The reusable shipper consists of three US-made components: a high-density polyethylene (HDPE) corrugated box, vacuum-sealed insulating panels with an R value of 40, and biodegradable phase-change material ("Greenbox" insulated shipper, Entropy Solutions , Minneapolis, MN).
The shipper's insulating panels use nanotechnology to slow the transmission of heat or cold. A tortuous path through pores of carbon silica compresses a high level of protection into a narrow space ("Thermal-Lok" insulating panels, Entropy Solutions).Phase-change material is supplied in a rigid plastic container ("E-Pack," Entropy Solutions) or flexible pillow pouch. The material shifts from liquid to solid or vice versa at preset temperatures. In this way, various combinations of color-coded packs or pouches maintain the shipper's contents within a narrow temperature range. Color-coding also expedites packing of shippers and reduces the chance of packing errors.
Small, medium, and large stock-box sizes offer payload areas of 288, 600, and 1,156 in.3, respectively. The small and medium boxes are rated for 72 h, the large size for 96 h. Entropy Solutions is developing a 30-day box that can be used as a mobile vaccine center.
Extremely durable components made of tough plastics and other materials allow shippers to withstand 100 trips or more. If a shipper is not used in a closed-loop system, the recipient sends it to a reclamation center where it is inspected, cleaned, and returned for reuse. If a component fails, the recipient returns it to the manufacturer for recycling. After a shipper's last use, all components (i.e., the box, insulated panels, and phase-change material) are recycled.
Reusable shippers provide great savings compared with traditional foam-based insulated shippers. Savings come from the elimination of overnight shipments and waste, minimization of product loss caused by temperature abuse, reduction of packing time, and reduction in warehouse space requirements. Based on a lifetime of 30 trips, the Greenbox cuts costs by an estimated 65% compared with traditional insulated shippers.
Coldchain Technology Services (Spring Branch, TX), a provider of consulting and logistics services, is one early adopter of the reusable system. The company uses the system exclusively to ship temperature-sensitive products, primarily vaccines, to its customers. The firm maintains 100 shippers for one medical group that sets up mobile flu-shot clinics for businesses and other organizations. At press time, each shipper had made an average of 10 trips.
"They still look brand new," reports Wayne Williams, Coldchain's executive director. "Even if something happened, for example, the outside shell got ripped or cut, you just replace that. You never have to replace the entire system unless it accidentally gets thrown away instead of being returned. [After one trip,] foam-based insulated shippers may change and no longer meet standards. We know Greenbox doesn't change at all."
The corrugated HDPE shipper establishes the narrow 2–8 °C temperature window that flu vaccine requires and maintains it for at least 72 h. Companies can thus use ground shipping rather than expensive overnight delivery services. The corrugated HDPE shipper is about 50% lighter than traditional insulated shippers. Its light weight reduces shipping costs and makes it easier for one person to handle.