32
3.4
Description of forming station
The forming station is the place at the in-feed end of the machine frame (see figure 3.7)
This is a composite drawing showing the various components of the forming station. The film
is situated between the forming die top part and the forming die bottom part and is ready for
processing. The depth of the package(s) can be changed by varying the number of filling
plates under the bottom plate(s). If many depth changes are needed each day, a forming
device with automatic forming depth adjustment via the control panel can be delivered with
the machine. Depending on the machine, the forming process can be done in a variety of
ways.
The basic principle is as follows:
-
Before the process starts the forming device closes.
-
The film is pressed against a heating plate in the top part by compressed air.
-
The hot and weak film is pressed and/or
sucked (depending on the machine’s
configuration) into the cavity or cavities in the bottom part.
-
The film cools and stiffens in the forming die bottom part. The package(s) has now
been formed.
-
Ventilation valves open to equalise the pressure inside and outside the forming
chamber.
-
The forming station opens.
-
The chain transports the film on to the loading area.
This process description gives a general picture of what happens in the forming station.
There are various designs of the forming station, described below.
top part
bottom part
lifting system
cylinder
Figure 3.7 Forming station
