A variety of bags, with a wide range of options can be made on our equipment. Depending on your needs you can select the type that suits your product and customer best.
The typical machine is loaded with a flat roll of plastic film, which has artwork applied to the exterior or interior of the film. The film approaches the back of a long cylindrical tube, which is called the forming tube. When the center of the plastic is near the tube, the outer edges of the film form flaps that wrap around the conical forming tube. The film is pulled downward around the outside of the tube and a vertical heat-sealing bar clamps onto the edges of the film, bonding the film by melting the seam edges together.
To start the bagging process, a horizontal sealing bar clamps across the bottom edge of the tube, bonding the film together, and cutting off any film below. This sealing bar can be at a fixed height, which is called an intermittent sealing process. Faster systems include a sealing bar that moves down with the bag while sealing. This is called a continuous packaging process. When the gross weight of the product filled bag is reached, filling stops, and the horizontal sealing bar seals the top of the bag, simultaneously forming the bottom of the next bag above. This bag is then cut off from the tube and is now a sealed package, ready to advance onward into the product boxing and shipping processes. Also look at our UltraSonic Sealing solutions.
The feeding of material and cutting of the bag can be determined either by bag length, or by indexing to an eyespot, which is detected by a visual sensor. Many food filled packages are filled with nitrogen to extend shelf life.
Food manufacturers are often looking for ways to improve their geographical reach or otherwise extend the shelf life of their product without the use of chemicals. Nitrogen filling is a natural means of extending shelf life.