The vacuum bag is sealed closed by a heating wire.
- A seal with one seal wire is called ” single seal”.
- Most common is the double seal which provides 2 seals for extra security.
With a “trenn seal” one wire will seal the bag and the other heating wire will almost melt off the remainder off the bag. By pulling the remainder off the bag will have a nicer appearance. Also possible product that might be left in the remaining plastic is removed for better hygiene.
Bi-active seal is especially used for very thick bags, mostly aluminium lined bags.