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Currently, to test new formulations of gel capsules at Pfizer, they must use the large-scale machine that requires a minimum of 25 kg of gel melt and produce hundreds of capsules per run. Production at a smaller scale to enable rapid changeover for research and development is desired. The team’s goal was to achieve continuous production of sealed capsules with 80% fill capacity. Capsule sealing was the prime consideration. Preliminary trials using the existing system and heat transfer analysis indicated localized heating was necessary to promote capsule sealing. To provide localized heating, a brass wedge was designed based on the pilot scale machine. The machined wedge was integrated with a PID control system. Using pre-made gelatin ribbons, the appropriate process parameters to achieve sealed capsules were determined. The critical, coupled parameters were die roll temperature, wedge temperature, wedge height, and die roll speed. Capsule sealing efficiency was highest at a speed of 4 capsules/min. For air-filled capsules, a sealing efficiency of 100% was achieved. For PEG-400-filled capsules, a sealing efficiency of 50% was achieved. Future work will include integration with the gelatin feed system and addition of a vacuum during capsule formation to increase fill capacity.

Publication Date



Gel capsules, heat transfer, encapsulation, temperature control


Chemical Engineering | Engineering

Faculty Advisor/Mentor

Christina Tang

VCU Capstone Design Expo Posters


© The Author(s)

Date of Submission

May 2018

Development of a Tabletop Soft Gel Encapsulation Machine