Vacuum Testers for Vials Pick up Speed
A new star wheel and timing screw hasten inspection of vacuum-sealed products.
|Electro-Technic Products's vacuum tester handles 350 vials per minute.|
The quicker, the better. That's what Electro-Technic Products Inc. (Chicago) was hearing from its pharmaceutical customers, who demanded high-speed vial inspection of lyophilized and vacuum-packaged pharmaceuticals. For more than half a decade, Electro-Technic Products Inc. has been making scientific, electronic, and control instruments for research, industrial, and educational use, including manual and automated vacuum testers for nondestructive vial inspection. But the firm's existing automated design, capable of 150 ppm, could not keep up with recent customer demands for higher-speed vacuum testers.
Electro-Technic Products needed a new design, but retrofitting proved impractical. According to president Jerry Cuzelis, a complete revision of the system, including the addition of a timing screw and star wheel to control the flow of vials from the conveyor into and out of the tester, was in order.
Electro-Technic Products turned to Morrison Timing Screw Co. (Glenwood, IL) for mechanical engineering expertise in designing the new system. Their collaborative effort produced the Model VC-105A Automated Vacuum Checker, which employs high-frequency and high-voltage spark technology to ensure reliable, accurate, nondestructive vial inspection at speeds up to 350 ppm.
"While Electro-Technic Products possesses the electrical and electronic logic expertise for this system, we needed a partner with comparable expertise for the mechanical container-handling portion," says Cuzelis. Morrison proved to be the right choice.
Nick Wilson, president of Morrison Timing Screw, explains that Morrison designed, manufactured, and assembled a timing-screw and star wheel system that includes feeding, spacing, and rejection components. The system also features a mechanical interface for Electro-Technic Products's high-voltage spark testing and electronics.
"The new system's flexible container-handling design makes change- over easy for different vial sizes. And Morrison also designed the material-handling portion of the system to hold and support the Allen-Bradley PLC touch screen, which suits the new VC-105A system for user interface from front to side, or up or down," says Cuzelis.
The Model VC-105A Automated Vial Vacuum Testing System requires no operator intervention and can be adapted easily to fit into conventional, in-line batch production systems. The VC-105A detects the ionization current, not the gas glow discharge characteristics which can vary, resulting in a more conclusive test for vacuum. Special logic ensures accurate and repeatable testing and automatic shutdown under a variety of conditions.
Reject parameters can be controlled and results tabulated. Several significant design features, which have been patented under the U.S. Patent Nos. 4,546,319, 4,882,543 and 5,123,518, make this possible. These include direct detection of the ionization current of the gas using a specialized output waveform and the addition of a momentary high-intensity light flash to permit a high-speed test.
"The first model of our new system is working well at our customer's facility, and we are already working on several more for other pharmaceutical companies. Morrison is great from a design standpoint. The company revised our existing system with the timing-screw expertise we need to translate the motion of the vials from the conveyor to star wheel, and they have excellent manufacturing ability and customer service. We are very pleased with what Morrison brought to the party. We couldn't have done it without them," Cuzelis concludes.