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Additive manufacturing, also known as 3D printing, grew from startup roots in the mid- 1980s to a $2.2 billion business by 2012, according to industry consultants Wohlers Associates, Fort Collins, CO. While it took 20 years to reach the $1 billion plateau, the industry reached its second billion in just five years and is expected to double again to $4 billion by 2015. The explosion of 3D printing has yielded a compound annual growth rate of 25 percent over the last 25 years, according to Wohlers Report 2013.

Fig. 1 – Plastics compounders play a vital role in taking virgin plastic resin and enhancing its performance with key additives to meet medical industry needs.
As analysts continue to focus on strong hobbyist demand as a growth driver, 3D printing is quietly poised to revolutionize the design and production of medical devices. To some degree, it already has. In June of this year, surgeons in Malaysia successfully treated a bone deformity in the arm of a 37-year-old man using custom surgical drill and saw guides created on 3D printers at Materialise’s Malaysia production facility. The guides were matched specifically to the bone structure of this patient and produced at the Materialise site. Materialise, Leuven, Belgium, is a leading software developer for 3D printing.

A little more than a year earlier, 3D printing was employed to save an infant with a life-threatening breathing condition. Doctors at the University of Michigan designed a splint for the baby’s failing airway, obtained FDA emergency clearance, and produced the device on a 3D printer using polycaprolactone, a bioresorbable polymer. The device is expected to be completely resorbed into the infant’s body within three years.

While the technical spotlight for these surgical successes shines brightly on innovative 3D printing equipment, longterm success won’t simply turn on the speed or portability of the additive manufacturing machinery. It will depend, in large part, on the ability of designers, manufacturers, and plastics compounders to collaboratively redefine an entrenched economic model—the volume- based production process that has driven the plastics industry for decades.

For plastics compounders, the marriage of medical device design with 3D printing isn’t just a rethinking of the supply chain. It also comes at a time when device designers are shifting away from metal and toward plastic as their material of choice for a growing number of products, particularly implantables. The convergence of increased demand for plastic materials and on-demand production technology presents compounders with significant opportunities to lend needed efficiencies to medical device production.

Compounders Adapt to New Speed-to-Market Model

The shift to single-unit 3D printing, in general, means a shift away from traditional volume-driven manufacturing. For medical device manufacturers, the change isn’t simply about production quantities. Additive manufacturing replaces volume with time as the primary production driver for device manufacturers. Being able to cheaply produce a single unit is nice, but it doesn’t elevate device manufacturing to its true potential if the path to market is no shorter than with traditional manufacturing methods. This is where compounders can evolve from their traditional supply/ support role to an active partner with OEMs, designers, and additive manufacturers. Such a partnership is not only beneficial for all involved, it’s necessary to ensure quality in a condensed production timeframe.

Turning a concept and design into a product requires accuracy in material selection, a secure supply chain from raw material through finished production, and a thorough knowledge of 3D printing’s capabilities for the design and material requirements of the device. In a traditional plastics supply chain, compounders supply additives or blended masterbatches that impart a wide variety of properties (e.g., flexibility, color, heat resistance, antimicrobial, biocompatibility) to a particular plastic resin.

While selection of the right polymer for the product is certainly a critical step in this process, the polymer itself is of little use to the manufacturer or end user without compounding. Because compounding can change physical properties, designers need to know ahead of time not only the right polymer for the device, but what compounding will be performed and its effect on the resulting plastic formulation. (See Figure 1) This process has been routine for decades under the current business model where molding production usually falls neatly into one of several major traditional equipment categories (extrusion, injection, blow molding), and where volume production is expected and lead time is rarely a critical driver.

Fig. 2 – Plastic Color Corp.’s California clean compounding facility was built specifically to produce engineered-grade materials for medical devices and packaging.
3D printing changes all that, and compounders need to be ready. The compounder brings a wealth of material knowledge to the table, informing OEMs and producers about material properties and how those properties can change in a variety of compounding scenarios and real-world applications. Bioresorbable rates, elasticity, color, security tagging, and a host of other properties can all change depending on the additive mixture, production process, and field use conditions. With 3D printing’s wide variety of manufacturing equipment, base polymers and additives may need to be matched with different output devices. A compounded plastic that works with fused deposition modeling may not perform as well when subjected to the different temperatures and processes of laser sintering or stereolithography. Changes in color, physical properties, or long-term performance can result if a compounded material isn’t designed for the appropriate production environment, as well as the appropriate end use. (See Figure 2)

Coeducational Model Involves Designers and Medical Community

The ideal partnership in this new environment would be coeducational. Not only would designers, medical practitioners, and compounders work closely on material selection and development, they all would share and learn from 3D printing experts whose industry is still in its infancy. Plenty of technological change lies ahead as economic models are developed and strategic intellectual capital alliances, such as the recent Stratasys acquisition of Makerbot, help define market segments and industry needs.

When time is the driving production factor, accuracy counts more than ever. Designers, compounders, and additive manufacturers need to be on the same page from the start and need to move forward with constant communication about their processes, capabilities, and limitations. These strategic alliances would also drive economies of scale that an industry evolving around a unit production model will need for sustainability. Some traditional molders have already adopted additive manufacturing to enable rapid prototyping and quickturn production in house.

While such a move can broaden customer appeal, it cannot restrain a fundamental advantage of 3D printing— mobility. Regulatory concerns notwithstanding, there’s no reason to believe that additive manufacturing won’t eventually become embedded into hospitals, surgical centers, and device design houses throughout the world.

Even though 3D printing is early in development, supply concerns of a printon- demand world are very real. Different 3D printing processes require material in different forms. Stereolithography starts with a liquid resin. Laser sintering uses finely powdered metal or plastic material. Fused deposition modeling somewhat resembles traditional extrusion molding and uses a thermoplastic semi-solid. Custom compounding of plastics for a single- unit production basis is costly enough without having to factor for the different 3D printer needs. It’s a concern that compounders, additive manufacturers, and device designers will likely have to collaboratively address as 3D printers come online en masse in the coming years.

Additive manufacturing technology continues to develop at a blistering pace. While regulatory concerns will remain an issue for years to come (for example, how can the FDA effectively regulate a device that wasn’t needed until a surgery was underway?), there can be little doubt that 3D printing will continue to significantly alter the medical device world. The promise of ondemand production for the medical device market lies not just in quick-turn production but in quick-turn application— from design to production to the patient environment in the shortest time possible. If 3D printing is going to realize its potential and truly revolutionize device manufacturing, the supply and support relationships that have fed plastic manufacturing’s volume model for decades need to change. Compounders are in an ideal position to drive that change.

This article was written by Timothy Workman, Vice President of Business Development, Plastics Color Corp., Calumet City, IL. For more information, visit http://info.hotims.com/45608-160.