Hot Tack Testing of Flexible Packings

The type of food products decides the type of packing it requires. And based on that packing, its sealing process it decided. Sealing is a very crucial process that assures the safety of the products. During the filling process, it is very important to have apt sealing factors so as to have a successful seal. Manufacturers often face a problem of seal breakage during the filling process. This happens due to weak strength when the bonding is still hot and in the process of attaining the room temperature. Hot tack tester is used to check the seal strength of the packets when the seal is still hot. 

 

There are certain points to be considered in the filling line make sure that no seals are breaking during the process. 

1. Due to the difference in the polymer structure, there is a difference in behaviour of polymer type. Due to this, there is a difference in the behaviour of the sealant. Thus, the performance of polymer with hot tack and strength of seal may vary. It is very important to identify the properties of the polymer to choose the right sealant. 

2. Sealant selection is a crucial aspect that decides the behaviour of the packet during the filling process. Melt index, density, Zero Shear Viscosity are important considerations. 

3. At what temperature sealant will form the bond with the substrate? This is very important to know so that right sealing temperature can be set. 

4. Hot tack strength can be defined as the force required to break the seal when it is still hot. If this strength is high, the chances of failure are very less. It is an important factor to evaluate the performance of the flexible packing. 

5. Dwell time is the period required by the sealant to form the bond. The shorter the dwell time is, the better is the seal quality. But it should not be compromised with the seal quality. It is often noticed that shorten dwell time may result in weak seal strength. So there has to be a balance between the both. 

 

Hot tack tester is the instrument which is used to measure the hot tack seal strength i.e. the strength of the seal when it is still hot. Presto is the leading manufacturer and supplier of seal testing machine and offers a highly standardised and precise testing machines for flexible packings.