How to Choosing a Sealer?
The procedure of achieving a perfect seal result includes matching the container cap, foil seal liner, and sealing machine; setting up an operating window, and establishing proper testing methods for reaching a perfect seal. So, understanding how to address and control induction-sealing variables, manufacturers can expect to achieve a perfect seal every single time.
Whether a container closure is made from plastic (no matter if it is PET, PVC, PE, PP, PS) a perfect seal can be achieved. With normal induction cap sealing method, metal caps will not seal properly. Screw caps are better choices as they provide enough pressure on the liner which cause to a better sealing on the bottle neck.
Choosing the right induction foil seal depends on the product being packaged. If the product contains any potentially aggressive or volatile ingredients (agro-chemicals, acids, solvents, high salt content, alcohol or vinegar) a protective layer or barrier layer may needed. It can be laminated between the heat-seal film and the foil to prevent corrosion.
The next consideration would be the foil liner. There are 2 main types. The first one is a single-piece (1 pc) liner, which has a typically a board, foam, or paper layer backing. When inducted, the entire structure seals to the container lip, leaving nothing in the closure for resealability. One-piece liners are mostly used in food, beverage and any other products that do not require a reseal liner in the cap after the foil liner is removed.
The other main classification is a two-piece liner type. A wax bonded material that has a backing that is usually a board, pulp, or foam bonded to the foil-seal structure with a temporary wax bond. Within the sealing process the wax will melt and absorbed into the backing that remains in the cap for re-seal ability.
A number of parameters need to be considered to select the appropriate induction sealer for an application. The foil liner diameter is one of the most important items in sizing the equipment. The larger the diameter of foil liner is, the higher amount of energy would be needed to seal the container. Since there are many types of Aluminum Liners and varying thicknesses, they can heat up differently, so it is essential to document the application’s foil type.
If your products are being packed on continues production line, the line speed is a very important variable. If the containers are traveling fast, the container will not be under the sealer head as long, therefore a more powerful sealer will be required. If there is possibility of reducing the line speed then a medium range sealing machine would be quite suitable.
Additionally, the range of applications must be determined. If a wide range a bottle & containers or closures are to be sealed, the system needs to be set up for the complete range of caps, containers and different speeds configurations.