Medical device manufacturers are increasingly adding automation to their processes, especially for molding silicone and other materials, to reduce costs, increase quality and safety, and hit delivery times for medical device components. Due to its versatility and biocompatibility, silicone is the material of choice for many medical devices, and automation is key to the silicone molding process, delivering absolute consistency and high-volume output for the applications that need it.

Design for manufacturability

Design for manufacturability (DfM) is the first consideration because of its significant time and cost savings. It’s imperative for medical device manufacturers to partner with molding vendors early in the design process to ensure the most cost-effective solutions. Often, a simple change to a part design will have no impact on the performance of the final piece, but will heavily impact the cost and time to manufacture it.

For example, sharp corners should be avoided in many part designs because they require high-injection pressure that can lead to more internal molded-in stress. Rather than adding venting to prevent a short shot being formed in the corner, redesigning a sharp corner to be more rounded increases the material flow. This reduces the injection pressure and minimizes the likelihood of a short shot.

A strong DfM practice, combined with a close partnership with your injection-molding vendor, can improve consistency and quality on a medical device production line, as well as the overall device performance.

When evaluating molding partners, medical device manufacturers should consider the suppliers’ existing and planned automation capabilities, capacity, in-house technical expertise, quality performance, certifications, and ability to add value to the product and development process.

Enhanced quality

Automation helps overcome potential manufacturing issues, such as short shots (underfilling the cavity), voids in parts due to air trapped in the cavity, and parts that are out of tolerance, either too large or too small. Automated manufacturing lines can be carefully calibrated to produce parts with high accuracy and speed and can minimize the possibility of distortion and tearing as parts are removed from molds.

Automated manufacturing is the first step toward Industry 4.0 or the Industrial Internet of Things (IIoT). Sensors on critical production equipment alert operators in real time to even fractional changes in critical processing parameters, preventing the manufacture of hundreds or, in some cases, thousands of incorrect parts.

Alerts currently prompt human intervention to diagnose and fix problems.

Soon, sensors will notify the equipment’s programmable logic controller (PLC), which will make the necessary adjustment without human involvement. In the future, even more sophisticated systems will employ preventive maintenance to analyze trends that indicate something is likely to slip out of spec within minutes or days so adjustments can be made before incorrect products are produced.

Companies manufacturing products at quantities too low to justify full automation can still take advantage of this technology. For example, product inspection and verification can be automated using cameras or automated pressure tests.

Delivery improvements

A third major reason to add automation to medical device manufacturing is its ability to improve delivery.

Enables constant cycle time; it doesn’t slow down due to worker fatigue or distraction

  • Free from repetitive tasks, shop-floor personnel can focus on process improvement, efficiency
  • Can feed into analytical systems, such as overall equipment effectiveness (OEE)

OEE measures availability, performance, and quality and an OEE score of 100% represents perfect manufacturing; only good parts, as fast as possible, with no downtime. OEE dashboards can be created or purchased and provide an accurate way to gauge how an automated cell is performing. Having real-time OEE enables those with in-depth knowledge of the manufacturing process to identify the root cause of deviations and slowdowns.

OEE and other analytic systems can also be used on semi- automated lines, enabling adjustments for expected downtime.

Increased scalability

Automated manufacturing makes financial sense for many processes used in medical device manufacturing because it can usually run faster than manual operations and has very little downtime. Maintenance, however, plays a vital role in the long-term success of any automation project, and it requires a robust and well-trained maintenance team.

The increased throughput enabled by automation can be significant, even when upgrading from a semi-automated cell to a fully automated one. For example, the number of parts produced per hour can more than triple.

Safety improvements

If needed, manual operations are generally made safe by including multiple fail-safes to protect operators. However, automation is inherently safer as it lessens the need for manual intervention during the manufacturing process. Sharp objects used to slit silicone, hot molds, and other possible dangers are common in medical device manufacturing. In these cases, even simple automation can prevent injuries.

Conclusion

Selecting the right molding partner that’s experienced in automation can improve production efficiencies and quality while reducing the total cost of ownership and speeding the time to market, especially when that partner is engaged early in the development process. Medical device manufacturers should do their research and ask questions. The upfront time spent evaluating suppliers will pay dividends later as products are scaled up to high-volume production.

Trelleborg Healthcare & Medical
https://www.trelleborg.com/en/healthcare

About the author: Chris Tellers is the director of engineering at Trelleborg Healthcare & Medical. He can be reached at chris.tellers@trelleborg.com.