ATP Enclosures Multitask, Lower Cost
The pharmaceutical and medical packaging industry continues to shift from traditional, single-purpose packaging to multifunction enclosures. Combination devices reduce material goods and lower costs for clients while appealing to consumers for their utility space reduction.
ATP Engineered Rubber & Plastics Group (Wayne, PA) recently developed a combination presentation tray and tool-holding system for restorative and aesthetic dental devices. The product posed logistical challenges to ATP, including determining program timing, material selection, color matches, assembly, and silk-screening. ATP’s client also needed the tray (and lids) in several sizes and assemblies. The most formidable challenge, however, required ATP to construct a device that could withstand repeated point-of-use sterilizations.
Polyphenylsulfone was chosen as the engineering plastic for the tray and cover because of its clarity (for the cover), its coloring characteristics (for the tray), minimum sink rates, ability to withstand repeated steam sterilizations, and its toughness and impact resistance. Another advantage of this resin was its ability to tolerate heat produced during the silicone overmolding process.
ATP used self-bonding silicone to give the trays a soft outer texture, needed for aesthetics, impact resistance, color stability, and ability to maintain material integrity during sterilization. Silicone, which plays an increasing role in healthcare because of its manufacturing versatility and unique chemical structure, tends to flash even with adequate shutoff systems and clamping forces. Instead of a two-shot mold, which better suits higher-volume applications, ATP first produced the plastic trays and then manually transferred them to the liquid-silicone injection machine in a batch operation. ATP engineers elected not to use pick-and-place robots to transfer the trays because different-sized trays created longer changeover times for the robots.