In a food processing facility, packaging equipment has to perform some of the most complex jobs in the plant. It takes a lot of movement and precision to uniformly fill containers with bulk products. Those containers must then be sealed in some way and loaded into boxes for transport. In many facilities, these actions are performed by separate machines, but cutting-edge designs can integrate many functions into one quick process, greatly increasing the speed at which products can be bagged and boxed.
The first piece of packaging equipment that is used for the product is a dispenser with some form of weight control. Manually weighing out the material to ensure precision is extremely time-consuming, so this is usually an automated process. These devices use a variety of feeders to place the food into separate containers, and they can do this with great accuracy, usually within an ounce or two of a target weight. These devices are compatible with nearly every bag possible, though each one is only capable of handling a certain range of weights.
Once the material is secured in the container, another piece of packaging equipment must close up the bag. The most common forms of sealers are sewing systems and heat systems. Sewing systems use a heavy duty sewing machine to punch a string of yarn through the top of the container. This is a common method of sealing in the pet food industry, though it is used for other food products as well. Sewing systems are able to work with most bags and can punch through thicker containers with their power. Heat systems consist of two kinds ofbag sealers– impulse heat sealers and direct heat systems. Direct heat sealers use jaws with extremely hot surfaces to melt and fuse the top of the container together. An impulse sealer closes up a container the same way, but does it with a quick surge of electricity through a resistance wire to create the heat. Direct heat devices are operated at higher temperatures and are in contact with the material longer, so they are used for thicker thermoplastics, cellophane or poly-coated material. Impulse sealers can be used with most thermoplastic bags, including polypropylene, PVC, polyethylene and some forms of polyester.
Once the container is sealed, packaging equipment must get the bags loaded onto a pallet or into a box for further transport. There are a wide variety of machines that can accomplish this job. Manual loaders assist an operator to position and stack bags without having to lift the material in the process. This improves worker safety and speeds up the process. Semi-automatic designs require an operator to push the containers onto a flat surface that is part of the machine. When all of the bags are in place, the device retracts the flat surface over a pallet, securing containers one layer at a time. There are also fully automatic pieces of packaging equipment, like articulated robot arms that can lift, position, and place containers in one motion.
Some manufacturers produce machinery that combines product feeding, bag sealing or sewing and palletizing or boxing into one device. These automatic bag hangers only require a constant feed of bags and product to prepare material for transport.