller than a match head, to prevent them getting lost in the IM machine or falling to the floor. Additionally, these features prevent operators coming into direct contact with the parts, which could result in contamination.

Ionisation within the cell is another important consideration. This is not just to keep the parts clean, but to keep the static out to ensure they do not stick together. The latter makes it easier for robots to handle the process and pack the components.

Flexibility and design freedom

The smaller tonnage IntElect units are geared towards the mass-production of medical microparts and accommodate a variety of tool configurations. The ability to install smaller 14 mm screws that have a large tie bar distance and mould space is a huge advantage for micromoulders. This level of control is made possible by the highly dynamic, direct-drive technology and advanced toggle system. Acceleration of the injection speed enables the IntElect to fill up to as many as 96 microcavities with precision, ensuring higher quality components are produced consistently. (Image 3)

Energy efficiency and total cost of ownership (TCO) are also greatly enhanced by the high-performance drives. Verified by extensive machine and part lifecycle durability tests, the clamp spindles were tested under the most extreme conditions and showed no evidence of visible wear, even after millions of cycles.

Increasing the capacity of the IntElect’s energy recovery system has not only improved energy efficiency but also extended the longevity of electrical components. Improved temperature control of the machine’s spindles, motors and inverters all help to guarantee safe operation of the machine, even for the most demanding micromoulding applications.

The more consistent operating temperature means that energy consumption is lower and less heat needs to be removed from air-conditioned environments, helping to reduce operational costs and increase profit margins. 

Furthermore, the introduction of strict user parameters ensures that explicit medical component quality assurance (QA) and validation standards are consistently adhered to. The key areas that might impact a stable process include changes in pressure, temperature, flow rate and cooling rate. If these are altered in any way, it can trigger a costly re-validation exercise. By limiting the range on what an operator is authorised to adjust, validated micro medical injection moulding processes can be maintained.

Predicting the future

In today’s globalised, multi-site medical component production facilities, the ability to monitor and reconcile data from numerous machine sources is now imperative. Having access to this data via a single gateway can assist production managers to better manage inefficiencies, reduce costs, improve TCO, troubleshoot, resolve equipment issues and minimise machine downtime.

Advanced batch tracking, contact-free inspection using cameras and highly automated assembly are among the latest developments to meet the market’s precision and quality control (QC) requirements. During the last 24 months, IntElect machine features such as remote diagnostics have been well-adopted by customers as they strive to maintain operational efficiency and save money while adhering to health and safety guidance and ensuring machine assets are safeguarded.

Matching market advances, exciting new processing features and digitalisation projects are already filtering through the Sumitomo (SHI) Demag R&D pipeline. One of the new features on the immediate horizon for IntElect machines is an internet-of-things (IoT) dashboard. The ultimate vision is an intelligent machine that can independently make predictions about part quality, machine wear and failures, and perform optimisations online.

Rapid microsurgical, nanotechnology, microoptics and microfluidics developments will inevitably increase demand for polymer injection micromoulding throughout Europe. As moulding companies continue to size up the opportunities, Sumitomo (SHI) Demag will continue to adapt its machinery lineup to meet growing demands.

Sumitomo (SHI) Demag

http://uk.sumitomo-shi-demag.eu

Reference1Lekhak, S. (2022). Micro injection moulded plastic market. [online] MarketsandMarkets.Available at: https://bit.ly/3nFTyjb