A REVIEW OF THE STATE OF ART IN HEAT SEALING OF MULTILAYER POLYMER FILMS

All sealing technologies present inconveniences to be solved. One of the most significant adverse effects in the sealing production lines is the amount of material waste that is genetated due to the difficulties of achieving the correct thermal phase change in the polymer film during the sealing process. Sealing methods such as Induction, ultrasonic or heated jaw have similar operating characteristics, minimum gradients in pressure and temperature that are nedeed to create an efficient polymer transition, to produce the correct molecular arrangements and to avoid zones with little or null interaction between melted surfaces. This review shows the factors that affect the performance of jaw-multilayer polymer films that produce bad seal integrity; through understanding the design parameters to generate a small pressure and temperature gradients also characterizing and testing this phenomenon, the result of the review will help to identify theoretical basis and opportunities to design an innovate heated jaw sealing system with a uniform pressure and temperature along the sealing area.