12
7. Interpretation of the results on press felts
When the felt goes through the nip, it’s compressed and afterwards
it will expand back.
During the lifetime of the felt this expansion will decrease and the
felt becomes compacted.
Compacted felts absorb less water than non-compacted felts.
Therefore the caliper of the felt should be judged in conjunction
with the felt weight.
h = caliper (height) of the felt
(mm)
s = solid (non-absorbing) part of the felt
(mm)
v = void (absorbing) part of the felt
(mm)
F = actual weight of 1m
2
felt
(g/m
2
)
ρ = density of press felt (approx. 1.14 for PA)
(g/cm
3
)
s =
COMPACTION =
* 100% =
* 11.4%
WATER STORAGE CAPACITY
[g/m
2
]
= 1000 *
- F