The Secret Revealed of the Cable Outer Sheath

PVC is the most widely used material in the cable industry, by far. When you open a household appliance or the distribution box of an ordinary building, over 90% of the outer skins of the wires and cables inside are PVC.

Advantages:

Low price: Among all cable materials, it is the cheapest. The processing technology is mature.

Soft and convenient to use: Good flexibility, easy to strip wires and connect, high construction efficiency.

Weaknesses:

Once PVC catches fire, it will release a large amount of thick black smoke and hydrogen chloride (HCl) gas - when exposed to water, it turns into hydrochloric acid, which can corrode electronic equipment and harm the respiratory system.
Ordinary PVC becomes harder and more brittle below -15°C, and is prone to cracking during winter construction; the continuous working temperature is usually only 70°C, and it is likely to soften and deform in high-temperature environments.

Cross-linked polyethylene (XLPE) is the product obtained by chemically or physically cross-linking polyethylene (PE). In simple terms, it is the process of "welding" the molecular chains of PE into a network structure, which directly improves the performance.

Advantages:

High temperature resistance and high current carrying capacity: The continuous operating temperature can reach 90°C, and it can withstand 250°C in a short circuit (while PVC can only withstand 70°C and 160°C). With the same conductor cross-section, XLPE cables can transmit more current.

Good mechanical strength and chemical resistance: More wear-resistant, more oil-resistant, and more resistant to environmental stress cracking than PVC.

Disadvantages:

More expensive than PVC. The material is relatively hard and its flexibility is inferior to that of rubber-based materials.

The flame retardancy is average (it needs to be treated with flame retardants to reach the flame retardant level).

Low-smoke and halogen-free materials, the core four words: Save lives in case of fire. Its design goal is not "not to burn", but "even if it burns, it won't harm people".
Advantages:
Extremely low smoke emission: During a fire, visibility is high, facilitating the escape of personnel and fire rescue operations.
Meets strict fire safety standards： Usually can pass international fire safety standards such as IEC60332, IEC60754, IEC61034.
Disadvantages：
Cost is higher than PVC and ordinary XLPE.
The material is relatively hard, and its flexibility is inferior to PVC at low temperatures.

If the cable needs to be twisted along with the equipment on the robotic arm, or dragged repeatedly on the ground, ordinary plastic materials will quickly become worn and crack. At this time, what is needed is thermoplastic elastomer (TPE).

Advantages

Similar to the elasticity of rubber and the easy processability of plastic, its price is usually lower than TPU.

Disadvantages: The quality of TPE on the market varies greatly. Different brands have significant differences in heat resistance, oil resistance, and hardness. When choosing, one needs to be particularly cautious.

The position of this cable in the industry is quite unique: it can withstand temperatures up to 200°C, endure -60°C cold, and remain flexible within such a wide temperature range. None of the materials mentioned above, such as PVC, XLPE, or LSZH, can achieve this.

Advantages:

Extremely wide temperature range: The working temperature ranges from -60°C to +200°C, which is its core selling point. Ordinary PVC becomes brittle at -15°C, XLPE is also hard at low temperatures, and silicone maintains elasticity in cold environments.

Aging resistance and weather resistance: Resistant to ozone, ultraviolet rays, and radiation, with a long lifespan. Moreover, after burning, it forms a layer of silicon dioxide (SiO₂) insulation, preventing conductor short circuits.

Soft and easy to install: Among all cable materials, its softness can be said to be in the top tier, especially suitable for scenarios requiring flexible routing.

Disadvantages:

Not resistant to oil or corrosion: Performs poorly in oil and organic solvent environments, and the sheath is prone to swelling or damage.

High price: Although the price has dropped significantly over the past decade, it is still much higher than PVC.