Theory of Operations
Rovema VPK Operators Manual
3/2000 VPK REV(B) PANELVIEW 600
4-6
Horizontal Sealing Cycle
The horizontal sealing cycle begins when the film starts moving. The
horizontal sealing device operates at a speed that will allow it to create
a specific number of bags each minute. As the sealing jaws close on
the film, they push the front and back sides of the film tube together.
As the crank arms drive the c-frames closer together, the c-frames
compress the jaw springs against the jaw carriers. The jaw carriers
transfer this force to the jaw bodies. The jaw bodies transfer the force
to the film. The heat and pressure cause the adhesive layer to hold
the front and back sides the outer film layer together.
During the horizontal sealing cycle, two other forming operations
typically occur; cutting and cooling. Just as the sealing jaws close on
the film tube, the motion controller signals the PLC to activate the
knife. The knife cuts the film tube between the top seal of the bag
below the sealing jaws and the bottom seal of the bag above the jaws.
As the sealing jaws open, the motion controller signals the PLC to
activate the cooling device. The cooling device release cool
compressed air onto the newly created horizontal seals.
