10 - 6
Heat sealing
10
.07
Malfunctions during the heat-sealing operation cycle
Malfunction
Cause/correction
Display "1999"
Broken sensor or line, change the hot wedge, see
Chapter 11.03 Changing and grinding the hot wedge.
LED "K1" lights up
Difference between the pre-selected heat-sealing
Hooter signal
temperature and the actual temperature of the hot
wedge is too great, wait until the hot wedge has heated
up or cooled down sufficiently.
Fig. 10 - 09
10.
06
Testing the seal
All tests are only to be carried out on cold seals.
10.
06.01
Testing the seal strength
The seal strength (pull resistance) can only be established by a destructive test. This is done
by way of a tearing test on the workpieces which can either be done manually or with a
tension dynamometer (for finding out the seal strength more exactly).
10.
06.02
Testing the tightness of the seal
The non-destructive test of seal tightness
can be carried out on an overlapping seal
with a test channel (see
chapter 9.01 Seal
types
).
This test can be carried out on PE-HD foils
with an air pressure of
2.5
to
5 bar
which is
pumped into the test channel between the
two seals.
The air pressure can drop up to
20%
in
10
minutes.