Vibratory feeders are widely used in blister packaging machines, especially continuous ones.
The vibratory feeder generally consists of a hopper, a linear vibration conveyor, a disk vibration conveyor, and a groove plate. The medicine falls into the linear vibration conveyor in the hopper and is then transferred to the disc vibration conveyor by the linear vibration conveyor. The medicine is placed on the disc. The conveyor moves in a circular motion. There is a row of drop holes on the disc-vibrating conveyor. When the medicine passes through the drop holes, it falls into the groove plate below. The bottom of the groove plate is aligned with the pockets of The formed web, and finally, the drug enters the blister pockets through the groove plate.
The formed web of the continuous blister machine moves forward uniformly, continuously bringing the medicine out of the groove plate and into the pocket to achieve blister filling. If it is an intermittent blister machine since the formed web operates intermittently and runs at high speed, if the drug is taken out directly from the groove plate at this time, it will cause feeding failure because the drug may be broken due to impact or Jump out of the pocket; to improve this unstable situation, engineers have improved the groove plate, that is: when the formed web runs forward, the groove plate takes the web as a reference and advances synchronously at a slightly lower speed than the web. At this time, the web at the bottom passes by at a constant speed for the groove plate, and the medicine is evenly taken out of the groove plate and into the pocket. When the web is stationary, the groove platen returns at a constant speed and the medicine is also brought into the pocket at a constant speed.
When it comes to cold-formed blisters, since the pocket size is much larger than the medicine’s, the web cannot directly bring out the medicine. At this time, a transition drum is usually added to the bottom of the groove plate. The circumferential surface of the drum has cavities (the shape and size are similar to the medicine). When the drum moves, the medicine is brought into these cavities. The medicine falls into the blister pocket when the cavities turn to the bottom and the pocket is aligned. This derived vibratory feeder is called a vibratory-drum feeder.
When this vibratory-drum feeder is used in an intermittent blister machine, the drum needs to be modified so that several groups of cavities are evenly distributed around its circumference (rather than the entire circumference being covered with cavities used in continuous blister machines). , the drum needs to run at two constant speeds; that is, when the web is stationary, the drum runs at a lower constant speed to stably bring the drug into the cavities. When the web starts to move, the drum synchronizes the linear speed of the web and drops the medicine into the blister pockets at a uniform speed.
Please find the links below to watch the videos of the blister vibratory feeder:
https://youtu.be/AseWjRjHNJ0
https://youtu.be/frLC3Xyf_-Y