Selecting the right materials is essential for ensuring the long-term stability and performance of optical cables. Different materials behave differently under extreme environmental conditions — ordinary materials may become brittle and crack at low temperatures, while at high temperatures they may soften or deform.
Below are several commonly used materials in optical cable design, each with its own advantages and suitable applications.
1. PBT (Polybutylene Terephthalate)
PBT is the most widely used material for optical cable loose tubes.
Through modification — such as adding flexible chain segments — its low-temperature brittleness can be greatly improved, easily meeting the -40 °C requirement.
It also maintains excellent rigidity and dimensional stability under high temperatures.
Advantages: balanced performance, cost-effectiveness, and wide applicability.
2. PP (Polypropylene)
PP provides excellent low-temperature toughness, preventing cracking even in extremely cold environments.
It also offers better hydrolysis resistance than PBT. However, its modulus is slightly lower, and rigidity is weaker.
The choice between PBT and PP depends on the cable’s structural design and performance needs.
3. LSZH (Low Smoke Zero Halogen Compound)
LSZH is one of the most popular sheath materials used today.
With advanced polymer formulations and synergistic additives, high-quality LSZH compounds can meet the -40 °C low-temperature impact test and ensure long-term stability at 85 °C.
They feature excellent flame retardancy (producing low smoke and no halogen gases during combustion), as well as strong resistance to stress cracking and chemical corrosion.
It’s a preferred choice for flame-retardant and environmentally friendly cables.
4. TPU (Thermoplastic Polyurethane)
Known as the “king of cold and wear resistance,” TPU sheathing material remains flexible even in very low temperatures while offering superior abrasion, oil, and tear resistance.
It is ideal for drag chain cables, mining cables, and automotive cables that require frequent movement or must withstand harsh cold environments.
However, attention should be paid to high-temperature and hydrolysis resistance, and high-quality grades are recommended.
5. PVC (Polyvinyl Chloride)
PVC is an economical option for optical cable sheaths.
Standard PVC tends to harden and become brittle below -10 °C, making it unsuitable for very low-temperature conditions.
Cold-resistant or low-temperature PVC formulations improve flexibility by adding large amounts of plasticizers, but this can reduce mechanical strength and aging resistance.
PVC can be considered when cost efficiency is a priority and long-term reliability requirements are not high.
Summary
Each of these optical cable materials offers distinct advantages depending on the application.
When designing or manufacturing cables, it’s important to consider environmental conditions, mechanical performance, and service life requirements to select the most suitable material.
Post time: Oct-31-2025