Liquified cheese fills a large tray, then an air cylinder pushes it to the next process station.
Using a process known as index and fill, the machines continuously weigh the cheese as it flows into trays. When it reaches a pre-set weight, a tray is moved to the next station. However, manually moving trays weighing up to 100 lb. along a conveyor line is hard work. To help automate the process, a major food manufacturer turned to Charter Engineering, Portland, Ore., a specialist in the design and construction of food-processing machinery. The goal was to streamline an operation that moves trays through the fill-and-weigh operations, then to the unloading station.
Charter’s engineers considered several options when designing the motion system. Competitive quotes showed electromechanical-based systems were more costly than other alternatives. Designs using conveyor belts also were evaluated, but they were considered too difficult to clean. The most efficient and cost-effective option was determined to be a pneumatic forward-push system that continuously moves the trays as they are filled and weighed.
For this particular challenge, Charter Engineering partnered with Clippard as its pneumatic component supplier. According to Jay Rosen, P. E., owner of the Charter Engineering Group, “Clippard components have been used by our company on many products over the years. The stainless-steel cylinders are long-life, offer washdown capability, and are reliable. Their costs are competitive but, more importantly, Clippard’s application engineering staff has always been helpful and supportive on product questions for new and custom applications.”
The fill-and-weigh motion system involves a three-stage process. After a tray reaches half of the required fill, stainless-steel air cylinders push it forward to the next station, where the filling process completes. Cylinders then push the trays forward to the unload position for transport to the cooling area.
The fully automatic forward-push system uses several Clippard products, including two UDR-32 stainless steel cylinders with magnetic pistons, an RPS-S3 magnetic reed switch, and a JFC flow-control valve to control the indexing.
Stainless Cylinders
Charter Engineering’s staff specified Clippard stainless-steel pneumatic cylinders for their rugged, long-life design. The UDR-32 cylinders have a 2-in. bore and were selected from more than 130 different models and 15 standard bores.
