Page 49 - Market Analysis Report of Optical Communications Field in China & Global market 2024

trFicighulroero3.aCceratidcle-atoc-igda,techimlopraocpt hofe1noklm, ionpstioclaul bfibleerinwitmh e24th2aμnmol, different from the current conventional PBT sleeve
etchoaatninogld,iaamceetteor ne, alkanes; c. Excellent high and low production process. In order to improve the use of PET
temperature resistance, can be used for a long time within for secondary coating of optical fibers in optical cables,
the temperature range of 120 ℃, can withstand high this article explores the entire production process of PET
temperatures of 150 ℃ for short-term use, can withstand sleeve optical cables from multiple perspectives, focusing
low temperatures of -70 ℃, and the high and low on solving multiple technical problems, such as reasonable
temperatures have little effect on its mechanical properties; control of PET sleeve extrusion processing temperature,
d. Low gas and water vapor permeability, indicating improvement of PET sleeve toughness, reasonable
excellent gas barrier, water, oil and odor resistance control of PET sleeve fiber excess length, improvement
performance; e. High transparency, can block ultraviolet of PET sleeve deformation and tie marks in the cable
rays, and has good luster; f. Non toxic, odorless, and forming process, and improvement of PET sleeve thermal
safe. However, PET used for secondary coating of optical deformation and tie marks in the cable sheath process.
fibers also has many disadvantages, such as severe high-
temperature deformation (which can be improved by glass 3.1 Reasonable control of extrusion processing tem-
fiber reinforcement), slow crystallization rate, poor flame perature for PET tubing
retardancy and self extinguishing properties. Compared with PBT for secondary coating of optical
fibers, which has a wider processing temperature range
Table.1 shows the performance indicators of PET and (230-260℃) and a lower melt index (7-15g/min), PET
PBT materials used for secondary coating of optical for secondary coating of optical fibers has a narrower
fibers. It can be seen that: a. Compared with PBT, PET processing temperature range (240-250℃) and a higher
has better resistance to high and low temperatures, melt index (20-38g/min). Therefore, more precise control
thermal deformation and decomposition temperatures, of the degree of fluid plasticization and the size of the
chemical resistance, and environmental friendliness, extrusion sleeve structure must be carried out during PET
while slightly lacking in bending and tensile properties. extrusion, which requires higher temperature control
Process optimization can be used to ensure that the PET
sleeve produced has excellent mechanical properties to Table.2 Analysis and Solutions to Process Problems in PET
more effectively protect the optical fibers. b. Compared to Sleeve Extrusion Process
PBT, PET has a higher melt index, better flowability after
melting, and is easier to extrude into shape. c. Compared
to PBT, PET has better rigidity and produces PET sleeves
with superior lateral compression resistance.

Table.1 Performance indicators of PET and PBT materials for
secondary coating of optical fibers

3. Exploration of PET process for second- 47
ary coating of optical fibers

Due to the different performance characteristics of PET
used for secondary coating of optical fibers compared
to PBT used for secondary coating of optical fibers, the
entire PET sleeve production process is significantly

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