Page 50 - Market Analysis Report of Optical Communications Field in China & Global market 2024

CHINA Table 3. Based on the number of experimental factors and
levels, a 5-factor 2-level orthogonal experiment (i.e. 25)
requirements for extrusion processing. After a period of was designed. The experimental results are shown in Table
tracking and statistics on the PET sleeve extrusion process, 4, and the significance analysis of each factor and level was
it was found that the main process problems encountered determined using the range method. The results are shown
were uneven plasticization, inability to pull the tube, brittle in Table 5. It can be seen that: a The factors affecting the
fracture of the sleeve, intermittent clumping, and difficulty elongation at break of PET tubing, in descending order of
in discharging. A root cause analysis was conducted importance, are as follows: the highest temperature of the
on this issue, and the main result was poor temperature machine head(θm); the temperature of the cooling water
control during PET sleeve extrusion processing. After tank in section I(θt); the production speed(v); the winding
implementing corresponding solutions, the quality of PET tension(Ttake-up); and the auxiliary traction tension(Ttow).
sleeves significantly improved, as shown in Table.2. The highest temperature of the machine head is the main
factor(θm); the temperature of the cooling water tank in
3.2 Improvement of PET sleeve flexibility section I(θt); and the production speed(v), are the secondary
Compared to PBT used for secondary coating of optical factors. The importance of the influencing factors on the
fibers, PET used for secondary coating of optical fibers bending diameter db of PET tubing is ranked from high to
has better rigidity and poorer bending performance due to low as follows: the temperature of the first stage cooling
the presence of rigid benzene rings in the molecular chain water tank(θt), the highest temperature of the machine
and short flexible carbon alkyl chain segments. Therefore, head(θm), the production vehicle speed v, the auxiliary
the extruded PET sleeve has better lateral pressure traction tension Ttow, and the winding tension(Ttake-up). That
resistance but poorer flexibility, and can be easily pulled is, the temperature of the first stage cooling water tank(θt) is
and broken by hand. The flexibility of casing is usually the main factor, and the highest temperature of the machine
measured by material deformation (elongation at break, head(θm) and the production vehicle speed(v) are secondary
ε) and degree of bending (bending diameter, db). After factors. As a result, optimization verification was carried
analysis, the influencing factors of PET sleeve flexibility out on the maximum temperature(θm) of the machine head,
include the highest temperature of the machine head(θm) the temperature(θt) of the cooling water tank in section I,
in the molding process parameters, the temperature and the production speed(v). The flexibility of the PET
of the first stage cooling water tank(θt), the auxiliary sleeve after process optimization has been improved, with
traction tension(Ttow), the winding tension(Ttake-up), and the a fracture elongation rate of not less than 900% and a
production speed(v). In order to improve the flexibility of minimum bending diameter db of not more than 20 mm.
PET tubing, an orthogonal experimental method was used This ensures that the PET sleeve does not deform during
to identify the key factors affecting the elongation at break the twisting process, meeting the requirements for long-
(ε) and bending diameter (db) of PET tubing, in order to term use of optical cable products.
optimize the process parameters of the molding process.
The factors and levels of orthogonal experimental design
for improving the flexibility of PET tubing are shown in

Figure 5. Cable carbon footprint is improved with reduced diameter optical fiber
Table.3 Factors and levels of orthogonal experimental design for improving the flexibility of PET tubing

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