Use a machine with a temperature
range of 1112 F (600 C), speed range of 0-40 feet (12 meters)
per minute, roller pressure of 0-50 PSI (3.5 Kglcm2).
It is also important to choose
a machine that will maintain an accurate temperature and set
speed, even during production. Use of a machine that does not
operate at the set speed or temperature can result in damaged
products, improperly sealing, burn through of tape and various
other costly problems.
6. TOUCH UP SEALING & REPAIRS
A treatment of sections where
seams cross
Normally, it is not necessary
to perform a secondary sealing operation. However, in very rare
instances, it might be necessary in order to improve sealing
and hydrostatic resistance after the taping process is completed.
This most often occurs where one taped seam crosses another.
If leaking occurs at the crossover, use a thermostatically controlled,
crossover type heat press to seal the crossover area, or run
the seam back through the hot air welding machine without additional
tape. Note that heat should be applied to the adhesive side of
the fabric not the membrane of the tape. Remember, adhesive will
be drawn towards the heat.