H-PU 55D coeﬃcient
55D
PTFE
25% Glass if
pressure,
β>
will
be greater
flow
limits
of the
materials
areGlass
smaller
(σ H-PU
Figure 5 shows the dimensions of the tested coaxial sealing systems (all dimensions
55D > σ Virgin PTFE > σ PTFE 25% Glass → β H-PU 55D < β Virgin PTFE < β PTFE 25% Glass).
are in mm). The seals were machined by turning on a NC lathe; because of the low
Figure
5 showsofthe
dimensions
of the must
tested
sealing
systems
dimension
thermal
conductivity
PTFE,
the temperature
becoaxial
carefully
regulated
while (all
turning.
are
in
mm).
The
seals
were
machined
by
turning
on
a
NC
lathe;
because
of
the
low
This entails using very sharp tools and abundant colling liquid. The following cutting therma
conductivity
ofselected
PTFE, the
temperature
must cutting
be carefully
regulated
while
turning. This
parameters
were
for turning
Virgin PTFE:
speed—270
m/min;
feed rate—
entails
using very sharp tools and abundant colling liquid. The following cutting param
0.08
mm/rev.
this case,
the initial
specificVirgin
radial PTFE:
deformation
is 15%. Them/min;
materialfeed
of the
etersInwere
selected
for turning
cuttingεr0speed—270
rate—0.08
cylinder
mm/rev.body that houses the two pistons is OLC45 steel (heat-treated quality carbon steel;
DIN EN AISI 1.0503 C45-1045).
Figure 6 shows a diagram and an image of the experimental test stand.
Polymers2024,
2024,16,
16,157
x FOR PEER REVIEW
Polymers

88 of
13
of 13

Figure 5. Dimensions of the coaxial sealing systems.
In this case, the initial specific radial deformation εr0 is 15%. The material of the cylinder body that houses the two pistons is OLC45 steel (heat-treated quality carbon steel;
DIN EN AISI 1.0503 C45-1045).
Figure 6 shows a diagram and an image of the experimental test stand.
Figure5.
5. Dimensions
Dimensions of
of the
the coaxial
coaxialsealing
sealingsystems.
systems.

### Language ###
English

### Assessment ###
The text contains specific information about the cutting speed used for turning Virgin PTFE, which could be a relevant technical detail someone might want to know.

### Query ###
What is the cutting speed for machining Virgin PTFE?
What is the cutting speed for machining Virgin PTFE?